US 12573872 B2 / Mar 10, 2026

Control of static transfer switch system for volt-second balance transfer

A power system performs a method comprising: applying normal voltages to a load as load voltages; upon detecting a power fault that necessitates applying alternate voltages to the load in place of the normal voltages, disconnecting the normal voltages from the load; while waiting to detect a volt-second balance between the alternate voltages and the load voltages, determining one or more qualified voltages of the alternate voltages that will not saturate the load, and applying the one or more qualified voltages to the load as the load voltages; upon detecting the volt-second balance, additionally applying to the load each alternate voltage that is not the one or more qualified voltages; and after additionally applying, volt-second balancing the alternate voltages with the load voltages.