SU406260A1 - - Google Patents

Description

RELAY VOLTAGE DIRECT SEQUENCE

This invention relates to direct sequence voltage control devices for a three phase voltage system.

The known devices containing a measuring three-phase three-rod transformer with primary windings connected in delta and a threshold organ have a large unbalance voltage and are complex.

In the proposed device, in order to reduce the unbalance voltage and simplify the secondary windings of the measuring transformer, each located on one of the three rods is connected to the memory capacitors via diodes, the "pluses of the diodes connected to the" beginning of the first and second windings and the "end of the third winding, the memory capacitors are connected in series and connected to the input of the threshold organ and parallel to the “emitter-collector junction of the transistor,” the emitter-base junction of which is connected through a diode and a zener diode to the fourth The first winding of the instrument transformer located on the same rod with the third secondary winding.

The schematic diagram of the proposed relay is shown in the drawing.

The relay consists of a measuring three-phase three-core transformer 1, which has primary windings., Connected in delta, secondary windings 1-3, each

2

of which is located on one of the three rods, and the secondary winding 4, located on one rod 5 with winding 3, diodes 6-8, memory capacitors 9 - // and threshold organ 12. Secondary windings / and 2 are connected to capacitors 9 and 10 through diodes 6 and 7, which transmit a current at a positive half-period of the voltage, and winding 3 is connected to the controller. And through the diode S. a passing-through diode at a negative half-period of the national phase. The capacitors 9-11 are interconnected in series so that the minus of the capacitor 9 is connected to the plus of the capacitor 10 and the minus of the capacitor 10 to the plus of the capacitor P.

A threshold organ 12 is connected to the extreme points of a series capacitor circuit and an emigter-collector junction of a resetting transistor 13 parallel to it. The secondary winding 4 through a diode 14 and a zener diode 15 passing current during a positive half-period eg; -;: eni connected to the emitter-base transition of the transistor 13.

The direct voltage relay operates as follows. The three-phase AC voltage under study is fed to the primary windings of the transformer. In this case, the voltages of the secondary windings (-3), corresponding to three linear voltages, capacitors Y-11 are charged through diodes 6-8. The arithmetic sum of all three linear voltages is fixed at the ends of the series circuit of capacitors 9-11 and at the input of the parallel-connected threshold organ 12 in parallel. In this case, the charge of the capacitors 9 -) / takes place in a time shorter than the period of the three-phase voltage, due to the fact that the secondary winding 3 is connected to the capacitor 11 through the diode 8, which passes current during the negative half-period of the voltage, and the secondary windings Y and 2 are connected to capacitors 9 and 10 through diodes 6 and 7 which carry a current through a positive half-period voltage. The secondary winding 4 through the diode 14 and the zenith 15, passing a positive half-period of the voltage, is connected to the emitter-base junction of the transistor 13, therefore, with the end of the summation of the three linear voltages, the capacitor circuit is discharged, and the series fixed sum of three linear stresses. Thus, by the beginning of the next period of the investigated three-phase AC voltage, the circuit is completely restored.

Subject invention

A direct-sequence voltage relay for a three-phase voltage system containing a measuring three-phase three-core transformer with triangular primary windings and four secondary windings, a threshold organ and a transistor, characterized in that, in order to reduce the unbalance voltage and simplify, in the case of unbalance voltage and simplification, The windings of the above mentioned measuring transformer, each located on one of:) M of three rods, are connected to the memory capacitors via diodes, and the "pluses of the diodes are connected to the" start of Oh and the second one and the “end of the third winding, the memory capacitors are connected in series and connected to the input of the threshold organ and parallel to the“ emitter-collector junction of the transistor, the “emitter-base junction of which is connected through the diode and the zener diode to the fourth secondary winding of the measuring transformer ,,,, located on the same terminal with the third; secondary winding.