Control Strategy for Parallel PWM Converters With Interleaved Discontinuous Space-Vector Modulation
Wen Chunxue1, 2, Li Jianlin1, Zhu Xiaoguang1, Xu Honghua1
1.Institute of Electrical Engineering Chinese Academic Sciences Beijing 100190 China 2.Graduate University of Chinese Academy of Sciences Beijing 100049 China
Abstract:Parallel PWM converter can significantly increase the capacity of the converter and improve the power quality of AC side, but the circulation which can lead to high switching loss and even damage the devices will easily exist in the direct parallel converters. In this paper, the circulation mathematical model of three-phase PWM rectifier parallel system is shown, and the circulation is a zero-axis circulating current with the DC offset. To address the circulation problem, a small signal model is established to analyze and determine the zero-sequence current loop, and the control strategy with interleaved discontinuous space-vector modulation (IDSVM) is used to eliminate and suppress the influences to entire system. Then the circulation can be described by dq axis components and inhibited through the power factor correction (PFC) circuit of the current loop. Finally, the effectiveness of control strategy is verified by the simulations and experiments in this paper.
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