Control and Implementation of Inverters Parallel Operation in Grid-Connected Photovoltaic

Traditional inverter parallel control schemes have connection among each module. With increase in the number of modules and the increases in the distance among modules, the signals among each module are vulnerable to suffer interference. According to the principle of parallel operation of inverters, this paper analyzes several parallel inverter control schemes, and compares advantages and disadvantages of several common PQ drop methods. Further studies of the control technology of parallel inverters without iconnection besides this paper also introduces a more suitable method for the grid-connected PV systems. This method takes into account the grid-connected line resistance and the impact of harmonics. Meanwhile, it also improves the dynamic response capability of the system. The simulation proves the feasibility of this method.