CN-121983903-A - Method and device for automatically detecting disconnection of voltage and current loops of relay protection device in standby state of primary equipment

CN121983903ACN 121983903 ACN121983903 ACN 121983903ACN-121983903-A

Abstract

The invention relates to the field of power systems, IN particular to a method and a device for automatically detecting voltage and current loop disconnection of a relay protection device IN a standby state of primary equipment, wherein the method comprises a judging module for judging the standby state of the primary equipment; the invention relates to a device for detecting broken wires, which comprises a judging module, a pulse output control module and a pulse current generator module, wherein the judging module is used for judging whether primary equipment is IN a standby state or not, the pulse output control module is IN communication connection with the judging module and is used for outputting pulse trigger signals when the primary equipment is judged to be IN the standby state by the standby state judging module, and the pulse current generator module is IN communication connection with the pulse output control module and is used for receiving the pulse trigger signals and outputting pulse currents.

Inventors

XU JUN
LI YI
LI BOYI
YUAN RENBIAO
FENG WENXIN
LIU CHANGFA
YANG BO
YU CHAO
SHU BIN
CHEN QIUPENG
XING FANGBO

Assignees

中国南方电网有限责任公司超高压输电公司贵阳局

Dates

Publication Date: 20260505
Application Date: 20251224

Claims (10)

1. The utility model provides a device that realizes relay protection device automated inspection voltage, current return circuit disconnection under primary equipment standby state which characterized in that includes: The standby state judging module is used for judging whether the primary equipment is in a standby state or not; The pulse output control module is connected with the standby state judging module and is used for outputting a pulse trigger signal when the primary equipment is judged to be in the standby state; And the pulse current generator is connected with the pulse output control module and is used for responding to the pulse trigger signal to output pulse current.
2. The apparatus of claim 1, further comprising the standby state discrimination module configured to discriminate whether a primary device is in a standby state based on current IA, IB, IC of a secondary winding loop of a current transformer associated with the primary device, a trip position signal of a circuit breaker associated with the primary device, and a state of an service clamp of a secondary device associated with the primary device.
3. The apparatus as recited in claim 1, further comprising: a lead A, which is wound on a secondary winding of a voltage transformer associated with the primary equipment and is connected with the pulse current generator so as to couple the pulse current to a secondary loop of the voltage transformer; And the lead B is used for being wound on a neutral point lead-out wire of a secondary winding of the current transformer associated with the primary equipment and is connected with the pulse current generator so as to couple the pulse current to a secondary loop of the current transformer.
4. The apparatus as recited in claim 1, further comprising: The circuit breaking judging module is used for acquiring currents IA, IB and IC of a secondary winding loop of the current transformer associated with the primary equipment after the pulse output control module outputs a pulse trigger signal, determining current abrupt change amounts delta IA, delta IB and delta IC, acquiring currents UA, UB and UC of a secondary winding loop of the voltage transformer associated with the primary equipment, determining voltage abrupt change amounts delta UA, delta UB and delta UC, and judging whether a corresponding loop is broken according to whether the current abrupt change amounts and the voltage abrupt change amounts are detected.
5. The apparatus of claim 2, wherein the standby state determination module determines that the instantaneous values of the currents IA, IB, and IC are less than a predetermined operational current value, a circuit breaker trip position signal is received, and the service pressure plate is in an exit state.
6. The apparatus of claim 3 wherein said wire A is wound around the neutral wire UN of the secondary winding of the voltage transformer and said wire B is wound around the neutral wire IN of the secondary winding of the current transformer.
7. The apparatus of claim 4, wherein the wire break discrimination module is configured to: If no voltage abrupt change is detected at a certain phase output end of the secondary winding of the voltage transformer within a preset judging time window, judging that the phase voltage loop is broken; if no current abrupt change is detected at a certain phase output end of the secondary winding of the current transformer within a preset judging time window, judging that the phase current loop is broken.
8. A method for realizing automatic detection of voltage and current loop disconnection of a relay protection device in a standby state of primary equipment is characterized by comprising the following steps: Step 1, acquiring current IA, IB, IC of a secondary circuit of a current transformer, a tripping position signal of a circuit breaker and an overhaul pressing plate state through a standby state judging module of primary equipment, and judging that the primary equipment is in the standby state when the current values of the IA, IB and IC are lower than a preset operation current fixed value, the tripping position signal of the circuit breaker exists and the overhaul pressing plate is in an exit state; Step 2, the standby state judging module triggers a pulse output control module, and the pulse output control module outputs a pulse trigger signal according to a set time interval; Step 3, the pulse current generator receives the pulse trigger signal and transmits the pulse current to a lead A wound on a neutral line UN of a secondary winding of the voltage transformer and a lead B wound on a neutral line IN of the secondary winding of the current transformer by outputting pulse current; And 4, judging that the phase voltage loop is disconnected if the phase voltage loop does not detect the corresponding voltage abrupt change, and judging that the phase current loop is disconnected if the phase current loop does not detect the corresponding current abrupt change.
9. The method according to claim 8, wherein in the step 1, the power failure state of the primary equipment is determined by combining the current with the position signal of the circuit breaker, and no maintenance work of the primary equipment is determined by the maintenance clamp plate withdrawing state.
10. The method of claim 8, wherein the predetermined operational current constant is a fixed threshold predetermined based on a rated current of the primary device and a sensitivity of the relay protection device, and the operational current constant is adjusted according to an on-site condition.

