EPE Association: EPE 2022 - DS2h: Standard and Advanced Current / Voltage / Synchronisation Control Techniques

EPE 2022 - DS2h: Standard and Advanced Current / Voltage / Synchronisation Control Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2022 ECCE Europe - Conference > EPE 2022 - Topic 04: Electrical Machines and Drive Systems > EPE 2022 - DS2h: Standard and Advanced Current / Voltage / Synchronisation Control Techniques

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   A Direct Model Predictive Control Strategy of Back-to-Back Modular Multilevel Converters Using Arm Energy Estimation
By Akseli HAKKILA [View]
[Download]

Abstract: This paper presents a model predictive control (MPC) algorithm for modular multilevel converters (MMCs). To meet the control objectives of phase current reference tracking and circulating current minimization, the proposed control scheme calculates the optimal number of submodules (SMs) to be inserted in each arm. In doing so, favorable steady-state and dynamic performance is achieved. Moreover, by estimating---instead of measuring---the arm energies in the predictive stage of the control loop, the proposed control scheme results in self-stabilizing open-loop arm energy balancing, while avoiding potential stability issues. Furthermore, to reduce the computational complexity of the MPC algorithm, the optimization problem is simplified by controlling each phase separately and assuming that the SM capacitors are balanced within an arm. To ensure that this assumption is always satisfied, a subsequent capacitor voltage balancing algorithm is designed to select the individual SMs that are switched on and off. The performance of the proposed control strategy is validated with simulations for a high voltage dc system (HVDC) that consists of two MMCs with 20 SMs per arm in a back-to-back configuration.

   A fast control for a three-switch multi-input DC-DC converter
By Simone COSSO [View]
[Download]

Abstract: In this paper, a double-input bidirectional DC-DC converter is taken into account. The converter allows to use less switches than a traditional solution and, moreover, it guarantees a higher efficiency. The modulation strategy proposed in the technical literature allows the converter to work in Discontinuous Conduction Mode at low-load and, therefore, to increase the efficiency in comparison to the CCM. However, such a control reduces the dynamics of the converter. To improve the transient response, a Feed-Forward approach is proposed in this paper. Since the converter model in DCM is complex and highly nonlinear, a simplified model is considered. The effectiveness of the proposed approach is proved with experimental results on a converter prototype.

   A Strategy for Smooth Microgrid Transitions without Phase Misalignment and Voltage mismatch
By Gabriel SILVA ROCHA [View]
[Download]

Abstract: In this work, it is proposed a modified control structure to provide smooth transitions of control modesof Grid-forming Converter without phase misalignment and voltage mismatch. A background of thetraditional structure is provided and a carefully description of the method is introduced. At the results,a comparison with methods in literature is carried out and it possible to prove that with the correct phase and voltage compensations, one can almost eliminate the transients in the grid voltage due to theswitching of control modes of the Grid-forming Converter and transition of the MG operating mode.

   A Theoretical Comparison of Different Virtual Synchronous Generator Implementations on Inverters
By Patrick KÖRNER [View]
[Download]

Abstract: The goal to overcome the global climate crisis leads to a rising demand for the usage of Renewable Energy Sources (RES). Decentralized control strategies are needed to allow the integration of RES into the grid. The Virtual Synchronous Generator (VSG) is proposed as a method to add virtual inertia to the grid by emulating the rotating mass of a Synchronous Generator (SG) on the control algorithm of an inverter. This paper presents the VSG control structure as well as the mathematical description in a unified form. Due to the fact that classical droop control can be seen as a special form of the VSG, their correlation is highlighted by evaluating the steady state output characteristics of the inverter. Furthermore, a theoretical comparison between different VSG topologies, including the VISMA-Method 2 and the synchronverter, is given. In order to achieve better voltage stability, principles to add virtual impedance to the inverter's output are described.

   Ageing Mitigation and Loss Control in Reconfigurable Batteries in Series-Level Setups
By Tomas KACETL [View]
[Download]

Abstract: This paper presents a novel control method that reduces the low-frequency ripple of dynamically reconfigurable battery technology to reduce cell ageing and loss. It furthermore shifts the residual ripple to higher frequencies where the lower impedance reduces heating and the dielectric capaci-tance of electrodes and electrolyte shunt the current around the electrochemical reactions.

