Impedance-Emulating Control Strategy for Series-Compensated Three-Phase Grid-Connected Inverters

doi:10.3969/j.issn.1008- 0198.2023.05.005

Abstract

Abstract: To increase the long-distance power transmission capacity of renewable energy power stations, series compensation is a common solution. However, oscillation problems are introduced by the interaction between grid-connected inverter and series-compensated power lines, threatening the safe operation of the power system. To address this challenge, an extended impedance-emulating control strategy without the phase-locked loop is proposed,and the proposed method can stabilize the system in weak grids and high series compensation level grids. Besides, the effectiveness of the method is verified by stability analysis. Eigenvalues analysis is performed to guide parameter design. Finally, theoretical analysis and proposed control strategy are validated with simulation and experimental results.

Key words: series-compensated power grid, three-phase grid-connected inverters, sub-synchronous oscillation, impedance-emulating control

CLC Number:

TM46

DENG Zini, SU Mei,SUN Yao, LIN Jianheng. Impedance-Emulating Control Strategy for Series-Compensated Three-Phase Grid-Connected Inverters[J]. Hunan Electric Power, 2023, 43(5): 31-37.

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