EPE Association: EPE 2022 - DS2e: Converter Modelling and Low-level Control, including Gate-Drives

EPE 2022 - DS2e: Converter Modelling and Low-level Control, including Gate-Drives
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2022 ECCE Europe - Conference > EPE 2022 - Topic 03: Measurement and Control > EPE 2022 - DS2e: Converter Modelling and Low-level Control, including Gate-Drives

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   A Simulation Model for SiC MOSFET Switching Transients Controlled by an Adaptive Gate Driver with the Capability of Reducing Switching Losses and EMI across the Full Operating Range
By Zheming LI [View]
[Download]

Abstract: In this paper, the performance of an intelligent-gate-driver-based self-regulating gate control approach, which can reduce switching losses and EMI at SiC MOSFET turn-off and turn-on, is investigated by simulation and verified by measurements. Firstly, a MOSFET behavior model is presented and confirmed with double pulse measurement results of this approach. Based on this model, the performance of this approach in continuous operation is evaluated and compared with measurement in continuous operation. It is verified that there is a good match between measurement and simulation. The trade-off between switching losses and EMI is improved sig-nificantly by the proposed gate control approach compared to simple gate control with a single gate resistance.

   Control of an Active Gate Driver for an Electric Vehicle Traction Inverter Using Artificial Neural Networks
By Julius WIESEMANN [View]
[Download]

Abstract: Electric vehicle drivetrains using wide-bandgap semiconductors face challenges regarding EMI and accelerated machine aging due to the fast switching transients. This paper presents a method of controlling a variable-resistance active gate driver with the help of a neural network in order to reduce the drawbacks of fast switching while increasing efficiency. Measurements covering the whole MOSFET operating range and a sinusoidal inverter output current prove that the proposed method effectively reduces losses while also reducing switching speed and, in this way, reduces EMI issues and machine damage.

   DC-Bus Control Considerations of Asymmetrical Multilevel Inverters with Embedded Buck-Boost Converter
By Theodoros MOUSELINOS [View]
[Download]

Abstract: This paper focuses on the DC-bus control of asymmetrical Multilevel inverter family featuring a Buck-Boost converter to boost the input voltage. To investigate the dynamic performance of the system a thorough analysis is presented on the DC-bus dynamic behavior. It is shown that with higher system bandwidth the input capacitance requirements and the peak current through the boosting inductor are increased, compromising the power density and the efficiency of the whole DC/AC converter. To improve the transient performance of the system without increasing the volume of the passive components, a control scheme with a feedforward current estimator term is proposed. Finally, the correctness of the theoretical analysis is validated via experimental probing on a laboratory prototype.

   Dynamic Control of the Switching Behavior of SiC MOSFETs in Converter Operation
By Jochen HENN [View]
[Download]

Abstract: This paper presents a control approach to regulate voltage slope and oscillation amplitude in a silicon carbide inverter during operation. Based on sensor measurements, the control adapts the switching characteristics using an adaptive gate driver and thus adjusts the level of voltage slopes, oscillation amplitude and consequently, electromagnetic emissions to a target level.

   Hardware-in-the-loop control of a modular induction motor drive in power electronics education
By Jens Peter KAERST [View]
[Download]

Abstract: The development and the utilisation of a modular inverter for control of an induction or synchronous motor in a power electronics and electrical drives laboratory allows students to gain deep understanding. For easy deployment of own code and verification of analytical calculations a hardware-in-the-loop controller is used.A modular laboratory hardware presented in previous work allows students to explore a variety of DC/DC-converter topologies. The most complex setup possible was an H-bridge designed for components with 200 V breakdown voltage at most. In order to extend this teaching concept to three-phase drives, a topology consisting of three inverter legs including an auxiliary voltage supply was developed extending the maximal component voltage to 600 V while retaining the modular structure. While a Arduino Nano was sufficient for the control of DC/DC-converters, its performance is by far insufficient for e.g. space vector modulation as used in field-oriented control. Since the PLECS simulation software from Plexim GmbH is used in the power electronics and drive technology lectures, it was straightforward to use it in combination with hardware-in-the-loop (HIL) control. Plexim offers the RTBox CE as an inexpensive entry-level HIL-System. In the context of this publication, a RTBox CE is connected directly to the modular inverter driving a three-phase motor via an interface board. In order to apply a variable load the three-phase motor is connected in a motor test bench to a DC motor via a speed/torque measuring shaft. Actual values of rotor speed and rotor angle are essential for field orientated control of the motor. Therefore the evaluation of the measuring shaft data is also performed by the RTBox.The set-up, its possibilities and limitations are presented as examples within the scope of this work.