   An Improved Multi-loop Resonant and plug-in Repetitive Control Schemes for Three-Phase Stand-Alone PWM Inverter Supplying Non-Linear Loads
By Ahmad Ali NAZERI [View]
[Download]

Abstract: This paper proposes an improved multi-loop control scheme for a three-phase voltage source inverter (VSI) for the island/microgrid operation. The constant voltage constant frequency (CVCF) pulse-width modulation (PWM) inverter can be used to regulate the output voltage with lower total harmonic distortion (THD). The output voltage is regulated under different load conditions, such as linear and rectifier loads for a CVCF for the uninterruptible power supply (UPS) inverter in stand-alone operation. An improved plug-in repetitive controller (RC) with the proportional-resonant (PR) control is used in the outer voltage loop to regulate the output AC voltage, and a simple proportional control is used in the inner current control loop for active damping and improving the transient performance. The instantaneous reference voltage of the converter is used as a feed-forward signal at the output of the converter to robust the system performance and simplify the controller design. This paper proposes a step-by-step design procedure of the voltage and current controllers, an analysis of the overall system stability from the frequency-response viewpoint, and the implementation of the PR with the improved plug-in RC for the three-phase stand-alone inverter supplying linear and non-linear loads. The improved plug-in RC combined with PR control offers high-quality sinusoidal output voltages, robustness to the parameter uncertainties, fast response, and the need for fewer sensors. Moreover, the modified plug-in RC is effective and simple to be implemented on a digital signal processor (DSP). The three-phase VSI with the proposed multi-loop control is simulated in MATLAB/Simulink and experimentally implemented on a 7.5 kW system on TMDSDOCK28379D 32-bit floating-point DSP from Texas Instruments to validate the excellent steady-state, dynamic and transient performance of the proposed control scheme with better harmonic mitigation.

   An Optimized Compensation Strategy of Direct Matrix Converter-Fed PMSM Drives with Field Weakening under Unbalanced Supply Conditions
By Jun XIE [View]
[Download]

Abstract: This paper presents an optimized compensation strategy for direct matrix converter (DMC) - fed permanent magnet synchronous motor (PMSM) drives with special consideration of the modification in field weakening control under unbalanced supply conditions. The imbalance of input voltage conditions in a three wire system are analysed and considered to be composed of positive and negative sequence components. To determine unbalance factor of the grid and decompose the positive and negative sequence components, the dual second order generalized integrator (DSOGI) and positive sequence calculator (PSC) algorithm are introduced. In order to achieve balanced output while optimizing the input current to be sinusoidal, the modulation index based on direct modulation method and the field weakening regulator are then adjusted according to unbalance factor of the input voltage conditions. The principle of the proposed compensation strategy is explained in detail. Simulation results are used to verify this proposed strategy. A low voltage laboratory platform consisting of DMC and servo motor is implemented and controlled using hybrid hardware concept based on field-programmable gate array (FPGA) and digital signal processor (DSP). Experimental studies on the laboratory prototype confirm the feasibility and effectiveness of the proposed method.

   Comprehensive Control of Matrix Converters in On-Board Electric Drive Applications
By Mirzaeva GALINA [View]
[Download]

Abstract: Matrix Converters are an attractive alternative to the traditional AC/DC/AC converters, particularly, in electric transportation. Their advantages include low weight and volume, high reliability and efficiency. However, variable frequency and variable power operation, typical for electric vehicles, poses control challenges. This paper addresses these challenges and proposes a robust control solution for MatrixConverters with a number of novel features. The paper compares the proposed and the conventional control schemes for Matrix Converters, and shows improvement with respect to power factor control, input resonance suppression, reference tracking and harmonics performance. Findings of the paper are supported by simulations results.

   Constrained Long-Horizon Direct Model Predictive Control for Grid-Connected Converters with LCL Filters
By Mattia ROSSI [View]
[Download]

Abstract: This paper presents a direct model predictive control algorithm for a three-level neutral point clampedconverter connected to the grid via an LCL filter. The proposed controller simultaneously controlsthe grid and converter currents as well as the filter capacitor voltage, while meeting the relevant gridstandards. Moreover, output constraints are included to ensure operation of the system within its safeoperating limits. This is achieved by formulating the direct MPC problem as a constrained integer least-squares optimization problem, wherein the output constraints are mapped into input constraints. Thepresented results verify the effectiveness of the proposed method.

