基于光伏并网低电压穿越的改进锁相环设计

基于光伏并网逆变系统对低电压穿越(LVRT)技术的严格要求,针对当电网发生不对称电压跌落时锁相环(PLL)可能出现锁相失败的情况,利用一种充当PLL前置滤波的二阶广义积分(SOGI)相序分离法对PLL进行改进,使改进后的PLL能够应对多种形式的电网电压跌落故障。最后,在Matlab中创建了仿真模型,从得到的理想波形可以证实此改进方法的可行性。

Improved Phase-Locked Loop Design Based on Photovoltaic Grid Low Voltage Ride Through

The photovoltaic grid inverter system has strict requirements for low voltage ride through （LVRT） technology. Based on it when the grid voltage dips asymmetricly phase-locked loop （PLL） may be locked failure, this paper uses a pre-fihering of the second-order PLL as the second-order generalized integral （SOGI） phase sequence separation method to improve PLL improvements. The improved PLL can cope with various forms of grid voltage drop failure. Finally, the Matlab simulation model was established and the simulation waveform is ideal, which proves the feasibility of this design in theory.