T型三电平PCS电能质量辅助治理控制策略

T-type Three-level PCS Power Quality Auxiliary Treatment Control Strategy

储能变流器(PCS)是储能介质与电网或负荷的接口,主要承担储能介质与电网或负荷的能量交换。为提高PCS的利用率,解决非线性以及不平衡负荷对电网电能质量造成的不良影响,提出一种混合坐标系下基于比例积分(PI)+矢量PI(VPI)的电能质量辅助治理控制策略。在同步旋转坐标系下,通过PI控制器实现基频有功功率、无功功率的控制,而VPI控制器实现不平衡负荷下的负序电流补偿;在两相静止坐标系下,通过VPI控制器实现各次谐波及其不平衡分量的分频补偿。实验结果证明PCS的电能质量辅助治理控制策略可有效改善电网电能质量。

The power conversion system(PCS)is the interface between the energy storage medium and the grid or load,and it is mainly responsible for the energy exchange between the energy storage medium and the grid or load.In order to improve the utilization rate of PCS and solve the adverse effects of non-linear and unbalanced loads on the power quality of the power grid,a proportional integral(PI)+vector PI(VPI)-based power quality auxiliary treatment control strategy in a hybrid coordinate system is proposed.In the synchronous rotating coordinate system,the PI controller is used to control the fundamental frequency active power and reactive power,and the VPI controller is used to realize the negative sequence current compensation under unbalanced load.In the two-phase static coordinate system,the VPI controller is used realize the frequency division compensation of each harmonic and its unbalanced components.The experimental results prove that the PCS power quality auxiliary treatment control strategy can effectively improve the power quality of the grid.