Operation risk assessment for distribution system with Photovoltaic Substation connections

In this paper, an operation risk assessment algorithm for distribution system with Photovoltaic Substation is proposed to effectively calculate the provided risk indices of the distribution system, and help dispatchers to determine the optimum control strategy which introduces the lowest risk to the distribution system. First, the relationship of operation risk assessment between transmission system and distribution system is analysed to clarify the assessment aim and the corresponding assessment indices. Then, the operation mode and the protection technique of the distribution network are discussed to obtain the presumed fault set and derive the probability of occurrence for elements in the fault set. Finally, a practical risk assessment algorithm is proposed and implemented to acquire the real-time operation risk value. The algorithm is tested on a modified IEEE 33-node radial distribution network to verify the effectiveness of the algorithm.