电流畸变时AC/DC双向功率变换器的控制策略

CONTROL STRATEGY OF AC/DC BIDIRE CTIONAL POWER CONVERTER WHEN CURRENT DISTORTION

在交直流混合微电网中,通过电力电子接口接入的可再生能源和非线性负载会使交流母线电流发生畸变。因此,要求AC/DC双向功率变换器不仅能可靠变换功率以保证交直流子网功率平衡,而且能抑制交流母线谐波电流。该文基于Fryze-Buchholz-Depenbrock(FBD)功率理论的谐波电流检测法,提出一种可以治理交流母线谐波电流的AC/DC双向功率变换器控制策略。该控制策略在实现交直流子网功率传输及母线电压稳定的基础上,还可以通过AC/DC双向功率变换器治理交流母线谐波电流,保证微电网具有良好的电能质量。最后通过仿真和实验验证了该控制策略的有效性。

In an AC-DC hybrid micro grid,the current of the AC bus is often distorted by the renewable energy generation and the nonlinear load connected through power electronic interface.Therefore,the AC/DC bidirectional power converter is required not only to reliably transmit the power to ensure the power balance between the AC and DC subnets,but also to suppress the AC bus harmonic current.Based on the harmonic current measurement method of Fryze-Buchholz-Depenbrock(FBD)power theory,this paper proposes a control strategy for AC/DC bidirectional power converter that can suppress the AC bus harmonic current.This control strategy suppresses AC bus harmonic current by controlling the AC/DC bidirectional power converter,and can also realize the power dispatch between the AC and DC subnets and maintain the buses voltage stability,thus ensuring good power quality of the micro grid.Finally,the effectiveness of the control strategy has been verified by simulations and experiments.