基于改进调制积分观测器的相控断路器基波提取方法

Fundamental Extraction of Phase-controlled Circuit Breaker with Improved Modulated Integral Observer

相控断路器能有效减小电力系统无功补偿电容器组投切过程中的涌流和过电压,从而准确提取电网电压基波信号,是实施相控开关技术的前提。基于调制积分观测器的基波信号提取方法具有收敛快、误差小的优点,但电网电压频率变化会影响其精度。提出采用线性自抗扰控制的锁相环获取电网电压频率,再设计调制积分观测器,在电网电压波动、谐波与噪声干扰情况下,实现电网电压基波信号的准确提取,并通过系统仿真进行了验证。

The phase-controlled circuit breaker can effectively reduce the transient inrush current and over-voltage generated during switching of the reactive power compensation capacitor bank of the power system.One of the key technologies for phase-controlled switching control is the fundamental voltage extraction of grid voltage.The modulation integral observer has the advantage of fast convergence and small error,however,the frequency of power grid affects the fundamental wave voltage extraction accuracy.A phase-locked loop with linear adaptive disturbance rejection control was proposed to obtain the grid voltage frequency,and then a modulation integration observer was designed to accurately extract the fundamental voltage signal of the grid voltage in the presence of grid voltage fluctuations,harmonics and noise interference.The system was verified by simulation.