Application of Beat Control with Plug-in Repetitive Controller in Grid-connected Inverter

Photovoltaic grid-connected inverter controlled by deadbeat control has such problems as current predict complexity and control delay, and the beat control and decreased control gain are applied to solve these two problems respectively, but the phase of output current will lag behind that of the reference current. In order to solve the problem of phase lag, a beat control strategy with plug-in repetitive controller is presented in this paper, and the design process of the repetitive controller is also given. According to this strategy, the phase lag is taken as a kind of periodic disturbance, the plug-in repetitive controller is used to restrain such periodic disturbance as phase lag and network voltage harmonic by repetitive control, which combines both advantages of deadbeat control and repetitive control. Simulation results verify the feasibility and validity of the proposed strategy.