   Control of a Zero-Voltage Switching Isolated Series-Resonant Power Circuitfor Direct 3-phase AC to DC Conversion
By Yusuf KOSESOY [View]
[Download]

Abstract: A novel control method is presented for a fully zero-voltage switching series-resonant isolated 3-phaseAC to DC converter. The control is derived from first principles such as energy and charge conservation.The approach results in operation with a high power factor at the AC grid side and is beneficial in termsof EMI due to soft switching and low dv/dt across the switches even when extremely fast WBG devicessuch as SiC or GaN are used.

   DAB frequency decoupling control with current minimization
By Simon UICICH [View]
[Download]

Abstract: This paper applies a new Dual-Active-Bridge (DAB) triple-phase-shift (TPS) model modulation tosimplify converter analysis, to simplify control and improve efficiency, and reduce transient currentstress in the power stage throughout a wide operating space. Achieved current stress is comparable tostate-of-the-art. The approach is validated through Simulink-Simscape.

   Design and Performance Analysis of a Modified Proportional Multi-Resonant (PMR) Controller for Three-Phase Voltage Source Inverters
By Ahmad Ali NAZERI [View]
[Download]

Abstract: The three-phase voltage source inverter (VSI) can be operated in grid-connected and/or stand-alone mode where the VSI is connected to the grid and/or critical loads at the point of common coupling (PCC). Proper voltage control is needed for the output voltage regulation in stand-alone operation and current control is needed for the grid current control. This paper presents a step-by-step design procedure, an extensive system stability analysis, and methods of discretization for the current control of three-phase power converters in the synchronous (dq) and stationary reference frame (SRF). A proportional-integral multi-resonant (PI-MR) controller in the synchronous reference frame (SynRF) is implemented for the regulation of the inner current loop. Moreover, the inverter inductor current controller in a stationary frame is proposed to provide active damping, and improve transients, and steady-state performance. The traditional PI-MR controller is compared for different load conditions with the modified practical proportional multi-resonant (PMR) controller in parallel with the harmonic compensators of orders 5th, 7th, 11th, and 13th to reduce low-order load current harmonics. The PMR controller shows superior performance with lower total harmonic distortion (THD) than the conventional PI and PI-MR controllers for highly non-linear load conditions. Moreover, the modified PMR controller has almost zero steady-state error, improved tracking of the reference signal, and better disturbance rejection compared to the conventional PI-MR control. A comprehensive design guideline of the proposed controller with a wider range of system stability margin is analyzed with harmonic damping of the three-phase VSI. Proper discretization methods for each controller have been outlined. The system is simulated in MATLAB/Simulink environment and experimentally implemented on a TMS320F28335 floating-point digital signal processor (DSP) for a 7.5 kW inverter to validate the performance of the controllers.

   High Switching Frequency Operation of a Single-Phase Five-Level Hybrid Active Neutral Point Clamped Inverter with a Model Predictive Control Approach
By Mohammad NAJJAR [View]
[Download]

Abstract: Wide bandgap (WBG) devices such as Silicon-Carbide (SiC) MOSFETs can be utilized to increase the switching frequency of power electronic converters. The size of passive components of an output filter can be reduced by increasing the switching frequency of converters or the number of output levels thorough the employment of multilevel topologies. Therefore, the combination of multilevel converters and WBG switches with a high switching frequency can improve the dynamic of converters. Meanwhile, a high bandwidth controller is also required to achieve a fast dynamic response of the system. In this paper, an advanced model predictive control (MPC) approach, based on the concept of hysteresis current control, is presented for a single-phase five-level hybrid active neutral point clamped (ANPC) inverter. A hybrid modulation technique with different switching frequencies is considered in this paper. As a result, different semiconductor technologies including SiC and Si are employed in the structure of the converter. Considering the AC and DC sides mathematical modeling of the converter, an MPC with the ability to control the neutral point (NP) voltage is designed. Finally, experimental results show that by utilizing the SiC MOSFETs and the proposed advanced MPC structure, the inverter's switching frequency is increased, with lower current ripple and fast dynamic performance.

