Impact of the distributed photovoltaic on the current protection of 10kV distribution network

Compared with other distributed generators, distributed photovoltaic (PV) is quite different in the fault characteristics. The impact of the distributed PV on the current protection of the distribution network is still unclear, making it difficult to guide the operation and management of power grid. In this paper, a typical model of distribution network with the distributed PV is established based on PV inverter control characteristics and relevant technical regulations of state grid corporation of China; the influence of the distributed PV capacity on fault currents of the distribution network is also quantitatively analyzed. Moreover, according to relationship between the different capacity of distributed PV and the amplitude of fault current, the corresponding countermeasures are proposed to provide technical support to renovation of relay protection for the distribution grid with high penetration of the distributed PVs.