Control Method of Two-Stage Grid-Connected PV Inverter System
摘要
A two-stage, grid-connected PV inverter, and its control method are proposed in this paper. By controlling the DC link voltage at the front stage and the PWM of the inverter circuit at backstage, an LCL-type PV three-phase grid-tied inverter system is established. The paper analyzes the inverter output by this control system and compares it with the PV output power on the DC link voltage and current for maximum power tracking. The results indicate the proposed method has an excellent performance from the PV modules, the output power is always very stable, and the total harmonic distortion is very small. The current and voltage generated at the output end of the inverter have fast dynamic response, smooth waveform and strong stability.