EPE Association: EPE 2013 - DS1d: Modulation Strategies: Converter Control, Current/Voltage Control

EPE 2013 - DS1d: Modulation Strategies: Converter Control, Current/Voltage Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 06: Modulation strategies and specific control methods for static converters > EPE 2013 - DS1d: Modulation Strategies: Converter Control, Current/Voltage Control

   [return to parent folder]

   A digital RMRAC controller based on a modified RLS algorithm applied to the control of the output currents of an LCL-filter connected to the grid
By Rodrigo TAMBARA, Jorge MASSING, Hilton GRUNDLING, Humberto PINHEIRO [View]
[Download]

Abstract: This paper proposes a digital Robust Model Reference Adaptive Control (RMRAC) applied to control the output current (by the grid side) of a three-phase LCL-filter to applications in static converters connected to electric grid. The proposed controller is based on a modified RLS algorithm applied to adaptation of the controller gains. Experimental results show the good performance of the proposed control system.

   A Novel Timing Control Method for Neural Network Based Digitally Controlled DC-DC Converter
By Hidenori MARUTA, Masashi MOTOMURA, Fujio KUROKAWA [View]
[Download]

Abstract: Generally, the training based control method for dc-dc converters has a problem due to the fact that there is a difference of behavior between a controlled system before the training and one after the training. Therefore, when it is adopted to improve the transient response of dc-dc converter, it is needed to consider the bad effect of the training since the training term does not take its own effect to the transient response into account. Especially, the suitable timing and duration of the training based control term is affected since the behavior of the system is changed by its own effect. In this paper, we study a timing control method for a neural network based digital control method to improve the transient response of dc-dc converters. The neural network control is a suitable training based method since it can be a time series predictor to compensate the transient response. In our presented method, the standard three-layer neural network is adopted to improve the transient response converters by reference modification of a conventional PID control. To address the problem about the timing control, we present a method to obtain the suitable timing and duration effect of the neural network control term with simple criteria. This timing control works to avoid the bad effect of the neural network control term and obtain improved results. Experimental results show that our method can contribute to the improvement of transient response effectively.

   A Novel Voltage Balancing Method of Cascaded H-Bridge Rectifiers for Locomotive Traction Applications
By Chunyang GU, Zedong ZHENG, Yongdong LI [View]
[Download]

Abstract: Cascaded H-bridge rectifier paves the way of high-voltage applications without input transformer such as locomotive tractions. In the current study, a novel voltage balancing method based on improved PD-SPWM (phase-disposition sinusoidal pulse width modulation) is proposed that eliminates the multiple PI regulators in traditional balancing algorithms. This algorithm is simple to realize and effective for voltage balancing in the condition of unbalanced loads and locomotive regenerations. The validity of the proposed method has been verified by simulation and experiments.

   An Analysis and A Solution for Inrush Current Elimination for Three-Phase PWM Voltage Source Inverters
By Surasak NUILERS, Natchpong HATTI, Jirayut PHONTIP, Kanokvate TUNGPIMOLRUT [View]
[Download]

Abstract: This paper analyzes the cause of the inrush current at the starting time of the three-phase PWM voltage source inverters (VSIs) based on d-q synchronous reference frame. Then the simple method for solving the problem is proposed. The proposed technique can be applied to either active power applications such as Battery Energy Storage Systems (BESSs) or reactive power applications such as STATCOMs (Static Synchronous Compensators). The computer simulation and experimental results well agree with each other and verify that the proposed solution can completely eliminate the inrush current of the inverters. In addition, the proposed technique does not affect the overall system performance and does not require any additional control or power circuitry. The experimental system is DSP (Digital Signal Processor) based and has a power rating of 2 kW, as a BESS, and 2 kVAR, as a STATCOM.

