Improved Predictive Control of Grid-Connected PV Inverter with LCL Filter

LCL filter has high insertion loss and is expected to replace LC filter in the grid-connected PV inverter. However, the inverter with LCL filter is hard to be control and instability is liable to be incurred. So it is necessary to research reliable control strategy for the inverter with LCL filter. This paper researched the problem in detail. Discrete state space model of the inverter with LCL filter was firstly obtained with Clarke transformation and ZOH method. Then, improved predictive control strategy was proposed and explained in detail. Simulation was carried on and the results verified control effect of the proposed control strategy. Compared with prior control strategies, the proposed control strategy has the merits of simplicity, fast response and robustness.