A Control Strategy for Grid-interactive Inverters with Rectifier Loads

A control strategy for grid-interactive inverters with rectifier loads is proposed. The utility-connected inverters can operate at both stand-alone and grid-connected modes. The impact of the rectifier loads on the grid current is analyzed. The influence of the rectifier load and filter capacitor on the grid current can be eliminated by adding the rectifier load current into the current loop,and the waveform quality of the grid current can be improved. The control method is simple and easy to be implemented. Simulation and experimental results illustrate the improvement of the waveform quality of the grid current and the external characteristics of the inverter at stand-alone mode.