   Comparative evaluation of the Single-phase “VIENNA I” and the Double Boost Effect “DBE” rectifiers under sliding mode current control
By Mohamed Fouad BENKHORIS, Mourad AIT-AHMED, Jean-Claude LE CLAIRE, Abdoulaye DIENG [View]
[Download]

Abstract: This paper deals with a comparative evaluation of the single-phase “VIENNA I” and the “DBE” rectifiers. Their cores respectively involve one and two coils. They operate in continuous current and PFC modes thanks to an AC side current control. The two coils allow to get a “Double Boost Effect” during each half-period of the mains, then transmitting the stored energy to both DC capacitors. This is not possible to get it with the “VIENNA I” rectifier. In order to demonstrate it, an itemized analysis is performed. Then the simulations and experimental results are done.

   COMPARISON OF FINITE-CONTROL-SET MODEL PREDICTIVE CONTROL VERSUS A SVM-BASED LINEAR CONTROLLER
By Hector YOUNG, Jose RODRIGUEZ [View]
[Download]

Abstract: In recent years, Finite Control Set Model Predictive Control (FCS-MPC) has received considerable attention due to advantages such as ease of implementation, flexibility in the definition of control objectives and superior transient performance. However, some drawbacks of FCS-MPC, such as variable switching frequency and steady-state error, have also been reported. In order to assess the performance of FCS-MPC, this paper presents a comprehensive comparison of this method and a synchronous PI controller with space vector modulation (PI-SVM) for current regulation in steady-state and transient operation. The parameters of the linear controller are designed according to the modulus optimum technique, in order to guarantee a fast transient response. Quantitative performance indices are applied to both control schemes in a wide range of operating points of the inverter. In simulation results, the steady-state performance of FCS-MPC is strongly influenced by the operating point. As for the transient response, the FCS-MPC is slightly faster than the PI-SVM, also offering a better decoupling capability between the d and q axes of the current.

   Constant Power Control of Grid Connected Inverters during Unbalanced Faults
By Ivan ANDRADE, Ramon BLASCO-GIMENEZ, Ruben PENA [View]
[Download]

Abstract: This paper includes the theoretical analysis and experimental validation of a control strategy for the direct powerand current control of grid-connected inverters. The studied control strategy allows for constant active and reactive power delivery during unsymmetrical faults and with supply voltage distortion, without the use of a PLL or FLL.It has been proven that only positive sequence current harmonics are necessary to deliver constant P and Q during unbalanced grid faults. The resulting stationary frame control has been experimentally validated during unbalanced voltage sags and swells.

   Development and evaluation of control and power hardware for a line side PWM current source inverter
By Klaus KRISCHAN, Wilfried WILTBERGER, Annette MUETZE [View]
[Download]

Abstract: Using PWMcurrent source inverters in drive systems shows some advantages over voltage source inverterssuch as reduction of losses in the machine due to the lower harmonic content in the machine currentsand better EMI behaviour.The paper presents the theoretical and experimental design of a line side PWM current source inverter.The work includes a comparative study of different power semiconductors together with the gate drivecircuits as well as the development of the control system maintaining the line side current waveform andthe commanded dc-link current.

   Digital Fast-P Slow-ID Control DC-DC Converter
By Fujio KUROKAWA, Ryuya YOSHIDA, Yudai FURUKAWA [View]
[Download]

Abstract: This paper presents a new digital control method for dc-dc converter which consists of two A-D converters with different sampling frequencies. In the presented method, the calculation process of P and ID controls are parallel. The sampling frequency for the P control is higher than the switching frequency and one for ID control is lower than the switching frequency. Therefore, the P control and ID control have different sampling frequency each other. Even in such different setting compared with the conventional PID control method, our presented method can realize the superior transient response. The presented method also contributes the low-cost design of A-D converters. In the experiments, it is obtained that the undershoot of the output voltage and the convergence time are improved by 44\% and 78\% respectively in the transient response. From the results, it is confirmed that our presented method can provide superior transient characteristics and the low cost implementation simultaneously.

   Finite Control Set Model Predictive Control with Increased Prediction Horizon for a 5 Level Cascaded H-Bridge StatCom
By Nathan MARKS, Terrence SUMMERS, Robert BETZ [View]
[Download]

Abstract: Model Predictive Control (MPC) can provide performance benefits over traditional schemes in power electronic converter control. A key variable in predictive control schemes is the prediction horizon. This paper examines the impact of increasing the prediction horizon of a five level StatCom via simulation and experimental results.

