Field Energy Evolution and Contact Optimization of 27.5-kV Vacuum Interrupter During Interruption Process Based on DBM-MOPSO

Abstract

The coupled effect of long-term current-carrying thermal stability, electromagnetic force on the arc during fault interruption, and post-arc dynamic insulation performance is the decisive factor for the operating performance of the vacuum circuit breaker (VCB). This article takes a $2 \times 27.5$ /T2500-31.5 environmentally friendly cubicle-type gas-insulated switch (C-GIS) as the research object, combining with the short-circuit interruption test of the prototype, modeling and simulation are carried out on the field energy and the spatiotemporal evolution process during the interruption process of the VCB. The characteristic values of temperature rise, magnetic arc-blowing, and breakdown withstand performance under the multiphysics field coupling effect of the VCB have been determined. Moreover, the effect of the key structural parameters (contact electrode diameter, slot width, and slot deflection angle) on the field energy evolution during the interruption process has been investigated. To improve the design efficiency of the VCB, a deep Boltzmann machine (DBM) is adopted to construct a surrogate model that can describe the effect of contact structure on the multiphysics performance characteristic values, and compared with a convolutional neural network (CNN) and support vector machine regression (SVR) to verify its prediction accuracy. Aiming at enhancing the energy bearing, utilization, and dissipation capacity of the VCB, the multiobjective particle swarm optimization (MOPSO) algorithm is applied for the parametric design of the contact structure. And the results show that the changes in contact structural parameters can significantly affect the multiphysics performance of the VCB. Compared with the initial design, the contact structure obtained by the optimized design method proposed in this article reduces the average temperature rise on the surface of the outlet terminals at both the movable and static sides of the VCB by 11.80%, and decreases the average electric field intensity at the contact edge by 1.31%, without compromising the magnetic arc-blowing performance. The method proposed in this article is applied to a 2.2 kV/5000 A–60 kA low-voltage high-current vacuum contactor and a 36 kV/2500 A–25 kA ring main unit (RMU) to verify the effectiveness of the method.