CN110007161B - Method for measuring direct current cable insulation space charge distribution at different temperatures - Google Patents
Method for measuring direct current cable insulation space charge distribution at different temperatures Download PDFInfo
- Publication number
- CN110007161B CN110007161B CN201910286772.9A CN201910286772A CN110007161B CN 110007161 B CN110007161 B CN 110007161B CN 201910286772 A CN201910286772 A CN 201910286772A CN 110007161 B CN110007161 B CN 110007161B
- Authority
- CN
- China
- Prior art keywords
- cable
- test
- space charge
- insulation
- charge distribution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/24—Arrangements for measuring quantities of charge
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Testing Relating To Insulation (AREA)
Abstract
The invention discloses a method for measuring the charge distribution of a DC cable insulation space at different temperatures, and relates to the field of measurement of the charge distribution of the DC cable insulation space. At present, most of samples for measuring insulation space charges at different temperatures are insulation sheets, but not real cables, and most of the samples are based on an electroacoustic pulse method, so that the measurement result of the insulation space charge distribution of the direct current cable is inaccurate. The technical scheme is that a thermal cycle test system is used for heating a test cable, and the test cable is consistent with the actual operation working condition, namely, heat is transferred outwards due to heating of a conductor; simulation cables with the same type and thermocouple temperature measurement on each layer are provided as temperature references to form the same cable loop for heating and cooling, and the insulation of the test cable is not damaged; and (3) performing space charge measurement on a real cable instead of an insulation slice by using a laser pressure wave method space charge test system. This technical scheme improves authenticity, the accuracy of direct current cable insulation space charge distribution measuring result from many aspects.
Description
Technical Field
The invention relates to the field of direct current cable insulation space charge distribution measurement, in particular to a method for measuring direct current cable insulation space charge distribution at different temperatures.
Background
The direct-current high-voltage transmission has the advantages of easiness in interconnection among power grids, lower electric energy loss, higher transmission capacity and the like. Dc cables are an important component in dc transmission systems. Compared with oil-filled cables and impregnated paper insulated cables, the crosslinked polyethylene insulated cables have the advantages of excellent electrical performance, good heat resistance, good mechanical performance, less auxiliary equipment and less installation limitation, and become the mainstream direction of cable development. The trapping in the crosslinked polyethylene insulating polymer causes a problem of space charge accumulation of the direct current cable, causes severe distortion of a local electric field, and then poses a threat to the performance and service life of the power cable. Therefore, measuring the insulation space charge distribution of the direct current cable is a key content for researching the insulation performance of the direct current cable.
At present, the mainstream methods for measuring space charge at home and abroad are as follows: 1. Electro-Acoustic pulse method (PEA); 2. a thermal process; 3. pressure Wave Propagation Method (PWP). For a real extra-high voltage long cable with a coaxial structure, an electroacoustic pulse method and a pressure wave method are suitable, and when the space charge of a high-temperature direct-current cable in operation is measured, the measurement accuracy of the electroacoustic pulse method has a large influence. Therefore, pressure wave methods are suitable for measuring space charge at different temperatures, especially for thicker insulation up to operating temperatures. At present, the samples for measuring the insulation space charge at different temperatures are mostly insulation sheets, not real cables, and are mostly based on an electroacoustic pulse method. The measurement result of the charge distribution of the insulation space of the direct current cable is inaccurate.
Disclosure of Invention
The technical problem to be solved and the technical task provided by the invention are to perfect and improve the prior technical scheme and provide a method for measuring the charge distribution of the insulation space of the direct current cable at different temperatures so as to achieve the aim of improving the accuracy of measuring the charge distribution of the insulation space of the direct current cable. Therefore, the invention adopts the following technical scheme.
A method for measuring the charge distribution of the insulation space of a direct current cable at different temperatures is characterized by comprising the following steps:
1) intercepting two sections of tested cable samples with the same type, wherein one section is a test cable and the other section is a simulation cable; the simulation cable is respectively punched at a plurality of positions, the punching depth comprises a conductor layer, an insulating layer and a filling layer, thermocouples are installed at the punching positions, and thermocouples are installed at the skins of the simulation cable and the test cable; the thermocouple temperature measuring range arranged on the simulation cable covers the conductor layer, the insulating layer, the filling layer and the outer skin;
2) building a thermal cycle test system, interconnecting two ends of a test cable and two ends of a simulation cable to form a cable loop, and coating the surfaces of the test cable and the simulation cable with heat insulation materials;
3) heating a cable loop by using a thermal cycle test system, adjusting loop current, and monitoring the temperature of a cable conductor by using a thermocouple;
4) when the cable conductor reaches the highest operation temperature, the thermal cycle test system is closed, and heating is stopped; the method comprises the following steps of (1) unfastening a cable loop, hanging a test cable on a cable frame, installing equalizing rings at two ends of the test cable, connecting a lead of a direct-current high-voltage generator to one end of the test cable, and inputting direct-current high voltage into the test cable by the direct-current high-voltage generator through the equalizing rings;
5) monitoring the temperature state of each structural layer of the simulation cable in real time through a thermocouple, and considering that the cooling speed of the simulation cable is consistent with that of the test cable under the same condition, namely the insulation temperature of the simulation cable is the insulation temperature of the test cable;
6) in the cable cooling process, a space charge measurement system based on a laser pressure wave method is adopted to measure the space charge distribution condition of the insulation of the test cable at different temperatures, and the insulation space charge distribution data of the direct current cable at different temperatures are obtained.