   Impedance-based analysis of HVDC converter control for robust stability in AC power systems
By André SCHÖN [View]
[Download]

Abstract: Ensuring robust control stability to varying grid conditions is a key requirement when installing a newHVDC station to the AC grid. With its very accessible criteria for stability margins, the Nyquist theoremfor single input/single output systems is commonly used to determine the robustness of the control system of HVDC converter stations and tune it accordingly. However, three-phase AC system are not single input/single output systems and the validity as well as the underlying assumptions of this investigation has rarely been under scrutiny. In this paper, the commonly used impedance based approach to assess stability and robustness of HVDC converter stations is reviewed from a control theoretical point of view. Starting with a clarification on the properties of commonly used reference system transformations, the repercussions for robustness investigations in a multivariable control environment are discussed. Based on that, possible shortcuts to allow classical single input/single output investigations as well as limitations to that approach are derived and explained in detail on a generic control model.

   Investigation About Operation and Performance of Gate Drivers for Power Electronics Converters for Cryogenic Temperatures
By Mustafeez UL HASSAN [View]
[Download]

Abstract: Utilization of power electronics converters under cryogenic temperatures (CT) offers higher powerefficiency and volumetric density. This becomes possible due to reduced channel resistance andswitching energies for Si and GaN-based devices. Therefore, both quantities, constituting a figure ofmerit for power converters; offer lower conduction losses and increased switching speeds with thereduction in temperatures. This leads to increased power efficiency, and lower volume of the passivecomponents involved. Since reliable and efficient operation of a power electronics converter dependsupon the operational characteristics of switching devices; gate drivers play a critical role as they notonly decide, but also help optimize the operating conditions of such devices. To take full advantage ofCT, not only proper working but also the quality of switching performance of gate driving circuits isextremely important. This paper presents operation and performance of numerous commercially off-the-shelf (COTS) gate drivers under cryogenic operating conditions. Gate drivers (GD) selected for theanalysis are capable enough to drive high-speed wide band gap (WBG) devices. As part of theexperimentation process, whole GD board was designed while selecting all the auxiliary components tobe compatible with CT. The paper compares five different GDs and presents successful operation of twoof them at CT of 77 K.

   Method to analyze the influence of switching behavior in hard switching halfbridge topologies for traction application
By Dominik NEHMER [View]
[Download]

Abstract: The current harmonics feed back (interference current) of railway traction inverter towards the grid has to be limited. The goal of this paper is to present a method which allows to model harmonics caused by switching behavior and turn on delay. Since simulation is limited by numerical errors due to the step size of the numerical solvers and also takes much time, an analytical method is chosen.

   Modelling and Control of 50kW SiC DAB Converter for Off-Board Chargers of Battery Electric Buses
By Haaris RASOOL [View]
[Download]

Abstract: The paper proposes the design of a 50kW isolated DC-DC Dual Active Bridge (DAB) converter for a high-power off-board charger for Electric vehicles (EVs) applications. The detailed electro-thermal simulation of the wide band gap (WBG) (i.e., SiC MOSFETs)-based bidirectional DAB is performed to determine the performance of the system in terms of efficiency at high-power operation. A linear model based on system identification has been created to design the control approach accurately. Dual-loop phase shift constant-current (CC) and constant-voltage (CV) control strategy is implemented on the dynamic simulation model at a higher switching frequency to validate the stability of the designed controller. The proposed DAB operates with an acceptable ripple and dual-loop voltage-current control that comprehensively tracks reference commands, while the maximum efficiency achieved is approximately 97.5\% at rated power.

