EPE Association: EPE 2020 - DS2i-1: Standard and Advanced current/voltage/synchronisation control techniques-1

EPE 2020 - DS2i-1: Standard and Advanced current/voltage/synchronisation control techniques-1
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 - DS2i-1: Standard and Advanced current/voltage/synchronisation control techniques-1

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   DC Capacitor Voltage Feedback Method for a Peak Voltage Suppression Control with Multiple Leg-Short-Circuits Using SiC-MOSFETs Employed in Power Converters
By Tomoyuki MANNEN [View]
[Download]

Abstract: This paper proposes control method for initial charge of grid connection converters using leg shortcircuits with a dc capacitor voltage feedback. The proposed method makes short-circuits of a fixed time duration based on the dc capacitor voltage. In the experiments, the proposed method exhibits smaller energy consumption in each short-circuits than the control using an adjusted timing and duration. As a result, the proposed method can increase the number of short-circuits without complexity and extend the lifetime of power converters employing the initial charge method.

   Family of Splitting Current Single-Loop Control for LCL-Type Grid-Connected Inverter
By Yuying HE [View]
[Download]

Abstract: The single-loop weighted average current (WAC) control is attractive for the LCL-type grid-connected inverter owing to its inherent active damping. High robustness can be naturally harvested without any additional damping methods, but it requires two current sensors. Depending on the different weight values, a family of the splitting current single-loop control schemes with the associated filter configurations is developed in this paper, where only one current sensor is needed. As a result, high robustness, high-quality grid current and cost-efficiency can be concurrently achieved. Finally, experimental results from a 6-kW setup confirm the effectiveness and practicality of the splitting current single-loop control.

   Passivity-Based Design for the Plug-and-Play Single-Loop Controlled LCL-Filtered Inverter
By Yuying HE [View]
[Download]

Abstract: The grid impedance variation poses a challenge to the stability of LCL-filtered inverter. Critical stable ranges have been revealed for the single-loop inverter-current-feedback (ICF) and grid-current-feedback (GCF) controlled ones. However, they are all derived under the assumption that the grid impedance is inductive, whereas the presence of parasitic grid capacitances will lead to different results. In this paper, considering the capacitive condition and based on passivity concept, it is found that the stability is hardly secured for either the ICF or GCF controlled ones. From perspective of passivity, the phase of inverter output impedance would better be shaped between -90° and 90°. In view of this, the feedforward of the voltage of the point of common coupling (PCC) is applied in this paper to achieve this target, and the proper feedforward solutions are given. As a result, the inverter could harvest the robust plug-and-play functionality regardless of grid impedance. The correctness of the theoretical analysis and effectiveness of the proposed methods are verified by simulation results.

EPE 2020 - DS2i-1: Standard and Advanced current/voltage/synchronisation control techniques-1
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 - DS2i-1: Standard and Advanced current/voltage/synchronisation control techniques-1
	[return to parent folder]

	DC Capacitor Voltage Feedback Method for a Peak Voltage Suppression Control with Multiple Leg-Short-Circuits Using SiC-MOSFETs Employed in Power Converters By Tomoyuki MANNEN	[View] [Download]
Abstract: This paper proposes control method for initial charge of grid connection converters using leg shortcircuits with a dc capacitor voltage feedback. The proposed method makes short-circuits of a fixed time duration based on the dc capacitor voltage. In the experiments, the proposed method exhibits smaller energy consumption in each short-circuits than the control using an adjusted timing and duration. As a result, the proposed method can increase the number of short-circuits without complexity and extend the lifetime of power converters employing the initial charge method.

	Family of Splitting Current Single-Loop Control for LCL-Type Grid-Connected Inverter By Yuying HE	[View] [Download]
Abstract: The single-loop weighted average current (WAC) control is attractive for the LCL-type grid-connected inverter owing to its inherent active damping. High robustness can be naturally harvested without any additional damping methods, but it requires two current sensors. Depending on the different weight values, a family of the splitting current single-loop control schemes with the associated filter configurations is developed in this paper, where only one current sensor is needed. As a result, high robustness, high-quality grid current and cost-efficiency can be concurrently achieved. Finally, experimental results from a 6-kW setup confirm the effectiveness and practicality of the splitting current single-loop control.

	Passivity-Based Design for the Plug-and-Play Single-Loop Controlled LCL-Filtered Inverter By Yuying HE	[View] [Download]
Abstract: The grid impedance variation poses a challenge to the stability of LCL-filtered inverter. Critical stable ranges have been revealed for the single-loop inverter-current-feedback (ICF) and grid-current-feedback (GCF) controlled ones. However, they are all derived under the assumption that the grid impedance is inductive, whereas the presence of parasitic grid capacitances will lead to different results. In this paper, considering the capacitive condition and based on passivity concept, it is found that the stability is hardly secured for either the ICF or GCF controlled ones. From perspective of passivity, the phase of inverter output impedance would better be shaped between -90° and 90°. In view of this, the feedforward of the voltage of the point of common coupling (PCC) is applied in this paper to achieve this target, and the proper feedforward solutions are given. As a result, the inverter could harvest the robust plug-and-play functionality regardless of grid impedance. The correctness of the theoretical analysis and effectiveness of the proposed methods are verified by simulation results.