This document provides an overview of power electronics and drives, focusing on modeling and simulation. It discusses power electronic systems and converters used in electrical drives, including DC and AC drives. It also covers modeling and control of electrical drives, specifically current controlled converters, modeling of power converters, and scalar control of induction motors. The document is intended to support a problem-based and project-oriented learning approach to the topics of power electronics, modeling, and drives.
These slides provide an elementary description of Power Electronics and its application domains. It also shows the different power devices and converters.
It is based on current transformer description
It's working and applications are present in it ,it also includes videos of it's windings and it's inrush ability of transformer, and also about instrument transformer and it's working with applications.Current transformers are used-in measuring high currents and connected with it in parallel to it
Power electronics involves controlling the flow of electrical energy through electronic circuits. Rectifiers and inverters are common examples. Power electronics emphasizes large semiconductor devices, magnetic energy storage, and control methods for nonlinear systems. It plays a central role in energy systems and alternative resources. Power electronic systems efficiently convert electrical energy from one form to another. Power electronics courses cover high voltage switching devices, rectifiers, DC-DC converters, and inverters. Thyristors like SCRs are semiconductor devices that act as open or closed switches for control applications. SCRs are used for power control, backup lighting, and over-voltage protection.
1. HVDC transmission systems use direct current for electricity transmission over long distances or through underwater cables. This became practical with the development of thyristors and solid state valves.
2. DC transmission has advantages over AC transmission for long distance transmission, as power transfer in DC lines is unaffected by distance. It also allows asynchronous interconnection between grids and monopolar operation.
3. While DC transmission has higher upfront equipment costs, it has better technical performance than AC transmission for long distance or underwater cables, making it economical beyond the break-even distance.
Power diodes are key components in rectifier circuits used in AC/DC converters. There are several types of power diodes including general purpose diodes, fast recovery diodes, and Schottky diodes. General purpose diodes have high reverse recovery times around 25μs and are used in low speed applications. Fast recovery diodes have very low reverse recovery times under 5μs and are used in switching circuits. Schottky diodes have the lowest forward voltage drop and recovery times in the nanosecond range but are limited to voltages below 100V. Key ratings for power diodes include peak inverse voltage, maximum average forward current, and reverse recovery time.
This presentation was presented to Dr. Chongru Liu in North China Electric Power University,Beijing,China by Mr. Aazim Rasool. This presentation will help to understand the control of HVDC system. Animations are not working like ppt. so I apologize on this.
These slides provide an elementary description of Power Electronics and its application domains. It also shows the different power devices and converters.
It is based on current transformer description
It's working and applications are present in it ,it also includes videos of it's windings and it's inrush ability of transformer, and also about instrument transformer and it's working with applications.Current transformers are used-in measuring high currents and connected with it in parallel to it
Power electronics involves controlling the flow of electrical energy through electronic circuits. Rectifiers and inverters are common examples. Power electronics emphasizes large semiconductor devices, magnetic energy storage, and control methods for nonlinear systems. It plays a central role in energy systems and alternative resources. Power electronic systems efficiently convert electrical energy from one form to another. Power electronics courses cover high voltage switching devices, rectifiers, DC-DC converters, and inverters. Thyristors like SCRs are semiconductor devices that act as open or closed switches for control applications. SCRs are used for power control, backup lighting, and over-voltage protection.
1. HVDC transmission systems use direct current for electricity transmission over long distances or through underwater cables. This became practical with the development of thyristors and solid state valves.
2. DC transmission has advantages over AC transmission for long distance transmission, as power transfer in DC lines is unaffected by distance. It also allows asynchronous interconnection between grids and monopolar operation.
3. While DC transmission has higher upfront equipment costs, it has better technical performance than AC transmission for long distance or underwater cables, making it economical beyond the break-even distance.
Power diodes are key components in rectifier circuits used in AC/DC converters. There are several types of power diodes including general purpose diodes, fast recovery diodes, and Schottky diodes. General purpose diodes have high reverse recovery times around 25μs and are used in low speed applications. Fast recovery diodes have very low reverse recovery times under 5μs and are used in switching circuits. Schottky diodes have the lowest forward voltage drop and recovery times in the nanosecond range but are limited to voltages below 100V. Key ratings for power diodes include peak inverse voltage, maximum average forward current, and reverse recovery time.
This presentation was presented to Dr. Chongru Liu in North China Electric Power University,Beijing,China by Mr. Aazim Rasool. This presentation will help to understand the control of HVDC system. Animations are not working like ppt. so I apologize on this.
Distribution System Voltage Drop and Power Loss CalculationAmeen San
Distribution System Voltage Drop and Power Loss
Calculation
Comparison of Overhead Versus Underground System
Power Loss Calculation,Voltage Drop Calculation
Busbar protection uses differential protection to isolate faults on the busbar. It works by comparing the current entering and leaving the busbar using CTs - any difference indicates an internal fault. Proper CT ratios and a stabilizing resistance are needed to restrain operation for external faults. PS class CTs are preferred over other classes due to more consistent accuracy. While busbar protection is important, it is currently not implemented in line at MRSS due to some unspecified reason.
This document discusses power quality and defines it as any deviation from the normal sinusoidal voltage or current waveform. It covers various power quality issues like voltage sags, swells, fluctuations, harmonics, interruptions and more. It explains the causes and impacts of different power quality problems. The document also discusses classification of issues, measurement and evaluation of power quality as well as relevant standards from organizations like IEEE.
The document provides an introduction to power system analysis. It discusses the components of a power system including generators, transformers, transmission lines and loads. It explains that power system analysis involves monitoring the system through load flow analysis, short circuit analysis and stability analysis in order to maintain the system safely and economically. It also discusses the need for power system analysis in planning and operating the system, and ensuring power demand is met through reliable generation and transmission of electricity.
Applications of power electronics in HVDCKabilesh K
Role of Power electronics in HVDC and Transmission system. What are the components of Power electronics used in HVDC. Types of HVDC Links. Advantages of HVDC over HVAC.
This document discusses distributed generation, which refers to small-scale power generation located near the end users. It can include sources like solar panels, wind turbines, fuel cells, and cogeneration. Distributed generation has advantages like reduced transmission losses and improved supply security. However, it also presents challenges like impacts on power quality from issues such as voltage regulation, grounding, harmonics, and islanding effects. The document outlines different distributed generation technologies and concludes that its integration into the power system is possible if interconnection designs adequately address power quality and safety considerations.
Current transformers are used to measure high currents in transmission lines. They have a primary winding with few turns connected in series to the transmission line, and a secondary winding with many more turns connected to a normal rating ammeter. This allows measurement of high primary currents through transformation to lower secondary currents. The core design aims to keep the exciting current drawn within the linear "ankle point" region for accurate measurement, and different types of current transformers are used depending on the required primary and secondary current ratings.
This document describes a three phase inverter that converts DC voltage to AC voltage. There are two main modes of conduction for a three phase inverter - 180 degree conduction and 120 degree conduction. 180 degree conduction involves three switches being on at a time, while 120 degree conduction only has two switches on at a time. The document provides circuit diagrams and equations to calculate the output voltages under each conduction mode. Waveforms are also shown to illustrate the phase and line voltages.
In microgrid, if fault occurs or any other contingency happens, then the problems would be created which are related to power flow, also there are various protection schemes are used for minimize or eliminate these problems.
Voltage control is used for reactive power balance and P-f control is used for active power control.
Various protection schemes such as, over current protection, differential protection scheme, zoning of network in adaptive protection scheme are used in microgrid system .
The document discusses electric drives and their components. It describes:
- Power modulators regulate power from the source to the motor. The control unit controls the power modulator and protects the drive. Sensing units measure parameters like motor current and speed.
- Drives have advantages like wide speed/torque ranges and flexible control. Disadvantages include high initial cost and vulnerability to power failures.
- Drives are classified as group, individual, or multi-motor depending on how many motors are used.
- Dynamics of the motor-load combination are described by the torque equation relating motor torque, load torque, and dynamic torque.
- Steady state stability depends on motor torque exceeding load torque
This document discusses issues related to interconnecting microgrids. It describes how a DC microgrid system utilizes a DC bus to distribute power from photovoltaic units and battery storage to local households. Interconnection can be done directly through switchgear or power electronic interfaces. Key issues that can arise include voltage and frequency fluctuations that occur due to imbalance between supply and demand, power factor correction needs, and harmonics produced by some loads. Unintentional islanding is also a safety concern that must be addressed when connecting microgrids to the main power grid.
This document discusses distributed generation (DG), also known as on-site power generation located near the load. DG provides benefits to end-users, distribution utilities, and power producers. It examines various DG technologies like reciprocating engines, combustion turbines, fuel cells, and renewables. The document also covers interface options with the utility grid, power quality issues, operating conflicts, and the role of DG in smart grids and rural electrification as supported by India's government policies.
This document discusses various protections provided for alternators, including mechanical protections from prime mover failure, field failure, overcurrent, overspeed, and overvoltage, as well as electrical protections from unbalanced loading and stator winding faults. It describes different protection mechanisms like differential protection, balanced earth fault protection, and inter-turn fault protection that are used to protect against faults in the alternator windings or unbalanced loading. The document emphasizes the importance of alternator protection given their high individual cost and importance in power generation.
MicroGrid and Energy Storage System COMPLETE DETAILS NEW PPT Abin Baby
A microgrid is a localized grouping of electricity generation, energy storage, and loads that normally operates connected to a traditional centralized grid (macrogrid). This single point of common coupling with the macrogrid can be disconnected. The microgrid can then function autonomously. Generation and loads in a microgrid are usually interconnected at low voltage. From the point of view of the grid operator, a connected microgrid can be controlled as if it were one entity.
Microgrid generation resources can include fuel cells, wind, solar, or other energy sources. The multiple dispersed generation sources and ability to isolate the microgrid from a larger network would provide highly reliable electric power. Produced heat from generation sources such as micro turbines could be used for local process heating or space heating, allowing flexible trade off between the needs for heat and electric power.