   Modular multilevel converter control with using a general space vector PWM method in medium voltage hydro power application
By Chengjun TANG [View]
[Download]

Abstract: This paper studies a generalized space vector PWM (SVPWM) method for modulating the modular multilevel converter (MMC) for a medium voltage hydropower application. In addition to the modulation of the MMC, the circulating current control and the submodule capacitor voltage balancing are included in the study. The simulation and experimental results show the feasibility of using the generalized SVPWM method for controlling the MMC. Furthermore, the loss study shows that the switching loss in the MMC can be reduced with 28\% when a modification of the generalized SVPWM method is utilized, thus, the total efficiency of the converter can be increased.

   Output Power Characteristics of Isolated Secondary-Resonant SAB DC-DC Converter for Output Voltage Variation
By Shota YAMASHITA [View]
[Download]

Abstract: The Secondary-Resonant Single Active Bridge (SR-SAB) converter is proposed as a high power, low-cost, compact, and high-efficiency DC-DC converter. The SR-SAB converter is composed of the H-bridge circuit, the high-frequency transformer, and the diode rectifier circuit with resonant capacitors connected in parallel. When primary H-bridge circuit switches, the resonant capacitors cause LC resonance. Due to LC resonance, the secondary diode rectifier circuit switching is delayed and the secondary voltage is lags behind the primary voltage like the DAB converter. While LC resonance occurs, large voltage is applied to leakage inductance and secondary current increase significantly. Therefore, the SR-SAB converter achieves high total power factor like DAB converter with simple SAB converter circuit. This paper presents the output power characteristics of the SR-SAB converter for the output voltage variation. The effectiveness of output power characteristics for output voltage variation of the SR-SAB converter is verified by experiments.

   Real-Time MRAC-Based Voltage Control Scheme for Multilevel Inverters Interfacing PV Applications
By Mohammad Sadegh ORFI YEGANEH [View]
[Download]

Abstract: Cascaded H-bridge multilevel inverters (CHB-MLIs) have a proper structure and significant advantages like filter-less topology due to their desired output voltage levels. They are suitable for employing isolated DC voltage sources that have been utilized in multi-sources applications such as photovoltaic (PV) power generation. However, unbalanced DC voltage sources of the DC/DC output section or fast voltage variations can decrease the output voltage quality and make some undesired fluctuations and harmonics, affecting the load behavior in different applications. To overcome these problems, a new real-time voltage control technique has been proposed to regulate the output voltage magnitude properly. This aim can be obtained by employing the model reference adaptive control (MRAC) technique for voltage regulation, to improve total harmonic distortion (THD), and to decrease some harmonic orders (HOs) magnitude, especially lower harmonics (3rd, 5th, and 7th). Therefore, the proposed solution is designed to stabilize the dynamic error originating from the DC side. At the same time, the DC sources are interfaced with variations, and they do not have equal magnitudes with each other. The effectiveness of the proposed control technique has been verified by simulation in MATLAB/Simulink.

   Systematic analysis of oscillations in DC-links of fast switching power electronics
By Tobias FRICKE [View]
[Download]

Abstract: Increasingly faster switching and higher switching frequencies amplify the impact of parasitics of theDC-link causing higher voltage overshoots, oscillations, losses and also EMI. Higher-frequency resonancesdue to polarization effects of dielectrica and oscillations between either different capacitors orcapacitors and switches (or even other components) due to a mismatch of pcb parasitics and componentimpedances are just some of the possible causes. This paper marks the beginning of a series of studieswith the aim of a set of design rules for DC-links of high switching frequency power electronics. Thereforecircuit simulations, impedance measurements (of capacitors and pcb's) and experiments using anevaluation platform are carried out. Some of the results are presented in this paper.

   Using System-on-Chip Boards for the Deployment of Controller for Verification and Prototyping
By Adeel JAMAL [View]
[Download]

Abstract: New control strategies for power converters are mainly tested using Hardware-in-the-Loop (HIL) based rapid control prototyping platforms in academia and industry research. In this paper, different strategies to use the system-on-chip is presented with the detailed workflow of hardware software co-design work flow utilizing Matlab's toolchain. The detailed approach to implement a controller that is cost-effective, offers more freedom for customization and will help decrease the product's time-to-market is presented. The introduced approach will be used to experimentally verify the performance of the exemplary PQ Controller designed for LC filter.

