光伏并网系统中逆变器平滑切换控制策略研究

Research on Inverter Smooth Switching Control Strategy in Photovoltaic Grid-connected System

由于光伏电站中经常出现光伏离网和并网不稳定的情况,针对光伏逆变器并网和与脱网时的控制方式进行研究。提出利用综合式控制策略(PQ控制和下垂控制)进行并网和脱网时的进行控制,并针对不同的控制策略使用不饿的滤波方式,以便达到并网和脱网之间的平滑切换。首先,建立逆变器的模型,然后分别进行下垂控制和PQ控制以及运行状态切换的仿真。仿真结果证明,在不同的时刻切换到合适的控制策略,可以实现逆变器的平滑切换。

This paper studied the grid-connected PV inverters and their control methods when they are off-grid and proposed the use of an integrated control strategy(PQ control and droop control)to perform control during grid connection and disconnection in order to achieve smooth switching between grid connection and off-network.First,the model of the inverter was established,and then droop control,PQ control,and running state switching simulation were performed.The simulation results show that switching to the appropriate control strategy at different times can a-chieve smooth switching of the inverter.