Metal Oxide Varistor Design Optimization and Main Breaker Branch Switch Control of a Progressively Switched Hybrid DC Circuit Breaker

In this article, metal oxide varistor (MOV) design optimization and switching control in the main circuit breaker (MCB) branch of a progressively switched hybrid dc (DCCB) is presented. A DCCB can achieve faster fault isolation with reduced peak current magnitude transient recovery voltage compared regular due to its modified strategy. Consequently, thermal stress on semiconductor devices MCB significantly reduced. Analytical model system dynamics during progressive derived demonstrate scheme’s effect energy-absorbing component, MOV, turn- off process. Derived analytical conjunction displacement curve fast mechanical switch utilized optimize components reduce MOV degradation through asymmetric energy dissipation. built PSCAD validate performance proposed method 10-kV/250-A four stage switching. Additionally, low at 380 V developed PLECS for two that works as basis experimental validation. This includes both lookup table-based device junction temperature estimation. Experimental results are provided 380-V near uniform absorption optimally selected MOVs.