A Prioritization Method for Switchgear Maintenance Based on Equipment Failure Mode Analysis and Integrated Risk Assessment

Switchgear is one of the key equipment in power grids. A proper maintenance strategy maximizes the cost-efficiency of switchgear maintenance expenses, meanwhile minimizing the power grid failure risk. Existing maintenance strategies that seldom consider the interconnected relation among different components in a power equipment are not applicable to switchgear which comprises of various moving and fixed parts and components. In this article, a prioritization method is proposed for medium voltage switchgear maintenance based on equipment failure mode analysis and power grid failure risk assessment. Failure mode analysis is first performed to analyze the interconnection between switchgear components and its failure mechanisms, giving a more accurate failure probability prediction result. An integrated risk assessment method is then developed to analyze the impact of switchgear failure on both the power grid losses and the cost-efficiency of maintenance activities. Based on that, the maintenance priority can be determined in a cost-efficient manner. Case studies are performed on the data of a 12 kV substation. Compared to time-based maintenance strategies, the proposed method achieves a 38% increase in cost-efficiency.