EPE Association: EPE 2001 - Topic 05a: Converter Control Sets and Modulation Strategies

EPE 2001 - Topic 05a: Converter Control Sets and Modulation Strategies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2001 - Conference > EPE 2001 - Topic 05: MODULATION STRATEGIES AND SPECIFIC CONTROL METHODS FOR STATIC CONVERTERS > EPE 2001 - Topic 05a: Converter Control Sets and Modulation Strategies

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   A Fully Digital PWM for Highest Precision Power Supplies
By F. Jenni; M. Emmenegger [View]
[Download]

Abstract: The width of fully digital generated Pulse Width Modulator (PWM) signals can be varied in discrete time steps only. In closed loop systems this limited resolution leads to limit cycles. With the multiple combination of PWM and a special pulse frequency modulation of the output values of high precision power supplies (PS) are controlled down to zero with a very high resolution.

   A new methodology to calculate times and regions in multilevel SVPWM
By O. Alonso; L. Marroyo; P. Sanchis [View]
[Download]

Abstract: This paper proposes a generalized methodology to calculate switching times and regions in SVPWM modulation of multilevel converters. The main attribute of the proposed method is that it keeps the same calculating difficulty independently of the number of the converter levels, being this difficulty equivalent to the classic methodology of the 2-level converter.

   Control of reactive power by means of matrix converters
By I. Galkin; L. Ribickis [View]
[Download]

Abstract: Reactive power flow in a 3 ×3 matrix converter is analyzed. An alternative approach with incomplete reactive power elimination at the input is suggested. Analysis of the process of reactive power transfer or its compensation by a power matrix is based on the rectifier-inverter model of the matrix converter. A control mode suitable for regulation of reactive power is discussed. The corresponding simulation results are presented

   Energy-efficient quasi-direct converter with reduced switching losses
By O. Harling; H. Raffel, B. Orlik [View]
[Download]

Abstract: An extreme minimization of energy storage elements in frequency converters is possible by using very high switching frequencies. After introducing a so-called quasi-direct converter with a load side inverter and a controllable input stage, the paper deals about the reduction of the switching losses. With an intelligent pulse width modulation strategy a suitable solution to decrease the switching losses of pulse-controlled converters for servo-technical applications can be achieved.

   Full Output-Controlled Parallel-Loaded Resonant Converter with Robust
By A. Conesa; E. Fossas; R. Piqué [View]
[Download]

Abstract: This paper introduces a new parallel resonant converter that includes two commutation matrices: the first one operates at constant frequency over the resonant tank, while the second one is a controllable structure that should perform a robust output voltage. The new converter is obtained by addition of a second input to the standard single input PRC. It is commanded by a One Cycle control strategy which, presuming a tank variables periodic behaviour, has shown to be robust with respect to variations in the load.

   Fuzzy Logic Based Pulse Width Modulation for Power Converters
By A. Dell'Aquila; M. Liserre [View]
[Download]

Abstract: The aim of the fuzzy logic based Pulse Width Modulation is to obtain a direct current control of three-phase power converters; in recent years it has already been tested in different applications with different reference signals. In the paper the introduction of the fuzzy modulation is motivated and its history is described with reference to papers present in literature. A deep theoretical analysis of how to derive the fuzzy rules both for the space-vector and separate-phase modulations is presented and discussed with the simulation results. Different types of algorithms for the fuzzy modulation, employing a different number of rules are also included.

   Generation of 3-Phase Voltage using Space Vector Modulation Method
By A. Baskys; V. Gobis [View]
[Download]

Abstract: The five methods of three-phase voltage generation for frequency converters of AC motor drives are analyzed. They are based on the same principles and allows to reach the same maximum output voltage as conventional SVPWM (Space Vector Pulse Width Modulation) method, but are differing in requirements for inverter switches dynamic characteristics, in keeping of control unit busy with voltage generation and in quality of generated voltage spectrum.

   Method to calculate the Conduction durations of the switches in VSI
By E. Semail; C. Rombaut [View]
[Download]

Abstract: The proposed method allows to calculate explicitly, using mathematical notions of barycenter and mixed product, the conduction duration switches of a n-leg 2-level Voltage Source Inverter (VSI) supplying a n-wire load. This method depends on a new geometrical and vectorial VSI characterization. Its geometrical feature enables optimization and graphic representation such as the Space Vector Method (SVM) for a 3-leg VSI. Its vectorial feature enables to generalize to n phase systems the properties found out with three phase systems.

