EPE Association: EPE-PEMC 2004 - Topic 03-1: Converter control sets and modulation strategies

EPE-PEMC 2004 - Topic 03-1: Converter control sets and modulation strategies
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2004 - Conference > EPE-PEMC 2004 - Topic 03: CONTROL OF CONVERTERS > EPE-PEMC 2004 - Topic 03-1: Converter control sets and modulation strategies

   [return to parent folder]

   A Method For Control Of Direct Frequency Conversion
By Laimonis Rutmanis, Janis Stabulnieks, Leonids Ribickis [View]
[Download]

Abstract: A method by means of which in each time interval selection, the most closest to output reference voltage and suitable for output voltage formation, among six given input voltages variously summed in 729 possible switching combinations, are accomplished for the case of three-phase, two-level input voltage regulator with forced commutation.

   A New Single-Phase Multilevel Modulator - A Fast And Accurate Method To Compute The Modulator Harmonic Spectra
By Sebastien Mariethoz, Alfred Rufer [View]
[Download]

Abstract: In the first part, a fast and accurate method to compute the harmonic spectra of PWM modulators is presented. This method allows to compute all measurements based on the harmonics values such as the THD or FWTHD. It is especially advantageous for multilevel modulators. In the second part a new modulation method that achieves very good performances for the single-phase multilevel inverters is presented. Finally, several modulation methods are compared with the proposed measurement tool.

   A Simplified Control For Inverters In Parallel Operation
By Lan Xiao, Lei Huang [View]
[Download]

Abstract: The control strategy that regulates the phase and the amplitude of the output voltage according to output active power and reactive power respectively is adopted generally in inverter parallel techniques. However, active power and reactive power are related to both voltage amplitude and voltage phase. This paper deduces the output impedance of the inverter and discusses the relationship between active power, reactive power and amplitude and phase of output voltage. The decouple control strategy can be realized through circuit parameters design. The influence of component’s tolerance on output voltage is discussed. Then a simplified load-sharing control strategy based on phase-synchronization and amplituderegulation of reference voltage is proposed and the model of parallel system is established. Performance of a parallel system is analyzed and experimental results are given.

   A Study Of Current Control Using Deadbeat Control For Utility Interractive Inverter
By Kenji Aoki, Naoki Uemura, Eigo Shimada, Tomoki Yokoyama [View]
[Download]

Abstract: In this paper, a new current control method for the utility interactive inverter based on the deadbeat control is proposed. In recernt years, distributed power systems like PV generation or fuel cells are expected as the alternative power resources for next generation. In the small capacity range of the distributed power systems, a single phase utility interactive inverter is required, and the controll ability of the output current should be improved when these systems with small capability are widely used. A new current control method for the single phase utility interactive inverter based on the voltage deadbeat control with the state observer is proposed. Tracking accuracy to the reference current is much improved with small LC filter component. The performance of the utility interactive inverter is evaluated through simulations and experiments.

   A Study Of Parallel Operation Control Technique Of Single Phase Inverters
By Rongbo Zhu, Xiaozhu Liu, Yuhang Yang [View]
[Download]

Abstract: Paralleling several inverters is not easy. We adopt the parallel control techniques based on preemptive priority. That method made no absolute master or slave inverter into reality. Synchronization signal generating mechanism, a parallel digital bus and a no-conflicted protocol on the bus also ensured N+1 redundant structure. A proposed local feedback controller and improved droop method implemented load sharing. The analysis of the proposed method and design procedure are provided. Simulation and experimental results are provided to prove the concepts.

   Adaptation And Transient Stability Of Current Regulator With Hysteresis Control And Clocked Commutation
By Yuri Kolokolov, Stanislav Koschinsky, Vladimir Bagrov [View]
[Download]

Abstract: The paper deals with adaptation and dynamics analysis of current regulator with hysteresis control and clocked commutation. The peculiarities of dynamics development of such system with hysteresis and load variation were analyzed. Different adaptation approaches of static control-to-output characteristic were considered from the point of view of overall system stability and performance. New adaptation scheme was presented and studied.

   Boost Converter Control: Comparison Of Pi-, Passivity-Based And Flatness-Based Methods
By Albrecht Gensior, Oliver Woywode, Joachim Rudolph, Henry Gueldner [View]
[Download]

Abstract: Three control concepts for a boost converter are compared. Standard PI-control is the starting point. Second, passivity based control (PBC) is reviewed. Finally, a control concept is presented, that benefits from trajectory planning resorting to the system’s flat output. Stabilisation strategies around the planned trajectory are discussed. Simulations verify the control concepts.