   Model Predictive Control-enabled Fault Ride Through Operation Strategy for High Power Wind Turbine
By Pedro CATALÁN [View]
[Download]

Abstract: The increasing penetration of wind power poses new requirements in terms of ancillary services tosupport the stable operation of power system. Based on the flexible positive and negative sequencecontrol (FPNSC) method for current reference generation, this paper presents a model predictive control(MPC)-enabled fault ride through operation strategy for high power wind turbine complying with nextgenerationgrid code requirements. The proposed strategy calculates the current references consideringthe converter current constraint, and further exploits the dynamic response of MPC to optimize thevoltage support capability during balanced and unbalanced grid faults. Simulation results are given tovalidate the operation performance of the proposed fault ride through operation strategy.

   SOC governed algorithm for a EV Cascaded H-Bridge connected to a DC charger
By Giulia TRESCA [View]
[Download]

Abstract: Cascaded H- Bridge (CHB) converters have been considered valid candidates for replacing thetwo-level inverter in EV powertrain applications. This paper presents a State of Charge-governedalgorithm for charging Li-Ion battery modules within a Cascaded H-Bridge converter for EVpowertrain, connected to a DC charger. The novelty of this algorithm lies in the balanced andconcurrent charge of the battery modules installed in all submodules of the three-phases, with noextra middle stage converter needed. Simulation and experimental results are shown to prove thevalidity of the novel architecture and the experimental setup is described.

   Stability Assessment and Optimization of MMC Energy Balancing for Drive Applications at Standstill Using an Averaging Approach
By Qiuye GUI [View]
[Download]

Abstract: A new controller design framework for periodic systems is presented and applied to the Modular Multilevel Converter energy balancing. It provides a rigorous stability analysis for the state-of-art averaging control and the approach using constants as reference for the instantaneous energies. An optimized controller with improved performance is derived and verified by simulation and experiment.

   Systematic Adaptive Robust State Feedback Control for Active Front-End Rectifiers
By Aidar ZHETESSOV [View]
[Download]

Abstract: This paper presents the systematic use of physics-based frequency-domain techniques to design the adaptive and robust state-feedback controller for an AFE rectifiers. The proposed design approach ensures robustness and stability of the controller and the converter, independent of the size of the DC-link capacitance. This will enable the optimization of the power circuit from the perspective of efficiency, power density, cost, etc. with the widest possible design space. Furthermore, the control structure is operating-point adaptive, optimally robust and computationally efficient due to closed form controller representation. Detailed analytical development of the controller is presented in the paper along with a proof for robustness verified using simulations that support the theoretical findings.

EPE 2022 - DS2h: Standard and Advanced Current / Voltage / Synchronisation Control Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2022 ECCE Europe - Conference > EPE 2022 - Topic 04: Electrical Machines and Drive Systems > EPE 2022 - DS2h: Standard and Advanced Current / Voltage / Synchronisation Control Techniques
	[return to parent folder]

	A Direct Model Predictive Control Strategy of Back-to-Back Modular Multilevel Converters Using Arm Energy Estimation By Akseli HAKKILA	[View] [Download]
Abstract: This paper presents a model predictive control (MPC) algorithm for modular multilevel converters (MMCs). To meet the control objectives of phase current reference tracking and circulating current minimization, the proposed control scheme calculates the optimal number of submodules (SMs) to be inserted in each arm. In doing so, favorable steady-state and dynamic performance is achieved. Moreover, by estimating---instead of measuring---the arm energies in the predictive stage of the control loop, the proposed control scheme results in self-stabilizing open-loop arm energy balancing, while avoiding potential stability issues. Furthermore, to reduce the computational complexity of the MPC algorithm, the optimization problem is simplified by controlling each phase separately and assuming that the SM capacitors are balanced within an arm. To ensure that this assumption is always satisfied, a subsequent capacitor voltage balancing algorithm is designed to select the individual SMs that are switched on and off. The performance of the proposed control strategy is validated with simulations for a high voltage dc system (HVDC) that consists of two MMCs with 20 SMs per arm in a back-to-back configuration.

	A fast control for a three-switch multi-input DC-DC converter By Simone COSSO	[View] [Download]
Abstract: In this paper, a double-input bidirectional DC-DC converter is taken into account. The converter allows to use less switches than a traditional solution and, moreover, it guarantees a higher efficiency. The modulation strategy proposed in the technical literature allows the converter to work in Discontinuous Conduction Mode at low-load and, therefore, to increase the efficiency in comparison to the CCM. However, such a control reduces the dynamics of the converter. To improve the transient response, a Feed-Forward approach is proposed in this paper. Since the converter model in DCM is complex and highly nonlinear, a simplified model is considered. The effectiveness of the proposed approach is proved with experimental results on a converter prototype.

