Risk assessment of rail transit system with photovoltaic and energy storage based on operation characteristics

Electric railroads need quickly achieve the efficient, environmentally friendly, and flexible development of their own energy use in order to support the implementation of the "building China's strength in transportation" strategy and the realization of the "carbon neutrality" vision. The rail transit energy system with photovoltaic and energy storage (RTESPES) is a practical solution recently proposed, but the uncertainty of supply and demand in both directions makes the operation of the rail transit self-consistent energy system riskier. To this end, a risk assessment method of rail transit system with photovoltaic and energy storage based on operation characteristics is proposed in this paper. The proposed method has the following features: 1) a Bayesian network is created based on the RTESPES' operation characteristics, considering the impact of equipment performance degradation on the equipment failure rate in the prior probability; and personnel, environmental, and management factors are then used as the evidence variables to determine the RTESPES' equipment failure rate. 2) To determine the priori probability, the thermal circuit model is built to determine the temperature rise of the equipment based on the equipment's heat dissipation process; by using the equipment temperature rise, the Miner-Weibull model is then created to quantity the equipment temperature rise in relation to the equipment loss and ultimately to the equipment failure rate. 3) The Fault Tree Analysis-Bayesian model is built based on the equipment's spatial structure and relay protection characteristics, and it quantifies the effects of system failure. This is done by taking into account the equipment's spatial structure and relay protection characteristics. Finally, the effectiveness of the proposed method is verified through case analysis.