This document presents a schematic block diagram of a photovoltaic system with an interleaved boost converter and maximum power point tracking using the perturbation and observation method. It includes a single diode model of a PV cell and discusses the charging and discharging modes of operation of the boost converter. Simulation waveforms are presented showing the improvement with MPPT control. Future work will involve designing a closed loop inverter for grid synchronization.
This document discusses the digital control of DC drives using microcomputers. It describes how microcomputers can be used to control the speed and current of DC motors through programs that implement constant torque and constant horsepower operations. The microcomputer provides reliable control, flexibility to change control strategies, and can incorporate additional features like diagnostics and protections. Microcomputers reduce costs and size compared to analog controls while improving control performance and reliability. Speed is detected and current sensed to provide feedback for the inner current and speed control loops implemented through the microcomputer.
A three-phase transformer can be constructed as a single unit or from three individual single-phase transformers connected together. A single-unit transformer has advantages like less space, weight, and cost, and is more efficient. However, if a phase fails, the entire transformer must be removed for repair unlike with individual transformers. The document discusses different three-phase transformer connections like star-star, delta-delta, and uses of tertiary windings.
This document discusses constraints and load flow analysis in power systems. It outlines four key constraints: active power constraint, reactive power constraint, voltage magnitude constraint, and load angle constraint. It also describes load flow analysis as a balanced mechanism between demand and generation under incremental loading. Load flow analysis is important for the safe and future operation of power systems. The document further discusses bus classification, basic power flow conditions including the proportional relationships between reactive power and voltage and active power and load angle. It also covers the development of the Y-bus matrix considering line resistances and inductances alone and then including line capacitances.
“MODELING AND ANALYSIS OF DC-DC CONVERTER FOR RENEWABLE ENERGY SYSTEM” Final...8381801685
This project portrays a comparative analysis of DC-DC Converters for Renewable Energy System. The electrolysis method which increases the hydrogen production and storage rate from wind-PV systems. It has been proved that DC-DC converter with transformer has the desirable features for electrolyser application. The converter operates in lagging PF mode for a very wide change in load and supply voltage variations, thus ensuring ZVS for all the primary switches. The peak current through the switches decreases with load current.This paper portrays a comparative analysis of DC-DC Converters for Renewable Energy System . The simulation and experimental results show that the power gain obtained by this method clearly increases the hydrogen production and storage rate from wind-PV systems. It has been proved that DC-DC converter with transformer has the desirable features for electrolyser application. Theoretical predictions of the selected configuration have been compared with the MATLAB simulation results. The simulation and experimental results indicate that the output of the inverter is nearly sinusoidal. The output of rectifier is pure DC due to the presence of LC filter at the output. It can be seen that the efficiency of DC-DC converter with transformer is 15% higher than the converter without transformer.
Lecture Outline
Introduction to subject
Application Areas
Power Electronic Devices
Power Converters
What is power electronics?
1) Definition
Power Electronics: is the electronics applied to conversion and control of electric power.
Prerequisites
Power electronics incorporates concepts from the fields of
Analog circuits
Electronic devices
Control systems
Power systems
Magnetics
Electric machines
Numerical simulation
Scope
It is not possible to build practical computers, cell phones, personal data devices, cars, airplanes, industrial processes, and other everyday products without power electronics.
Alternative energy systems such as wind generators, solar power, fuel cells, and others require power electronics to function.
Technology advances such as electric and hybrid vehicles, laptop computers, microwave ovens, flat-panel displays, LED lighting, and hundreds of other innovations were not possible until advances in power electronics enabled their implementation.
Although no one can predict the future, it is certain that power electronics will be at the heart of fundamental energy innovations.
Applications: Electric VehicleTesla Model S
Functions of the power electronics:
1. Convert the DC battery voltage to the variable AC required to drive the AC motor
240 V battery
Variable-frequency, variable-voltage AC drives the motor
AC motor propels the rear axle
Up to 330 kW (acceleration)
Up to 60 kW regenerative braking
2. Control charging of the battery
Interface to 240 V 60 Hz 1φ 100 A circuit in garage.
Control AC current waveform to be sinusoidal, unity power factor.
Control charging of battery to maximize life.
Applications: Hybrid VehiclesPrius
Power Electronics Module:
Convert the DC battery voltage to the variable AC required to drive the AC motor.
Includes dc-dc boost converter and dc-3φ ac inverter
Control system can operate in all-electric mode or in hybrid gas+electric mode
Partial-power electronics
The document discusses electrical drive systems and power electronic converters used in drives. It begins by explaining what power electronics are and their applications. Modern electrical drive systems often use power electronic converters to efficiently control electric motors and improve performance over traditional fixed speed drives. Power electronic converters can be configured in different ways depending on the drive application and whether an AC or DC motor is used. Common converter configurations for DC drives include AC-DC, AC-DC-DC, and various DC-DC converter topologies.
The document provides an overview of power electronic devices. It begins by defining power electronic devices as semiconductor devices used to convert or control electric power. It then discusses the key features of power electronic devices, including that they must handle large power levels and typically operate in switching states. The document outlines the basic configuration of a power electronic system and classifications of devices. It provides details on uncontrolled diodes, half-controlled thyristors, and fully-controlled devices. It also discusses characteristics, specifications, applications and history.
Distribution System Voltage Drop and Power Loss CalculationAmeen San
Distribution System Voltage Drop and Power Loss
Calculation
Comparison of Overhead Versus Underground System
Power Loss Calculation,Voltage Drop Calculation
Busbar protection uses differential protection to isolate faults on the busbar. It works by comparing the current entering and leaving the busbar using CTs - any difference indicates an internal fault. Proper CT ratios and a stabilizing resistance are needed to restrain operation for external faults. PS class CTs are preferred over other classes due to more consistent accuracy. While busbar protection is important, it is currently not implemented in line at MRSS due to some unspecified reason.
This document discusses power quality and defines it as any deviation from the normal sinusoidal voltage or current waveform. It covers various power quality issues like voltage sags, swells, fluctuations, harmonics, interruptions and more. It explains the causes and impacts of different power quality problems. The document also discusses classification of issues, measurement and evaluation of power quality as well as relevant standards from organizations like IEEE.
The document provides an introduction to power system analysis. It discusses the components of a power system including generators, transformers, transmission lines and loads. It explains that power system analysis involves monitoring the system through load flow analysis, short circuit analysis and stability analysis in order to maintain the system safely and economically. It also discusses the need for power system analysis in planning and operating the system, and ensuring power demand is met through reliable generation and transmission of electricity.
Applications of power electronics in HVDCKabilesh K
Role of Power electronics in HVDC and Transmission system. What are the components of Power electronics used in HVDC. Types of HVDC Links. Advantages of HVDC over HVAC.
This document discusses distributed generation, which refers to small-scale power generation located near the end users. It can include sources like solar panels, wind turbines, fuel cells, and cogeneration. Distributed generation has advantages like reduced transmission losses and improved supply security. However, it also presents challenges like impacts on power quality from issues such as voltage regulation, grounding, harmonics, and islanding effects. The document outlines different distributed generation technologies and concludes that its integration into the power system is possible if interconnection designs adequately address power quality and safety considerations.
Current transformers are used to measure high currents in transmission lines. They have a primary winding with few turns connected in series to the transmission line, and a secondary winding with many more turns connected to a normal rating ammeter. This allows measurement of high primary currents through transformation to lower secondary currents. The core design aims to keep the exciting current drawn within the linear "ankle point" region for accurate measurement, and different types of current transformers are used depending on the required primary and secondary current ratings.
This document describes a three phase inverter that converts DC voltage to AC voltage. There are two main modes of conduction for a three phase inverter - 180 degree conduction and 120 degree conduction. 180 degree conduction involves three switches being on at a time, while 120 degree conduction only has two switches on at a time. The document provides circuit diagrams and equations to calculate the output voltages under each conduction mode. Waveforms are also shown to illustrate the phase and line voltages.
In microgrid, if fault occurs or any other contingency happens, then the problems would be created which are related to power flow, also there are various protection schemes are used for minimize or eliminate these problems.
Voltage control is used for reactive power balance and P-f control is used for active power control.
Various protection schemes such as, over current protection, differential protection scheme, zoning of network in adaptive protection scheme are used in microgrid system .
The document discusses electric drives and their components. It describes:
- Power modulators regulate power from the source to the motor. The control unit controls the power modulator and protects the drive. Sensing units measure parameters like motor current and speed.
- Drives have advantages like wide speed/torque ranges and flexible control. Disadvantages include high initial cost and vulnerability to power failures.
- Drives are classified as group, individual, or multi-motor depending on how many motors are used.
- Dynamics of the motor-load combination are described by the torque equation relating motor torque, load torque, and dynamic torque.
- Steady state stability depends on motor torque exceeding load torque
This document discusses issues related to interconnecting microgrids. It describes how a DC microgrid system utilizes a DC bus to distribute power from photovoltaic units and battery storage to local households. Interconnection can be done directly through switchgear or power electronic interfaces. Key issues that can arise include voltage and frequency fluctuations that occur due to imbalance between supply and demand, power factor correction needs, and harmonics produced by some loads. Unintentional islanding is also a safety concern that must be addressed when connecting microgrids to the main power grid.
This document discusses distributed generation (DG), also known as on-site power generation located near the load. DG provides benefits to end-users, distribution utilities, and power producers. It examines various DG technologies like reciprocating engines, combustion turbines, fuel cells, and renewables. The document also covers interface options with the utility grid, power quality issues, operating conflicts, and the role of DG in smart grids and rural electrification as supported by India's government policies.
This document discusses various protections provided for alternators, including mechanical protections from prime mover failure, field failure, overcurrent, overspeed, and overvoltage, as well as electrical protections from unbalanced loading and stator winding faults. It describes different protection mechanisms like differential protection, balanced earth fault protection, and inter-turn fault protection that are used to protect against faults in the alternator windings or unbalanced loading. The document emphasizes the importance of alternator protection given their high individual cost and importance in power generation.
