FIELD: power stations.
SUBSTANCE: upon load disconnection from supply mains load and supply mains voltages are checked and phase difference is determined. Variation in phase difference is approximated by two values of load and supply mains voltages. Time moment when phase difference approaches desired value is calculated. ON-operation time of stand-by bushing circuit breaker is subtracted from values obtained. Least positive time difference is assumed as time delay in sending instruction for closing stand-by circuit breaker. This minimizes inrush currents during switch-over operations. In addition closing time of given circuit breaker is measured each time and measurement results are entered in memory for use during next ON-operation.
EFFECT: enhanced reliability.
2 cl, 2 dwg
