EPE Association: EPE 2018 - DS2d: Standard and Advanced Control techniques for Power Converters I

EPE 2018 - DS2d: Standard and Advanced Control techniques for Power Converters I
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 03: Measurement and Control > EPE 2018 - DS2d: Standard and Advanced Control techniques for Power Converters I

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   A feed-forward control strategy of bidirectional inductive power transfer system for rail transit
By Longbin JIANG [View]
[Download]

Abstract: Inductive power transfer (IPT) is one of the most promising power supply methods for rail transit. Thebidirectional IPT system can fed regenerative braking energy back to the primary side to save electricenergy. However, during accelerating or braking of rail transit vehicle, the output voltage of the IPTsystem usually fluctuate dramatically. The analysis of the existing control strategy shows that there isa large time lag in the regulation of the voltage control loop. This paper proposed a feed-forwardcontrol strategy in which the current of output side capacitor is feed-forward to output voltage controlloop to reduce the fluctuation and recovery time of output voltage. The proposed control strategy isverified by simulation results.

   Analysis and Control Strategy of Modular Multilevel Converter with Integrated Battery Energy Storages System Based on Voltage Source Mode
By Zhe WANG [View]
[Download]

Abstract: This paper analyzes the equivalent model of MMC with integrated BESS and designs the control structure based on voltage source mode at battery side. The optimized multi-level state of charge (SoC) balancing scheme and battery current control strategy are proposed. The experimental results validate the effectiveness and feasibility of the proposed control strategy.

   Analysis and Evaluation of Repetitive Controllers for Circulating Current Suppression in Modular Multilevel Converters
By Gard RØDAL [View]
[Download]

Abstract: A method to suppress the circulating current in Modular Multilevel Converter using the repetitive control is discussed. The parallel and series structure of repetitive controller is investigated. It is shown that the performance of the repetitive controller and resonant controller are comparable at high bandwidth, however, at low bandwidths the performance of the repetitive controller deteriorates. The controllers are implemented in Xilinx SoC, where the repetitive control structure is found to give similar steady state error while maintaining lower resource use when implemented with 16- and 32-bit word length compared with the proportional resonant control.

   Current Control for a Multiphase Interleaved-Switched Inverter Using Field Oriented Coordinates
By Manuel FISCHER [View]
[Download]

Abstract: To reduce the influence of current ripple in power electronic applications a multiphase interleavedswitchedinverter instead of a conventional inverter is considered. Multiple half bridge branches for eachphase are driven interleaved to increase the effective switching frequency and to decrease ripple contentin the inverter's output currents.Furthermore, this paper presents a current control system to enlarge the output current's frequency byusing field oriented coordinates. Thus, the control system doesn't limit the output current's amplitudeanymore.

   Dead Time as a Correction Variable for Junction Temperature Control
By Johannes RUTHARDT [View]
[Download]

Abstract: Junction temperature cycles, caused by load changes in power electronics, lead to a decrease of the expected lifetime of power semiconductor devices. The reason is, that power semiconductor devices consist of different material layers with their own coefficient of thermal expansion. This again leads to mechanical strain. A junction temperature control system is able to counter these occurring temperature cycles. To realize a junction temperature control, a possibility to affect the junction temperature is required. Influencing the power losses while the power semiconductor device is working is a well-known method to affect the junction temperature. This paper presents investigations on the suitability of the dead time as a correction variable in order to vary the power losses.

   Direct multivariable control of Modular Multilevel Converters
By Daniel DINKEL [View]
[Download]

Abstract: While Modular Multilevel Converters (MMC) have become state of the art in many high power/high voltage applications like HVDC, other important future applications (i.e. multiterminal-DC-grids, wind parks, electric ships, ...) are still under development. The increased number of variables available for essentially improved control of MMC has to be made accessible and fully used by improved control concepts. Future progress in hardware, especially smaller submodule capacitors, is tightly interrelated to progress of control performance. The same applies to fully electronic fault management and protection at the system level, which will be very valuable and important in future. A novel multivariable control concept for MMC, according to these requirements, is presented and explained. Its performance is investigated by extensive simulation results.