	A Strategy for Smooth Microgrid Transitions without Phase Misalignment and Voltage mismatch By Gabriel SILVA ROCHA	[View] [Download]
Abstract: In this work, it is proposed a modified control structure to provide smooth transitions of control modesof Grid-forming Converter without phase misalignment and voltage mismatch. A background of thetraditional structure is provided and a carefully description of the method is introduced. At the results,a comparison with methods in literature is carried out and it possible to prove that with the correct phase and voltage compensations, one can almost eliminate the transients in the grid voltage due to theswitching of control modes of the Grid-forming Converter and transition of the MG operating mode.

	A Theoretical Comparison of Different Virtual Synchronous Generator Implementations on Inverters By Patrick KÖRNER	[View] [Download]
Abstract: The goal to overcome the global climate crisis leads to a rising demand for the usage of Renewable Energy Sources (RES). Decentralized control strategies are needed to allow the integration of RES into the grid. The Virtual Synchronous Generator (VSG) is proposed as a method to add virtual inertia to the grid by emulating the rotating mass of a Synchronous Generator (SG) on the control algorithm of an inverter. This paper presents the VSG control structure as well as the mathematical description in a unified form. Due to the fact that classical droop control can be seen as a special form of the VSG, their correlation is highlighted by evaluating the steady state output characteristics of the inverter. Furthermore, a theoretical comparison between different VSG topologies, including the VISMA-Method 2 and the synchronverter, is given. In order to achieve better voltage stability, principles to add virtual impedance to the inverter's output are described.

	Ageing Mitigation and Loss Control in Reconfigurable Batteries in Series-Level Setups By Tomas KACETL	[View] [Download]
Abstract: This paper presents a novel control method that reduces the low-frequency ripple of dynamically reconfigurable battery technology to reduce cell ageing and loss. It furthermore shifts the residual ripple to higher frequencies where the lower impedance reduces heating and the dielectric capaci-tance of electrodes and electrolyte shunt the current around the electrochemical reactions.

	An Improved Multi-loop Resonant and plug-in Repetitive Control Schemes for Three-Phase Stand-Alone PWM Inverter Supplying Non-Linear Loads By Ahmad Ali NAZERI	[View] [Download]
Abstract: This paper proposes an improved multi-loop control scheme for a three-phase voltage source inverter (VSI) for the island/microgrid operation. The constant voltage constant frequency (CVCF) pulse-width modulation (PWM) inverter can be used to regulate the output voltage with lower total harmonic distortion (THD). The output voltage is regulated under different load conditions, such as linear and rectifier loads for a CVCF for the uninterruptible power supply (UPS) inverter in stand-alone operation. An improved plug-in repetitive controller (RC) with the proportional-resonant (PR) control is used in the outer voltage loop to regulate the output AC voltage, and a simple proportional control is used in the inner current control loop for active damping and improving the transient performance. The instantaneous reference voltage of the converter is used as a feed-forward signal at the output of the converter to robust the system performance and simplify the controller design. This paper proposes a step-by-step design procedure of the voltage and current controllers, an analysis of the overall system stability from the frequency-response viewpoint, and the implementation of the PR with the improved plug-in RC for the three-phase stand-alone inverter supplying linear and non-linear loads. The improved plug-in RC combined with PR control offers high-quality sinusoidal output voltages, robustness to the parameter uncertainties, fast response, and the need for fewer sensors. Moreover, the modified plug-in RC is effective and simple to be implemented on a digital signal processor (DSP). The three-phase VSI with the proposed multi-loop control is simulated in MATLAB/Simulink and experimentally implemented on a 7.5 kW system on TMDSDOCK28379D 32-bit floating-point DSP from Texas Instruments to validate the excellent steady-state, dynamic and transient performance of the proposed control scheme with better harmonic mitigation.