   Comparative Evaluation Of Pwm Schemes For Three-Phase Pwm Current-Source Pfc Rectifier
By Yasuyuki Nishida [View]
[Download]

Abstract: The PWM strategies with the carrier and reference signals comparison schemes for the 3-phase-bridge Current- Source (i.e., buck-mode) PFC rectifiers with different carrier and reference waveforms have been compared and evaluated. The “saw-tooth” and the “triangular” waveforms as the carrier signal and the standard “3-phase symmetrical sinusoidal, “with triplen harmonics” and “flat-top” waveforms as the reference signal are chosen in the comparative study. Although the study of the PWM schemes for the 3-phase Voltage-Source- Inverter/Rectifier has been done well so far, that for the 3-phase Current-Source-Inverter/Rectifier has not explored well until now. The paper investigates the duality and difference between the properties of the PWM schemes for the 3-phase Voltage- Source-Inverter/Rectifier and Current-Source-Inverter/Rectifier. Then, the performances of the selected PWM strategies have been evaluated theoretically as well as referring to several experimental results. Finally, a discussion to select the most attractive PWM strategy for the 3-phase Current-Source- Rectifier (i.e., Buck Rectifier) has been done.

   Comparison Between Hysteresis And Space Vector Modulation Techniques For Npc Inverters
By Armando Bellini, Stefano Bifaretti, Stefano Costantini [View]
[Download]

Abstract: The paper analyzes and compares two different kind of modulation techniques specifically designed for three-phase Neutral Point Clamped (NPC) inverters. In the last years, the authors proposed different modulation techniques useful for NPC inverters; in particular, they presented new solutions to perform Hysteresis and Space Vector Modulation techniques (SVM). The first ones have been developed applying subsequent and significant improvement to the classical modulation, while SVM technique was designed to maintain, also in NPC inverters, all the advantages of SVM used in traditional twolevel inverters. The paper present, at first, a description of the proposed Hysteresis and Space Vector Modulation techniques pointing out, in addition, an accurate description of the methodology used for implementing the SVM procedure on a modern microcontroller. Finally, the performances of both modulation systems are analyzed and compared, using specific simulation programs.

   Cross-Over Distortion Reduction On 3 Level Pwm For Audio Amplifiers
By Victor Antunes, V. Fernao Pires, J. Fernando Silva [View]
[Download]

Abstract: A new control/modulation method for digital audio power amplifiers is proposed. With this approach the cross-over harmonic distortion is reduced. The use of three-level PWM output voltage instead of two-level is another characteristic of this approach. From the use of the three-level two main advantages can be obtained: more resolution and increased efficiency. However, there is an important disadvantage: higher cross-over distortion and worst THD+N for signals with small amplitude, than the obtained with two level PWM output voltage. Therefore, to overcome this disadvantage the proposed control/modulation method uses three-level PWM output voltage for signals with large amplitude and two-level for signals with small amplitude. This allows the construction of a completely digital audio power amplifier with better efficiency than those using two-level PWM output, with comparable THD+N.

   Development Of Direct Torque Control System With Adaptive Flux, Torque And Speed Estimation
By I. Ya. Braslavsky, Z. Sh. Ishmatov, E. I. Barats [View]
[Download]

Abstract: The paper deals with direct torque control (DTC) system for induction motor drive. The DTC concept is based on hysteresis control of stator flux and torque by means of proper voltage vector selection. The absence of intermediate phase current control loops allows to develop the extremely fast speed control loop in comparison with traditional field-oriented systems. The main attention is given to development of adaptive flux, torque and speed observer. An original algorithm providing highquality flux estimation and adaptive to winding parameters fluctuations caused by motor heating and saturation is proposed. The prior estimation of motor parameters is derived during several commissioning tests. The estimated values are corrected before every start and during operation.

