EPE Association: EPE 2020 - DS2g: PWM and Control Techniques

EPE 2020 - DS2g: PWM and Control Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 03: Measurement and Control > EPE 2020 - DS2g: PWM and Control Techniques

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   Approximated sliding-mode control of parallel-connected grid inverters
By Albrecht GENSIOR [View]
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Abstract: An approximated sliding-mode controller for an inverter system consisting of parallel connected voltage source converters is presented. The model-based control design considers the whole inverter system and leads to a controller carrying out the control of the grid currents and circulating currents in separate tasks. Due to using hysteresis controllers for both of them, the scheme benefits from advantages of sliding-mode implementations such as fast response to reference changes and good suppression of disturbances. Thus, even sudden changes in the configuration caused by the loss of communication to one of the converters can be mitigated almost perfectly. Furthermore, it features a variable switching frequency avoiding unnecessary switching actions. Since it leads to an interleaved operation of the converters, it offers a lower harmonic content of the grid currents than a benchmark solution with individual hysteresis controllers for each converter with comparable losses. The results are verified experimentally.

   Decrease of power electronic switching losses using variable switching events
By Hannes RAMM [View]
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Abstract: The electric range of an electric vehicle depends amongst others on the efficiency of electric components. This paper focuses on the efficiency of the inverter in one-phase operation. A comparison of three different PWM patterns is presented concerning their efforts to minimize the switching losses of the inverter and reducing the distortion of produced phase current. For one-phase systems, we show that an appropriate switching strategy will decrease the switching losses by up to 33\%. Furthermore, this strategy is able to reduce the distortion factor of phase current, as a quantity of signal quality, by up to 18\%.

   FPGA Implementation of Modified Space Vector Modulation (SVM) for High-Frequency Hybrid Active Neutral-Point-Clamped (NPC) Power Factor Correction Rectifier
By Mohammad NAJJAR [View]
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Abstract: This paper presents a model-based implementation of modified space vector modulation (SVM) for a three-level three-phase active neutral-point clamped (ANPC) rectifier. To optimize and reduce the number of high frequency active switches, this paper uses a hybrid modulation technique in which only two switches out of 6 active switches are switching at high frequency and the rest are working at fundamental frequency (50 Hz). However, using space vector-based hybrid modulation for ANPC introduces several limitations on selecting the output vectors such as zero-vector that is generated by connecting all three phases to the positive DC rail. To deal with this issue, a modified hybrid SVM is utilized to adjust the voltages of the DC link. A prototype is made using Gallium-nitride (GaN) FETs and the modified SVM is implemented in a field programmable gate array (FPGA). To show that the modified SVM can control the DC link voltages, an experimental comparison is carried out between a carrier-based modulation and the modified SVM.

   Insight into the Peculiarities of Optimized Pulse Patterns for Permanent-Magnet Synchronous Machines
By Georgios DARIVIANAKIS [View]
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Abstract: We use the notion of dynamic phasors to analytically formulate the optimized pulse patterns (OPPs) problem for permanent-magnet synchronous machines affected by magnetic saliency. Comparing to OPPs computed by ignoring saliency, we observe that our approach brings considerable improvement in minimizing the current harmonic distortions.

   Online Trajectory Planning During Low-Voltage FRT of a Modular Multilevel Converter
By Hendrik FEHR [View]
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Abstract: Balancing the modular multilevel converter arm energies in case of a sudden grid voltage sag is achallenging open-loop control problem, because it requires the solution of a differential equation. Unlike existing numerical approaches, an analytical solution was obtained. Ride-through experiments are conducted on a low-voltage MMC test bench using a grid emulator. In contrast to feedback balancing alone, a faster return of the cell voltages into the region of stationary operation is achieved.

EPE 2020 - DS2g: PWM and Control Techniques
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 03: Measurement and Control > EPE 2020 - DS2g: PWM and Control Techniques
	[return to parent folder]

	Approximated sliding-mode control of parallel-connected grid inverters By Albrecht GENSIOR	[View] [Download]
Abstract: An approximated sliding-mode controller for an inverter system consisting of parallel connected voltage source converters is presented. The model-based control design considers the whole inverter system and leads to a controller carrying out the control of the grid currents and circulating currents in separate tasks. Due to using hysteresis controllers for both of them, the scheme benefits from advantages of sliding-mode implementations such as fast response to reference changes and good suppression of disturbances. Thus, even sudden changes in the configuration caused by the loss of communication to one of the converters can be mitigated almost perfectly. Furthermore, it features a variable switching frequency avoiding unnecessary switching actions. Since it leads to an interleaved operation of the converters, it offers a lower harmonic content of the grid currents than a benchmark solution with individual hysteresis controllers for each converter with comparable losses. The results are verified experimentally.

	Decrease of power electronic switching losses using variable switching events By Hannes RAMM	[View] [Download]
Abstract: The electric range of an electric vehicle depends amongst others on the efficiency of electric components. This paper focuses on the efficiency of the inverter in one-phase operation. A comparison of three different PWM patterns is presented concerning their efforts to minimize the switching losses of the inverter and reducing the distortion of produced phase current. For one-phase systems, we show that an appropriate switching strategy will decrease the switching losses by up to 33\%. Furthermore, this strategy is able to reduce the distortion factor of phase current, as a quantity of signal quality, by up to 18\%.

	FPGA Implementation of Modified Space Vector Modulation (SVM) for High-Frequency Hybrid Active Neutral-Point-Clamped (NPC) Power Factor Correction Rectifier By Mohammad NAJJAR	[View] [Download]
Abstract: This paper presents a model-based implementation of modified space vector modulation (SVM) for a three-level three-phase active neutral-point clamped (ANPC) rectifier. To optimize and reduce the number of high frequency active switches, this paper uses a hybrid modulation technique in which only two switches out of 6 active switches are switching at high frequency and the rest are working at fundamental frequency (50 Hz). However, using space vector-based hybrid modulation for ANPC introduces several limitations on selecting the output vectors such as zero-vector that is generated by connecting all three phases to the positive DC rail. To deal with this issue, a modified hybrid SVM is utilized to adjust the voltages of the DC link. A prototype is made using Gallium-nitride (GaN) FETs and the modified SVM is implemented in a field programmable gate array (FPGA). To show that the modified SVM can control the DC link voltages, an experimental comparison is carried out between a carrier-based modulation and the modified SVM.

	Insight into the Peculiarities of Optimized Pulse Patterns for Permanent-Magnet Synchronous Machines By Georgios DARIVIANAKIS	[View] [Download]
Abstract: We use the notion of dynamic phasors to analytically formulate the optimized pulse patterns (OPPs) problem for permanent-magnet synchronous machines affected by magnetic saliency. Comparing to OPPs computed by ignoring saliency, we observe that our approach brings considerable improvement in minimizing the current harmonic distortions.

	Online Trajectory Planning During Low-Voltage FRT of a Modular Multilevel Converter By Hendrik FEHR	[View] [Download]
Abstract: Balancing the modular multilevel converter arm energies in case of a sudden grid voltage sag is achallenging open-loop control problem, because it requires the solution of a differential equation. Unlike existing numerical approaches, an analytical solution was obtained. Ride-through experiments are conducted on a low-voltage MMC test bench using a grid emulator. In contrast to feedback balancing alone, a faster return of the cell voltages into the region of stationary operation is achieved.