Research On Intelligent Control Technology Of Three-phase PV Inverter

The three-phase PV inverter is divided into two stages in this paper:the start-up stage and the running stage. An intelligent control strategy for different stages according to different operating characteristics is given. The main contents of the paper are as follows:1. A modified fuzzy PID control strategy is given. According to the characteristics of start-up stage, a modified fuzzy PID controller parameter setting principle is designed, which adds the completion of the ramp function to fuzzy inference engine with the error and error rate. Simulation results show that the method can improve the dynamic and steady-state performances of the start-up stage and reduce the adjusting time and the overshoot volume.2. Voltage differential feedback control system based on repetitive control is proposed for the running stage. Simulation results show that the method can improve the dynamic characteristic and steady state performance by capacitor voltage as outer loop while its differential as inner loop without current sensor.3. Three-phase PV inverter hardware and software are achieved. Modified fuzzy PID control algorithm and voltage differential feedback control system based on repetitive control algorithm are achieved. Four different experiments have been applied in three-phase PV inverter platform. Simulation and experiment results verifie the feasibility and effectiveness of the proposed method.