	An Optimized Compensation Strategy of Direct Matrix Converter-Fed PMSM Drives with Field Weakening under Unbalanced Supply Conditions By Jun XIE	[View] [Download]
Abstract: This paper presents an optimized compensation strategy for direct matrix converter (DMC) - fed permanent magnet synchronous motor (PMSM) drives with special consideration of the modification in field weakening control under unbalanced supply conditions. The imbalance of input voltage conditions in a three wire system are analysed and considered to be composed of positive and negative sequence components. To determine unbalance factor of the grid and decompose the positive and negative sequence components, the dual second order generalized integrator (DSOGI) and positive sequence calculator (PSC) algorithm are introduced. In order to achieve balanced output while optimizing the input current to be sinusoidal, the modulation index based on direct modulation method and the field weakening regulator are then adjusted according to unbalance factor of the input voltage conditions. The principle of the proposed compensation strategy is explained in detail. Simulation results are used to verify this proposed strategy. A low voltage laboratory platform consisting of DMC and servo motor is implemented and controlled using hybrid hardware concept based on field-programmable gate array (FPGA) and digital signal processor (DSP). Experimental studies on the laboratory prototype confirm the feasibility and effectiveness of the proposed method.

	Comprehensive Control of Matrix Converters in On-Board Electric Drive Applications By Mirzaeva GALINA	[View] [Download]
Abstract: Matrix Converters are an attractive alternative to the traditional AC/DC/AC converters, particularly, in electric transportation. Their advantages include low weight and volume, high reliability and efficiency. However, variable frequency and variable power operation, typical for electric vehicles, poses control challenges. This paper addresses these challenges and proposes a robust control solution for MatrixConverters with a number of novel features. The paper compares the proposed and the conventional control schemes for Matrix Converters, and shows improvement with respect to power factor control, input resonance suppression, reference tracking and harmonics performance. Findings of the paper are supported by simulations results.

	Constrained Long-Horizon Direct Model Predictive Control for Grid-Connected Converters with LCL Filters By Mattia ROSSI	[View] [Download]
Abstract: This paper presents a direct model predictive control algorithm for a three-level neutral point clampedconverter connected to the grid via an LCL filter. The proposed controller simultaneously controlsthe grid and converter currents as well as the filter capacitor voltage, while meeting the relevant gridstandards. Moreover, output constraints are included to ensure operation of the system within its safeoperating limits. This is achieved by formulating the direct MPC problem as a constrained integer least-squares optimization problem, wherein the output constraints are mapped into input constraints. Thepresented results verify the effectiveness of the proposed method.

	Control of a Zero-Voltage Switching Isolated Series-Resonant Power Circuitfor Direct 3-phase AC to DC Conversion By Yusuf KOSESOY	[View] [Download]
Abstract: A novel control method is presented for a fully zero-voltage switching series-resonant isolated 3-phaseAC to DC converter. The control is derived from first principles such as energy and charge conservation.The approach results in operation with a high power factor at the AC grid side and is beneficial in termsof EMI due to soft switching and low dv/dt across the switches even when extremely fast WBG devicessuch as SiC or GaN are used.

	DAB frequency decoupling control with current minimization By Simon UICICH	[View] [Download]
Abstract: This paper applies a new Dual-Active-Bridge (DAB) triple-phase-shift (TPS) model modulation tosimplify converter analysis, to simplify control and improve efficiency, and reduce transient currentstress in the power stage throughout a wide operating space. Achieved current stress is comparable tostate-of-the-art. The approach is validated through Simulink-Simscape.

	Design and Performance Analysis of a Modified Proportional Multi-Resonant (PMR) Controller for Three-Phase Voltage Source Inverters By Ahmad Ali NAZERI	[View] [Download]
Abstract: The three-phase voltage source inverter (VSI) can be operated in grid-connected and/or stand-alone mode where the VSI is connected to the grid and/or critical loads at the point of common coupling (PCC). Proper voltage control is needed for the output voltage regulation in stand-alone operation and current control is needed for the grid current control. This paper presents a step-by-step design procedure, an extensive system stability analysis, and methods of discretization for the current control of three-phase power converters in the synchronous (dq) and stationary reference frame (SRF). A proportional-integral multi-resonant (PI-MR) controller in the synchronous reference frame (SynRF) is implemented for the regulation of the inner current loop. Moreover, the inverter inductor current controller in a stationary frame is proposed to provide active damping, and improve transients, and steady-state performance. The traditional PI-MR controller is compared for different load conditions with the modified practical proportional multi-resonant (PMR) controller in parallel with the harmonic compensators of orders 5th, 7th, 11th, and 13th to reduce low-order load current harmonics. The PMR controller shows superior performance with lower total harmonic distortion (THD) than the conventional PI and PI-MR controllers for highly non-linear load conditions. Moreover, the modified PMR controller has almost zero steady-state error, improved tracking of the reference signal, and better disturbance rejection compared to the conventional PI-MR control. A comprehensive design guideline of the proposed controller with a wider range of system stability margin is analyzed with harmonic damping of the three-phase VSI. Proper discretization methods for each controller have been outlined. The system is simulated in MATLAB/Simulink environment and experimentally implemented on a TMS320F28335 floating-point digital signal processor (DSP) for a 7.5 kW inverter to validate the performance of the controllers.

