Overvoltage risk analysis in distribution networks with high penetration of PVs

Solar power has become one of the mainstream distributed renewable energy sources due to its clean and renewable feature and the global push for renewable energy. In a distribution network with high penetration of photovoltaics (PVs), overvoltage is a common and major issue that needs to be addressed to assure system reliability and security. Increasing interests have been given to real time operation of PVs to fully utilize PV generation capacity while the voltage is regulated within a proper range. However, little research has been done on exploring the overvoltage risk at the planning phase. This paper proposes a probabilistic method to evaluate the overvoltage risk in a distribution network with different PV capacity sizes under different load levels. Kolmogorov-Smirnov test (K-S test) is used to identify the most proper probability distributions for solar irradiance in different months. To increase accuracy, an iterative process is used to obtain the maximum allowable injection of active power from PVs. The effectiveness of proposed method is verified on a 33-bus system.