   Exact Grid Side Current Control Modeling for a Medium Voltage Wind Farm
By Eduardo BURGUETE [View]
[Download]

Abstract: The low switching frequency of medium voltage drives requires an accurate current control model to design the controller, as delays and discretization process are no longer negligible. In addition, the gridimpedance and the feed-forward voltage also affect the response of the system. This paper presents aprocedure that exactly models the current control loop of a medium voltage wind farm. The modelingprocedure is experimentally validated.An exact current control model allows the designer to tune the controller and analyze the stability of awind farm under different circumstances, such as different grid short circuit ratios (SCR) with a highreliability. The differences with the experimental results will only be limited to deviations between theimpedances of the model and real plant.

   Finite-Control-Set Model Predictive Control for Cascaded H-bridge Inverter with Improved Transient Response
By Sangshin KWAK [View]
[Download]

Abstract: This paper proposes the MPC algorithm with reduced computational complexity and fast dynamicresponse for the CHB inverters. During steady state, only optimal vector at a present step and its adjacentvectors are considered. However, this paper defines a new candidate vector subset for transient state forfast dynamic speed.

   Lyapunov-function based control of an AC/DC buck-boost converter with active power decoupling circuit
By Soonhwan HWANG [View]
[Download]

Abstract: Active power decoupling(APD) method is a suitable solution to increase the lifetime of power conversion systems by replacing electrolytic capacitors(E-Caps) with _lm capacitors using an auxiliary circuit. However, due to the increased non-linearity and uncertainty of the entire circuit, conventional control methods cannot guarantee global stability. This paper proposes nonlinear control strategy based on Lyapunov's direct method for AC/DC buck-boost converter with an APD circuit. The contribution of this paper is to guarantee global stability of the APD circuit based converters. The effectiveness of the proposed method is shown by experiments using a 100 W drive.

   Model predictive control method with preselected control options for reduced computational complexity in modular multilevel converters (MMCs)
By Sangshin KWAK [View]
[Download]

Abstract: Even though Model Predictive Control (MPC) has a straightforward implementation, multivariable control capability and outstanding dynamic response, it suffers from an excessive increase in computational complexity when the number of submodules (SMs) per arm (N) is increased in Modular Multilevel Converters (MMCs).The high computational complexity of the MPC controller for MMCs can be improved by decoupling the submodule (SM) capacitor voltage control from the cost function and balance them in an external voltage sorting algorithm. In this paper, further reduction in the computational burden for the MPC is realized by the preselection of control options that are able to satisfy the control objectives in the next sampling time. The preselection algorithm generates a small number of control options to be computed by a single MPC loop at each sampling time, thus, it can generate 2N+1 output voltage levels and suppress the circulating currents. The performance of the MMC operating with the proposed method is verified by simulation and experimental results

   Statistical Performance Verification of FCS-MPC Applied to Three Level Neutral Point Clamped Converter
By Mateja NOVAK [View]
[Download]

Abstract: In this paper we demonstrate how a statistical model checking approach can be used to check the dynamic performance of the finite set model predictive control algorithm for a standalone 3-level neutral point diode clamped converter. The robustness of the control algorithm under parameter uncertainty is also analyzed. Finite control set model predictive control (FCS-MPC) algorithm has found many applications in power electronics due to the straightforward control design and the possibility to include different control objectives. The control algorithm for 3-level neutral point diode clamped (NPC) converter has to address several objectives to provide optimal reference tracking during load transients. Therefore, looking from the perspective of the implementation, the FCS-MPC algorithm suits the control requirements of NPC converter. However, the problem remains in performing an analytical performance verification of the algorithm to demonstrate its robustness, which is compulsory for any industrial application. In this paper, we present how a statistical model checking approach can be used to solve this problem and also provide valuable data about the algorithm's performance during transients and in the case of parameter uncertainty. A benchmark model is created in Matlab/Simulink to validate the correct system modeling in UPPAAL SMC toolbox.

   Systematic and Easy-To-Use Design Procedure for Proportional-Integral-Resonant Controllers
By David LUMBRERAS [View]
[Download]

Abstract: The control of grid-connected inverters is an important issue nowadays. Different current controltechniques have been recently studied, appearing resonant controllers as a very good alternative to solvethe traditional problems of PI controllers. However, the resonant controllers' design is a non-widelyinvestigated task. In this paper a systematic and easy-to-use design procedure which can be applied to thedesign of any Proportional-Integral-Resonant (PIR) controller is developed. The proposal is applied tothe PIR controller of the current control loop of a three-phase photovoltaic inverter, showing the potentialof this controllers.