EPE 2022 - DS2e: Converter Modelling and Low-level Control, including Gate-Drives
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2022 ECCE Europe - Conference > EPE 2022 - Topic 03: Measurement and Control > EPE 2022 - DS2e: Converter Modelling and Low-level Control, including Gate-Drives
	[return to parent folder]

	A Simulation Model for SiC MOSFET Switching Transients Controlled by an Adaptive Gate Driver with the Capability of Reducing Switching Losses and EMI across the Full Operating Range By Zheming LI	[View] [Download]
Abstract: In this paper, the performance of an intelligent-gate-driver-based self-regulating gate control approach, which can reduce switching losses and EMI at SiC MOSFET turn-off and turn-on, is investigated by simulation and verified by measurements. Firstly, a MOSFET behavior model is presented and confirmed with double pulse measurement results of this approach. Based on this model, the performance of this approach in continuous operation is evaluated and compared with measurement in continuous operation. It is verified that there is a good match between measurement and simulation. The trade-off between switching losses and EMI is improved sig-nificantly by the proposed gate control approach compared to simple gate control with a single gate resistance.

	Control of an Active Gate Driver for an Electric Vehicle Traction Inverter Using Artificial Neural Networks By Julius WIESEMANN	[View] [Download]
Abstract: Electric vehicle drivetrains using wide-bandgap semiconductors face challenges regarding EMI and accelerated machine aging due to the fast switching transients. This paper presents a method of controlling a variable-resistance active gate driver with the help of a neural network in order to reduce the drawbacks of fast switching while increasing efficiency. Measurements covering the whole MOSFET operating range and a sinusoidal inverter output current prove that the proposed method effectively reduces losses while also reducing switching speed and, in this way, reduces EMI issues and machine damage.

	DC-Bus Control Considerations of Asymmetrical Multilevel Inverters with Embedded Buck-Boost Converter By Theodoros MOUSELINOS	[View] [Download]
Abstract: This paper focuses on the DC-bus control of asymmetrical Multilevel inverter family featuring a Buck-Boost converter to boost the input voltage. To investigate the dynamic performance of the system a thorough analysis is presented on the DC-bus dynamic behavior. It is shown that with higher system bandwidth the input capacitance requirements and the peak current through the boosting inductor are increased, compromising the power density and the efficiency of the whole DC/AC converter. To improve the transient performance of the system without increasing the volume of the passive components, a control scheme with a feedforward current estimator term is proposed. Finally, the correctness of the theoretical analysis is validated via experimental probing on a laboratory prototype.

	Dynamic Control of the Switching Behavior of SiC MOSFETs in Converter Operation By Jochen HENN	[View] [Download]
Abstract: This paper presents a control approach to regulate voltage slope and oscillation amplitude in a silicon carbide inverter during operation. Based on sensor measurements, the control adapts the switching characteristics using an adaptive gate driver and thus adjusts the level of voltage slopes, oscillation amplitude and consequently, electromagnetic emissions to a target level.

	Hardware-in-the-loop control of a modular induction motor drive in power electronics education By Jens Peter KAERST	[View] [Download]
Abstract: The development and the utilisation of a modular inverter for control of an induction or synchronous motor in a power electronics and electrical drives laboratory allows students to gain deep understanding. For easy deployment of own code and verification of analytical calculations a hardware-in-the-loop controller is used.A modular laboratory hardware presented in previous work allows students to explore a variety of DC/DC-converter topologies. The most complex setup possible was an H-bridge designed for components with 200 V breakdown voltage at most. In order to extend this teaching concept to three-phase drives, a topology consisting of three inverter legs including an auxiliary voltage supply was developed extending the maximal component voltage to 600 V while retaining the modular structure. While a Arduino Nano was sufficient for the control of DC/DC-converters, its performance is by far insufficient for e.g. space vector modulation as used in field-oriented control. Since the PLECS simulation software from Plexim GmbH is used in the power electronics and drive technology lectures, it was straightforward to use it in combination with hardware-in-the-loop (HIL) control. Plexim offers the RTBox CE as an inexpensive entry-level HIL-System. In the context of this publication, a RTBox CE is connected directly to the modular inverter driving a three-phase motor via an interface board. In order to apply a variable load the three-phase motor is connected in a motor test bench to a DC motor via a speed/torque measuring shaft. Actual values of rotor speed and rotor angle are essential for field orientated control of the motor. Therefore the evaluation of the measuring shaft data is also performed by the RTBox.The set-up, its possibilities and limitations are presented as examples within the scope of this work.

