基于模糊PI控制的双同步解耦坐标系三相不平衡锁相环设计

Design of Fuzzy PI Control Based Three-phase Unbalanced Phase-locked Loop in Decoupled Double Synchronous Coordinate System

针对传统锁相环在电网电压不平衡时对正序基波分量的幅值和相位不能快速实时检测等问题,提出了一种基于模糊PI控制的双同步解耦坐标系三相不平衡锁相环。该控制系统通过在线调整PI参数能更精确迅速地将电网电压正序基波分量分离,从而实现基波分量相位的快速实时检测。仿真结果表明,与传统单同步和双同步锁相环相比,基于模糊PI控制的双同步解耦坐标系锁相环在电网电压不平衡和发生畸变时能更准确、迅速地检测正序基波分量的幅值和相位。

Aiming at the problem that the amplitude and phase of positive sequence fundamental component(PSFC)cannot be detected quickly and in real-time in traditional phase-locked loop(PLL)when grid voltage is unbalanced,a fuzzy PI control based three-phase unbalanced PLL in decoupled double synchronous coordinate(DDSC)system is proposed.The control system can separate the PSFC of power grid voltage more accurately and promptly via online adjustment for PI parameters so as to realize real-time detection of the fundamental component phase.Simulation results show that the fuzzy PI control based DDSC PLL can detect the amplitude and phase of the PSFC more accurately and quickly than traditional single and double synchronous PLLs when grid voltage is unbalanced and distorted.