   Frequency Response Analysis of Proposed Digital Control System for DPWM-POL
By Kenji MII, Daisuke KANEMOTO, Tamotsu NINOMIYA, Yoichi ISHIZUKA [View]
[Download]

Abstract: This paper will discuss about the proposed hardware logic type digital controller for on-board SMPS which has a very small time-delay in control loop. Experimental results of the load current change experiment and the frequency characteristic of open loop transfer function has been described respectively. These results reveal the validity of the proposed technique.

   Handling of disturbance variables within a multi-phase interleaved-switched inverter by a discrete-time decoupling network
By Christian NEMEC, Julian WÖLFLE, Maximilian NITZSCHE, Jorg ROTH-STIELOW [View]
[Download]

Abstract: This paper presents investigations on the control block diagram of a multi-phase interleaved-switched inverter. Disturbing influences caused by the interleaved switching affect the desired simplicity of the block diagram. A possibility to eliminate these disturbances by a novel discrete-time decoupling network is presented and its functionality and advantage are approved by measurements.

   Impact of PWM Jitter to Switching-Mode Power Converter Efficiency
By Yaow-Ming CHEN, Feng-Yu WU, Cheng-Wei CHEN [View]
[Download]

Abstract: This paper proposes a methodology to demonstrate the impact of the Pulse-Width-Modulation (PWM) jitter effect to the power conversion efficiency of switching power converters. First, the origin of PWM jitter is introduced. The power-loss equivalent circuit model with corresponding equations are developed to understand the mechanism of power losses. Both computer simulation and hardware circuit are established to verify the impact of the PWM jitter to the conversion efficiency. An external sinusoidal perturbation signal with variable frequency is induced to the voltage control loop to produce a controllable PWM jitter in order to observe the change of power converter efficiency. The validity of the proposed methodology is verified by the simulated and the measured results.

   New Control Strategy for Grid Connecting of Wind Turbine Inverter without Converter Reactor
By Tonny RASMUSSEN, Daniel BJORNEBOE, Kasper Brokob SØRENSEN [View]
[Download]

Abstract: Wind turbines and the belonging converters increase in size and price. A reduction in the number of main components is desirable while it reduces need of space, investments and increases the efficiency. A wind turbine contains both a converter reactor and a step up transformer. The paper presents theory and laboratory measurements for a new control strategy which make it possibly to connect a wind turbine converter to the utility grid without using the converter reactor or make measurements at the high voltage side of the transformer. The capability to control the DC voltage and reactive power are shown with a three level diode clamped 20kVA converter for laboratory experiments.

   Optimization of d-q-hysteresis controller
By Philip DOST, Sebastian R. JARZABEK, Constantinos SOURKOUNIS [View]
[Download]

Abstract: The optimal choice of switches within a hysteresis controller with a d-q-related constraint is discussedin this paper. The hysteresis controller controls a bidirectional two-level three-phase standard inverter.This paper expands the options of switching processes to a former published d-q-hysteresis controller.Despite a separate active and reactive hysteresis constraint which is offered, further advantages for thed-q-controller are evaluated.This Paper describes the main functionality of the floating d-q-hysteresis controller and demonstrates acomparison with the a-b-control-structure.

   Performance comparison between nonlinear and linear controllers applied to a Buck converter using poles placement design
By Claudinor NASCIMENTO, Marcelo PEDROSO, Mauricio KASTER, Angelo TUSSET [View]
[Download]

Abstract: A performance comparison of four control techniques (PID, LQR, SDRE and ANLPID-GGF) applied to a Buck converter is presented. The controllers are set so the operating point of the closed loop system presents the same natural frequency. The poles placement technique was used. Analyses of the results are performed.

   Simple DCM or CRM Analog Peak Current Controller for HV Capacitor Charge-Discharge Applications
By Ionut TRINTIS, Emmanouil DIMOPOULOS, Stig MUNK-NIELSEN [View]
[Download]

Abstract: This paper presents a simple analog current controller suitable for buck and boost converter topologies.The controller operates in DCM or CRM, depending on the setup. The experimental results are presentedto validate the proposed controller functionality for a high voltage capacitor charge-discharge application.