   Implementation Of High-Speed Frequency Detection For Single Phase Utility Interactive Inverter System
By Tsuyoshi Komiyama, Tatsuya Kojima, Tomoki Yokoyama [View]
[Download]

Abstract: In this paper, a high speed frequency detection method for the single phase utility interactive inverter is proposed. Distributed power system is considered as a solution of the environmental problems. As the distributed power system spreads, the stability and the reliability of the utility interactive system becomes important. In the utility interactive system, it is necessary to synchronize to a utility voltage. In the case of a single phase system, it is dificult to detect the instantaneous phase angle of the voltage not same as the 3 phase system. This paper describes a new highspeed frequency detection method using quasi dq transformation. Quasi dq transformation is applied to construct the PLL control with multi sampling parallel processing method based on the FPGA implementation. Evaluations and hardware implementations are described with simulations and experiments.

   Instantaneous Deadbeat Control For Single Phase And Three Phase Pwm Inverter Using Fpga Based Hardware Controller
By Tomoki Yokoyama, Shinsuke Simogata, Motoki Horiuchi, Toshihiro Ide [View]
[Download]

Abstract: A new approach for real time digital feedback control of PWM inverter is proposed, in which a deadbeat control is realized using FGPA based hardware controller. From the viewpoint of FPGA implementation, control strategies for single phase and three phase systems are discussed through simulations and experiments for CVCF deadbeat control such as single rate deadbeat control and multirate deadbeat control. Also current control method using voltage deadbeat control and PLL control with quasi dq transformation with multisampling parallel processing method are implemented in FPGA based hardware controller for single phase utility interactive inverter.

   Modeling Of DC-DC Converters Using Polynomial Representation Technique
By Ali Altowati, Kai Zenger, Teuvo Suntio [View]
[Download]

Abstract: In this paper, an alternative technique for the analysis of switching DC-DC converters operating in continuous inductor current mode (CICM) with either voltage mode control (VMC) or peak current mode control (PCMC) is presented. The proposed method is based on the use of inputoutput polynomial approach and two-port unterminated modeling technique. The approach is used to study the dynamic behavior of converters in the presence of input filter. The modeling and dynamic analysis procedure presented is verified by a design example.

   New PWM Technique Based On The Centroid Method
By R. A. Villarreal-Ortiz, M. Hernandez-Angeles, C. R. Fuerte-Esquivel, R. O. Villanueva-Chavez [View]
[Download]

Abstract: In this paper a new PWM technique for commutation control of CD-CA static converters is presented. The technique determines the commutation angles based on equilibrium points, which are obtained by calculating the Centroid of the area under the curve of the voltage sinusoidal function, within a time interval defined by the method of equal areas. Hence, the power inverter commutation angles are computed| directly from closedform equations

   Pulse Rectifier Current-Type Is Friendly To EMC
By Pavel Hlisnikovsky, Petr Chlebish [View]
[Download]

Abstract: This document deals with the three-phase pulse rectifier current-type as a modern controlled rectifier, which is suitable for speed control of DC motors or as an input unit of indirect frequency converters current-type, because its low emissions of harmonics to network, controlled power factor, quick reaction on control changes and excellent regulation of the output rectified current. There is a comparison of the converter with the usual phase-controlled thyristor rectifier. The modulation method of the rectifier, the vector pulse width modulation, is also described in the contribution as well as other parts of the control like synchronization with the supply voltage and the power factor of the converter. The measured results on realized physical models are enclosed at the end of the contribution.

   Pulse System Dynamics Forecasting Using On-Line Time Series Data
By Yury Kolokolov(ru), Anna Monovskaya(ru), Kondo Adjallah(fr) [View]
[Download]

Abstract: An approach to dynamics forecasting is proposed by an example of DC-DC PWM converter dynamics simulation. The main algorithm of this approach allows on-line identification of sub-harmonic motion types and corresponding parameter vectors. The consistency of the identification results forms the tendency of the parameter variation. Then forecasting of dynamics evolution in relation to the nearest bifurcation boundaries, constructed preliminary, is suggested.

   Stability Analysis Of Three Interleaved Dc-Dc Boost Converters Under Pwm Control With Pi Compensator
By Mohamed B. Debbat, Abdelali El Aroudi, Roberto Giral, L. Martinez-Salamero [View]
[Download]

Abstract: In this paper, stability analysis of three interleaved DC-DC boost converters under PWM control with proportional and integral (PI) compensator, is presented. Continuous Conduction Mode (CCM) is assumed. The generalized discretetime model of the system is built. The PI compensator is taken into account in the model. Taking the proportional term, the integral term, and the current feedback gains as bifurcation parameters, it is obtained that the 1-periodic orbit loses its stability via Hopf bifurcation. As result, the attractor is a torus T2 and the behavior is quasiperiodic. The Jacobian matrix of the system is obtained and its eigenvalues are computed. It is shown that one pair of complex conjugate eigenvalues crosses the unit circle when bifurcations parameters are varied. It is also shown that sometimes the system mode of operation changes from CCM to Intermittent Conduction Mode (ICM) when the system nominal periodic orbit loses stability.

