EPE Association: EPE 2022 - LS5d: Control of Power Converters

EPE 2022 - LS5d: Control of Power Converters
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 - LS5d: Control of Power Converters

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   Comparison of redundancy requirements for Modular Multilevel Converter considering manufacturer reliability inputs and mission profile
By Diego VELAZCO [View]
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Abstract: During the design phase, target reliability values of components - including semi-conductors - allow the computation of converter level reliability and redundancy requirements. This work proposes a more accurate method based on manufacturer lifetime models and mission profile evaluation. The new method is applied on a Modular Multilevel Converter.

   Experimental Comparison of FPGA-Implemented Model Predictive Voltage Control to Cascaded Proportional Resonant Control for a Three-Phase Four-Wire Three-Level Grid-Forming Inverter of 250 kVA
By Jarren LANGE [View]
[Download]

Abstract: Modern microgrid systems require inverters capable of forming an acceptable grid voltage, during islanded operation, both supplying and absorbing power, through unbalanced load conditions and transients. In order to address this concern, the steady state and transient performance of two control methods are compared which are both capable to supply unbalanced three-phase loads. The first method is a cascaded proportional resonant (PR) control, which is a state-of-the-art controller for single-phase-capable voltage-source inverters but suffers from lower performance in transient conditions. The second method is a new field-programmable gate array (FPGA)-implemented finite control set model-based predictive control (FCS-MPC) which shows high performance for transients as well as black-start capability. Experimental results show the model-based predictive controller (MPC) to have better steady-state performance, with an average total-harmonic-distortion (THD) over the entire steady-state operation range of 1.4 \% vs. 2.2 \% for the PR controller, and a voltage regulation error of 0.71 \% for the MPC vs. 1.1 \% for the PR controller over the entire operating range. The MPC also shows advantages over the PR controller during transient response conditions, enabling settling times within 600 µs vs. 100 ms of the PR controller.

   Investigation and Mitigation of Common-mode Voltage in Four-level NPC Converters Modulated by Redundant Level Modulation
By Jun WANG [View]
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Abstract: Redundant level modulation (RLM) has emerged as a powerful modulation-based voltage balancing method for a range of multilevel converters. For four-level neutral point clamped (4L-NPC) topologies, utilizing redundant voltage levels is the mandatory solution in principle to enable the single-end 4L-NPC converters to keep a voltage balance under all operating conditions, without requiring auxiliary circuits. However, the side effects of RLM caused by the extra switching actions have not been fully studied, with the common-mode voltage in particular. Hence, this work investigates the worsened common-mode voltage problem induced by RLM through theoretical analysis and simulations, followed by a simple carrier-based mitigation method that is verified in experiments.

EPE 2022 - LS5d: Control of Power Converters
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 - LS5d: Control of Power Converters
	[return to parent folder]

	Comparison of redundancy requirements for Modular Multilevel Converter considering manufacturer reliability inputs and mission profile By Diego VELAZCO	[View] [Download]
Abstract: During the design phase, target reliability values of components - including semi-conductors - allow the computation of converter level reliability and redundancy requirements. This work proposes a more accurate method based on manufacturer lifetime models and mission profile evaluation. The new method is applied on a Modular Multilevel Converter.

	Experimental Comparison of FPGA-Implemented Model Predictive Voltage Control to Cascaded Proportional Resonant Control for a Three-Phase Four-Wire Three-Level Grid-Forming Inverter of 250 kVA By Jarren LANGE	[View] [Download]
Abstract: Modern microgrid systems require inverters capable of forming an acceptable grid voltage, during islanded operation, both supplying and absorbing power, through unbalanced load conditions and transients. In order to address this concern, the steady state and transient performance of two control methods are compared which are both capable to supply unbalanced three-phase loads. The first method is a cascaded proportional resonant (PR) control, which is a state-of-the-art controller for single-phase-capable voltage-source inverters but suffers from lower performance in transient conditions. The second method is a new field-programmable gate array (FPGA)-implemented finite control set model-based predictive control (FCS-MPC) which shows high performance for transients as well as black-start capability. Experimental results show the model-based predictive controller (MPC) to have better steady-state performance, with an average total-harmonic-distortion (THD) over the entire steady-state operation range of 1.4 \% vs. 2.2 \% for the PR controller, and a voltage regulation error of 0.71 \% for the MPC vs. 1.1 \% for the PR controller over the entire operating range. The MPC also shows advantages over the PR controller during transient response conditions, enabling settling times within 600 µs vs. 100 ms of the PR controller.

	Investigation and Mitigation of Common-mode Voltage in Four-level NPC Converters Modulated by Redundant Level Modulation By Jun WANG	[View] [Download]
Abstract: Redundant level modulation (RLM) has emerged as a powerful modulation-based voltage balancing method for a range of multilevel converters. For four-level neutral point clamped (4L-NPC) topologies, utilizing redundant voltage levels is the mandatory solution in principle to enable the single-end 4L-NPC converters to keep a voltage balance under all operating conditions, without requiring auxiliary circuits. However, the side effects of RLM caused by the extra switching actions have not been fully studied, with the common-mode voltage in particular. Hence, this work investigates the worsened common-mode voltage problem induced by RLM through theoretical analysis and simulations, followed by a simple carrier-based mitigation method that is verified in experiments.