METHOD OF THE BACKUP POWER SUPPLY FAST SWITCHING ON AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2018 - IPC H02J9/06 

FIELD: electrical equipment.

SUBSTANCE: backup power supply fast switching on method and device for its implementation relates to electrical equipment and, in particular, to the substations with the 6–35 kV voltage emergency control devices. Method consists in measuring of the main and backup power supply buses direct sequence voltage and current, angle between the main and backup power buses direct sequence voltage vectors, determination of the power direction at the main and backup sources input, switching the bus section from the main to the backup power source with the at least one phase power sign changing or reducing the input current of any phase below the set value and simultaneous decreasing the main power supply busbars direct sequence voltage below the predetermined level, or with the angle between the direct input sequence voltage vectors increase above the predetermined value, while the voltages on the backup input line exceed the predetermined value; according to the invention, with reduction of one or more line voltages in the main input below the predetermined value and the absence of conditions for the starting device triggering during the predetermined time interval T, blocking the starting device until voltages at this input are restored, and to determine the power direction, the phase current values are multiplied by the delayed linear voltage values for time T between the same input two other phases, obtained values are integrated, determining the sign of the result, at that, the delay time T is selected taking into account of the industrial frequency period and the set maximum sensitivity angle. Device contains main [1] and backup [2] power supplies, operating inputs [3] and [4] input circuit breakers, sectional switch [5], substation bus sections [6] and [7], three-phase current transformer [8] at the input of the main power sources, voltage transformers [9], [10] on the main and backup power supplies buses, high-speed starting device (SD), circuit breakers control unit [26]. Quick acting starting device includes: minimum voltage relay unit [11], time delay element [12], angle between the main and backup power sources [13] – [15] direct sequence vectors determining relay units, maximum voltage relay unit [16], “4OR” logic element [17], “4AND” logic element [18], phase power direction determination units P1–P3, each of which consists of delay line [19], multiplier [20], adder-accumulator [21], sign determination unit [22], minimum current detection unit [23], “2OR” logic element [24], which outputs are combined by the “3OR” logic element [25]. By its inputs the “4AND” logic element combines the time delay element [12] inverted output, the of “4OR” logic element [17] output, maximum voltage relay unit [16] output, “3OR” logic element [25] output.

EFFECT: method and device allow to increasing the emergency modes in substation power supply circuits detection reliability, eliminate false alarms and reduce the consumers to backup source switching times.

2 cl, 1 dwg