   Small Signal Modeling of the Quasi-Z-Source-Inverter and a Novel Control Strategy to Minimize the Influence of Input Voltage Disturbances
By Thomas LANNERT, Michael BRAUN, Matthias ISEN [View]
[Download]

Abstract: The Quasi-Z-Source-Inverter (QZSI) reveals an asymmetrical L-C-network structure in which unwantedoscillations can be triggered by input voltage disturbances (IVD). This paper presents an AC small signalmodel of the QZSI, derived from State Space Averaging, with emphasis on the influence of IVD. Afterthe discussion of the small signal model, a novel cascade control strategy is developed to adequatelycompensate the influence of IVD on the DC-link voltage. The effectiveness of the proposed controlstrategy is verified by simulation and experimental results on a laboratory test bench with an inductionmachine as load.

   Space Vector-Based Modeling and Control of a Modular Multilevel Converter in HVDC Applications
By Marco BONAVOGLIA, Giacomo CASADEI, Luca ZARRI, Michele MENGONI, Angelo TANI, Giovanni SERRA, Remus TEODORESCU [View]
[Download]

Abstract: Modular multilevel converter (MMC) is an emerging multilevel topology for high-voltage applications that has been developed in recent years. In this paper, the modeling and the control of MMCs are restated in terms of space vectors, which may allow a deeper understanding of the converter behavior. As a result, a control scheme for three-phase MMCs based on the previous theoretical analysis is presented. Numerical simulations are used to test its feasibility.

   Stability Analysis of Digitally-Controlled PFC Converters Using LTP Approach
By Rafael Zanatta SCAPINI, Lucas Vizzotto BELLINASO, Leandro MICHELS [View]
[Download]

Abstract: This paper presents an stability analysis methodology for discrete-time control systems employing linear time-periodic models. This methodology provides a multi-step periodic invariant representation whose characteristic is linear time-invariant. The stability analysis of a full-bridge PFC rectifier is presented in order to demonstrate the proposed methodology. Simulations results are presented to validate the proposed technique.

   The LQ controller for the 3-phase 4-leg inverter with an LC output filter - choosing the right reference frame
By Arkadiusz KASZEWSKI, Bartlomiej UFNALSKI, Lech GRZESIAK [View]
[Download]

Abstract: In this paper three different implementations of the full-state feedback linear-quadratic (LQ) controllerfor a 3-phase 4-leg sine wave inverter are compared. The LQ controller is designed in stationary ref-erence frames $abc$ and $\alpha\beta\gamma$ as well as in $dq0$ reference frame rotating with the fundamental outputfrequency, and is not cascaded with any inner controller. In the proposed control schemes integral andmulti-oscillatory terms are added to the input of the LQ controller to ensure high quality output voltagewaveforms for unbalanced and nonlinear loads. All three approaches are tested in an experimental in-verter (a physical model at the level 10kVA). The experimental results for linear and nonlinear loads arepresented, discussed and some remarks on choosing the best reference frame are then given.

   Use of a full wave correct-by-design command to control a multilevel modular converter
By Romain SOULAT, Guillaume HERAULT, Gilles FELD, Laurent FRIBOURG, Bertrand REVOL, Stephane LEFEBVRE [View]
[Download]

Abstract: This paper proposes a method to synthesize a full wave control applied to a multilevel modular converter (MMC). This method guarantees the output waveform and the balancing of the capacitors. Numerical simulations and experiments are used to check the validity of the approach.

   Variable Carrier Frequency Deadbeat Control with Hysteresis Band using SoC-FPGA for Utility Interactive Inverter
By Tomoki YOKOYAMA, Morito YOSHIDA [View]
[Download]

Abstract: Using SoC-FPGA based hardware controller, the real time gain calculation of deadbeat control can be realized, which result in the realization of variable carrier frequency control of PWM inverter for utility interactive system based on deadbeat control. Precise current control with adjustable hysteresis band was realized with the calculation capability of Soc-FPGA. It is verified that the control accuracy and the efficiency of the inverter can be adjustable.