EPE 2018 - DS2d: Standard and Advanced Control techniques for Power Converters I
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2018 ECCE Europe - Conference > EPE 2018 - Topic 03: Measurement and Control > EPE 2018 - DS2d: Standard and Advanced Control techniques for Power Converters I
	[return to parent folder]

	A feed-forward control strategy of bidirectional inductive power transfer system for rail transit By Longbin JIANG	[View] [Download]
Abstract: Inductive power transfer (IPT) is one of the most promising power supply methods for rail transit. Thebidirectional IPT system can fed regenerative braking energy back to the primary side to save electricenergy. However, during accelerating or braking of rail transit vehicle, the output voltage of the IPTsystem usually fluctuate dramatically. The analysis of the existing control strategy shows that there isa large time lag in the regulation of the voltage control loop. This paper proposed a feed-forwardcontrol strategy in which the current of output side capacitor is feed-forward to output voltage controlloop to reduce the fluctuation and recovery time of output voltage. The proposed control strategy isverified by simulation results.

	Analysis and Control Strategy of Modular Multilevel Converter with Integrated Battery Energy Storages System Based on Voltage Source Mode By Zhe WANG	[View] [Download]
Abstract: This paper analyzes the equivalent model of MMC with integrated BESS and designs the control structure based on voltage source mode at battery side. The optimized multi-level state of charge (SoC) balancing scheme and battery current control strategy are proposed. The experimental results validate the effectiveness and feasibility of the proposed control strategy.

	Analysis and Evaluation of Repetitive Controllers for Circulating Current Suppression in Modular Multilevel Converters By Gard RØDAL	[View] [Download]
Abstract: A method to suppress the circulating current in Modular Multilevel Converter using the repetitive control is discussed. The parallel and series structure of repetitive controller is investigated. It is shown that the performance of the repetitive controller and resonant controller are comparable at high bandwidth, however, at low bandwidths the performance of the repetitive controller deteriorates. The controllers are implemented in Xilinx SoC, where the repetitive control structure is found to give similar steady state error while maintaining lower resource use when implemented with 16- and 32-bit word length compared with the proportional resonant control.

	Current Control for a Multiphase Interleaved-Switched Inverter Using Field Oriented Coordinates By Manuel FISCHER	[View] [Download]
Abstract: To reduce the influence of current ripple in power electronic applications a multiphase interleavedswitchedinverter instead of a conventional inverter is considered. Multiple half bridge branches for eachphase are driven interleaved to increase the effective switching frequency and to decrease ripple contentin the inverter's output currents.Furthermore, this paper presents a current control system to enlarge the output current's frequency byusing field oriented coordinates. Thus, the control system doesn't limit the output current's amplitudeanymore.

	Dead Time as a Correction Variable for Junction Temperature Control By Johannes RUTHARDT	[View] [Download]
Abstract: Junction temperature cycles, caused by load changes in power electronics, lead to a decrease of the expected lifetime of power semiconductor devices. The reason is, that power semiconductor devices consist of different material layers with their own coefficient of thermal expansion. This again leads to mechanical strain. A junction temperature control system is able to counter these occurring temperature cycles. To realize a junction temperature control, a possibility to affect the junction temperature is required. Influencing the power losses while the power semiconductor device is working is a well-known method to affect the junction temperature. This paper presents investigations on the suitability of the dead time as a correction variable in order to vary the power losses.

	Direct multivariable control of Modular Multilevel Converters By Daniel DINKEL	[View] [Download]
Abstract: While Modular Multilevel Converters (MMC) have become state of the art in many high power/high voltage applications like HVDC, other important future applications (i.e. multiterminal-DC-grids, wind parks, electric ships, ...) are still under development. The increased number of variables available for essentially improved control of MMC has to be made accessible and fully used by improved control concepts. Future progress in hardware, especially smaller submodule capacitors, is tightly interrelated to progress of control performance. The same applies to fully electronic fault management and protection at the system level, which will be very valuable and important in future. A novel multivariable control concept for MMC, according to these requirements, is presented and explained. Its performance is investigated by extensive simulation results.