According to the technical scheme, the laser pressure wave method is adopted to measure the space charge of the real crosslinked polyethylene insulated direct current cable at different temperatures. And measuring the insulated space charge distribution condition of the real crosslinked polyethylene direct current cable at different operating temperatures. The measurement result is basically consistent with the actual situation, and the measurement result of the charge distribution of the insulation space of the direct current cable is real and accurate.
As a preferable technical means: the thermal cycle test system comprises a feed-through transformer for heating the cable conductor, a current transformer for detecting the current of the cable conductor, a thermocouple for detecting the temperature, and a thermal cycle test controller connected with the feed-through transformer, the current transformer and the thermocouple.
As a preferable technical means: three punching holes are selected at two ends of the simulation cable, and the depth of the three punching holes respectively reaches the conductor layer, the insulating layer and the filling layer.
As a preferable technical means: when a thermal cycle test system is set up, a plurality of feedthrough transformers are arranged at the middle section of the analog cable, and a current transformer is arranged on the analog cable between the outermost feedthrough transformer and the thermocouple in a penetrating manner; a space charge test electrode is arranged in the middle of the test cable, and stress cones are arranged at two ends of the test cable; and the two ends of the cable and the two ends of the simulation cable are butted through a crimping type cable conductor joint to form a thermal cycle test loop.
As a preferable technical means: the laser pressure wave space charge measuring system comprises a laser, a cable frame and an oscilloscope.
As a preferable technical means: before the temperature state of each structural layer of the simulation cable is monitored in real time, the cooling rate can be improved by a mode of untying the heat insulation layer.
As a preferable technical means: before space charge measurement, after a cable loop is untied, a test cable is hung on a cable frame by a travelling crane, and two ends of the test cable are hung on the cable frame.
As a preferable technical means: the length of the test cable is 9-11 meters.
As a preferable technical means: the length of the test cable is 9-11 meters.
Has the advantages that:
the technical scheme is that a thermal cycle test system is used for heating a test cable, and the test cable is consistent with the actual operation working condition, namely, heat is transferred outwards due to heating of a conductor; simulation cables with the same type and thermocouple temperature measurement on each layer are provided as temperature references to form the same cable loop for heating and cooling, and the insulation of the test cable is not damaged; and (3) performing space charge measurement on a real cable instead of an insulation slice by using a laser pressure wave method space charge test system. This technical scheme improves authenticity, the accuracy of direct current cable insulation space charge distribution measuring result from many aspects. The method realizes measurement of the insulated space charge distribution condition of the real crosslinked polyethylene direct current cable at different operating temperatures.
Drawings
FIG. 1 is a flow chart of the present invention.
FIG. 2 is a thermal cycling test loop diagram of the present invention.
Fig. 3 is a diagram of a test cable arrangement at the time of space charge measurement of the present invention.
In the figure: 1. testing the cable; 2. simulating a cable; 3. a thermocouple; 4. a feedthrough transformer; 5. a cable rack; 6. a grading ring; 7. a current transformer; 8. a space charge test electrode; 9. a stress cone; 10. a crimp-style cable conductor connector; 11. and a direct current high voltage generator lead.
Detailed Description
The technical scheme of the invention is further explained in detail by combining the drawings in the specification.
As shown in fig. 1, the present invention comprises the steps of:
s01: two sections of cables with the same model and specification are cut, one section is a simulation cable 2, the other section is a test cable 1, a plurality of positions of the simulation cable 2 are punched to install thermocouples 3, and the temperature measuring range covers a conductor layer, an insulating layer, a filling layer and an outer skin.
S02: and (3) building a thermal cycle test system according to the figure 2, and coating the surfaces of the test cable 1 and the simulation cable 2 with heat insulation materials.