   Switching Strategies For High Bandwidth Multiconverter Systems
By Maria Stefania Carmeli, Francesco Castelli Dezza, Gabrio Superti Furga [View]
[Download]

Abstract: The present paper focuses on current modulation strategies for multiconverter systems. Current control methods are preferred when high bandwidth is required. Three different modulation techniques are analysed and compared: smart modulation algorithm performed on branch currents; hysteresis current modulation and multilevel smart modulation algorithm performed on external current with an additional control on branch currents. Simulation results are presented.

   The Ineffectiveness Of Anti-Aliasing Filtering In A Current Loop Modeling With Specific Numerical PWM Converter
By P. Ph. Robet, M. Gautier [View]
[Download]

Abstract: The paper investigates two carriers used in industrial applications with digital control of a current closed loop. It focuses on the theoretical approach showing the uselessness of the anti-aliasing filter for a control scheme of the PWM based on a triangular carrier wave.

   Unified Scheme Of Direct Power And Torque Control For Space Vector Modulated AC/DC/AC Converter- Fed Induction Motor
By Marek Jasinski, M. P. Kazmierkowski, M. Zelechowski [View]
[Download]

Abstract: A novel control scheme for PWM rectifier-inverter system is proposed. Fast control strategies such as line voltage Sensorless Virtual Flux (VF) based Direct Power Control with Space Vector Modulator (DPC-SVM) for rectifier and Direct Torque Control with Space Vector Modulator (DTC-SVM) for inverter side are used. These strategies lead to good dynamic and static behaviour of the proposed control system – Direct Power and Torque Control- Space Vector Modulated (DPTSVM). Simulations and experiment results obtained show good performance of the proposed system. Additional power feedforward loop from motor to rectifier control side improved dynamic behaviours of the power flow control. As a result, better input-output energy matching allows decreasing the size of the dc-link capacitor.

EPE-PEMC 2004 - Topic 03-1: Converter control sets and modulation strategies
You are here: EPE Documents > 04 - EPE-PEMC Conference Proceedings > EPE-PEMC 2004 - Conference > EPE-PEMC 2004 - Topic 03: CONTROL OF CONVERTERS > EPE-PEMC 2004 - Topic 03-1: Converter control sets and modulation strategies
	[return to parent folder]

	A Method For Control Of Direct Frequency Conversion By Laimonis Rutmanis, Janis Stabulnieks, Leonids Ribickis	[View] [Download]
Abstract: A method by means of which in each time interval selection, the most closest to output reference voltage and suitable for output voltage formation, among six given input voltages variously summed in 729 possible switching combinations, are accomplished for the case of three-phase, two-level input voltage regulator with forced commutation.

	A New Single-Phase Multilevel Modulator - A Fast And Accurate Method To Compute The Modulator Harmonic Spectra By Sebastien Mariethoz, Alfred Rufer	[View] [Download]
Abstract: In the first part, a fast and accurate method to compute the harmonic spectra of PWM modulators is presented. This method allows to compute all measurements based on the harmonics values such as the THD or FWTHD. It is especially advantageous for multilevel modulators. In the second part a new modulation method that achieves very good performances for the single-phase multilevel inverters is presented. Finally, several modulation methods are compared with the proposed measurement tool.

	A Simplified Control For Inverters In Parallel Operation By Lan Xiao, Lei Huang	[View] [Download]
Abstract: The control strategy that regulates the phase and the amplitude of the output voltage according to output active power and reactive power respectively is adopted generally in inverter parallel techniques. However, active power and reactive power are related to both voltage amplitude and voltage phase. This paper deduces the output impedance of the inverter and discusses the relationship between active power, reactive power and amplitude and phase of output voltage. The decouple control strategy can be realized through circuit parameters design. The influence of component’s tolerance on output voltage is discussed. Then a simplified load-sharing control strategy based on phase-synchronization and amplituderegulation of reference voltage is proposed and the model of parallel system is established. Performance of a parallel system is analyzed and experimental results are given.