MicroGrid and Energy Storage System COMPLETE DETAILS NEW PPT Abin Baby
A microgrid is a localized grouping of electricity generation, energy storage, and loads that normally operates connected to a traditional centralized grid (macrogrid). This single point of common coupling with the macrogrid can be disconnected. The microgrid can then function autonomously. Generation and loads in a microgrid are usually interconnected at low voltage. From the point of view of the grid operator, a connected microgrid can be controlled as if it were one entity.
Microgrid generation resources can include fuel cells, wind, solar, or other energy sources. The multiple dispersed generation sources and ability to isolate the microgrid from a larger network would provide highly reliable electric power. Produced heat from generation sources such as micro turbines could be used for local process heating or space heating, allowing flexible trade off between the needs for heat and electric power.
This document presents a schematic block diagram of a photovoltaic system with an interleaved boost converter and maximum power point tracking using the perturbation and observation method. It includes a single diode model of a PV cell and discusses the charging and discharging modes of operation of the boost converter. Simulation waveforms are presented showing the improvement with MPPT control. Future work will involve designing a closed loop inverter for grid synchronization.
This document discusses the digital control of DC drives using microcomputers. It describes how microcomputers can be used to control the speed and current of DC motors through programs that implement constant torque and constant horsepower operations. The microcomputer provides reliable control, flexibility to change control strategies, and can incorporate additional features like diagnostics and protections. Microcomputers reduce costs and size compared to analog controls while improving control performance and reliability. Speed is detected and current sensed to provide feedback for the inner current and speed control loops implemented through the microcomputer.
A three-phase transformer can be constructed as a single unit or from three individual single-phase transformers connected together. A single-unit transformer has advantages like less space, weight, and cost, and is more efficient. However, if a phase fails, the entire transformer must be removed for repair unlike with individual transformers. The document discusses different three-phase transformer connections like star-star, delta-delta, and uses of tertiary windings.
This document discusses constraints and load flow analysis in power systems. It outlines four key constraints: active power constraint, reactive power constraint, voltage magnitude constraint, and load angle constraint. It also describes load flow analysis as a balanced mechanism between demand and generation under incremental loading. Load flow analysis is important for the safe and future operation of power systems. The document further discusses bus classification, basic power flow conditions including the proportional relationships between reactive power and voltage and active power and load angle. It also covers the development of the Y-bus matrix considering line resistances and inductances alone and then including line capacitances.
“MODELING AND ANALYSIS OF DC-DC CONVERTER FOR RENEWABLE ENERGY SYSTEM” Final...8381801685
This project portrays a comparative analysis of DC-DC Converters for Renewable Energy System. The electrolysis method which increases the hydrogen production and storage rate from wind-PV systems. It has been proved that DC-DC converter with transformer has the desirable features for electrolyser application. The converter operates in lagging PF mode for a very wide change in load and supply voltage variations, thus ensuring ZVS for all the primary switches. The peak current through the switches decreases with load current.This paper portrays a comparative analysis of DC-DC Converters for Renewable Energy System . The simulation and experimental results show that the power gain obtained by this method clearly increases the hydrogen production and storage rate from wind-PV systems. It has been proved that DC-DC converter with transformer has the desirable features for electrolyser application. Theoretical predictions of the selected configuration have been compared with the MATLAB simulation results. The simulation and experimental results indicate that the output of the inverter is nearly sinusoidal. The output of rectifier is pure DC due to the presence of LC filter at the output. It can be seen that the efficiency of DC-DC converter with transformer is 15% higher than the converter without transformer.
Lecture Outline
Introduction to subject
Application Areas
Power Electronic Devices
Power Converters
What is power electronics?
1) Definition
Power Electronics: is the electronics applied to conversion and control of electric power.
Prerequisites
Power electronics incorporates concepts from the fields of
Analog circuits
Electronic devices
Control systems
Power systems
Magnetics
Electric machines
Numerical simulation
Scope
It is not possible to build practical computers, cell phones, personal data devices, cars, airplanes, industrial processes, and other everyday products without power electronics.
Alternative energy systems such as wind generators, solar power, fuel cells, and others require power electronics to function.
Technology advances such as electric and hybrid vehicles, laptop computers, microwave ovens, flat-panel displays, LED lighting, and hundreds of other innovations were not possible until advances in power electronics enabled their implementation.
Although no one can predict the future, it is certain that power electronics will be at the heart of fundamental energy innovations.
Applications: Electric VehicleTesla Model S
Functions of the power electronics:
1. Convert the DC battery voltage to the variable AC required to drive the AC motor
240 V battery
Variable-frequency, variable-voltage AC drives the motor
AC motor propels the rear axle
Up to 330 kW (acceleration)
Up to 60 kW regenerative braking
2. Control charging of the battery
Interface to 240 V 60 Hz 1φ 100 A circuit in garage.
Control AC current waveform to be sinusoidal, unity power factor.
Control charging of battery to maximize life.
Applications: Hybrid VehiclesPrius
Power Electronics Module:
Convert the DC battery voltage to the variable AC required to drive the AC motor.
Includes dc-dc boost converter and dc-3φ ac inverter
Control system can operate in all-electric mode or in hybrid gas+electric mode
Partial-power electronics
The document discusses electrical drive systems and power electronic converters used in drives. It begins by explaining what power electronics are and their applications. Modern electrical drive systems often use power electronic converters to efficiently control electric motors and improve performance over traditional fixed speed drives. Power electronic converters can be configured in different ways depending on the drive application and whether an AC or DC motor is used. Common converter configurations for DC drives include AC-DC, AC-DC-DC, and various DC-DC converter topologies.
The document provides an overview of power electronic devices. It begins by defining power electronic devices as semiconductor devices used to convert or control electric power. It then discusses the key features of power electronic devices, including that they must handle large power levels and typically operate in switching states. The document outlines the basic configuration of a power electronic system and classifications of devices. It provides details on uncontrolled diodes, half-controlled thyristors, and fully-controlled devices. It also discusses characteristics, specifications, applications and history.
This document discusses electric drives and AC motor drives. It defines electric drives as systems that use 50% of electrical energy produced and can operate equipment at constant or variable speeds. The main components of electric drives are motors, including DC and AC types, and power sources like batteries or utilities. It also summarizes different types of single-phase and three-phase DC drives classified by their converter configurations. For AC drives, it explains that speed and torque can be controlled through stator voltage, rotor voltage or frequency control. It concludes that variable speed AC drives can increase system efficiency from 15-27% compared to constant speed operation.
This document discusses power electronics and provides an overview of key concepts:
1. Power electronics refers to controlling and converting electrical power using power semiconductor devices like SCRs. Main applications include rectification, inversion, DC-DC conversion, and AC-AC conversion.
2. Rectification can be uncontrolled using diodes or controlled using SCRs. Common rectifier configurations include single and three-phase bridge rectifiers. Inversion converts DC to AC using devices like SCRs, IGBTs, and MOSFETs.
3. DC-DC conversion is commonly done using switch-mode power supplies with devices like BJTs and MOSFETs. AC-AC conversion using cycloconverters
The document discusses various power electronics applications including energy storage elements like inductors and capacitors, uninterruptible power supplies (UPS), and switch mode power supplies (SMPS). It describes the basic working principles of inductors, capacitors, different types of UPS systems including static and rotary, and various SMPS topologies such as forward, flyback, non-isolated, and isolated converter modes. Key applications and components of these power electronic circuits are explained in detail across multiple pages.
A solenoid is a coil of wire that produces a magnetic field when electric current passes through it. Inside the solenoid, the magnetic field lines are parallel and uniform. Outside the solenoid, the magnetic field is non-uniform and weak due to cancellation of opposing field lines between coil turns. Solenoids can operate using direct current (DC) or alternating current (AC). DC solenoids consist of a coil, field/helix, and plunger that moves in one direction when energized. Solenoids have many applications including locking mechanisms, automotive systems, medical devices, railways, and industrial machinery.
This document discusses different types of thyristors including silicon-controlled rectifiers (SCRs), triacs, and diacs. SCRs allow current to flow in one direction when triggered by a positive gate signal and can be used to control both AC and DC circuits. Triacs are bidirectional and can control current flowing in either direction when triggered by a positive or negative gate signal. Diacs are required for triggering triacs due to their nonsymmetrical triggering characteristics. The document provides schematics and diagrams of the different thyristor components.
This document discusses how solenoids work to convert electrical power into mechanical work. It describes how applying a current generates a magnetic field that attracts a plunger, creating motion. Different types of solenoids are presented, including push, pull, clapper, and rotary varieties. Common applications like valve actuators and sorting machines are reviewed. Size, stroke length, and force limitations of solenoids are also covered. Web resources for learning more about solenoids are provided.
A solenoid valve is an electrically controlled valve that uses a solenoid to regulate air movement. It contains a magnetic coil, valve stem, valve sheet, inlet, outlet, plunger and breakaway pin. Solenoid valves are used to control hydraulic systems and mix or distribute air in applications like RO purifiers and dust collectors.
The document discusses the triode for alternating current (TRIAC). A TRIAC is a bidirectional thyristor that can conduct current in both directions, unlike an SCR which only conducts in one direction. The TRIAC has symmetrical characteristics in the first and third quadrants of its IV curve. It can be triggered by either a positive or negative gate signal, unlike the SCR which only responds to a positive gate signal. The TRIAC turns on when a positive or negative voltage is applied to its gate terminal to create a triggering current and remains on until the current through its main terminals drops below the holding current.
A solenoid is a coil of wire that generates a nearly uniform magnetic field when electric current passes through it. The magnetic field is greatly intensified when an iron core is placed inside the coil. When current flows through the coil, it produces a magnetic field that travels in a doughnut shape around the coil and through its center, and this magnetic field can be used to move or attract the iron core or other ferromagnetic materials.
