基于非线性PI控制器的三相锁相环实现

Implementation of Nonlinear PI Controller Based on Three Phase Phase-locked Loop System

三相锁相环作为电力系统中相位跟踪的一个重要元件,为提高常规PI控制方式锁相环的相位跟踪精度及速度,提出了一种可变增益非线性PI控制方式的三相锁相环实现方法。分析了非线性PI控制方式的三相锁相环工作原理和非线性控制器的设计方法。基于Matlab/Simulink的仿真结果显示,在对称三相、不对称三相和对称三相频率突变时,非线性PI控制器的比例增益及积分增益能够按照偏差信号的变化进行自动调整,比常规PI控制方式的锁相环跟踪速度更快、跟踪精度更高,能够很好地满足有源电力滤波器对谐波检测的高精度和实时性的要求。

Three-phase phase-locked loop is an important element in power system phase tracking. In order to improve the phase tracking precision and speed of the conventional PI control method of PLL, a novel control method of nonlinear PI controller based three phase PLL system was proposed.The working principle of the nonlinear PI control method of three-phase phase-locked loop and design method of nonlinear controller was analyzed. The results of Matlab/ Simulink simulation show that in symmetrical and asymmetric three-phase and symmetric three-phase frequency mutation system, the proportional gain and integral gain of the nonlinear PI controller can adapt variety of the phase error.It is faster than conventional PI control method of phase-locked loop tracking speed and has higher tracking precision.It can well satisfy the real time and high precision of active power filter for harmonic detection requirements.