EPE 2013 - DS1d: Modulation Strategies: Converter Control, Current/Voltage Control
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 06: Modulation strategies and specific control methods for static converters > EPE 2013 - DS1d: Modulation Strategies: Converter Control, Current/Voltage Control
	[return to parent folder]

	A digital RMRAC controller based on a modified RLS algorithm applied to the control of the output currents of an LCL-filter connected to the grid By Rodrigo TAMBARA, Jorge MASSING, Hilton GRUNDLING, Humberto PINHEIRO	[View] [Download]
Abstract: This paper proposes a digital Robust Model Reference Adaptive Control (RMRAC) applied to control the output current (by the grid side) of a three-phase LCL-filter to applications in static converters connected to electric grid. The proposed controller is based on a modified RLS algorithm applied to adaptation of the controller gains. Experimental results show the good performance of the proposed control system.

	A Novel Timing Control Method for Neural Network Based Digitally Controlled DC-DC Converter By Hidenori MARUTA, Masashi MOTOMURA, Fujio KUROKAWA	[View] [Download]
Abstract: Generally, the training based control method for dc-dc converters has a problem due to the fact that there is a difference of behavior between a controlled system before the training and one after the training. Therefore, when it is adopted to improve the transient response of dc-dc converter, it is needed to consider the bad effect of the training since the training term does not take its own effect to the transient response into account. Especially, the suitable timing and duration of the training based control term is affected since the behavior of the system is changed by its own effect. In this paper, we study a timing control method for a neural network based digital control method to improve the transient response of dc-dc converters. The neural network control is a suitable training based method since it can be a time series predictor to compensate the transient response. In our presented method, the standard three-layer neural network is adopted to improve the transient response converters by reference modification of a conventional PID control. To address the problem about the timing control, we present a method to obtain the suitable timing and duration effect of the neural network control term with simple criteria. This timing control works to avoid the bad effect of the neural network control term and obtain improved results. Experimental results show that our method can contribute to the improvement of transient response effectively.

	A Novel Voltage Balancing Method of Cascaded H-Bridge Rectifiers for Locomotive Traction Applications By Chunyang GU, Zedong ZHENG, Yongdong LI	[View] [Download]
Abstract: Cascaded H-bridge rectifier paves the way of high-voltage applications without input transformer such as locomotive tractions. In the current study, a novel voltage balancing method based on improved PD-SPWM (phase-disposition sinusoidal pulse width modulation) is proposed that eliminates the multiple PI regulators in traditional balancing algorithms. This algorithm is simple to realize and effective for voltage balancing in the condition of unbalanced loads and locomotive regenerations. The validity of the proposed method has been verified by simulation and experiments.

	An Analysis and A Solution for Inrush Current Elimination for Three-Phase PWM Voltage Source Inverters By Surasak NUILERS, Natchpong HATTI, Jirayut PHONTIP, Kanokvate TUNGPIMOLRUT	[View] [Download]
Abstract: This paper analyzes the cause of the inrush current at the starting time of the three-phase PWM voltage source inverters (VSIs) based on d-q synchronous reference frame. Then the simple method for solving the problem is proposed. The proposed technique can be applied to either active power applications such as Battery Energy Storage Systems (BESSs) or reactive power applications such as STATCOMs (Static Synchronous Compensators). The computer simulation and experimental results well agree with each other and verify that the proposed solution can completely eliminate the inrush current of the inverters. In addition, the proposed technique does not affect the overall system performance and does not require any additional control or power circuitry. The experimental system is DSP (Digital Signal Processor) based and has a power rating of 2 kW, as a BESS, and 2 kVAR, as a STATCOM.