	Exact Grid Side Current Control Modeling for a Medium Voltage Wind Farm By Eduardo BURGUETE	[View] [Download]
Abstract: The low switching frequency of medium voltage drives requires an accurate current control model to design the controller, as delays and discretization process are no longer negligible. In addition, the gridimpedance and the feed-forward voltage also affect the response of the system. This paper presents aprocedure that exactly models the current control loop of a medium voltage wind farm. The modelingprocedure is experimentally validated.An exact current control model allows the designer to tune the controller and analyze the stability of awind farm under different circumstances, such as different grid short circuit ratios (SCR) with a highreliability. The differences with the experimental results will only be limited to deviations between theimpedances of the model and real plant.

	Finite-Control-Set Model Predictive Control for Cascaded H-bridge Inverter with Improved Transient Response By Sangshin KWAK	[View] [Download]
Abstract: This paper proposes the MPC algorithm with reduced computational complexity and fast dynamicresponse for the CHB inverters. During steady state, only optimal vector at a present step and its adjacentvectors are considered. However, this paper defines a new candidate vector subset for transient state forfast dynamic speed.

	Lyapunov-function based control of an AC/DC buck-boost converter with active power decoupling circuit By Soonhwan HWANG	[View] [Download]
Abstract: Active power decoupling(APD) method is a suitable solution to increase the lifetime of power conversion systems by replacing electrolytic capacitors(E-Caps) with _lm capacitors using an auxiliary circuit. However, due to the increased non-linearity and uncertainty of the entire circuit, conventional control methods cannot guarantee global stability. This paper proposes nonlinear control strategy based on Lyapunov's direct method for AC/DC buck-boost converter with an APD circuit. The contribution of this paper is to guarantee global stability of the APD circuit based converters. The effectiveness of the proposed method is shown by experiments using a 100 W drive.

	Model predictive control method with preselected control options for reduced computational complexity in modular multilevel converters (MMCs) By Sangshin KWAK	[View] [Download]
Abstract: Even though Model Predictive Control (MPC) has a straightforward implementation, multivariable control capability and outstanding dynamic response, it suffers from an excessive increase in computational complexity when the number of submodules (SMs) per arm (N) is increased in Modular Multilevel Converters (MMCs).The high computational complexity of the MPC controller for MMCs can be improved by decoupling the submodule (SM) capacitor voltage control from the cost function and balance them in an external voltage sorting algorithm. In this paper, further reduction in the computational burden for the MPC is realized by the preselection of control options that are able to satisfy the control objectives in the next sampling time. The preselection algorithm generates a small number of control options to be computed by a single MPC loop at each sampling time, thus, it can generate 2N+1 output voltage levels and suppress the circulating currents. The performance of the MMC operating with the proposed method is verified by simulation and experimental results

	Statistical Performance Verification of FCS-MPC Applied to Three Level Neutral Point Clamped Converter By Mateja NOVAK	[View] [Download]
Abstract: In this paper we demonstrate how a statistical model checking approach can be used to check the dynamic performance of the finite set model predictive control algorithm for a standalone 3-level neutral point diode clamped converter. The robustness of the control algorithm under parameter uncertainty is also analyzed. Finite control set model predictive control (FCS-MPC) algorithm has found many applications in power electronics due to the straightforward control design and the possibility to include different control objectives. The control algorithm for 3-level neutral point diode clamped (NPC) converter has to address several objectives to provide optimal reference tracking during load transients. Therefore, looking from the perspective of the implementation, the FCS-MPC algorithm suits the control requirements of NPC converter. However, the problem remains in performing an analytical performance verification of the algorithm to demonstrate its robustness, which is compulsory for any industrial application. In this paper, we present how a statistical model checking approach can be used to solve this problem and also provide valuable data about the algorithm's performance during transients and in the case of parameter uncertainty. A benchmark model is created in Matlab/Simulink to validate the correct system modeling in UPPAAL SMC toolbox.

	Systematic and Easy-To-Use Design Procedure for Proportional-Integral-Resonant Controllers By David LUMBRERAS	[View] [Download]
Abstract: The control of grid-connected inverters is an important issue nowadays. Different current controltechniques have been recently studied, appearing resonant controllers as a very good alternative to solvethe traditional problems of PI controllers. However, the resonant controllers' design is a non-widelyinvestigated task. In this paper a systematic and easy-to-use design procedure which can be applied to thedesign of any Proportional-Integral-Resonant (PIR) controller is developed. The proposal is applied tothe PIR controller of the current control loop of a three-phase photovoltaic inverter, showing the potentialof this controllers.