Silicon-controlled rectifiers (SCRs), TRIACs, and DIACs are types of thyristors. SCRs control current flowing in one direction using a gate signal, and can handle large currents up to 1400 amps and high frequencies up to 30,000 Hz. TRIACs control current bi-directionally like two SCRs back-to-back but have lower ratings. DIACs are used as trigger devices for TRIACs due to their nonsymmetrical triggering characteristics.
This document discusses solenoids and their applications. It defines a solenoid as an electromechanical device that uses electrical energy to cause mechanical movement. It describes how solenoids are commonly used in valves, locks, punches, and other devices to activate or control mechanical systems. The document provides examples of common uses of rotary and linear solenoids and includes the standard symbol for a solenoid.
Different types of transistors and their functionselprocus
This article discusses about types of transistors and basic applications.Common types of transistor are BJT, FET, HBT, Darlington, Schottky, JFET, Diffusion
This document discusses the theory and working of thyristors, which are semiconductor devices used in controlled rectification applications. It explains that thyristors like SCRs conduct current in only one direction when a gate signal is applied, and continue conducting even after the gate signal is removed. The document describes the internal structure of a thyristor and its operation, involving a PNP and NPN transistor structure triggered by a gate signal. It also provides examples of uncontrolled and controlled full-wave rectification using thyristors in bridge configurations, and discusses the principle of DC motor speed control using a thyristor-based drive.
The document discusses four main types of actuators used in robots: hydraulic, pneumatic, electrical, and micro actuators. Hydraulic actuators use pressurized fluids like oil to provide force and motion, while pneumatic actuators use compressed air. Electrical actuators include motors, solenoids, and linear motors. Each type has advantages like power capacity or accuracy, and disadvantages such as cost, size, or environmental sensitivity. The document provides details on examples of each type of actuator and compares their key characteristics.
The document discusses various power control devices including silicon controlled rectifiers (SCRs), triacs, diacs, gate turn-off thyristors (GTOs), bipolar junction transistors (BJTs), and metal-oxide-semiconductor field-effect transistors (MOSFETs). SCRs, triacs, and diacs can only be turned off by reducing the anode current below a threshold, while GTOs can be turned off by a negative gate signal. BJTs and MOSFETs can be used as electronic switches by controlling the base/gate current to turn the device on or off.
The document summarizes different types of field-effect transistors (FETs). It describes the invention of the transistor in 1947 and its impact. It then discusses the basic principles and constructions of junction FETs (JFETs), metal-oxide-semiconductor FETs (MOSFETs) including n-channel and p-channel enhancement and depletion mode MOSFETs. Key differences between FETs, BJTs, and operating characteristics such as different regions of operation are also summarized. The document provides a high-level overview of various FET technologies.
Reliability evaluation of MPPT based interleaved boost converter for PV systemAsoka Technologies
The demand for power supply and depletion of the conventional energy sources are increasing drastically. So to overcome this problem, the best alternative power generation for conventional fossil fuel is Photovoltaic solar cell based system because of its advantage of pollution free and its availability in abundance with free of cost. In the MPPT based PV system the converters are the most sensitive part. Therefore to provide uninterrupted power supply without compromising the quality of power, reliability evaluation of interleaved boost converter becomes necessary. MATLAB/Simulink is used for the simulation studies and to determine the power losses of various components of the converter which is used in calculating the failure rates and reliability of the interleaved boost converter. Reliability studies of IBC have not been studied much. However there exists few literature in which reliability expression has been developed using Markov technique which is a more complex method as compare to Reliability Block Diagram (RBD). Therefore this paper proposes reliability modeling and reliability evaluation of Interleaved boost converter in MPPT based photo-voltaic system by using simple RBD method.
development and experimental validation of a global simulation model of an high power electrical drive (Ansaldo Sistemi Industiali) in a cement plant (Italcementi)
COUPLED FIELD ANALYSIS OF PIEZOELECTRIC CANTILEVER BEAMijiert bestjournal
Electromechanical modelling efforts in the research field of vibration-based energy harvesting have been mostly focused on forms of vibrational in put as in the typical case of harmonic excitation at resonance. However,ambient vibration al energy often has broader frequency content than a single harmonic. Piezoelectric energ y harvesting is a promising technology for extracting the power from environmental vibrations. It generates the electrical power of few orders of amplitudes which is sufficient to drive s everal autonomous electrical devices. Such vibration-based energy harvester generates the most energy when the generator is excited at its resonance frequency. Simplest model to be start ed is of rectangular Aluminium cantilever beam with unimorph piezoelectric patch which is per fectly bonded to the substrate plate at the end. The resulting relative motion between the piez oelectric patch and the base produces stress on piezoelectric material,which is converte d into electrical power by virtue of direct piezoelectric effect. The ability of piezoelectric material of different thickness to generate voltage at different frequency is explained in this paper. Its capability to work over a range of frequency is predicted by use of ANSYS software. Th e solid model is design and analyzed using finite element software.
This document discusses the implementation of low power integrators and differentiators using memristors. It presents the mathematical models of memristors and describes how memristor-based integrator and differentiator circuits were designed and simulated. The results show that the memristor-based circuits achieve much lower power consumption in the nano-watt range compared to traditional op-amp based implementations, demonstrating the potential of memristors for low power analog circuit applications.
This document discusses the implementation of low power integrators and differentiators using memristors. It first provides background on memristors and describes the linear ion drift model used to model memristor behavior. It then shows circuit diagrams for traditional op-amp-based integrators and differentiators and their memristor-based counterparts. Transient analyses are performed and results show the memristor-based circuits provide significantly lower power dissipation in the nano-Watt range compared to milli-Watt ranges for traditional designs. Therefore, memristors allow for more compact and reliable analog circuit implementation with reduced power consumption.
The main objective of this research work is to develop KY conveter topology for renewable energy sources.Solar energy is the readily available and is the cheapest form of energy. It is non-polluting and environment friendly. The development of high static gain DC-DC converters is an important research area due to the crescent demand of this technology for several applications supplied by low DC output voltage power sources. It is used to provide the uninterruptable power supply and battery powered to the system. So here, step-up DC-DC converters based on the KY converter are proposed for LED lighting systems. The proposed topologies present high voltages and high efficiency for low input voltage and high output voltage applications. The simulation results of the proposed topology have been presented using MATLAB/SIMULINK software.
MULTIPLE TESTS ON TRANSFORMER WITH THE HELP OF MATLAB SIMULINKIRJET Journal
The document describes using MATLAB Simulink to model and simulate transformer tests, including open circuit, short circuit, and load tests. This allows performing the tests in a simpler, more efficient manner compared to traditional methods that require extensive manual measurements. The MATLAB model calculates key parameters like resistance, inductance, and efficiency. It reduces errors and human effort compared to conventional test equipment. The model is verified by comparing results to manual calculations and can be a useful educational and analysis tool.
EFFICIENT AND COST EFFECTIVE MODEL FOR AN ECO-FRIENDLY SOLAR COLONYcscpconf
A simple and successful design is developed which has the objective to put together a cost effective model, scaled down both in size and energy required for an average residential home
driven through Solar Panels. It also deals with the autonomous illumination of streets of a
model colony through solar panels to meet the requirements and attain the maximum efficiency
of the available energy. The Photovoltaic system along with an inverter and intensity control circuit counts for the basic design. The effort deals with the efficient, cost effective and needful
implementation of Photovoltaic systems which would be useful primarily in rural and remote parts of India for both social and economic development of the people.
Automobile alternators can provide a low-cost alternative to conventional stepper motors for speed control applications. By disconnecting the rectifier stack and connecting a transistorized inverter, an alternator can function as a stepper motor. Typical performance curves show a alternator-based motor can output up to 180W at 1800 rpm, with a holding torque of 1-3 Nm and maximum speed of 2500 rpm. Compared to traditional stepper motors, alternator-based motors have similar performance at a lower cost, making them suitable for constant-speed control applications.
This manual is very much useful for PG students belongs to ME Power Electronics and Drives
By
M.MURUGANANDAM. M.E.,(Ph.D).,MIEEE.,MISTE,
Assistant Professor & Head / EIE,
Muthayammal Engineering College,
Rasipuram,
Namakkal-637 408.
Cell No: 9965768327
This is Solar Array Simulator to test the solar inverters for Maximum Power Point Tracking (MPPT) with dynamic simulation of Voc, Isc (I-V curves), Irradiation, Temperature coefficients, diff daly light conditions including cloudy, rainy dark conditions.
About 7 installations already in India in research & educational institutions
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IRJET- Electrical Simulation Model of IEC 61400-27-1 Doubly-Fed Induction Gen...IRJET Journal
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19EEC03 Linear Integrated Circuits and its ApplicationsDr.Raja R
This document outlines a course on linear integrated circuits and their applications. It discusses operational amplifiers, timers, and voltage regulators. The course objectives are to provide in-depth instruction on the characteristics and applications of these components. The course covers topics like op-amp characteristics, analog signal processing circuits, timers, and voltage regulators. It lists 5 intended learning outcomes and the topics to be covered in the 5 units of the course. It also provides details of reference books and concludes with brief descriptions of integrated circuits and their advantages.
1) The document presents a seminar on controlling a switched reluctance machine operating in generating mode using a microcontroller.
2) A mathematical model of the switched reluctance machine is developed using analytical modeling techniques to determine flux linkage and inductance.
3) A power converter circuit, rotor position and speed sensors, and control feedback system are modeled in MATLAB and interfaced with a microcontroller.
4) The microcontroller is programmed to control the speed and current of the switched reluctance generator based on the mathematical model and simulations.
IRJET- Partial Discharge Investigation of Insulators using SimulationIRJET Journal
This document describes a simulation of partial discharge (PD) activity in solid insulation materials used in high voltage power equipment. The simulation models a small cylindrical or cubical void inside the insulation material and studies the PD behavior under varying applied voltages using MATLAB Simulink. Equivalent circuit models are developed to calculate the capacitances of the insulation material and void. Simulations are conducted for cylindrical and cubical voids up to 14kV and the maximum PD magnitudes are recorded, showing that PD increases with higher applied voltages. The study provides useful information for power engineers to evaluate insulation quality in high voltage equipment.
