配电静止同步补偿器的补偿电流检测方法

配电静止同步补偿器(distribution static synchronous compensator，DSTATCOM)用于负荷补偿时，补偿电流指令信号的检测环节对其补偿性能有着重要的影响。该文提出了一种基于同步旋转坐标变换的谐波、无功和负序电流综合检测方法。该方法利用电网电压中的一相电压构造虚拟的对称三相系统，然后以对称三相电压形成的合成矢量作为同步旋转坐标系中的 轴，将负荷电流矢量投影到电网电压矢量上，通过低通滤波器后便可得到要检测的补偿电流指令信号。与传统的同步旋转坐标变换法相比较，该方法计算简单，且在电网电压不对称条件下，仍能很好地检测出负荷电流中的谐波、无功和负序分量，满足DSTATCOM负荷补偿的要求。同时还根据功率平衡准则对文中所提检测方法的原理进行了简单的分析。理论分析和仿真结果证明了该文所提检测方法的正确性和有效性。

Detection Method of Compensation Current for DSTATCOM

The detection of compensator current has important influence on the compensation performance of DSTATCOM when it is used for load compensation. A detection method based on synchronous reference frame is proposed. A single-phase voltage is derived and used to form virtual symmetrical three-phase system. The axis of the synchronous reference frame is always synchronous with the voltage vector in virtual symmetrical three-phase system. The load current is projected on voltage vector. The component of axis of the load current, which synchronous with the voltage vector is feed into low pass filter and the compensation current is derived. Compared with traditionally detection method based on synchronous transformation the detection method proposed in this paper need simple calculation and can detect compensation current accurately under unbalance voltage conditions. The principle of the detection method is interpreted by power balance theory. The feasibility and effectiveness of the detection method is verified by theoretic analysis and simulation results.