CN-116500356-B - Non-electric quantity on-line detection device and detection method for 220kV power high-voltage insulated cable fault

CN116500356BCN 116500356 BCN116500356 BCN 116500356BCN-116500356-B

Abstract

The invention relates to a non-electric quantity on-line detection device and a detection method for a 220kV power high-voltage insulated cable fault, wherein the non-electric quantity on-line detection device comprises a high-voltage insulated cable, a high-purity nitrogen gas inlet module and a non-electric quantity on-line detection module which are arranged at two ends of the high-voltage insulated cable, an air inlet joint and an air outlet joint are respectively connected with outermost protective layers at two ends of the high-voltage insulated cable, the nitrogen gas inlet module is connected with the air inlet joint, the non-electric quantity on-line detection module comprises an air outlet pipe connected with the air outlet joint, and a low-molecular hydrocarbon gas sensor, a carbon dioxide sensor, a carbon monoxide sensor and a palladium hydrogen sensor are sequentially arranged on the air outlet pipe along the gas flowing direction. The high-voltage insulating cable fault detection device has the advantages that the characteristic that fault characteristic gas can be generated when the high-voltage insulating cable breaks down is utilized, the fault characteristic gas filled in the multi-layer gap space of the high-voltage insulating cable is subjected to targeted non-electric quantity detection, whether the high-voltage insulating cable breaks down or has hidden danger is judged, and then the high-voltage insulating cable in electrified operation can be timely detected online.

Inventors

LIAN HONGSONG
HUANG YOUCONG
LIU HUIXIN
LAI YONGHUA
ZHENG DONGSHENG
LIN XIAOMING
ZHENG ZHONGNAN
LIN ZIQI
ZHANG YING

Assignees

国网福建省电力有限公司电力科学研究院
国网福建省电力有限公司

Dates

Publication Date: 20260508
Application Date: 20230323

Claims (7)