   Methods Reducing Distortions on PWM-Voltage Source Inverters
By F. Herty [View]
[Download]

Abstract: This paper presents six methods improving the output current waveform of a PWM voltage source inverter. Due to several delays and other effects during a switch over process of a half bridge typical delay errors can be seen which are not in context to the modulation strategy. Considering drive systems designed for low torque ripple or high speed it is definitely not sufficient using an optimised modulating strategy only. In contrast to the decreased load current harmonics the delay errors are coming more and more into effect when the switching frequency is increased.

   Poligonal Flux Modulation for Matrix Converters
By C. Klumpner; F. Blaabjerg; I. Boldea; P. Nielsen [View]
[Download]

Abstract: This paper presents a new modulation method for matrix converters based on the indirect modulation model. During the switching period, the proposed modulation method uses a combination of only one active vector and a zero vector in the inversion stage to achieve minimum stator flux error, while in the rectification stage a single current vector is selected, according to the angle error of the input current reference vector. This reduces the number of switching sequences in the switching period, improving the accuracy of generating the output voltages, especially in the low modulation index range. Supplementary, the direct control of the input current vector is implemented. The estimation of the angle of the input current vector is done by applying the inverse transformation corresponding to the applied active vector to the output currents.

   Robust Matrix Converter Commutation without explicit Sign Measurement
By J. Mahlein; J. Igney; M. Braun; O. Simon [View]
[Download]

Abstract: A new operation method for matrix converters is presented which eliminates the extra measuring circuits of voltage or current signs that were necessary for the commutation in the past. The paper explains the new robust method that minimises switching losses. Advantages and disadvantages of different approaches are discussed and measurements on a 5.5 kW matrix converter system are shown.

   Smart modulation: a new approach to power converter control
By M. S. Carmeli; F. Castelli-Dezza; G. Superti-Furga [View]
[Download]

Abstract: A new modulation algorithm for current control voltage source converters is presented. It is a threshold method characterised by constant switching frequency and controllable ripple phase angle. The proposed method overcomes the limits of traditional current hysteresis techniques, while keeping accurate and fast response. The approach is completely general and can also be applied to all Voltage Source Converters. A significative laboratory configuration has been set up for simulation and experimental test.

   Spectrum Optimisation for Random PWM Techniques using MOGA
By T-X. Mei [View]
[Download]

Abstract: Spectrum optimisation for random PWM techniques is studied. Multi-Objective Genetic Algorithms are used to generate random sequences which optimise distributions of frequency components of power converters. It demonstrates that optimal power distributions can be obtained with reduced harmonics power at low frequencies and minimised magnitude at high frequencies. Two random PWM techniques are studied, - the randomised switching frequency PWM (RSPWM) and randomised pulse positions PWM (RPPWM). Results from the optimised random PWM techniques are compared with standard regular sampled PWM and non-optimised random methods, and significant improvements are achieved by the use of the optimisation procedure.

   The carrier-based PWM for voltage balance of flying capacitor inverter
By S-G. Lee; D-W. Kang; Y-H. Lee; D-S. Hyun [View]
[Download]

Abstract: This paper proposes a new solution by carrier-based PWM method to solve the most serious problem of flying capacitor multi-level inverter that is the unbalance of capacitor voltages. The voltage unbalance occurs due to the difference of each capacitor's charging and discharging time applied to Flying Capacitor Inverter. New solution controls the variation of capacitor voltages into the mean '0' during some period by means of new carriers using the leg voltage redundancy in the flying capacitor inverter. The solution can be easily expanded to the multi-level inverter. Also, this method can make the switching loss and conduction loss of device equal by the use of leg voltage redundancy. First, this paper will examine the unbalance of capacitor voltage and the conventional theory of self-balance using phase-shifted carrier. And then the new method that is suitable to the flying capacitor inverter will be explained. The simulation results would be shown to verify the proposed method.

   Unified Constant-frequency Integration control of Three-phase Grid-c
By Chongming Qiao [View]
[Download]

Abstract: THIS PAPER WAS WITHDRAWN FROM THE EPE 2001 CONFERENCE !!!

   variable structure control for imbricated cells multi-levels inverter
By F. Ben Ammar [View]
[Download]

Abstract: The paper presents the study of Variable Structure Controller of the series multicell voltage source inverter feeding a high power squirrel-cage induction motor. An appropriate multilevel switching table has been developed to achieve fast torque response and to give a floating capacitor voltage distribution balanced and stable with an optimised output waveform.

