TRV Assessment of 500-kV Shunt Reactor Switching Using Black-Box Circuit-Breaker Arc Models in ATPDraw

Abstract

Frequent switching of 500-kV shunt reactors for voltage and reactive-power regulation can produce severe transient recovery voltage (TRV), current chopping, and reignition across circuit-breaker contacts. This paper proposes a practical standard-based dielectric recovery algorithm for high-voltage SF6 circuit breakers and couples it with three dynamic arc equations, namely the Cassie-Mayr, Schwarz-Avdonin, and Schavemaker models. The proposed algorithm replaces unavailable manufacturer-specific dielectric recovery curves with a dielectric-recovery screening reference derived from circuit-breaker catalogue information and IEC TRV requirements, thereby allowing reignition and restrike decisions to be included in ATPDraw simulations. The models are implemented in MODELS as black-box circuit-breaker representations and are compared with the built-in ATP breaker model for a 128-Mvar shunt reactor in a Vietnamese 500-kV transmission system. The Phase-A peak TRV increases from 870 kV with the default ATP breaker to 874 kV, 946 kV, and 1600 kV with the Cassie-Mayr, Schwarz-Avdonin, and Schavemaker models, respectively. The mitigation study shows that a surge arrester reduces the Cassie-Mayr reference TRV to 840 kV, while the combined surge-arrester and neutral-grounding-disconnector configuration further reduces it to 774 kV. The adopted network, arc-model, TRV-envelope, and reignition parameters are reported to support reproducibility. The obtained values should be interpreted as comparative engineering estimates rather than manufacturer-specific breaker ratings.