Research on Key Points and Evaluation Strategies for Interruption Performance of Circuit Breakers Under High Current Conditions

The reliable operation of circuit breakers is crucial for maintaining the safety and stability of the power grid. This article focuses on the evaluation of the breaking capacity of circuit breakers under high current conditions. By establishing a magnetohydrodynamic model, the evaluation method of the breaking capacity of circuit breakers is systematically explored. The key areas of airflow field regulation and the role of zero front resistance in the evaluation of breaking capacity were studied with emphasis. Firstly, the paper discusses in detail the two key areas of airflow field regulation, namely the highest flow velocity area and the cyclone formation area, and points out design criteria to optimize the airflow field, increase flow velocity, and avoid unnecessary airflow movement. Secondly, this article analyzes the importance of zero front resistance in evaluating the breaking capacity of circuit breakers. Through a thermodynamic based thermal breakdown model, the temperature field thermal breakdown mechanism and dielectric recovery characteristics were studied, and the important embodiment of zero front resistance in key performance such as reaction interruption time and arc voltage was demonstrated. Overall, this study explores the key roles of airflow field regulation and zero front resistance in circuit breaker performance evaluation, filling the existing research gap in evaluating the breaking capacity of circuit breakers under extreme operating conditions. This provides important theoretical guidance for improving the design and performance of circuit breakers.