1. The non-electric quantity on-line detection device for the faults of the 220kV electric power high-voltage insulated cable is characterized by comprising a high-voltage insulated cable, a high-purity nitrogen gas inlet module and a non-electric quantity on-line detection module which are respectively arranged at two ends of the high-voltage insulated cable, wherein the outermost protective layers at two ends of the high-voltage insulated cable are respectively connected with an air inlet joint and an air outlet joint; the high-purity nitrogen gas inlet module comprises a nitrogen gas inlet pipe, an electric heating sleeve is sleeved on the outer side of the nitrogen gas inlet pipe, one end of the nitrogen gas inlet pipe is connected with a stop valve at the output end of the high-purity nitrogen gas cylinder, and the other end of the nitrogen gas inlet pipe is connected with an air inlet joint; The pressure reducing valve, the pressure stabilizing valve, the pressure sensor and the temperature sensor are sequentially arranged on the nitrogen inlet pipe along the conveying direction of nitrogen, and the pressure sensor and the temperature sensor are respectively positioned at two sides of the electric heating sleeve; The high-purity nitrogen gas inlet module with stable heating temperature and stable voltage range provides carrier gas for the work of the non-electric quantity on-line detection module and can provide heating, drying and moisture-removing for the inter-layer interval part of the high-voltage insulated cable, which is affected with moisture.
2. The device for detecting the fault of the 220kV power high-voltage insulated cable on line according to claim 1, wherein the air inlet connector is connected with a first three-way pipe, one end of the first three-way pipe is connected with a nitrogen air inlet pipe through a first electromagnetic valve, and the other end of the first three-way pipe is connected with a first emptying pipe through a first emptying electromagnetic valve.
3. The non-electric quantity on-line detection device for the faults of the 220kV electric high-voltage insulated cable is characterized in that the air outlet connector is connected with a second three-way pipe through a connecting pipeline, a humidity sensor is arranged on the connecting pipeline, one end of the second three-way pipe is connected with an air outlet pipe through a second electromagnetic valve, and the other end of the second three-way pipe is connected with a second emptying pipe through a second emptying electromagnetic valve.
4. The device for on-line detection of failure of a 220kV power high-voltage insulated cable of claim 3, further comprising a control module, wherein the input end of the control module is electrically connected with the output ends of the palladium-grid hydrogen sensor, the carbon monoxide sensor, the carbon dioxide sensor, the low-molecular hydrocarbon gas sensor, the humidity sensor, the temperature sensor and the pressure sensor respectively, and the output end of the control module is electrically connected with the pressure stabilizing valve, the first electromagnetic valve, the second electromagnetic valve, the first emptying electromagnetic valve, the second emptying electromagnetic valve, the electric heating sleeve and the alarm respectively.
5. The device for detecting faults of 220kV power high-voltage insulated cables on line, which is characterized in that joint connection holes are formed in the outermost protective layers at two ends of the high-voltage insulated cables.
6. The device for detecting the fault of the 220kV power high-voltage insulated cable on line, which is characterized in that the two ends of the high-voltage insulated cable are connected with high-voltage insulated cable terminals, and a cable supporting rod which is vertically arranged is fixed between the high-voltage insulated cable terminals and the ground.
7. A non-electric quantity on-line detection method for a 220kV power high-voltage insulated cable fault is characterized by comprising the following steps of: (1) The control module presets an exceeding alarm value of humidity, hydrogen, carbon monoxide, carbon dioxide and low-molecular hydrocarbon gas and a setting range of stable temperature and pressure of high-purity nitrogen; (2) Firstly, starting a temperature sensor and a pressure sensor of a high-purity nitrogen gas inlet module; (3) Opening a first emptying electromagnetic valve; (4) The pressure reducing valve is regulated to set output pressure, then the stop valve, the pressure stabilizing valve and the electric heating sleeve on the high-purity nitrogen cylinder are sequentially opened, and the high-purity nitrogen subjected to pressure stabilization and heating is discharged through the first emptying electromagnetic valve; (5) When the temperature and the pressure of the high-purity nitrogen reach the set values stably, opening a first electromagnetic valve, closing a first emptying electromagnetic valve, and enabling the high-purity nitrogen with stable temperature and pressure to enter an interlayer gap inside the high-voltage insulated cable through an air inlet connector and fill the high-voltage insulated cable along the path until the other end of the high-voltage insulated cable is connected with an air outlet connector; (6) When the pressure of the pressure sensor reaches a preset value, starting a humidity sensor, a palladium-grid hydrogen sensor, a carbon monoxide sensor, a carbon dioxide sensor and a low-molecular hydrocarbon gas sensor; (7) Opening a second electromagnetic valve of the non-electric quantity online detection module; (8) The high-purity nitrogen carries various gases contained between the internal layers of the high-voltage insulated cable, and sequentially flows through a humidity sensor, a palladium-grid hydrogen sensor, a carbon monoxide sensor, a carbon dioxide sensor and a low-molecular hydrocarbon gas sensor together to respectively detect the moisture content, the hydrogen content, the carbon monoxide content, the carbon dioxide content and the low-molecular hydrocarbon gas content, and the detected gases flow out to the atmosphere; (9) When one or more detection values of the moisture content, the hydrogen content, the carbon monoxide content, the carbon dioxide content and the low molecular hydrocarbon gas content exceed preset standards, an alarm alarms to inform related personnel of further inspection and treatment before; (10) After the detection test is finished, sequentially closing a humidity sensor, a palladium-grid hydrogen sensor, a carbon monoxide sensor, a carbon dioxide sensor and a low-molecular hydrocarbon gas sensor; (11) Opening a second emptying electromagnetic valve, closing the second electromagnetic valve, and discharging interlayer gap gas inside the high-voltage insulated cable into the atmosphere; (12) If only the humidity 1 index exceeds the standard, continuing to start the humidity sensor and introducing hot high-purity nitrogen except for alarming by an alarm, heating and drying the inter-layer gaps in the damped high-voltage insulated cable until the humidity reaches the requirement, and then closing the humidity sensor; (13) Closing the electric heating sleeve and the temperature sensor; (14) Closing the stop valve, the pressure stabilizing valve and the first electromagnetic valve of the high-purity nitrogen cylinder for the next time, and continuously keeping the pressure reducing valve at a set pressure reducing position so as to be convenient for detection and use for the next time; (15) When the pressure is reduced to normal pressure, closing the pressure sensor, and closing the second emptying electromagnetic valve; (16) And ending the non-electric quantity detection test of the high-voltage insulated cable, and waiting for detection of the next period.