	A Study Of Current Control Using Deadbeat Control For Utility Interractive Inverter By Kenji Aoki, Naoki Uemura, Eigo Shimada, Tomoki Yokoyama	[View] [Download]
Abstract: In this paper, a new current control method for the utility interactive inverter based on the deadbeat control is proposed. In recernt years, distributed power systems like PV generation or fuel cells are expected as the alternative power resources for next generation. In the small capacity range of the distributed power systems, a single phase utility interactive inverter is required, and the controll ability of the output current should be improved when these systems with small capability are widely used. A new current control method for the single phase utility interactive inverter based on the voltage deadbeat control with the state observer is proposed. Tracking accuracy to the reference current is much improved with small LC filter component. The performance of the utility interactive inverter is evaluated through simulations and experiments.

	A Study Of Parallel Operation Control Technique Of Single Phase Inverters By Rongbo Zhu, Xiaozhu Liu, Yuhang Yang	[View] [Download]
Abstract: Paralleling several inverters is not easy. We adopt the parallel control techniques based on preemptive priority. That method made no absolute master or slave inverter into reality. Synchronization signal generating mechanism, a parallel digital bus and a no-conflicted protocol on the bus also ensured N+1 redundant structure. A proposed local feedback controller and improved droop method implemented load sharing. The analysis of the proposed method and design procedure are provided. Simulation and experimental results are provided to prove the concepts.

	Adaptation And Transient Stability Of Current Regulator With Hysteresis Control And Clocked Commutation By Yuri Kolokolov, Stanislav Koschinsky, Vladimir Bagrov	[View] [Download]
Abstract: The paper deals with adaptation and dynamics analysis of current regulator with hysteresis control and clocked commutation. The peculiarities of dynamics development of such system with hysteresis and load variation were analyzed. Different adaptation approaches of static control-to-output characteristic were considered from the point of view of overall system stability and performance. New adaptation scheme was presented and studied.

	Boost Converter Control: Comparison Of Pi-, Passivity-Based And Flatness-Based Methods By Albrecht Gensior, Oliver Woywode, Joachim Rudolph, Henry Gueldner	[View] [Download]
Abstract: Three control concepts for a boost converter are compared. Standard PI-control is the starting point. Second, passivity based control (PBC) is reviewed. Finally, a control concept is presented, that benefits from trajectory planning resorting to the system’s flat output. Stabilisation strategies around the planned trajectory are discussed. Simulations verify the control concepts.

	Comparative Evaluation Of Pwm Schemes For Three-Phase Pwm Current-Source Pfc Rectifier By Yasuyuki Nishida	[View] [Download]
Abstract: The PWM strategies with the carrier and reference signals comparison schemes for the 3-phase-bridge Current- Source (i.e., buck-mode) PFC rectifiers with different carrier and reference waveforms have been compared and evaluated. The “saw-tooth” and the “triangular” waveforms as the carrier signal and the standard “3-phase symmetrical sinusoidal, “with triplen harmonics” and “flat-top” waveforms as the reference signal are chosen in the comparative study. Although the study of the PWM schemes for the 3-phase Voltage-Source- Inverter/Rectifier has been done well so far, that for the 3-phase Current-Source-Inverter/Rectifier has not explored well until now. The paper investigates the duality and difference between the properties of the PWM schemes for the 3-phase Voltage- Source-Inverter/Rectifier and Current-Source-Inverter/Rectifier. Then, the performances of the selected PWM strategies have been evaluated theoretically as well as referring to several experimental results. Finally, a discussion to select the most attractive PWM strategy for the 3-phase Current-Source- Rectifier (i.e., Buck Rectifier) has been done.

	Comparison Between Hysteresis And Space Vector Modulation Techniques For Npc Inverters By Armando Bellini, Stefano Bifaretti, Stefano Costantini	[View] [Download]
Abstract: The paper analyzes and compares two different kind of modulation techniques specifically designed for three-phase Neutral Point Clamped (NPC) inverters. In the last years, the authors proposed different modulation techniques useful for NPC inverters; in particular, they presented new solutions to perform Hysteresis and Space Vector Modulation techniques (SVM). The first ones have been developed applying subsequent and significant improvement to the classical modulation, while SVM technique was designed to maintain, also in NPC inverters, all the advantages of SVM used in traditional twolevel inverters. The paper present, at first, a description of the proposed Hysteresis and Space Vector Modulation techniques pointing out, in addition, an accurate description of the methodology used for implementing the SVM procedure on a modern microcontroller. Finally, the performances of both modulation systems are analyzed and compared, using specific simulation programs.