	Comparative evaluation of the Single-phase “VIENNA I” and the Double Boost Effect “DBE” rectifiers under sliding mode current control By Mohamed Fouad BENKHORIS, Mourad AIT-AHMED, Jean-Claude LE CLAIRE, Abdoulaye DIENG	[View] [Download]
Abstract: This paper deals with a comparative evaluation of the single-phase “VIENNA I” and the “DBE” rectifiers. Their cores respectively involve one and two coils. They operate in continuous current and PFC modes thanks to an AC side current control. The two coils allow to get a “Double Boost Effect” during each half-period of the mains, then transmitting the stored energy to both DC capacitors. This is not possible to get it with the “VIENNA I” rectifier. In order to demonstrate it, an itemized analysis is performed. Then the simulations and experimental results are done.

	COMPARISON OF FINITE-CONTROL-SET MODEL PREDICTIVE CONTROL VERSUS A SVM-BASED LINEAR CONTROLLER By Hector YOUNG, Jose RODRIGUEZ	[View] [Download]
Abstract: In recent years, Finite Control Set Model Predictive Control (FCS-MPC) has received considerable attention due to advantages such as ease of implementation, flexibility in the definition of control objectives and superior transient performance. However, some drawbacks of FCS-MPC, such as variable switching frequency and steady-state error, have also been reported. In order to assess the performance of FCS-MPC, this paper presents a comprehensive comparison of this method and a synchronous PI controller with space vector modulation (PI-SVM) for current regulation in steady-state and transient operation. The parameters of the linear controller are designed according to the modulus optimum technique, in order to guarantee a fast transient response. Quantitative performance indices are applied to both control schemes in a wide range of operating points of the inverter. In simulation results, the steady-state performance of FCS-MPC is strongly influenced by the operating point. As for the transient response, the FCS-MPC is slightly faster than the PI-SVM, also offering a better decoupling capability between the d and q axes of the current.

	Constant Power Control of Grid Connected Inverters during Unbalanced Faults By Ivan ANDRADE, Ramon BLASCO-GIMENEZ, Ruben PENA	[View] [Download]
Abstract: This paper includes the theoretical analysis and experimental validation of a control strategy for the direct powerand current control of grid-connected inverters. The studied control strategy allows for constant active and reactive power delivery during unsymmetrical faults and with supply voltage distortion, without the use of a PLL or FLL.It has been proven that only positive sequence current harmonics are necessary to deliver constant P and Q during unbalanced grid faults. The resulting stationary frame control has been experimentally validated during unbalanced voltage sags and swells.

	Development and evaluation of control and power hardware for a line side PWM current source inverter By Klaus KRISCHAN, Wilfried WILTBERGER, Annette MUETZE	[View] [Download]
Abstract: Using PWMcurrent source inverters in drive systems shows some advantages over voltage source inverterssuch as reduction of losses in the machine due to the lower harmonic content in the machine currentsand better EMI behaviour.The paper presents the theoretical and experimental design of a line side PWM current source inverter.The work includes a comparative study of different power semiconductors together with the gate drivecircuits as well as the development of the control system maintaining the line side current waveform andthe commanded dc-link current.

	Digital Fast-P Slow-ID Control DC-DC Converter By Fujio KUROKAWA, Ryuya YOSHIDA, Yudai FURUKAWA	[View] [Download]
Abstract: This paper presents a new digital control method for dc-dc converter which consists of two A-D converters with different sampling frequencies. In the presented method, the calculation process of P and ID controls are parallel. The sampling frequency for the P control is higher than the switching frequency and one for ID control is lower than the switching frequency. Therefore, the P control and ID control have different sampling frequency each other. Even in such different setting compared with the conventional PID control method, our presented method can realize the superior transient response. The presented method also contributes the low-cost design of A-D converters. In the experiments, it is obtained that the undershoot of the output voltage and the convergence time are improved by 44\% and 78\% respectively in the transient response. From the results, it is confirmed that our presented method can provide superior transient characteristics and the low cost implementation simultaneously.

	Finite Control Set Model Predictive Control with Increased Prediction Horizon for a 5 Level Cascaded H-Bridge StatCom By Nathan MARKS, Terrence SUMMERS, Robert BETZ	[View] [Download]
Abstract: Model Predictive Control (MPC) can provide performance benefits over traditional schemes in power electronic converter control. A key variable in predictive control schemes is the prediction horizon. This paper examines the impact of increasing the prediction horizon of a five level StatCom via simulation and experimental results.