	Impedance-based analysis of HVDC converter control for robust stability in AC power systems By André SCHÖN	[View] [Download]
Abstract: Ensuring robust control stability to varying grid conditions is a key requirement when installing a newHVDC station to the AC grid. With its very accessible criteria for stability margins, the Nyquist theoremfor single input/single output systems is commonly used to determine the robustness of the control system of HVDC converter stations and tune it accordingly. However, three-phase AC system are not single input/single output systems and the validity as well as the underlying assumptions of this investigation has rarely been under scrutiny. In this paper, the commonly used impedance based approach to assess stability and robustness of HVDC converter stations is reviewed from a control theoretical point of view. Starting with a clarification on the properties of commonly used reference system transformations, the repercussions for robustness investigations in a multivariable control environment are discussed. Based on that, possible shortcuts to allow classical single input/single output investigations as well as limitations to that approach are derived and explained in detail on a generic control model.

	Investigation About Operation and Performance of Gate Drivers for Power Electronics Converters for Cryogenic Temperatures By Mustafeez UL HASSAN	[View] [Download]
Abstract: Utilization of power electronics converters under cryogenic temperatures (CT) offers higher powerefficiency and volumetric density. This becomes possible due to reduced channel resistance andswitching energies for Si and GaN-based devices. Therefore, both quantities, constituting a figure ofmerit for power converters; offer lower conduction losses and increased switching speeds with thereduction in temperatures. This leads to increased power efficiency, and lower volume of the passivecomponents involved. Since reliable and efficient operation of a power electronics converter dependsupon the operational characteristics of switching devices; gate drivers play a critical role as they notonly decide, but also help optimize the operating conditions of such devices. To take full advantage ofCT, not only proper working but also the quality of switching performance of gate driving circuits isextremely important. This paper presents operation and performance of numerous commercially off-the-shelf (COTS) gate drivers under cryogenic operating conditions. Gate drivers (GD) selected for theanalysis are capable enough to drive high-speed wide band gap (WBG) devices. As part of theexperimentation process, whole GD board was designed while selecting all the auxiliary components tobe compatible with CT. The paper compares five different GDs and presents successful operation of twoof them at CT of 77 K.

	Method to analyze the influence of switching behavior in hard switching halfbridge topologies for traction application By Dominik NEHMER	[View] [Download]
Abstract: The current harmonics feed back (interference current) of railway traction inverter towards the grid has to be limited. The goal of this paper is to present a method which allows to model harmonics caused by switching behavior and turn on delay. Since simulation is limited by numerical errors due to the step size of the numerical solvers and also takes much time, an analytical method is chosen.

	Modelling and Control of 50kW SiC DAB Converter for Off-Board Chargers of Battery Electric Buses By Haaris RASOOL	[View] [Download]
Abstract: The paper proposes the design of a 50kW isolated DC-DC Dual Active Bridge (DAB) converter for a high-power off-board charger for Electric vehicles (EVs) applications. The detailed electro-thermal simulation of the wide band gap (WBG) (i.e., SiC MOSFETs)-based bidirectional DAB is performed to determine the performance of the system in terms of efficiency at high-power operation. A linear model based on system identification has been created to design the control approach accurately. Dual-loop phase shift constant-current (CC) and constant-voltage (CV) control strategy is implemented on the dynamic simulation model at a higher switching frequency to validate the stability of the designed controller. The proposed DAB operates with an acceptable ripple and dual-loop voltage-current control that comprehensively tracks reference commands, while the maximum efficiency achieved is approximately 97.5\% at rated power.