Now-a-days, power generation and utilization became more complicated which further affects the economy of a country. The available non-renewable energy sources that supply the demanded power do not consider environmental challenges like global warming and pollution. This leads to the development of power generation based on Renewable Energy Resources (RES). These RES are connected to the grid through power electronic converters which offer countless power quality issues that must be rectified to deliver a quality power to the end users. The proposed work uses a three phase Voltage Source Inverter (VSI) based Shunt Active Power Filter (SAPF) fed by solar Photo Voltaic (PV) system to eliminate current harmonics at the source side of the grid. The output of the PV system is given to a boost converter along with self–lift single-ended primary-inductor converter (SEPIC) for supplying high voltage gain which is accompanied by a Perturb & Observe Maximum Power Point Tracking (MPPT).The main objective of this paper is to eliminate the current harmonics at the grid side using SAPF. Also, the proposed SAPF is used for exporting the power generated from PV to the grid. The overall system performance is validated with a help of MATLAB/SIMULINK.
Modeling of Photo Voltaic Module under Partial Shaded Conditions Using PSO MP...IJMTST Journal
In this paper a modified BOOST converter is presented for maximum power point tracking (MPPT) with PI
controller to improve the performance of PV system. SEPI converter is proposed as interface between load and
PV module array as DC-DC converter. Whichis more advantageous over boost converter for step up and step
down operations. The P&O and PSO based BOOST converter proposed are main key factors for high
efficiency output at foul weather conditions. The MATLAB/SIMULINK power system tool box will be used to
stimulate the proposed system.
MATLAB Based Model for Analysis of the Effect of Equivalent Circuit Parameter...IOSR Journals
This document presents a MATLAB/Simulink model of a three-phase squirrel cage induction motor to analyze the effects of varying the equivalent circuit parameters of the motor on its dynamic characteristics. The model simulates the motor performance under different tests that vary the rotor resistance, rotor inductance, stator resistance, and stator inductance. The simulation results show the impact of parameter variations on the motor's torque-speed characteristics, currents, speed, torque over time. Increasing the rotor resistance slightly reduces starting jerks, while increasing stator inductance significantly prolongs the transient period until steady-state is reached and draws excessively high current. To achieve satisfactory motor performance, the stator parameters should be kept as low as
Enterprise Knowledge’s Joe Hilger, COO, and Sara Nash, Principal Consultant, presented “Building a Semantic Layer of your Data Platform” at Data Summit Workshop on May 7th, 2024 in Boston, Massachusetts.
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Power Electronics
1. Power Electronics and Drives
–Modeling & Simulation
A Problem Based and Project Oriented
Learning
B.Chitti Babu
Member IEEE (USA), Student Member IET (UK)
Department of Electrical Engineering,
National Institute of Technology,Rourkela
bcbabunitrkl@ieee.org
B Chitti Babu,
14 August 2009 1
EE NIT Rourkela
2. CONTENTS
Pre Requisite of Power Electronics System
Power Electronic Systems
Power Electronic Converters in Electrical Drives
:: DC and AC Drives
Modeling and Control of Electrical Drives
:: Current controlled Converters
:: Modeling of Power Converters
:: Scalar control of IM
B Chitti Babu,
14 August 2009 2
EE NIT Rourkela
3. Power Electronics-An Enabling Technology
Energy System
REFRIGERATOR
SOLAR CELLS TELEVISION
DC
AC
SOLAR LIGHT
ENERGY TRANSFORMER
3 3 3 1-3 MOTOR
POWER STATION TRANSFORMER PUMP
FACTS
ROBOTICS
COMPEN-
SATOR
INDUSTRY
TRANSFORMER FUEL DC
CELLS AC
☯
3 POWER SUPPLY
a d
WIND TURBINE ~
FUEL =
COMMUNICATION
TRANSPORT
COMBUSTION
ENGINE
B Chitti Babu,
14 August 2009 Courtesy:
EE NIT Rourkela
Aalborg University,Denmark
3
4. Implementation of problem-oriented and
project-organised education
Literature Lectures Group
studies
Problem Problem Report
analysis solving
Field work/ Experiments/
Tutorials Simulation Prototyping
B Chitti Babu,
14 August 2009 4
EE NIT Rourkela
5. Prerequisite for Power Electronics
• Study of Second Order System, Control
Concepts and Mathematics
• Role of Passive Elements
• Physics concepts of Devices
• Device Selection
………………………………
• Modeling and Simulation
• Build and Evaluate
• Design & Development
• Research and Innovate
B Chitti Babu,
14 August 2009 5
EE NIT Rourkela
6. Modeling & Simulation?
• Modeling here refers to the process of analysis and syntheses to arrive at a suitable
mathematical description that encompasses the relevant dynamic characteristics of the
component, preferably in terms of parameters that can be easily determined in practice
• Model supposely imitates or reproduces certain essential characteristics or conditions of
the actual-This is called SIMULATION.
• Modeling & Simulation-Simulation is a technique that involves setting up a model of a real
situation and performing experiments on the model.
• Simulation to be an experiment with logical and mathematical models, especially
mathematical representations of the dynamic kind that are characterized by a mix of
differential and algebraic equations.
B Chitti Babu,
14 August 2009 6
EE NIT Rourkela
7. Simulation Formulation
• Observing the Physical system.
• Formulating the hypotheses or mathematical model to
explain the observation.
• Predicting the behavior of the system from solutions
or properties of the mathematical model.
• Testing the validity of the Hypotheses or
Mathematical Model.
B Chitti Babu,
14 August 2009 7
EE NIT Rourkela
8. Mathematical Models
• Linear or Nonlinear
• Lumped or Distributed parameters
• Static & Dynamic
• Continuous or Discrete
• Deterministic or Stochastic
Courtesy: Dynamic Simulation of Electric Machinery-
By Chee Mun Ong
B Chitti Babu,
14 August 2009 8
EE NIT Rourkela
9. Simulation Packages
1)General Purpose:
Equation Oriented in that they require input in the form of
differential or algebraic equations. Eg:IESL, SABER, IMSL,
ODEPAK & DASSL etc.
2)Application-Specific Packages:
Ready to use models of commonly used components for a specific
applications. Eg:SPICE2, EMTP, PSCAD etc.
MATLAB & SIMULINK:They are Registered
Trade mark of the THE MATHWORKS. Inc.,
USA
B Chitti Babu,
14 August 2009 9
EE NIT Rourkela
10. Power Electronic Systems
What is Power Electronics ?
A field of Electrical Engineering that deals
with the application of power semiconductor
devices for the control and conversion of
electric power
sensors
Input Power
Source Electronics Load
- AC
- DC Converters Output
- unregulated - AC
- DC
POWER ELECTRONIC
CONVERTERS – the
Reference
Controlle heart of power a power
r electronics system
B Chitti Babu,
14 August 2009 10
EE NIT Rourkela
11. Power Electronic Systems
Why Power Electronics ?
Power semiconductor devices Power switches
isw
ON or OFF
+ vsw −
=0
isw = 0
Ploss = vsw× isw = 0
+ vsw −
Losses ideally ZERO !
B Chitti Babu,
14 August 2009 11
EE NIT Rourkela
12. Power Electronic Systems
Why Power Electronics ?
Power semiconductor devices Power switches
K K K
− − −
G G
Vak Vak Vak
+ + +
ia ia ia
A A A
B Chitti Babu,
14 August 2009 12
EE NIT Rourkela
13. Power Electronic Systems
Why Power Electronics ?
Power semiconductor devices Power switches
D
C
iD
+ ic
+
VDS G
G VCE
−
−
S
E
B Chitti Babu,
14 August 2009 13
EE NIT Rourkela
14. Power Electronic Systems
Why Power Electronics ?
Passive elements High frequency
+ VL transformer
−
i
L
+ +
Inductor
V V2
1
+ VC −
− −
i
C
B Chitti Babu,
14 August 2009 14
EE NIT Rourkela
15. Passive Elements In Power Electronics
• Resistors
• Capacitors
• Inductors
• Transformers
• Filters
• Integrated Magnetics
B Chitti Babu,
14 August 2009 15
EE NIT Rourkela
16. Resistors in
Power Electronics
• Resistors are mostly used in Power
Electronics to dissipate the trapped
energy from other components as well to
provide damping.
• Thus, resistors can carry significant
amount of high frequency currents.
• Resistors can carry fundamental ac
component currents in ac circuits and also
carry dc component currents under steady
state.
• No resistor is ideal, so their behavior
depends upon the applied frequency The
peak temperature rise depends on the
energy dissipated in the resistors.
B Chitti Babu,
14 August 2009 16
EE NIT Rourkela
17. Capacitors in
Power Electronics
• Capacitors are mostly used in Power
Electronics to by-pass high frequency
components of voltages and currents.
• Thus, capacitors can carry significant
amount of high frequency currents
Capacitors can carry fundamental ac
component.
• currents in ac circuits but cannot carry dc
component currents under steady state.
• No capacitor is ideal, so their behavior
depends upon the applied frequency
• The breakdown voltage depends on the peak
voltage charge
B Chitti Babu,
14 August 2009 17
EE NIT Rourkela
18. Inductors in
Power Electronics
• Inductors are mostly used in Power
Electronics to block the flow of high
frequency components of currents.
• Thus, inductors can drop significant
amount of high frequency voltages.
• Inductors can have fundamental ac
component voltage drop in ac circuits but
cannot drop dc component voltages under
steady state.
• No inductor is ideal, so their behavior
depends upon the applied frequency
• The peak flux density depends on the peak
instantaneous current.
Courtesy: Dr.Sujit K. Biswas, Lecture Notes, Jadavpur University
B Chitti Babu,
14 August 2009 18
EE NIT Rourkela
19. Power Electronic Systems
Why Power Electronics ?
sensors
Input Power
Source Electronics Load
IDEALLY
- AC
Converters LOSSLESS !
