关键词: 光伏发电系统, 锁相环, 相位, 频率

Abstract:

The phase-locked loop is an important part of photovoltaic power generation system and network.The main role of the phase locked loop is to maintain a fixed phase difference value of the input and output voltages when the frequency of the input and output signals are equal,i.e.,the phase of the input and output voltage is locked.This paper introduces the working process of the three parts of a phase-locked loop.The combined phase-locked chip CD4046 achieves the collection of voltage signal frequency and the phase data locking,and through the lock,and the loss of lock signal input inverter.When there is a serious deviation of the phase,frequency and amplitude of the inverter output voltage from the normal grid value in the photovoltaic power generation system,an alarm is sent for the grid separation by isolating the switch.