The thermal cycle test system comprises a feed-through transformer 4 for heating the cable conductor, a current transformer 7 for detecting the current of the cable conductor, a thermocouple 3 for detecting the temperature, and a thermal cycle test controller connected with the feed-through transformer 4, the current transformer 7 and the thermocouple 3. Wherein the thermocouples 3 embedded at the punching holes are positioned at the two ends of the simulation cable 2, and the embedding depths of the three thermocouples 3 reach the conductor layer, the insulating layer and the filling layer respectively. A plurality of feed-through transformers 4 are arranged at the middle section of the analog cable 2, and a current transformer 7 is arranged on the analog cable 2 between the outermost feed-through transformer 4 and the thermocouple 3 in a penetrating manner; a space charge test electrode 8 is arranged in the middle of the test cable 1, and stress cones 9 are arranged at two ends of the test cable 1; the two ends of the cable are butted with the two ends of the simulation cable 2 through a crimping type cable conductor joint 10 to form a thermal cycle test loop.
S03: a thermal cycle test system is utilized to heat a cable loop, loop current is adjusted, and a thermocouple 3 temperature measurement system is used for monitoring the temperature of a cable conductor, so that the cable conductor can reach the highest operating temperature quickly.
S04: and closing the thermal cycle test system, unfastening a cable loop, hoisting the test cable 1 to a cable rack 5 of the space charge test system by using a travelling crane, and arranging the test cable 1 according to the figure 2.
The two ends of the test cable 1 are hung on the cable frame 5, the hung test cable 1 is arc-shaped, the equalizing rings 6 are arranged at the two ends of the test cable 1, the lead 11 of the direct-current high-voltage generator is connected to one end of the test cable 1, and the direct-current high-voltage generator inputs direct-current high voltage to the test cable 1 through the equalizing rings 6.
S05: the temperature states of all structural layers of the simulation cable 2 are monitored in real time through a thermocouple 3 temperature measurement system, and the simulation cable 2 and the test cable 1 are considered to be consistent in cooling speed and temperature of all layers under the same condition.
S06: through the cable natural cooling, utilize laser pressure wave method space charge test system to measure the insulated space charge distribution condition of test cable 1 under the different temperatures, for improving cooling rate, can go on through untiing the heat preservation mode.
The above method for measuring the insulation space charge distribution of a dc cable at different temperatures shown in fig. 1-3 is a specific embodiment of the present invention, and it has been demonstrated that the substantial features and improvements of the present invention can be implemented, and it is within the scope of the present invention to modify the shape, structure, etc. of the dc cable equally according to the practical needs.
Claims (8)
1. A method for measuring the charge distribution of the insulation space of a direct current cable at different temperatures is characterized by comprising the following steps:
1) intercepting two sections of tested cable samples with the same type, wherein one section is a test cable (1) and the other section is a simulation cable (2); the simulation cable (2) is respectively punched at a plurality of positions, the punching depth comprises a conductor layer, an insulating layer and a filling layer, thermocouples (3) are installed at the punching positions, and the thermocouples (3) are installed at the skins of the simulation cable (2) and the test cable (1); the thermocouple (3) arranged on the simulation cable (2) covers the conductor layer, the insulating layer, the filling layer and the outer skin in the temperature measuring range;
2) building a thermal cycle test system, interconnecting two ends of a test cable (1) and two ends of a simulation cable (2) to form a cable loop, and coating the surfaces of the test cable (1) and the simulation cable (2) with heat insulation materials;
3) heating a cable loop by using a thermal cycle test system, adjusting loop current, and monitoring the temperature of a cable conductor by using a thermocouple (3);
4) when the cable conductor reaches the highest operation temperature, the thermal cycle test system is closed, and heating is stopped; the method comprises the following steps of (1) unwinding a cable loop, hanging a test cable (1) on a cable frame (5), installing equalizing rings (6) at two ends of the test cable (1), connecting a direct-current high-voltage generator lead (11) to one end of the test cable (1), and inputting direct-current high voltage to the test cable (1) through the equalizing rings (6) by the direct-current high-voltage generator;
5) monitoring the temperature state of each structural layer of the simulation cable (2) in real time through the thermocouple (3), and considering that the cooling speed of the simulation cable (2) is consistent with that of the test cable (1) under the same condition, namely the insulation temperature of the simulation cable (2) is the insulation temperature of the test cable (1);
6) in the cable cooling process, a space charge measurement system based on a laser pressure wave method is adopted to measure the space charge distribution condition of the insulation of the test cable (1) at different temperatures, and the insulation space charge distribution data of the direct current cable at different temperatures are obtained.
2. The method for measuring the insulation space charge distribution of the direct current cable at different temperatures according to claim 1, wherein the method comprises the following steps: the thermal cycle test system comprises a feed-through transformer (4) for heating the cable conductor, a current transformer (7) for detecting the current of the cable conductor, a thermocouple (3) for detecting the temperature, and a thermal cycle test controller connected with the feed-through transformer (4), the current transformer (7) and the thermocouple (3).
