As a fundamental component in substations, power cables are abundant and widely dispersed, serving to interconnect various devices, on-site operational systems, and remote control systems within the substation. Their condition often determines the converter station's ability to operate normally. As substation construction continues to evolve, the station is faced with numerous power cables, challenges in daily operations and maintenance, and potential safety risks in fire and security. This paper initially examines the ignition mechanisms of internal fires in power cables, identifies the intrinsic factors causing their combustion, and assesses the aging state of power cables, thereby providing a basis for risk evaluation of power cable fires. Subsequently, leveraging the evaluation criteria for single-phase grounding arcs and conductor temperature, a risk assessment model for power cable fires is developed employing the Analytic Hierarchy Process (AHP) and Fuzzy Comprehensive Evaluation, encompassing three dimensions: cable operational parameters, cable faults, and cable laying, to quantify the risk level of power cable fires. Through case studies, this approach enables the preemptive identification of fire risks in power cables, the proactive implementation of various measures for power cables, and consequently bolsters the safe and stable operation of the substation's underground power grid.

Power cables, AHP, Fuzzy comprehensive evaluation, Risk assessment model, Aging state