	Frequency Response Analysis of Proposed Digital Control System for DPWM-POL By Kenji MII, Daisuke KANEMOTO, Tamotsu NINOMIYA, Yoichi ISHIZUKA	[View] [Download]
Abstract: This paper will discuss about the proposed hardware logic type digital controller for on-board SMPS which has a very small time-delay in control loop. Experimental results of the load current change experiment and the frequency characteristic of open loop transfer function has been described respectively. These results reveal the validity of the proposed technique.

	Handling of disturbance variables within a multi-phase interleaved-switched inverter by a discrete-time decoupling network By Christian NEMEC, Julian WÖLFLE, Maximilian NITZSCHE, Jorg ROTH-STIELOW	[View] [Download]
Abstract: This paper presents investigations on the control block diagram of a multi-phase interleaved-switched inverter. Disturbing influences caused by the interleaved switching affect the desired simplicity of the block diagram. A possibility to eliminate these disturbances by a novel discrete-time decoupling network is presented and its functionality and advantage are approved by measurements.

	Impact of PWM Jitter to Switching-Mode Power Converter Efficiency By Yaow-Ming CHEN, Feng-Yu WU, Cheng-Wei CHEN	[View] [Download]
Abstract: This paper proposes a methodology to demonstrate the impact of the Pulse-Width-Modulation (PWM) jitter effect to the power conversion efficiency of switching power converters. First, the origin of PWM jitter is introduced. The power-loss equivalent circuit model with corresponding equations are developed to understand the mechanism of power losses. Both computer simulation and hardware circuit are established to verify the impact of the PWM jitter to the conversion efficiency. An external sinusoidal perturbation signal with variable frequency is induced to the voltage control loop to produce a controllable PWM jitter in order to observe the change of power converter efficiency. The validity of the proposed methodology is verified by the simulated and the measured results.

	New Control Strategy for Grid Connecting of Wind Turbine Inverter without Converter Reactor By Tonny RASMUSSEN, Daniel BJORNEBOE, Kasper Brokob SØRENSEN	[View] [Download]
Abstract: Wind turbines and the belonging converters increase in size and price. A reduction in the number of main components is desirable while it reduces need of space, investments and increases the efficiency. A wind turbine contains both a converter reactor and a step up transformer. The paper presents theory and laboratory measurements for a new control strategy which make it possibly to connect a wind turbine converter to the utility grid without using the converter reactor or make measurements at the high voltage side of the transformer. The capability to control the DC voltage and reactive power are shown with a three level diode clamped 20kVA converter for laboratory experiments.

	Optimization of d-q-hysteresis controller By Philip DOST, Sebastian R. JARZABEK, Constantinos SOURKOUNIS	[View] [Download]
Abstract: The optimal choice of switches within a hysteresis controller with a d-q-related constraint is discussedin this paper. The hysteresis controller controls a bidirectional two-level three-phase standard inverter.This paper expands the options of switching processes to a former published d-q-hysteresis controller.Despite a separate active and reactive hysteresis constraint which is offered, further advantages for thed-q-controller are evaluated.This Paper describes the main functionality of the floating d-q-hysteresis controller and demonstrates acomparison with the a-b-control-structure.

	Performance comparison between nonlinear and linear controllers applied to a Buck converter using poles placement design By Claudinor NASCIMENTO, Marcelo PEDROSO, Mauricio KASTER, Angelo TUSSET	[View] [Download]
Abstract: A performance comparison of four control techniques (PID, LQR, SDRE and ANLPID-GGF) applied to a Buck converter is presented. The controllers are set so the operating point of the closed loop system presents the same natural frequency. The poles placement technique was used. Analyses of the results are performed.

	Simple DCM or CRM Analog Peak Current Controller for HV Capacitor Charge-Discharge Applications By Ionut TRINTIS, Emmanouil DIMOPOULOS, Stig MUNK-NIELSEN	[View] [Download]
Abstract: This paper presents a simple analog current controller suitable for buck and boost converter topologies.The controller operates in DCM or CRM, depending on the setup. The experimental results are presentedto validate the proposed controller functionality for a high voltage capacitor charge-discharge application.

