SU418930A1 - DEVICE FOR MONITORING THE CORRECTION OF THE SECONDARY CHAINS OF THE THREE-WATER TRANSFORMER VOLTAGE - Google Patents

Description

one

The proposed device can be used to monitor the operability of three-winding voltage transformer circuits, as well as to output from the action of high-speed relay protection connected to the phase voltages of the star winding of a three-winding voltage transformer in the event of a fault in the voltage circuits.

A number of devices are known that monitor the integrity of the voltage circuits. However, the known devices do not solve the problem completely. Devices with a zero-sequence voltage filter do not respond to faults in the windings of an open triangle. Differential devices containing intermediate transformers have too much consumption and do not control the serviceability of the neutral wire of the voltage transformer star winding.

In the proposed device, in order to increase reliability, intermediate transformers connected in an open triangle-star circuit are connected to the windings of an open triangle of a voltage transformer, phase wires of a star of intermediate transformers and phase wires of a voltage star starter are connected to an output relay and through ballast resistances - to the neutral wire of the winding - voltage transformer stars and the neutral wire intermediate t ansformatorov interconnected.

Diagram of the device shown in the drawing.

The device is connected to the secondary circuits of the star winding and the open triangle of a voltage transformer (element) and includes three intermediate two-winding transformers connected in an open triangle - star circuit (element 2), two three-phase semi-period rectification circuits (elements 3 and 4 ), a comparison circuit for absolute values of rectified voltages (element 5), including two ballasts and an output relay.

The device works as follows. The switching circuit and transformation ratios of intermediate transformers are chosen so that the three-phase voltage system at their output is exactly equal to the voltage system of the star winding of the voltage transformer. Therefore, when the secondary circuits are in good condition and under load conditions and short circuits in the primary network, the voltages at the outputs of the rectifier circuit 3 and 4 are equal to each other, and the current in the output relay does not flow.

Short circuit and disconnect

phase or zero automata (fuses) in the windings of the star of the trapsformator voltage emf straightening circuit 4 decreases or becomes zero. A current flows through the output relay. The relay is activated and gives a fault signal. For any malfunctions in an open triangle circuit, the rectified voltage is also violated, which causes the output relay to operate. The ballast creates a current path through the output relay coils.

Subject invention

A device for monitoring the health of secondary circuits of a three-winding voltage transformer, comprising three intermediate transformers connected in an open triangle-star circuit and a reacting organ, characterized in that

In order to improve reliability, the primary windings of the intermediate transformers are connected to the openings of the open triangle of the controlled transformer, and the outputs of the star windings of the intermediate transformer

and controlled transformers through three-phase rectifying circuits are connected to the reacting organ and through ballasts to the common neutral wire of the star windings of the intermediate and controlled transformers.