EPE 2001 - Topic 05a: Converter Control Sets and Modulation Strategies
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2001 - Conference > EPE 2001 - Topic 05: MODULATION STRATEGIES AND SPECIFIC CONTROL METHODS FOR STATIC CONVERTERS > EPE 2001 - Topic 05a: Converter Control Sets and Modulation Strategies
	[return to parent folder]

	A Fully Digital PWM for Highest Precision Power Supplies By F. Jenni; M. Emmenegger	[View] [Download]
Abstract: The width of fully digital generated Pulse Width Modulator (PWM) signals can be varied in discrete time steps only. In closed loop systems this limited resolution leads to limit cycles. With the multiple combination of PWM and a special pulse frequency modulation of the output values of high precision power supplies (PS) are controlled down to zero with a very high resolution.

	A new methodology to calculate times and regions in multilevel SVPWM By O. Alonso; L. Marroyo; P. Sanchis	[View] [Download]
Abstract: This paper proposes a generalized methodology to calculate switching times and regions in SVPWM modulation of multilevel converters. The main attribute of the proposed method is that it keeps the same calculating difficulty independently of the number of the converter levels, being this difficulty equivalent to the classic methodology of the 2-level converter.

	Control of reactive power by means of matrix converters By I. Galkin; L. Ribickis	[View] [Download]
Abstract: Reactive power flow in a 3 ×3 matrix converter is analyzed. An alternative approach with incomplete reactive power elimination at the input is suggested. Analysis of the process of reactive power transfer or its compensation by a power matrix is based on the rectifier-inverter model of the matrix converter. A control mode suitable for regulation of reactive power is discussed. The corresponding simulation results are presented

	Energy-efficient quasi-direct converter with reduced switching losses By O. Harling; H. Raffel, B. Orlik	[View] [Download]
Abstract: An extreme minimization of energy storage elements in frequency converters is possible by using very high switching frequencies. After introducing a so-called quasi-direct converter with a load side inverter and a controllable input stage, the paper deals about the reduction of the switching losses. With an intelligent pulse width modulation strategy a suitable solution to decrease the switching losses of pulse-controlled converters for servo-technical applications can be achieved.

	Full Output-Controlled Parallel-Loaded Resonant Converter with Robust By A. Conesa; E. Fossas; R. Piqué	[View] [Download]
Abstract: This paper introduces a new parallel resonant converter that includes two commutation matrices: the first one operates at constant frequency over the resonant tank, while the second one is a controllable structure that should perform a robust output voltage. The new converter is obtained by addition of a second input to the standard single input PRC. It is commanded by a One Cycle control strategy which, presuming a tank variables periodic behaviour, has shown to be robust with respect to variations in the load.

	Fuzzy Logic Based Pulse Width Modulation for Power Converters By A. Dell'Aquila; M. Liserre	[View] [Download]
Abstract: The aim of the fuzzy logic based Pulse Width Modulation is to obtain a direct current control of three-phase power converters; in recent years it has already been tested in different applications with different reference signals. In the paper the introduction of the fuzzy modulation is motivated and its history is described with reference to papers present in literature. A deep theoretical analysis of how to derive the fuzzy rules both for the space-vector and separate-phase modulations is presented and discussed with the simulation results. Different types of algorithms for the fuzzy modulation, employing a different number of rules are also included.

	Generation of 3-Phase Voltage using Space Vector Modulation Method By A. Baskys; V. Gobis	[View] [Download]
Abstract: The five methods of three-phase voltage generation for frequency converters of AC motor drives are analyzed. They are based on the same principles and allows to reach the same maximum output voltage as conventional SVPWM (Space Vector Pulse Width Modulation) method, but are differing in requirements for inverter switches dynamic characteristics, in keeping of control unit busy with voltage generation and in quality of generated voltage spectrum.

	Method to calculate the Conduction durations of the switches in VSI By E. Semail; C. Rombaut	[View] [Download]
Abstract: The proposed method allows to calculate explicitly, using mathematical notions of barycenter and mixed product, the conduction duration switches of a n-leg 2-level Voltage Source Inverter (VSI) supplying a n-wire load. This method depends on a new geometrical and vectorial VSI characterization. Its geometrical feature enables optimization and graphic representation such as the Space Vector Method (SVM) for a 3-leg VSI. Its vectorial feature enables to generalize to n phase systems the properties found out with three phase systems.