	High Switching Frequency Operation of a Single-Phase Five-Level Hybrid Active Neutral Point Clamped Inverter with a Model Predictive Control Approach By Mohammad NAJJAR	[View] [Download]
Abstract: Wide bandgap (WBG) devices such as Silicon-Carbide (SiC) MOSFETs can be utilized to increase the switching frequency of power electronic converters. The size of passive components of an output filter can be reduced by increasing the switching frequency of converters or the number of output levels thorough the employment of multilevel topologies. Therefore, the combination of multilevel converters and WBG switches with a high switching frequency can improve the dynamic of converters. Meanwhile, a high bandwidth controller is also required to achieve a fast dynamic response of the system. In this paper, an advanced model predictive control (MPC) approach, based on the concept of hysteresis current control, is presented for a single-phase five-level hybrid active neutral point clamped (ANPC) inverter. A hybrid modulation technique with different switching frequencies is considered in this paper. As a result, different semiconductor technologies including SiC and Si are employed in the structure of the converter. Considering the AC and DC sides mathematical modeling of the converter, an MPC with the ability to control the neutral point (NP) voltage is designed. Finally, experimental results show that by utilizing the SiC MOSFETs and the proposed advanced MPC structure, the inverter's switching frequency is increased, with lower current ripple and fast dynamic performance.

	Model Predictive Control-enabled Fault Ride Through Operation Strategy for High Power Wind Turbine By Pedro CATALÁN	[View] [Download]
Abstract: The increasing penetration of wind power poses new requirements in terms of ancillary services tosupport the stable operation of power system. Based on the flexible positive and negative sequencecontrol (FPNSC) method for current reference generation, this paper presents a model predictive control(MPC)-enabled fault ride through operation strategy for high power wind turbine complying with nextgenerationgrid code requirements. The proposed strategy calculates the current references consideringthe converter current constraint, and further exploits the dynamic response of MPC to optimize thevoltage support capability during balanced and unbalanced grid faults. Simulation results are given tovalidate the operation performance of the proposed fault ride through operation strategy.

	SOC governed algorithm for a EV Cascaded H-Bridge connected to a DC charger By Giulia TRESCA	[View] [Download]
Abstract: Cascaded H- Bridge (CHB) converters have been considered valid candidates for replacing thetwo-level inverter in EV powertrain applications. This paper presents a State of Charge-governedalgorithm for charging Li-Ion battery modules within a Cascaded H-Bridge converter for EVpowertrain, connected to a DC charger. The novelty of this algorithm lies in the balanced andconcurrent charge of the battery modules installed in all submodules of the three-phases, with noextra middle stage converter needed. Simulation and experimental results are shown to prove thevalidity of the novel architecture and the experimental setup is described.

	Stability Assessment and Optimization of MMC Energy Balancing for Drive Applications at Standstill Using an Averaging Approach By Qiuye GUI	[View] [Download]
Abstract: A new controller design framework for periodic systems is presented and applied to the Modular Multilevel Converter energy balancing. It provides a rigorous stability analysis for the state-of-art averaging control and the approach using constants as reference for the instantaneous energies. An optimized controller with improved performance is derived and verified by simulation and experiment.

	Systematic Adaptive Robust State Feedback Control for Active Front-End Rectifiers By Aidar ZHETESSOV	[View] [Download]
Abstract: This paper presents the systematic use of physics-based frequency-domain techniques to design the adaptive and robust state-feedback controller for an AFE rectifiers. The proposed design approach ensures robustness and stability of the controller and the converter, independent of the size of the DC-link capacitance. This will enable the optimization of the power circuit from the perspective of efficiency, power density, cost, etc. with the widest possible design space. Furthermore, the control structure is operating-point adaptive, optimally robust and computationally efficient due to closed form controller representation. Detailed analytical development of the controller is presented in the paper along with a proof for robustness verified using simulations that support the theoretical findings.