	Small Signal Modeling of the Quasi-Z-Source-Inverter and a Novel Control Strategy to Minimize the Influence of Input Voltage Disturbances By Thomas LANNERT, Michael BRAUN, Matthias ISEN	[View] [Download]
Abstract: The Quasi-Z-Source-Inverter (QZSI) reveals an asymmetrical L-C-network structure in which unwantedoscillations can be triggered by input voltage disturbances (IVD). This paper presents an AC small signalmodel of the QZSI, derived from State Space Averaging, with emphasis on the influence of IVD. Afterthe discussion of the small signal model, a novel cascade control strategy is developed to adequatelycompensate the influence of IVD on the DC-link voltage. The effectiveness of the proposed controlstrategy is verified by simulation and experimental results on a laboratory test bench with an inductionmachine as load.

	Space Vector-Based Modeling and Control of a Modular Multilevel Converter in HVDC Applications By Marco BONAVOGLIA, Giacomo CASADEI, Luca ZARRI, Michele MENGONI, Angelo TANI, Giovanni SERRA, Remus TEODORESCU	[View] [Download]
Abstract: Modular multilevel converter (MMC) is an emerging multilevel topology for high-voltage applications that has been developed in recent years. In this paper, the modeling and the control of MMCs are restated in terms of space vectors, which may allow a deeper understanding of the converter behavior. As a result, a control scheme for three-phase MMCs based on the previous theoretical analysis is presented. Numerical simulations are used to test its feasibility.

	Stability Analysis of Digitally-Controlled PFC Converters Using LTP Approach By Rafael Zanatta SCAPINI, Lucas Vizzotto BELLINASO, Leandro MICHELS	[View] [Download]
Abstract: This paper presents an stability analysis methodology for discrete-time control systems employing linear time-periodic models. This methodology provides a multi-step periodic invariant representation whose characteristic is linear time-invariant. The stability analysis of a full-bridge PFC rectifier is presented in order to demonstrate the proposed methodology. Simulations results are presented to validate the proposed technique.

	The LQ controller for the 3-phase 4-leg inverter with an LC output filter - choosing the right reference frame By Arkadiusz KASZEWSKI, Bartlomiej UFNALSKI, Lech GRZESIAK	[View] [Download]
Abstract: In this paper three different implementations of the full-state feedback linear-quadratic (LQ) controllerfor a 3-phase 4-leg sine wave inverter are compared. The LQ controller is designed in stationary ref-erence frames $abc$ and $\alpha\beta\gamma$ as well as in $dq0$ reference frame rotating with the fundamental outputfrequency, and is not cascaded with any inner controller. In the proposed control schemes integral andmulti-oscillatory terms are added to the input of the LQ controller to ensure high quality output voltagewaveforms for unbalanced and nonlinear loads. All three approaches are tested in an experimental in-verter (a physical model at the level 10kVA). The experimental results for linear and nonlinear loads arepresented, discussed and some remarks on choosing the best reference frame are then given.

	Use of a full wave correct-by-design command to control a multilevel modular converter By Romain SOULAT, Guillaume HERAULT, Gilles FELD, Laurent FRIBOURG, Bertrand REVOL, Stephane LEFEBVRE	[View] [Download]
Abstract: This paper proposes a method to synthesize a full wave control applied to a multilevel modular converter (MMC). This method guarantees the output waveform and the balancing of the capacitors. Numerical simulations and experiments are used to check the validity of the approach.

	Variable Carrier Frequency Deadbeat Control with Hysteresis Band using SoC-FPGA for Utility Interactive Inverter By Tomoki YOKOYAMA, Morito YOSHIDA	[View] [Download]
Abstract: Using SoC-FPGA based hardware controller, the real time gain calculation of deadbeat control can be realized, which result in the realization of variable carrier frequency control of PWM inverter for utility interactive system based on deadbeat control. Precise current control with adjustable hysteresis band was realized with the calculation capability of Soc-FPGA. It is verified that the control accuracy and the efficiency of the inverter can be adjustable.