DC Current Component Suppression and Parameters Design for Grid-connected Inverter

doi:10.11985/2021.03.007

Abstract

Abstract:

Transformerless grid-connected inverters have been widely used in distributed grid-connected due to their outstanding advantages such as high conversion efficiency, light weight, and low cost. But this also causes the inverter to inject DC current components into the grid. In order to eliminate this DC component, some scholars have proposed a “virtual capacitor” method, in which a capacitor is connected in series on the AC side of the inverter through a control algorithm without increasing the hardware circuit to isolate the DC current. However, the existing virtual capacitance method controller parameter selection does not consider the stability and dynamic performance of the grid-in current controller. Therefore, a PR+C (Proportional resonant controller and virtual capacitor) controller parameter optimization method is proposed, which aims to balance the DC component suppression speed and the grid-in current tracking effect. The evaluation index in the proposed method is simple and clear, which can provide guidance for the parameter tuning of the inverter controller.

Key words: Transformerless inverters, DC current injection, virtual capacitor, parameters optimization

CLC Number:

TM46

YU Bin, XIE Min, GAO Bo, SUN Hui, DING Jinjin, ZHANG Feng, WANG Peng, XIAO Huafeng. DC Current Component Suppression and Parameters Design for Grid-connected Inverter[J]. Journal of Electrical Engineering, 2021, 16(3): 47-53.

Figures/Tables 12

References 17

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