基于瞬时对称分量法的三相四线制D-STATCOM控制研究

配电网中三相负载不对称,会导致三相电流电压不对称。基于瞬时对称分量法对三相电压和电流量进行分解,提出了一种新的正序、负序和零序电流直接控制方法,应用于三相四线制配电网并联型D-STATCOM(配电网静止同步无功发生器)。正序电流控制使D-STATCOM发出电网中需要补偿的无功电流和谐波电流;负序、零序电流由abc坐标系转换到dq0同步旋转坐标系与期望值0做差进行控制,用以补偿三相负荷不平衡。仿真结果表明,所提出的控制方法可以使D-STATCOM有效补偿配电网三相负荷不平衡,提高配电网功率因数,同时消除非线性负荷引起的电流畸变。

Study on Three-Phase Four-Wire Wiring D-STATCOM Control Mode Based on Instantaneous Symmetrical Components Method

The difference of three-phase load leads to the three-phase voltage and current unbalance. A new positive sequence, negative sequence and zero sequence direct current control method based on the instantaneous symmetrical components based decompositions of voltage and current has been proposed. It is mainly applied to the three-phase four-wire system that paralleled D-STATCOM in the distribution network, making the three-phase current symmetry at grid side. The positive sequence current control is used to control the three-phase positive sequence current which gird is required that the D-STATCOM generates. Negative sequence and zero sequence current are transformed from the ABC coordinate system to the DQ0 synchronous rotating coordinate system and subtract with the expected value 0 to maintain the three-phase current balance. The simulation results show that the proposed control strategy can make the line side three-phase current balance with unbalance load and eliminating harmonic distortion of current with D-STATCOM.