Yang Guosheng

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.

A new protection technology for smart distribution network

Because of the requirements of the accessing distribution generation and the high quality power supply to the protection of smart distribution, firstly, the drawbacks are analyzed to the existing stepped protection of distribution network; secondly, a new protection with multiple types of data based on the serial communication is proposed. The proposed protection achieves the new algorithm with the function of closed-loop control via the communication technology. It has the ability of following the changing structure of the tracking system to be protected, and also has the ability of achieve the reconstruction capabilities of the protection functional in the secondary equipment failure. So, it can achieve a high-performance protection.