Output
- DC
- unregulated - AC
- DC
Reference
Controlle
r
B Chitti Babu,
14 August 2009 19
EE NIT Rourkela
20. Power Electronic Systems
Why Power Electronics ?
Other factors:
• Improvements in power semiconductors
• fabrication
• Power Integrated Module (PIM),
Intelligent Power Modules (IPM)
• Decline cost in power semiconductor
• Advancement in semiconductor fabrication
• ASICs • FPGA • DSPs
• Faster and cheaper to implement
complex algorithm
B Chitti Babu,
14 August 2009 20
EE NIT Rourkela
21. Power Electronic Systems
Some Applications of Power Electronics :
Typically used in systems requiring efficient control and conversion of
electric energy:
Domestic and Commercial Applications
Industrial Applications
Telecommunications
Transportation
Generation, Transmission and Distribution of electrical energy
Power rating of < 1 W (portable equipment)
Tens or hundreds Watts (Power supplies for computers /office equipment)
kW to MW : drives
Hundreds of MW in DC transmission system (HVDC)
B Chitti Babu,
14 August 2009 21
EE NIT Rourkela
22. Modern Electrical Drive Systems
• About 50% of electrical energy used for drives
• Can be either used for fixed speed or variable speed
• 75% - constant speed, 25% variable speed (expanding)
• Variable speed drives typically used PEC to supply the motors
DC motors (brushed) AC motors
SRM - IM
BLDC - PMSM
B Chitti Babu,
14 August 2009 22
EE NIT Rourkela
23. Modern Electrical Drive Systems
Classic Electrical Drive for Variable Speed Application :
• Bulky
• Inefficient
• inflexible
B Chitti Babu,
14 August 2009 23
EE NIT Rourkela
24. Modern Electrical Drive Systems
Typical Modern Electric Drive Systems
Power Electronic Converters Electric Motor
Electric Energy Electric Energy Electric Mechanical
- Unregulated - - Regulated - Energy Energy
POWER IN Power
Moto Loa
Electronic d
r
Converters
feedback
Reference
Controller
B Chitti Babu,
14 August 2009 24
EE NIT Rourkela
25. Modern Electrical Drive Systems
Example on VSD application
Constant speed Variable Speed Drives
valve
Supply
motor pump
Power out
Power
In
Power loss
Mainly in valve
B Chitti Babu,
14 August 2009 25
EE NIT Rourkela
26. Modern Electrical Drive Systems
Example on VSD application
Constant speed Variable Speed Drives
valve
Supply Supply
motor pump motor
PEC pump
Power out
Power out
Power
Power
In
In
Power loss
Power loss
Mainly in valve
B Chitti Babu,
14 August 2009 26
EE NIT Rourkela
27. Modern Electrical Drive Systems
Example on VSD application
Constant speed Variable Speed Drives
valve
Supply Supply
motor pump motor
PEC pump
Power out
Power out
Power
Power
In
In
Power loss
Power loss
Mainly in valve
B Chitti Babu,
14 August 2009 27
EE NIT Rourkela
28. Modern Electrical Drive Systems
Example on VSD application
Electric motor consumes more than half of electrical energy in the US
Fixed speed Variable speed
Improvements in energy utilization in electric motors give large
impact to the overall energy consumption
HOW ?
Replacing fixed speed drives with variable speed drives
Using the high efficiency motors
Improves the existing power converter–based drive systems
B Chitti Babu,
14 August 2009 28
EE NIT Rourkela
29. Modern Electrical Drive Systems
Overview of AC and DC drives
Before semiconductor devices were introduced (<1950)
• AC motors for fixed speed applications
• DC motors for variable speed applications
After semiconductor devices were introduced (1960s)
• Variable frequency sources available – AC motors in variable
speed applications
• Coupling between flux and torque control
• Application limited to medium performance applications –
fans, blowers, compressors – scalar control
• High performance applications dominated by DC motors –
tractions, elevators, servos, etc
B Chitti Babu,
14 August 2009 29
EE NIT Rourkela
30. Modern Electrical Drive Systems
Overview of AC and DC drives
After vector control drives were introduced (1980s)
• AC motors used in high performance applications – elevators,
tractions, servos
• AC motors favorable than DC motors – however control is
complex hence expensive
• Cost of microprocessor/semiconductors decreasing –predicted
30 years ago AC motors would take over DC motors
B Chitti Babu,
14 August 2009 30
EE NIT Rourkela
31. Modern Electrical Drive Systems
Overview of AC and DC drives
Courtesy: Electrical Drives by Ion Boldea ,CRC Press
B Chitti Babu,
14 August 2009 31
EE NIT Rourkela
32. Power Electronic Converters in ED Systems
Converters for Motor Drives
(some possible configurations)
DC Drives AC Drives
AC Source DC Source AC Source DC Source
DC-AC-
DC-DC
DC
AC-DC- AC-DC- DC-DC-
AC-DC AC-AC DC-AC
DC AC AC
Const. Variable NCC FCC
DC
DCChitti Babu,
B
14 August 2009 32
EE NIT Rourkela
33. Power Electronic Converters in ED Systems
DC DRIVES
Available AC source to control DC motor (brushed)
AC-DC-
AC-DC DC
Uncontrolled Rectifier
Single-phase Control
Control
Three-phase
Controlled Rectifier DC-DC Switched mode
Single-phase 1-quadrant, 2-quadrant
Three-phase 4-quadrant
B Chitti Babu,
14 August 2009 33
EE NIT Rourkela
34. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC
400
200
0
+ 2 Vm
Vo = cos α
-200
π
-400
0.4 0.405 0.41 0.415 0.42 0.425 0.43 0.435 0.44
50Hz Vo 10
1-phase Average voltage
5
over 10ms
−
0
0.4 0.405 0.41 0.415 0.42 0.425 0.43 0.435 0.44
500
0
50Hz
+ -500
3-phase 0.4 0.405 0.41 0.415 0.42 0.425 0.43 0.435 0.44
3VL − L , m
Vo Vo = cos α
π
30
20
− Average voltage
10
over 3.33 ms
0
B Chitti Babu, 0.4 0.405 0.41 0.415 0.42 0.425 0.43 0.435 0.44
14 August 2009 34
EE NIT Rourkela
35. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC
2 Vm
π
+ 2 Vm
Vo = cos α
π
50Hz Vo 90o 180o
1-phase Average voltage
over 10ms
− 2 Vm
−
π
3VL − L , m
π
50Hz
+
3-phase
3VL − L , m
Vo Vo = cos α
π 90o 180o
− Average voltage
over 3.33 ms 3VL − L , m
−
π
B Chitti Babu,
14 August 2009 35
EE NIT Rourkela
36. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC
ia
+
Vt
3-phase
Vt Q2 Q1
supply
− Q3 Q4 Ia
- Operation in quadrant 1 and 4 only
B Chitti Babu,
14 August 2009 36
EE NIT Rourkela
37. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC
+
3-
phase 3-phase
Vt supply
supply
−
ω
Q2 Q1
Q3 Q4
T
B Chitti Babu,
14 August 2009 37
EE NIT Rourkela
38. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC
F1 R1
3-phase
supply
+ Va -
R2 F2
ω
Q2 Q1
Q3 Q4
T
B Chitti Babu,
14 August 2009 38
EE NIT Rourkela
39. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC
Cascade control structure with armature reversal (4-quadrant):
iD
ω
ωref + Speed iD,ref + Current
Firing
control Control Circuit
ler _ ler
_
iD,ref
Armature
iD, reversal Babu,
B Chitti
14 August 2009 39
EE NIT Rourkela
40. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC
Uncontrolled control
rectifier
Switch Mode DC-DC
1-Quadrant
2-Quadrant
4-Quadrant
B Chitti Babu,
14 August 2009 40
EE NIT Rourkela
41. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC
control
B Chitti Babu,
14 August 2009 41
EE NIT Rourkela
42. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Two-quadrant Converter
Va
T1 D1
+
ia
Vdc Q2 Q1
+ Ia
− D2
T2
Va
-
T1 conducts → va = Vdc
B Chitti Babu,
14 August 2009 42
EE NIT Rourkela
43. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Two-quadrant Converter
Va
T1 D1
+
ia
Vdc Q2 Q1
+ Ia
− D2
T2
Va
-
D2 conducts → va = 0 T1 conducts → va = Vdc
Va Eb
Quadrant 1 The average voltage is made larger than the back emf
B Chitti Babu,
14 August 2009 43
EE NIT Rourkela
44. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Two-quadrant Converter
Va
T1 D1
+
ia
Vdc Q2 Q1
+ Ia
− D2
T2
Va
-
D1 conducts → va = Vdc
B Chitti Babu,
14 August 2009 44
EE NIT Rourkela
45. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Two-quadrant Converter
Va
T1 D1
+
ia
Vdc Q2 Q1
+ Ia
− D2
T2
Va
-
T2 conducts → va = 0 D1 conducts → va = Vdc
Va Eb
Quadrant 2 The average voltage is made smallerr than the back emf, thus
forcing the current to flow in the reverse direction
B Chitti Babu,
14 August 2009 45
EE NIT Rourkela
46. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Two-quadrant Converter
vc
2vtri
+
vA Vdc
-
0
+
vc
B Chitti Babu,
14 August 2009 46
EE NIT Rourkela
47. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Four-quadrant Converter
leg A leg B
+ D1 D3
Q1 Q3
+ Va −
Vdc
− D4 D2
Q4 Q2
Positive current
va = Vdc when Q1 and Q2 are ON
B Chitti Babu,
14 August 2009 47
EE NIT Rourkela
48. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Four-quadrant Converter
leg A leg B
+ D1 D3
Q1 Q3
+ Va −
Vdc
− D4 D2
Q4 Q2
Positive current
va = Vdc when Q1 and Q2 are ON
va = -Vdc when D3 and D4 are ON
va = 0 when current freewheels through Q and D
B Chitti Babu,
14 August 2009 48
EE NIT Rourkela
49. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Four-quadrant Converter
leg A leg B
+ D1 D3
Q1 Q3
+ Va −
Vdc
− D4 D2
Q4 Q2
Positive current Negative current
va = Vdc when Q1 and Q2 are ON va = Vdc when D1 and D2 are ON
va = -Vdc when D3 and D4 are ON
va = 0 when current freewheels through Q and D
B Chitti Babu,
14 August 2009 49
EE NIT Rourkela
50. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Four-quadrant Converter
leg A leg B
+ D1 D3
Q1 Q3
+ Va −
Vdc
− D4 D2
Q4 Q2
Positive current Negative current
va = Vdc when Q1 and Q2 are ON va = Vdc when D1 and D2 are ON
va = -Vdc when D3 and D4 are ON va = -Vdc when Q3 and Q4 are ON
va = 0 when current freewheels through Q and D va = 0 when current freewheels through Q and D
B Chitti Babu,
14 August 2009 50
EE NIT Rourkela
51. Power Electronic Converters in ED Systems
DC DRIVES
Bipolar switching scheme – output
AC-DC-DC swings between VDC and -VDC
vc
2vtri
Vdc
Vdc
+ + vA
vA vB 0
- - Vdc
vB
0
vc Vdc
+ vAB
_ -Vdc
B Chitti Babu,
14 August 2009 51
EE NIT Rourkela
52. Power Electronic Converters in ED Systems
DC DRIVES
Unipolar switching scheme – output
AC-DC-DC swings between Vdc and -Vdc
vc
Vtri
-vc
Vdc
+ + Vdc
vA vB
vA
-
0
-
Vdc
vc vB
0
+
Vdc
_
vAB
0
-vc
B Chitti Babu,
14 August 2009 52
EE NIT Rourkela
53. Power Electronic Converters in ED Systems
DC DRIVES
AC-DC-DC DC-DC: Four-quadrant Converter
Armature
200 current 200
150 150 Armature
Vdc 100 Vdc 100 current
50 50
0 0
-50 -50
Vdc -100 -100
-150 -150
-200 -200
0.04 0.0405 0.041 0.0415 0.042 0.0425 0.043 0.0435 0.044 0.0445 0.045 0.04 0.0405 0.041 0.0415 0.042 0.0425 0.043 0.0435 0.044 0.0445 0.045
Bipolar switching scheme Unipolar switching scheme
• Current ripple in unipolar is smaller
• Output frequency in unipolar is effectively doubled
B Chitti Babu,
14 August 2009 53
EE NIT Rourkela
54. Power Electronic Converters in ED Systems
AC DRIVES
AC-DC-AC
control
The common PWM technique: CB-SPWM with ZSS
14 August 2009 SVPWM
B Chitti Babu,
54
EE NIT Rourkela
55. Modeling and Control of Electrical Drives
• Control the torque, speed or position
• Cascade control structure
Example of current control in cascade control structure
θ* ω* T*
+ + +
− − −
position speed current
controller controller controller converter Motor
kT
ω
θ
1/s
B Chitti Babu,
14 August 2009 55
EE NIT Rourkela
56. Modeling and Control of Electrical Drives
Current controlled converters in DC Drives - Hysteresis-based
+
ia
Vdc
+
iref
− Va
−
va
iref + ierr q
_ q
• High bandwidth, simple implementation,
insensitive to parameter variations
ierr
• Variable switching frequency – depending on
operating conditions B Chitti Babu,
14 August 2009 56
EE NIT Rourkela
57. Modeling and Control of Electrical Drives
Current controlled converters in AC Drives - Hysteresis-based
i*a +
Converter
i*b +
i*c +
• For isolated neutral load, ia + ib + ic = 0
∴control is not totally independent 3-phase
• Instantaneous error for isolated neutral load can
AC Motor
reach double the band
B Chitti Babu,
14 August 2009 57
EE NIT Rourkela
58. Modeling and Control of Electrical Drives
Current controlled converters in AC Drives - Hysteresis-based
iq
is
Δh Δh Δh Δh
id
• For isolated neutral load, ia + ib + ic = 0
∴control is not totally independent
• Instantaneous error for isolated neutral load can
reach double the band
B Chitti Babu,
14 August 2009 58
EE NIT Rourkela
59. Modeling and Control of Electrical Drives
Current controlled converters in AC Drives - Hysteresis-based
• Δh = 0.3 A • Vdc = 600V
Con u s
tin ou • Sinusoidal reference current, 30Hz load
• 10Ω, 50mH
powergui
Scope
iaref
TW
o orkspace1 g
+ i
A + -
D Voltage Source
C B Series R BranchC
LC 3urrent Measurem 3
ent
c1 p1 -
C
i
c2 p2 + -
U ersal Bridge 1
niv
c3 p3 Series R Branch urrent M
LC C1 easurem 1
ent
ina p4 i
+ -
Sine W e
av
inb p5 Series R Branch urrent M
LC C2 easurem 2
ent
inc p6
Subsystem
Sine W e 1
av
Sine W e 2
av
B Chitti Babu,
14 August 2009 59
EE NIT Rourkela
60. Modeling and Control of Electrical Drives
Current controlled converters in AC Drives - Hysteresis-based
Actual and reference currents Current error
0.5
10
0.4
0.3
5
0.2
10
0.1
0 0
9
-0.1
-0.2
-5 8
-0.3
7 -0.4
-10
-0.5
0.005 0.01 6
0.015 0.02 0.025 0.03
-0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5
5
4
4 6 8 10 12 14 16
-3
x 10
B Chitti Babu,
14 August 2009 60
EE NIT Rourkela
61. Modeling and Control of Electrical Drives
Current controlled converters in AC Drives - Hysteresis-based
Actual current locus Current error
10 0.5
5
0 0.6A
-0.5
0
0.04 0.042 0.044 0.046 0.048 0.05 0.052 0.054 0.056 0.058 0.06
-5
0.5
-10
-10 -5 0 5 10 0 0.6A
-0.5
0.04 0.042 0.044 0.046 0.048 0.05 0.052 0.054 0.056 0.058 0.06
0.5
0 0.6A
-0.5
0.04 0.042 0.044 0.046 0.048 0.05 0.052 0.054 0.056 0.058 0.06
B Chitti Babu,
14 August 2009 61
EE NIT Rourkela
62. Modeling and Control of Electrical Drives
Current controlled converters in DC Drives - PI-based
Vdc
iref + vc vPulse width
tri
PI vc modulator
q
q
q
−
B Chitti Babu,
14 August 2009 62
EE NIT Rourkela
63. Modeling and Control of Electrical Drives
Current controlled converters in DC Drives - PI-based
i*a +
PI PWM
Converter
i*b +
PI PWM
i*c + PWM
PI
• Sinusoidal PWM
Motor
• Interactions between phases → only require 2 controllers
• Tracking error
B Chitti Babu,
14 August 2009 63
EE NIT Rourkela
64. Modeling and Control of Electrical Drives
Current controlled converters in DC Drives - PI-based
• Perform the 3-phase to 2-phase transformation
- only two controllers (instead of 3) are used
• Perform the control in synchronous frame
- the current will appear as DC
• Interactions between phases → only require 2 controllers
• Tracking error
B Chitti Babu,
14 August 2009 64
EE NIT Rourkela
65. Modeling and Control of Electrical Drives
Current controlled converters in AC Drives - PI-based
i*a +
PI PWM
Converter
i*b +
PI PWM
i*c + PWM
PI
Motor
B Chitti Babu,
14 August 2009 65
EE NIT Rourkela
66. Modeling and Control of Electrical Drives
Current controlled converters in AC Drives - PI-based
i*a
PI
SVM Converter
i*b
3-2 2-3
PI
i*c
3-2
Motor
B Chitti Babu,
14 August 2009 66
EE NIT Rourkela
67. Modeling and Control of Electrical Drives
Current controlled converters in AC Drives - PI-based
va*
id* + PI
controller
−
vb*
id dq→abc SVM
or SPWM IM
iq* + VSI
PI vc*
− iq controller
ωs
Synch speed
ωs
estimator
abc→dq
B Chitti Babu,
14 August 2009 67
EE NIT Rourkela
68. Modeling and Control of Electrical Drives
Current controlled converters in AC Drives - PI-based
Stationary - ia Stationary - id
4 4
2 3
0 2
-2 1
-4 0
0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 0.01 0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 0.02
4 Rotating - ia 4 Rotating - id
2 3
0 2
-2 1
-4 0
0 0.001 0.002 0.003 0.004 0.005 0.006 0.007 0.008 0.009 0.01 0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016 0.018 0.02
B Chitti Babu,
14 August 2009 68
EE NIT Rourkela
69. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with Controlled rectifier
+
vc firing α controlled
circuit rectifier Va
–
vc(s) va(s)
? DC motor
The relation between vc and va is determined by the firing circuit
B Chitti Babu,
14 August 2009 69
It is desirable to have a linear NIT Rourkela
EE relation between vc and va
70. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with Controlled rectifier
Cosine-wave crossing control
Vm
Input voltage
0 π 2π 3π 4π
vc vs
Cosine wave compared with vc
Results of comparison trigger SCRs
Output voltage
B Chitti Babu,
14 August 2009 70
EE NIT Rourkela
71. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with Controlled rectifier
Cosine-wave crossing control
cos(ωt)
Vscos(α) = vc
Vm
⎛v ⎞
0 π 2π 3π 4π α = cos −1 ⎜ c ⎟
⎜v ⎟
⎝ s⎠
vc vs
α
2Vm v c ⎛ −1 ⎛ v c ⎞ ⎞
Va = cos⎜α ) ⎜ ⎟ ⎟
(
π vs ⎝ ⎜ cos ⎜ v ⎟ ⎟
⎝ s ⎠⎠
α
A linear relation between vc and Va
B Chitti Babu,
14 August 2009 71
EE NIT Rourkela
72. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with Controlled rectifier
Va is the average voltage over one period of the waveform
- sampled data system
Delays depending on when the control signal changes – normally taken