Description

Method and device for automatically detecting disconnection of voltage and current loops of relay protection device in standby state of primary equipment Technical Field The invention relates to the field of power systems, in particular to a method and a device for automatically detecting disconnection of a voltage and current loop of a relay protection device in a standby state of primary equipment. Background In the operation process of the power system, the disconnection of the voltage and current loops of the relay protection device is one of the core causes for causing incorrect actions of relay protection. According to the statistics data of the power system protection and control, ten false operation reasons of the voltage/current loop disconnection bit row in the relay protection false operation event are disclosed. In order to avoid the problem of misoperation, the existing microcomputer relay protection device has the automatic detection capability of broken line faults, and main flow judging logic of the microcomputer relay protection device needs to rely on the electrified working condition of a loop, namely, whether the loop is broken or not can be judged through logic analysis of voltage and current sampling values only when primary equipment is in an operation state, so that misoperation of the device is avoided, and operation and maintenance personnel are reminded of processing the faults. However, the technology has some limitations that when the primary equipment is in a standby state, the primary equipment comprises hot standby and cold standby, the hot standby refers to equipment which has operation conditions and can be switched on by one key, the cold standby refers to equipment which has no safety measures and obvious disconnection points at each side, the primary equipment does not operate, and a secondary circuit has no voltage and current. In a standby state, the disconnection discrimination logic of the existing relay protection device is completely invalid, and the hidden danger of disconnection of a loop cannot be checked. If the circuit broken line in the standby state is not found, serious accidents are easily caused when equipment is put into operation, for example, when a transformer station circuit is overhauled and put into operation, a circuit is forced to be powered off and replaced due to the fact that a circuit terminal is burnt out by a secondary side open circuit of a current transformer, and when a transformer station is put into operation, an impedance protection misoperation is caused because a secondary side air switch of a high-voltage side voltage transformer is not switched on. Therefore, the prior art has the problem that the power grid equipment accidents in the operation stage are difficult to avoid from the source. Disclosure of Invention The invention aims to provide a method and a device for automatically detecting voltage and current loop disconnection of a relay protection device in a standby state of primary equipment, so as to solve the problems in the background technology. In order to achieve the above object, the present invention provides the following technical solutions: device for realizing automatic detection of voltage and current loop disconnection of relay protection device in standby state of primary equipment, comprising: The standby state judging module is used for judging whether the primary equipment is in a standby state or not; The pulse output control module is connected with the standby state judging module and is used for outputting a pulse trigger signal when the primary equipment is judged to be in the standby state; And the pulse current generator is connected with the pulse output control module and is used for responding to the pulse trigger signal to output pulse current. The judging module judges whether primary equipment is in a standby state or not based on currents IA, IB and IC of a secondary circuit of the current transformer, a tripping position signal of a circuit breaker and a state of an overhaul pressing plate. After receiving the trigger signal, the pulse current generator outputs pulse current to the wire A and the wire B. Further, the standby state discrimination module is configured to discriminate whether primary equipment is in a standby state or not by the state of an overhaul pressure plate of secondary equipment associated with the primary equipment, by the current IA, IB, IC of a secondary winding loop of a current transformer associated with the primary equipment, a trip position signal of a breaker associated with the primary equipment. Further, a wire A is used for being wound on a secondary winding of the voltage transformer associated with the primary equipment and is connected with the pulse current generator so as to couple the pulse current to a secondary loop of the voltage transformer. Further, a lead B is used for being wound on a neutral point lead-out wire of a secondary winding of the curr