Analysis and Optimization Suggestions on the Automatic Transfer Switching Logic of the 10kV Station Service Power System in Converter Stations

Compared to alternating current (hereinafter referred to as:AC) substations, direct current (hereinafter referred to as: DC) converter stations impose more stringent requirements on the reliability of their auxiliary power supply systems. To ensure this reliability, DC converter stations are typically equipped with three redundant power sources and employ a three-stage Automatic Transfer Switching (ATS) logic. This paper provides an in-depth analysis of a three-stage ATS logic applied to the 10kV auxiliary power system of a converter station. It focuses specifically on: Voltage Status Determination Logic (judging busbar/line voltage status based on incoming circuit breaker positions); Action Conditions (encompassing switch status combinations and interlocking logic under eight distinct operational scenarios); Action Logic (including tripping upon power loss, closing for power restoration, and blocking mechanisms). Furthermore, the paper identifies specific deficiencies in the existing logic and proposes optimization recommendations.