as half of sampling period
B Chitti Babu,
14 August 2009 72
EE NIT Rourkela
73. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with Controlled rectifier
Va is the average voltage over one period of the waveform
- sampled data system
Delays depending on when the control signal changes – normally taken
as half of sampling period
B Chitti Babu,
14 August 2009 73
EE NIT Rourkela
74. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with Controlled rectifier
T
− s
G H (s) = Ke 2
Single phase, 50Hz
vc(s) Va(s)
2Vm
K= T=10ms
πVs
Three phase, 50Hz
3VL − L ,m
K= T=3.33ms
πVs
Simplified if control bandwidth is reduced to much lower than the
sampling frequency
B Chitti Babu,
14 August 2009 74
EE NIT Rourkela
75. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with Controlled rectifier
+
iref current vc firing α controlled
controller Va
circuit rectifier
–
• To control the current – current-controlled converter
• Torque can be controlled
• Only operates in Q1 and Q4 (single converter topology)
B Chitti Babu,
14 August 2009 75
EE NIT Rourkela
76. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with Controlled rectifier
• Input 3-phase, 240V, 50Hz • Closed loop current control
with PI controller
Scope3
+
- v Continuous
Voltage Measurement4
+ i powergui
- Scope2
AC Voltage Source Current Measurement 1 Step
s
AC Voltage Source1 +
g -
+ v
A Controlled Voltage Source
Series RLC Branch
AC Voltage Source2 B To Workspace
+ - i
- v C - + ia
Voltage Measurement2 Universal Bridge Current Measurement To Workspace1
+ +
- v - v
alpha_deg
Voltage Measurement Voltage Measurement3
AB ux Scope
BC pulses
+
- v
CA
Block
Voltage Measurement1
Synchronized Mu
6-Pulse Generator
Scope1 ir
To Workspace2
PID acos -K-
Signal
PID Controller Saturation
1
Generator
7
Constant 1
B Chitti Babu,
14 August 2009 76
EE NIT Rourkela
77. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with Controlled rectifier
• Input 3-phase, 240V, 50Hz • Closed loop current control
with PI controller
1000
1000
500
500
0
Voltage
0
-500 -500
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.22 0.23 0.24 0.25 0.26 0.27 0.28
15 15
10
10
5
Current
5
0
0.22 0.23 0.24 0.25 0.26 0.27 0.28
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
B Chitti Babu,
14 August 2009 77
EE NIT Rourkela
78. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
B Chitti Babu,
14 August 2009 78
EE NIT Rourkela
79. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Vdc
Switching signals obtained by comparing
control signal with triangular wave +
Va
−
vtri
q
vc
We want to establish a relation between vc and Va
AVERAGE voltage
vc(s) Va(s)
? DC motor
B Chitti Babu,
14 August 2009 79
EE NIT Rourkela
80. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Ttri
⎧1 Vc > Vtri
q=⎨
vc
⎩0 Vc < Vtri
1 t + Ttri
d=
Ttri ∫ t
q dt
1
t on
=
0 Ttri
ton
Vdc
1 dTtri
Va = ∫ Vdcdt = dVdc
Ttri 0
B Chitti Babu,
14 August 2009 0
EE NIT Rourkela
80
81. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
d
0.5
vc
-Vtri
Vtri
-Vtri vc
For vc = -Vtri → d = 0
B Chitti Babu,
14 August 2009 81
EE NIT Rourkela
82. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
d
0.5
vc
-Vtri -Vtri
Vtri
vc
Vtri
For vc = -Vtri → d = 0
For vc = 0 → d = 0.5
14 August 2009
EE NIT
→ Rourkela
For vc = VtriChitti d = 1
B Babu,
82
83. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
d
0.5
vc
-Vtri -Vtri
Vtri vc
1
d = 0.5 + vc
2Vtri
Vtri
For vc = -Vtri → d = 0
For vc = 0 → d = 0.5
14 August 2009
EE NIT
→ Rourkela
For vc = VtriChitti d = 1
B Babu,
83
84. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Thus relation between vc and Va is obtained as:
V dc
V a = 0 . 5 V dc + vc
2 V tri
Introducing perturbation in vc and Va and separating DC and AC components:
V dc
DC: V a = 0 . 5 V dc + vc
2 V tri
AC: ~ = V dc ~
va vc
2 V tri
B Chitti Babu,
14 August 2009 84
EE NIT Rourkela
85. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Taking Laplace Transform on the AC, the transfer function is obtained as:
v a (s) V dc
=
v c ( s ) 2 V tri
vc(s) V dc va(s)
DC motor
2 V tri
B Chitti Babu,
14 August 2009 85
EE NIT Rourkela
86. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Bipolar switching scheme
Vdc
vc
2vtri
-Vdc
q
vtri
+
Vdc
Vdc vA
+ VAB −
0
−
vc Vdc
vB
0
q
Vdc
vAB
v v
d A = 0.5 + c dB = 1 − d A = 0.5 − c -Vdc
2Vtri 2Vtri
Vdc Vdc Vdc
VA = 0.5Vdc + vc VB = 0.5Vdc − vc VA − VB = VAB = vc
2Vtri 2Vtri Vtri
B Chitti Babu,
14 August 2009 86
EE NIT Rourkela
87. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Bipolar switching scheme
v a ( s ) V dc
=
v c (s) V tri
vc(s) V dc va(s)
DC motor
V tri
B Chitti Babu,
14 August 2009 87
EE NIT Rourkela
88. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Vdc
Unipolar switching scheme vc
Leg b
Vtri
+ -vc
vtri Vdc
qa
vc −
vA
Leg a
vtri
-vc qb vB
vc − vc vAB
d A = 0.5 + dB = 0.5 +
2Vtri 2Vtri
Vdc Vdc Vdc
VA = 0.5Vdc + vc VB = 0.5Vdc − vc VA − VB = VAB = vc
2Vtri 2Vtri Vtri
The same average value we’ve seen for bipolar !
B Chitti Babu,
14 August 2009 88
EE NIT Rourkela
89. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Unipolar switching scheme
v a ( s ) V dc
=
v c (s) V tri
vc(s) V dc va(s)
DC motor
V tri
B Chitti Babu,
14 August 2009 89
EE NIT Rourkela
90. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
DC motor – separately excited or permanent magnet
dia dωm
v t = ia R a + L a + ea Te = Tl + J
dt dt
Te = kt ia ee = kt ω
Extract the dc and ac components by introducing small
perturbations in Vt, ia, ea, Te, TL and ωm
ac components dc components
~
~ = ~ R + L d ia + ~
v t ia a ea Vt = Ia R a + E a
a
dt
~ ~
Te = k E ( ia ) Te = k E Ia
~ = k (ω )
ee ~ Ee = k Eω
E
~
~ ~ ~ + J d(ω )
Te = TL + B ω Te = TL + B(ω)
14 August 2009 dt B Chitti Babu,
90
EE NIT Rourkela
91. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
DC motor – separately excited or permanent magnet
Perform Laplace Transformation on ac components
~
~
~ = i R +L d ia ~ Vt(s) = Ia(s)Ra + LasIa + Ea(s)
vt a a a + ea
dt
~ ~ Te(s) = kEIa(s)
Te = k E ( ia )
~ = k (ω )
ee ~ Ea(s) = kEω(s)
E
~
~ ~ ~ + J d(ω )
Te = TL + B ω Te(s) = TL(s) + Bω(s) + sJω(s)
dt
B Chitti Babu,
14 August 2009 91
EE NIT Rourkela
92. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
DC motor – separately excited or permanent magnet
Tl (s )
-
Va (s ) I a (s ) Te (s ) ω (s )
1 1
kT
+ Ra + sL a +
B + sJ
-
kE
B Chitti Babu,
14 August 2009 92
EE NIT Rourkela
93. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
q
vtri
Torque +
controller
Tc +
Vdc
–
−
q kt
DC motor
Tl (s )
Converter
T e (s ) Torque V dc Va (s ) 1 I a (s ) Te (s ) -
1 ω (s )
kT
controller Ra + sL a B + sJ
+ V tri ,peak + +
- -
kE
B Chitti Babu,
14 August 2009 93
EE NIT Rourkela
94. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Closed-loop speed control – an example
Design procedure in cascade control structure
• Inner loop (current or torque loop) the fastest –
largest bandwidth
• The outer most loop (position loop) the slowest –
smallest bandwidth
• Design starts from torque loop proceed towards
outer loops
B Chitti Babu,
14 August 2009 94
EE NIT Rourkela
95. Modeling and Control of Electrical Drives
Modeling of the Power Converters: DC drives with SM Converters
Closed-loop speed control – an example
OBJECTIVES:
• Fast response – large bandwidth
• Minimum overshoot
good phase margin (>65o) BODE PLOTS
• Zero steady state error – very large DC gain
METHOD
• Obtain linear small signal model
• Design controllers based on linear small signal model
• Perform large signal simulation for controllers verification
B Chitti Babu,
14 August 2009 95
EE NIT Rourkela
96. Modeling and Control of Electrical Drives
Modeling of the Power Converters: IM drives
INDUCTION MOTOR DRIVES
Scalar Control Vector Control
Const. V/Hz is=f(ωr) FOC DTC
Rotor Flux Stator Flux
Circular Hexagon DTC
Flux Flux SVM
B Chitti Babu,
14 August 2009 96
EE NIT Rourkela
97. Modeling and Control of Electrical Drives
Modeling of the Power Converters: IM drives
Control of induction machine based on steady-state
model (per phase SS equivalent circuit):
Is Lls Llr’
Rs Ir’
+
+
Lm
Vs Rr’/s
Eag
– Im –
B Chitti Babu,
14 August 2009 97
EE NIT Rourkela
98. Modeling and Control of Electrical Drives
Modeling of the Power Converters: IM drives
Te
Pull out
Torque Intersection point
(Tmax) (Te=TL) determines the
Te
steady –state speed
Trated TL
sm ωratedrotorωs
ω ωr
s
B Chitti Babu,
14 August 2009 98
EE NIT Rourkela