Simulation analysis of a gridconnected PV system based on current decoupled controlling

ZHANG Qiqi, XV Zheng
(College of Electrical Engineering, Zhejiang University, Hangzhou 310027,China)

Abstract: Gridconnected photovoltaic(PV) system is considered as an important part of the solar energy. Aiming at gridconnected inverters structure and control strategy of PV systems, a singlestage threephase gridconnected PV system with double closedloop controlling was established in PSCAD/EMTDC. According to the theory of the feedback linearization of nonlinear system, a current decoupled controller based on inputoutput variable feedback linearization was designed as current inner loop, PI controllers were used in the outside loop. The simulation results verify that the control strategy has high control accuracy, great stability domain. Meanwhile, the gridconnected PV systems can regulate reactive power in certain range to improve the stability of distribution network.
Key words: photovoltaic(PV) system; gridconnected inverter; current decoupled controlling; PSCAD/EMTDC; reactive power regulation