基于改进的同步旋转参考坐标变换的静止无功补偿装置

静止无功补偿器(SVC)用于负荷补偿时,补偿导纳的计算对其补偿性能有着重要的影响。笔者提出了一种基于改进的同步旋转参考坐标变换的补偿电纳计算方法。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,由其形成的合成矢量作为同步旋转坐标系中的d轴,将负载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正序电流和负序电流,由此可以准确计算所需的补偿电纳。该方法计算简单,基于该法的静止无功补偿器不需要硬件锁相环,能够快速、准确地补偿负荷的无功功率,维持电网电压的稳定。仿真和实验结果证明了所提补偿电纳计算方法的可行性和有效性。

An Improved Susceptance Calculation Method for Static Var Compensator

The susceptance calculation of compensation has important influence on the compensation performance of static var compensator when it is used for load compensation.A new susceptance calculation method of SVC based on synchronous symmetrical component is proposed in this paper.A single-phase voltage is derived and used to form the 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.Then the load current is projected on the voltage vector.The components of positive and negative sequence load current,which is feed into low pass filter,are obtained,and the compensation susceptance is therefore calculated accurately.This method is simple in calculation,and the SVC based on the method without phase locked loop(PLL) of hardware can compensate reactive power accurately and keep voltage stable quickly.The feasibility and effectiveness of the susceptance calculation method is verified by simulation and experimental results.