	Modular multilevel converter control with using a general space vector PWM method in medium voltage hydro power application By Chengjun TANG	[View] [Download]
Abstract: This paper studies a generalized space vector PWM (SVPWM) method for modulating the modular multilevel converter (MMC) for a medium voltage hydropower application. In addition to the modulation of the MMC, the circulating current control and the submodule capacitor voltage balancing are included in the study. The simulation and experimental results show the feasibility of using the generalized SVPWM method for controlling the MMC. Furthermore, the loss study shows that the switching loss in the MMC can be reduced with 28\% when a modification of the generalized SVPWM method is utilized, thus, the total efficiency of the converter can be increased.

	Output Power Characteristics of Isolated Secondary-Resonant SAB DC-DC Converter for Output Voltage Variation By Shota YAMASHITA	[View] [Download]
Abstract: The Secondary-Resonant Single Active Bridge (SR-SAB) converter is proposed as a high power, low-cost, compact, and high-efficiency DC-DC converter. The SR-SAB converter is composed of the H-bridge circuit, the high-frequency transformer, and the diode rectifier circuit with resonant capacitors connected in parallel. When primary H-bridge circuit switches, the resonant capacitors cause LC resonance. Due to LC resonance, the secondary diode rectifier circuit switching is delayed and the secondary voltage is lags behind the primary voltage like the DAB converter. While LC resonance occurs, large voltage is applied to leakage inductance and secondary current increase significantly. Therefore, the SR-SAB converter achieves high total power factor like DAB converter with simple SAB converter circuit. This paper presents the output power characteristics of the SR-SAB converter for the output voltage variation. The effectiveness of output power characteristics for output voltage variation of the SR-SAB converter is verified by experiments.

	Real-Time MRAC-Based Voltage Control Scheme for Multilevel Inverters Interfacing PV Applications By Mohammad Sadegh ORFI YEGANEH	[View] [Download]
Abstract: Cascaded H-bridge multilevel inverters (CHB-MLIs) have a proper structure and significant advantages like filter-less topology due to their desired output voltage levels. They are suitable for employing isolated DC voltage sources that have been utilized in multi-sources applications such as photovoltaic (PV) power generation. However, unbalanced DC voltage sources of the DC/DC output section or fast voltage variations can decrease the output voltage quality and make some undesired fluctuations and harmonics, affecting the load behavior in different applications. To overcome these problems, a new real-time voltage control technique has been proposed to regulate the output voltage magnitude properly. This aim can be obtained by employing the model reference adaptive control (MRAC) technique for voltage regulation, to improve total harmonic distortion (THD), and to decrease some harmonic orders (HOs) magnitude, especially lower harmonics (3rd, 5th, and 7th). Therefore, the proposed solution is designed to stabilize the dynamic error originating from the DC side. At the same time, the DC sources are interfaced with variations, and they do not have equal magnitudes with each other. The effectiveness of the proposed control technique has been verified by simulation in MATLAB/Simulink.

	Systematic analysis of oscillations in DC-links of fast switching power electronics By Tobias FRICKE	[View] [Download]
Abstract: Increasingly faster switching and higher switching frequencies amplify the impact of parasitics of theDC-link causing higher voltage overshoots, oscillations, losses and also EMI. Higher-frequency resonancesdue to polarization effects of dielectrica and oscillations between either different capacitors orcapacitors and switches (or even other components) due to a mismatch of pcb parasitics and componentimpedances are just some of the possible causes. This paper marks the beginning of a series of studieswith the aim of a set of design rules for DC-links of high switching frequency power electronics. Thereforecircuit simulations, impedance measurements (of capacitors and pcb's) and experiments using anevaluation platform are carried out. Some of the results are presented in this paper.

	Using System-on-Chip Boards for the Deployment of Controller for Verification and Prototyping By Adeel JAMAL	[View] [Download]
Abstract: New control strategies for power converters are mainly tested using Hardware-in-the-Loop (HIL) based rapid control prototyping platforms in academia and industry research. In this paper, different strategies to use the system-on-chip is presented with the detailed workflow of hardware software co-design work flow utilizing Matlab's toolchain. The detailed approach to implement a controller that is cost-effective, offers more freedom for customization and will help decrease the product's time-to-market is presented. The introduced approach will be used to experimentally verify the performance of the exemplary PQ Controller designed for LC filter.