	Cross-Over Distortion Reduction On 3 Level Pwm For Audio Amplifiers By Victor Antunes, V. Fernao Pires, J. Fernando Silva	[View] [Download]
Abstract: A new control/modulation method for digital audio power amplifiers is proposed. With this approach the cross-over harmonic distortion is reduced. The use of three-level PWM output voltage instead of two-level is another characteristic of this approach. From the use of the three-level two main advantages can be obtained: more resolution and increased efficiency. However, there is an important disadvantage: higher cross-over distortion and worst THD+N for signals with small amplitude, than the obtained with two level PWM output voltage. Therefore, to overcome this disadvantage the proposed control/modulation method uses three-level PWM output voltage for signals with large amplitude and two-level for signals with small amplitude. This allows the construction of a completely digital audio power amplifier with better efficiency than those using two-level PWM output, with comparable THD+N.

	Development Of Direct Torque Control System With Adaptive Flux, Torque And Speed Estimation By I. Ya. Braslavsky, Z. Sh. Ishmatov, E. I. Barats	[View] [Download]
Abstract: The paper deals with direct torque control (DTC) system for induction motor drive. The DTC concept is based on hysteresis control of stator flux and torque by means of proper voltage vector selection. The absence of intermediate phase current control loops allows to develop the extremely fast speed control loop in comparison with traditional field-oriented systems. The main attention is given to development of adaptive flux, torque and speed observer. An original algorithm providing highquality flux estimation and adaptive to winding parameters fluctuations caused by motor heating and saturation is proposed. The prior estimation of motor parameters is derived during several commissioning tests. The estimated values are corrected before every start and during operation.

	Implementation Of High-Speed Frequency Detection For Single Phase Utility Interactive Inverter System By Tsuyoshi Komiyama, Tatsuya Kojima, Tomoki Yokoyama	[View] [Download]
Abstract: In this paper, a high speed frequency detection method for the single phase utility interactive inverter is proposed. Distributed power system is considered as a solution of the environmental problems. As the distributed power system spreads, the stability and the reliability of the utility interactive system becomes important. In the utility interactive system, it is necessary to synchronize to a utility voltage. In the case of a single phase system, it is dificult to detect the instantaneous phase angle of the voltage not same as the 3 phase system. This paper describes a new highspeed frequency detection method using quasi dq transformation. Quasi dq transformation is applied to construct the PLL control with multi sampling parallel processing method based on the FPGA implementation. Evaluations and hardware implementations are described with simulations and experiments.

	Instantaneous Deadbeat Control For Single Phase And Three Phase Pwm Inverter Using Fpga Based Hardware Controller By Tomoki Yokoyama, Shinsuke Simogata, Motoki Horiuchi, Toshihiro Ide	[View] [Download]
Abstract: A new approach for real time digital feedback control of PWM inverter is proposed, in which a deadbeat control is realized using FGPA based hardware controller. From the viewpoint of FPGA implementation, control strategies for single phase and three phase systems are discussed through simulations and experiments for CVCF deadbeat control such as single rate deadbeat control and multirate deadbeat control. Also current control method using voltage deadbeat control and PLL control with quasi dq transformation with multisampling parallel processing method are implemented in FPGA based hardware controller for single phase utility interactive inverter.

	Modeling Of DC-DC Converters Using Polynomial Representation Technique By Ali Altowati, Kai Zenger, Teuvo Suntio	[View] [Download]
Abstract: In this paper, an alternative technique for the analysis of switching DC-DC converters operating in continuous inductor current mode (CICM) with either voltage mode control (VMC) or peak current mode control (PCMC) is presented. The proposed method is based on the use of inputoutput polynomial approach and two-port unterminated modeling technique. The approach is used to study the dynamic behavior of converters in the presence of input filter. The modeling and dynamic analysis procedure presented is verified by a design example.

