配电网静止同步补偿器的无电流传感器电压控制策略

Voltage control strategy of distribution static synchronous compensator without current sensor

配电静止同步补偿器(D-STATCOM)通过与电网交换无功功率可以有效地改善电压质量。重点论述了D-STATCOM用于维持公共连接点电压恒定且平衡的控制策略。以瞬时功率理论为基础,分析了D-STATCOM系统中的功率交换关系,得到D-STATCOM输出电压正序分量和负序分量与相应输出电流的关系式。提出了D-STATC0M的无电流内环的电压控制策略,省去了电流传感器及相应的信号调理电路。与传统的电压外环/电流内环相比较,该控制策略具有结构简单、容易设计等优点。整个电压控制器采用了正序电压控制器和负序电压控制器相叠加的结构,仿真和实验结果表明,所提电压控制策略在实现公共连接点电压维持恒定的同时能实现三相电压的平衡。

D-STATCOM （Distribution-STATic synchronous COMpensator）improves voltage quality by exchanging reactive power with power grid. The control strategy of using D-STATCOM to maintain and balance the voltage of common connecting point is emphasized. The power exchange in D-STATCOM system is analyzed based on the instantaneous power theory and the relationship between the positive/negative sequence component of output voltage and the output current is derived. The voltage control strategy without inner current loop is presented, which does not need current transducer and corresponding conditioning circuit. Compared with the traditional way of outer voltage loop plus inner current loop, the proposed control strategy is of simple structure and easy design. The voltage controller consists of positive and negative se- quence voltage controllers. Simulative and experimental results show that the voltage of common connecting point is stable and balanced simultaneously.