基于NPC三电平变换器的STATCOM研究

为实现对中点箝位式三电平静止同步无功补偿器(STATCOM)的有效控制,提出了一种结合空间电压矢量调制(SVPWM)和电流解耦控制的方法。该方法通过对有功无功电流的解耦控制可以实现对负载无功电流的精确快速跟踪;采用的SVPWM调制算法使计算简化,便于在数字系统上实现。基于实物实验台进行的实验结果表明,提出的控制方法可以对STATCOM进行有效控制,实现了对无功负载变化的大范围快速响应,控制系统具有良好的静动态特性。

Study of the Control of STATCOM Based on Neutral-Point Clamped Three-level Inverter

To achieve better control of STATCOM based on the Neutral Point Clamped (NPC) three-level inverter, working principles and characteristics of STATCOM are analyzed. A control method based on active-reactive current decoupling combined with space vector modulation (SVPWM) is proposed. In this method, current of active and reactive power are decoupled, achieving accurate and fast tracking of reactive current; The SVPWM modulation algorithm may lower the switching frequency, whitch is easy to be applied in a digital system. Experimental results shows that the proposed method can control the STATCOM effectively, the control system has good static and dynamic characteristics.