The application of renewable energy, such as solar energy and wind energy, has emerged and gradually became one of alternatives of fossil fuel. The photovoltaic (PV) technology, one of the most efficient ways of solar energy utilization, is applied broadly in various capacities, scales and operation types. Compared to traditional generation system, the PV generation is costly, instable and needs complex control method. The distributed PV generation systems can be divided into the stand-alone systems and gri...