	Methods Reducing Distortions on PWM-Voltage Source Inverters By F. Herty	[View] [Download]
Abstract: This paper presents six methods improving the output current waveform of a PWM voltage source inverter. Due to several delays and other effects during a switch over process of a half bridge typical delay errors can be seen which are not in context to the modulation strategy. Considering drive systems designed for low torque ripple or high speed it is definitely not sufficient using an optimised modulating strategy only. In contrast to the decreased load current harmonics the delay errors are coming more and more into effect when the switching frequency is increased.

	Poligonal Flux Modulation for Matrix Converters By C. Klumpner; F. Blaabjerg; I. Boldea; P. Nielsen	[View] [Download]
Abstract: This paper presents a new modulation method for matrix converters based on the indirect modulation model. During the switching period, the proposed modulation method uses a combination of only one active vector and a zero vector in the inversion stage to achieve minimum stator flux error, while in the rectification stage a single current vector is selected, according to the angle error of the input current reference vector. This reduces the number of switching sequences in the switching period, improving the accuracy of generating the output voltages, especially in the low modulation index range. Supplementary, the direct control of the input current vector is implemented. The estimation of the angle of the input current vector is done by applying the inverse transformation corresponding to the applied active vector to the output currents.

	Robust Matrix Converter Commutation without explicit Sign Measurement By J. Mahlein; J. Igney; M. Braun; O. Simon	[View] [Download]
Abstract: A new operation method for matrix converters is presented which eliminates the extra measuring circuits of voltage or current signs that were necessary for the commutation in the past. The paper explains the new robust method that minimises switching losses. Advantages and disadvantages of different approaches are discussed and measurements on a 5.5 kW matrix converter system are shown.

	Smart modulation: a new approach to power converter control By M. S. Carmeli; F. Castelli-Dezza; G. Superti-Furga	[View] [Download]
Abstract: A new modulation algorithm for current control voltage source converters is presented. It is a threshold method characterised by constant switching frequency and controllable ripple phase angle. The proposed method overcomes the limits of traditional current hysteresis techniques, while keeping accurate and fast response. The approach is completely general and can also be applied to all Voltage Source Converters. A significative laboratory configuration has been set up for simulation and experimental test.

	Spectrum Optimisation for Random PWM Techniques using MOGA By T-X. Mei	[View] [Download]
Abstract: Spectrum optimisation for random PWM techniques is studied. Multi-Objective Genetic Algorithms are used to generate random sequences which optimise distributions of frequency components of power converters. It demonstrates that optimal power distributions can be obtained with reduced harmonics power at low frequencies and minimised magnitude at high frequencies. Two random PWM techniques are studied, - the randomised switching frequency PWM (RSPWM) and randomised pulse positions PWM (RPPWM). Results from the optimised random PWM techniques are compared with standard regular sampled PWM and non-optimised random methods, and significant improvements are achieved by the use of the optimisation procedure.

	The carrier-based PWM for voltage balance of flying capacitor inverter By S-G. Lee; D-W. Kang; Y-H. Lee; D-S. Hyun	[View] [Download]
Abstract: This paper proposes a new solution by carrier-based PWM method to solve the most serious problem of flying capacitor multi-level inverter that is the unbalance of capacitor voltages. The voltage unbalance occurs due to the difference of each capacitor's charging and discharging time applied to Flying Capacitor Inverter. New solution controls the variation of capacitor voltages into the mean '0' during some period by means of new carriers using the leg voltage redundancy in the flying capacitor inverter. The solution can be easily expanded to the multi-level inverter. Also, this method can make the switching loss and conduction loss of device equal by the use of leg voltage redundancy. First, this paper will examine the unbalance of capacitor voltage and the conventional theory of self-balance using phase-shifted carrier. And then the new method that is suitable to the flying capacitor inverter will be explained. The simulation results would be shown to verify the proposed method.

	Unified Constant-frequency Integration control of Three-phase Grid-c By Chongming Qiao	[View] [Download]
Abstract: THIS PAPER WAS WITHDRAWN FROM THE EPE 2001 CONFERENCE !!!

	variable structure control for imbricated cells multi-levels inverter By F. Ben Ammar	[View] [Download]
Abstract: The paper presents the study of Variable Structure Controller of the series multicell voltage source inverter feeding a high power squirrel-cage induction motor. An appropriate multilevel switching table has been developed to achieve fast torque response and to give a floating capacitor voltage distribution balanced and stable with an optimised output waveform.