三相并网逆变器坐标基准选取

Selection of Coordinate Reference for Three-phase Grid-connected Inverter

通过逆变器接入电网的可再生能源发电系统中,锁相环(Phase-Locked Loop,PLL)是逆变器控制策略重要组成部分,它实现逆变器与电网同步。三相并网逆变器系统中一般采用基于dq坐标系的锁相环模型。以基于对称分量法、双同步坐标系解耦以及双二阶广义积分器的闭环锁相环为研究对象,阐述工作原理并应用Matlab2018b/Simulink搭建仿真模型,研究比较了电网电压异常状态下的锁相能力。仿真结果表明,基于二阶广义积分器的锁相环在电网电压各种异常情况下,均能实现快速精准锁相。

In the renewable energy power generation system connected to the grid through the inverter,the phase-locked loop is an important part of the inverter control strategy,which realizes the synchronization of the inverter and the grid.A phase-locked loop model based on the dq coordinate system is generally used in a three-phase grid-connected inverter system.This paper takes the closed-loop phase-locked loop based on symmetrical component method,double synchronous coordinate system decoupling and double second-order generalized integrator as the research object,explains the working principle and uses Matlab2018 b/Simulink to build a simulation model,and compares the grid voltage Phase lock capability under abnormal conditions.