Double-power-supply incoming line switch and bus coupler switch interlocking wiring circuit

Abstract

The invention relates to a double-power-supply incoming line switch and bus coupler switch interlocking wiring circuit, which comprises first and second power supply incoming line switches K1 and K2 and a bus coupler switch K3, wherein the input end of a microcomputer protection unit is connected with the output end of a control switch, the output end of the microcomputer protection unit is connected with a switch-on loop of any one switch in the three switches, and the normally closed contacts of the other two switches are connected between the input end of the microcomputer protection unit and the control switch after being connected in parallel. The circuit is used for connecting the normally closed contacts of the two locked switches to the input end of the microcomputer protection unit after the parallel connection, when all of the normally closed contacts in parallel connection are opened, when the microcomputer protection unit detects the circuit breaking of a control loop, control loop circuit breaking warning signals cannot be sent, and meanwhile, the locking function is realized.

Description

technical field [0001] The invention belongs to the technical field of relay protection of electric power systems, and in particular relates to an interlocking wiring circuit of a double power supply incoming line switch and a bus tie switch. Background technique [0002] For most high-voltage users, in order to ensure the reliability of power supply, the primary wiring adopts a single-bus section wiring method, and two independent power supplies are connected to each other for backup. There is a bus tie between the two bus sections, such as figure 1 As shown, when one of the power switches K1 or K2 is disconnected, the bus tie switch K3 is turned on to make both bus sections electrified, but when both power switches K1 and K2 are powered, the bus tie switch K3 is turned on, which will cause different systems to be out of sync Parallel, endanger the stability of the power system. Therefore, it is necessary to add a necessary interlock circuit to any one of the three switche...

AI Technical Summary

Problems solved by technology

[0003] Most of the interlocking circuits are connected between the microcomputer protection device and the closing coil HQ, figure 2 Shown is the interlock circuit for power switch K2, when figure 1 The power switch K1 and the bus tie switch K3 are in the closed position, figure 2 The normally closed contact K1QF1 of the power switch K1 and the normally closed contact K3QF3 of the bus tie switch K3 are disconnected, and the closing coil HQ is not charged, then figure 1 The power switch K2 in the

However, when the microcomputer protection device detects the disconnection of the control loop, it always detects whether there is a disconnection between the node a of the protection device and the node b of the control power supply. Due to the normally closed contact K1QF1 of the power switch K1 and the normally closed The closing contact K3QF3 is disconnected, so that the closing circuit of the power switch K2 in the opening position is disconnected, causing the microcomputer protection device to often send a control circuit disconnection alarm signal

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