PWM型动态无功补偿技术的研究

提出了一种新型的可连续调节的PWM型动态无功补偿技术,以较小的逆变容量实现了系统的动态无功补偿。该补偿装置主要包括PWM调压电路和电容器组两部分。PWM调压电路输出侧与补偿电感串联后直接并入电网,通过检测计算出电网电流中所含的基波无功电流分量,利用PWM脉宽调制技术控制PWM调压电路的开关占空比,使补偿器输出相应的无功电流,从而动态连续补偿电网无功。该装置不仅实现动态无功补偿,而且补偿的过程中动态响应速度快,向系统注入的谐波含量小。

Research on Technique of PWM Dynamic Reactive Power Compensation

This paper presents a novel technique of dynamic reactive power compensation,which can adjust continuously,with a smaller inverter capacity. The compensation device mainly includes PWM voltage regulation circuit and capacitors. Output side of PWM voltage regulation circuit in series with compensation reactor is directly connected to grid, and the PWM pulse width modulation technology is adopted to control the switching duty cycle of the PWM voltage regulation circuit. By detecting and calculating fundamental reactive current component in grid current, the compensator generates correspondent reactive current, thus reactive power in grid can be dynamically and continuously improved.The device realizes the dynamic reactive power compensation, fast dynamic response in the compensation process and minimal harmonic content injected to the system.Key words: dynamical reactive power compensation; PWM voltage regulation circuit; capacitors; inverter capacity