	New PWM Technique Based On The Centroid Method By R. A. Villarreal-Ortiz, M. Hernandez-Angeles, C. R. Fuerte-Esquivel, R. O. Villanueva-Chavez	[View] [Download]
Abstract: In this paper a new PWM technique for commutation control of CD-CA static converters is presented. The technique determines the commutation angles based on equilibrium points, which are obtained by calculating the Centroid of the area under the curve of the voltage sinusoidal function, within a time interval defined by the method of equal areas. Hence, the power inverter commutation angles are computed\| directly from closedform equations

	Pulse Rectifier Current-Type Is Friendly To EMC By Pavel Hlisnikovsky, Petr Chlebish	[View] [Download]
Abstract: This document deals with the three-phase pulse rectifier current-type as a modern controlled rectifier, which is suitable for speed control of DC motors or as an input unit of indirect frequency converters current-type, because its low emissions of harmonics to network, controlled power factor, quick reaction on control changes and excellent regulation of the output rectified current. There is a comparison of the converter with the usual phase-controlled thyristor rectifier. The modulation method of the rectifier, the vector pulse width modulation, is also described in the contribution as well as other parts of the control like synchronization with the supply voltage and the power factor of the converter. The measured results on realized physical models are enclosed at the end of the contribution.

	Pulse System Dynamics Forecasting Using On-Line Time Series Data By Yury Kolokolov(ru), Anna Monovskaya(ru), Kondo Adjallah(fr)	[View] [Download]
Abstract: An approach to dynamics forecasting is proposed by an example of DC-DC PWM converter dynamics simulation. The main algorithm of this approach allows on-line identification of sub-harmonic motion types and corresponding parameter vectors. The consistency of the identification results forms the tendency of the parameter variation. Then forecasting of dynamics evolution in relation to the nearest bifurcation boundaries, constructed preliminary, is suggested.

	Stability Analysis Of Three Interleaved Dc-Dc Boost Converters Under Pwm Control With Pi Compensator By Mohamed B. Debbat, Abdelali El Aroudi, Roberto Giral, L. Martinez-Salamero	[View] [Download]
Abstract: In this paper, stability analysis of three interleaved DC-DC boost converters under PWM control with proportional and integral (PI) compensator, is presented. Continuous Conduction Mode (CCM) is assumed. The generalized discretetime model of the system is built. The PI compensator is taken into account in the model. Taking the proportional term, the integral term, and the current feedback gains as bifurcation parameters, it is obtained that the 1-periodic orbit loses its stability via Hopf bifurcation. As result, the attractor is a torus T2 and the behavior is quasiperiodic. The Jacobian matrix of the system is obtained and its eigenvalues are computed. It is shown that one pair of complex conjugate eigenvalues crosses the unit circle when bifurcations parameters are varied. It is also shown that sometimes the system mode of operation changes from CCM to Intermittent Conduction Mode (ICM) when the system nominal periodic orbit loses stability.

	Switching Strategies For High Bandwidth Multiconverter Systems By Maria Stefania Carmeli, Francesco Castelli Dezza, Gabrio Superti Furga	[View] [Download]
Abstract: The present paper focuses on current modulation strategies for multiconverter systems. Current control methods are preferred when high bandwidth is required. Three different modulation techniques are analysed and compared: smart modulation algorithm performed on branch currents; hysteresis current modulation and multilevel smart modulation algorithm performed on external current with an additional control on branch currents. Simulation results are presented.

	The Ineffectiveness Of Anti-Aliasing Filtering In A Current Loop Modeling With Specific Numerical PWM Converter By P. Ph. Robet, M. Gautier	[View] [Download]
Abstract: The paper investigates two carriers used in industrial applications with digital control of a current closed loop. It focuses on the theoretical approach showing the uselessness of the anti-aliasing filter for a control scheme of the PWM based on a triangular carrier wave.

	Unified Scheme Of Direct Power And Torque Control For Space Vector Modulated AC/DC/AC Converter- Fed Induction Motor By Marek Jasinski, M. P. Kazmierkowski, M. Zelechowski	[View] [Download]
Abstract: A novel control scheme for PWM rectifier-inverter system is proposed. Fast control strategies such as line voltage Sensorless Virtual Flux (VF) based Direct Power Control with Space Vector Modulator (DPC-SVM) for rectifier and Direct Torque Control with Space Vector Modulator (DTC-SVM) for inverter side are used. These strategies lead to good dynamic and static behaviour of the proposed control system – Direct Power and Torque Control- Space Vector Modulated (DPTSVM). Simulations and experiment results obtained show good performance of the proposed system. Additional power feedforward loop from motor to rectifier control side improved dynamic behaviours of the power flow control. As a result, better input-output energy matching allows decreasing the size of the dc-link capacitor.