As a renewable resource, photovoltaic power generation has become more and more attracted and applicable. According to Test Procedures for Photovoltaic Power Station Connected to Power Grid, the paper develops a grid disturbances device with functions of energy feedback applied to photovoltaic grid-connected detection, to simulate the disturbances of the frequency, amplitude of the voltage of power networks. The device has a back-to-back double PWM topology, including two-level PWM rectifier and three-level PWM inverter. The rectifier uses the voltage and current dual-loop control, and the inverter uses voltage loop control. The control strategies can accurately track the reference, respond quickly and the steady-state error is small. The simulation and experiment results show that the circuit design and control strategy are feasible and efficient.