Description

Non-electric quantity on-line detection device and detection method for 220kV power high-voltage insulated cable fault Technical field: the invention belongs to the technical field of high-voltage insulated cable detection in the power industry, and particularly relates to a non-electric quantity on-line detection device and a detection method for a 220kV power high-voltage insulated cable fault. The background technology is as follows: In recent years, with the continuous increase of the requirements of the transmission capacity and the power supply quality of the urban power grid, high-voltage insulated cables have become a necessary choice for constructing a reliable urban power grid. The high-voltage insulated cable is of a multi-layer protection wrapping structure, the innermost part of the high-voltage insulated cable is a conductor inner core, the outer wrapping section interlayer is generally divided into a conductor shield, an insulation shield, a water-blocking buffer layer, an aluminum sheath, an outer protective layer and the like from inside to outside, as shown in figure 1, the whole high-voltage insulated cable is sealed with the outside except that conductors at two ends are strictly connected in a sealing manner through a cable head, and the other outer surface parts of the whole high-voltage insulated cable are mutually permeable to air between interlayer layers in the cable. Because the high-voltage insulated cable is of an armor-wrapped multilayer structure and is mostly buried in the ground deeply, if the middle barrier of the armor of the high-voltage insulated cable is wetted or damaged during operation, the middle barrier is difficult to discover in time, and faults generally need to be developed to a certain extent when the middle barrier of the armor of the high-voltage insulated cable is wetted and damaged, the faults can be detected by special electrical measuring instruments through obvious electric quantity change signals, or the high-voltage insulated cable is powered off, and defects are discovered by insulating, withstand voltage or leakage current test detection, so that the faults are often seriously delayed from the discovery and development of the faults. Therefore, there is a need to design a device and a method for detecting a high-voltage insulated cable in live operation in a timely and online manner. The invention comprises the following steps: The invention aims at improving the problems existing in the prior art, namely the technical problem to be solved by the invention is to provide the non-electric quantity on-line detection device and the detection method for the faults of the 220kV power high-voltage insulated cable, which are reasonable in design and can be used for on-line non-electric quantity detection of the incoming line of the high-voltage insulated cable. In order to achieve the aim, the technical scheme is that the non-electric quantity on-line detection device for the faults of the 220kV electric power high-voltage insulated cable comprises a high-voltage insulated cable, a high-purity nitrogen gas inlet module and a non-electric quantity on-line detection module, wherein the high-purity nitrogen gas inlet module and the non-electric quantity on-line detection module are respectively arranged at two ends of the high-voltage insulated cable, two outermost protection layers at two ends of the high-voltage insulated cable are respectively connected with an air inlet joint and an air outlet joint, the output end of the nitrogen gas inlet module is connected with the air inlet joint, the non-electric quantity on-line detection module comprises an air outlet pipe connected with the air outlet joint, and a low-molecular hydrocarbon gas sensor, a carbon dioxide sensor, a carbon monoxide sensor and a palladium hydrogen sensor are sequentially arranged on the air outlet pipe along the gas flowing direction. Further, the high-purity nitrogen gas inlet module comprises a nitrogen gas inlet pipe with an electric heating sleeve sleeved on the outer side, one end of the nitrogen gas inlet pipe is connected with a stop valve of the output end of the high-purity nitrogen gas cylinder, and the other end of the nitrogen gas inlet pipe is connected with an air inlet joint. Further, the nitrogen gas inlet pipe is sequentially provided with a pressure reducing valve, a pressure stabilizing valve, a pressure sensor and a temperature sensor along the conveying direction of nitrogen gas, and the pressure sensor and the temperature sensor are respectively positioned at two sides of the electric heating sleeve. Further, the air inlet connector is connected with a first three-way pipe, one end of the first three-way pipe is connected with the nitrogen air inlet pipe through a first electromagnetic valve, and the other end of the first three-way pipe is connected with a first emptying pipe through a first emptying electromagnetic valve. Furthermore, the air outlet joint is conn