Risk Assessment Method for Transmission-distribution Integrated System with Distributed PV

摘要

In the traditional risk assessment of power system, the analysis of transmission system and distribution system were conducted separately. However, the power supply reliability of the distribution network users is not only related to the reliability of the distribution network components, but also to the power supply capability of the transmission system to the distribution system. The risk assessment method of transmission and distribution system that conducted separately cannot reflect the impact of changes in the transmission network on the reliability of power supply in distribution system. In this paper, a risk assessment method for transmission-distribution integrated system is proposed. Risk assessment is carried out in the transmission system first according to the load state of the system to evaluate the operation risk of the transmission system, and to obtain the probability distribution of the bus power of the transmission network. The probability distribution of bus power of transmission network is substituted into the root node of distribution network. Considering the possible island operation mode with the distributed PV connected in the distribution network, the loss of load in the case of component fault of distribution network is analyzed, and the risk index of load loss of the system is calculated. Finally, correctness and effectiveness of the proposed method are validated by a modified IEEE RTS and IEEE 33-bus system.