3. The method for measuring the insulation space charge distribution of the direct current cable at different temperatures according to claim 2, wherein the method comprises the following steps: three punching holes are selected at two ends of the simulation cable (2), and the punching depths of the three punching holes respectively reach the conductor layer, the insulating layer and the filling layer.
4. A method for measuring the space charge distribution of the insulation of a dc cable at different temperatures according to claim 3, wherein: when a thermal cycle test system is built, a plurality of feedthrough transformers (4) are arranged at the middle section of the analog cable (2), and a current transformer (7) is arranged on the analog cable (2) between the outermost feedthrough transformer (4) and the thermocouple (3) in a penetrating manner; a space charge testing electrode (8) is arranged in the middle of the testing cable (1), and stress cones (9) are arranged at two ends of the testing cable (1); the two ends of the cable and the two ends of the simulation cable (2) are butted through a crimping type cable conductor joint (10) to form a thermal cycle test loop.
5. The method for measuring the insulation space charge distribution of the direct current cable at different temperatures according to claim 1, wherein the method comprises the following steps: the laser pressure wave space charge measuring system comprises a laser, a cable frame (5) and an oscilloscope.
6. The method for measuring the insulation space charge distribution of the direct current cable at different temperatures according to claim 5, wherein the method comprises the following steps: before the temperature state of each structural layer of the simulation cable (2) is monitored in real time, the heat-insulating layer is untied so as to improve the cooling rate.
7. The method for measuring the insulation space charge distribution of the direct current cable at different temperatures according to claim 6, wherein the method comprises the following steps: before space charge measurement, after a cable loop is untied, a test cable (1) is hung to a cable rack (5) by a travelling crane, and two ends of the test cable (1) are hung on the cable rack (5).
8. The method for measuring the insulation space charge distribution of the direct current cable at different temperatures according to claim 1, wherein the method comprises the following steps: the length of the test cable (1) is 9-11 meters.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910286772.9A CN110007161B (en) | 2019-04-10 | 2019-04-10 | Method for measuring direct current cable insulation space charge distribution at different temperatures |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910286772.9A CN110007161B (en) | 2019-04-10 | 2019-04-10 | Method for measuring direct current cable insulation space charge distribution at different temperatures |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110007161A CN110007161A (en) | 2019-07-12 |
| CN110007161B true CN110007161B (en) | 2021-04-02 |
Family
ID=67170955
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910286772.9A Active CN110007161B (en) | 2019-04-10 | 2019-04-10 | Method for measuring direct current cable insulation space charge distribution at different temperatures |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110007161B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112462208A (en) * | 2020-11-13 | 2021-03-09 | 国网浙江省电力有限公司舟山供电公司 | Multi-parameter-based direct current cable insulation diagnosis and performance test system |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1164415A (en) * | 1997-08-26 | 1999-03-05 | Hitachi Cable Ltd | Measurement method for storage space charge distribution of power cable |
| CN101738546B (en) * | 2009-12-18 | 2013-10-23 | 西安交通大学 | Device, system and method for measuring space charges by using electro-acoustic (PEA) method |
| JP5718601B2 (en) * | 2010-09-15 | 2015-05-13 | 株式会社日立ハイテクインスツルメンツ | Die bonder and semiconductor manufacturing method |
| CN104297646B (en) * | 2014-10-14 | 2017-02-15 | 中国南方电网有限责任公司电网技术研究中心 | Load cycle test insulating temperature gradient control method and system for high-voltage direct-current cables |
| CN106597135B (en) * | 2016-12-13 | 2019-05-03 | 哈尔滨理工大学 | The space charge measurement device realized under temperature gradient using induced with laser pressure wave |
| CN108089068B (en) * | 2017-12-08 | 2020-03-17 | 西安交通大学 | Composite flat plate sample three-dimensional space charge measuring device based on electroacoustic pulse method |
| CN108508286A (en) * | 2018-05-18 | 2018-09-07 | 深圳供电局有限公司 | A kind of direct current cables space charge measuring system |
-
2019
- 2019-04-10 CN CN201910286772.9A patent/CN110007161B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110007161A (en) | 2019-07-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Bahder et al. | Electrical and electro-chemical treeing effect in polyethylene and crosslinked polyethylene cables | |
| Förstel et al. | Grid diagnostics: Monitoring cable aging using power line transmission | |
| Dong et al. | Analysis of cable failure modes and cable joint failure detection via sheath circulating current | |
| CN108646152B (en) | Method for detecting and evaluating insulation aging state of stator bar by polarization/depolarization current method | |
| CN110007161B (en) | Method for measuring direct current cable insulation space charge distribution at different temperatures | |
| CN109406347A (en) | A kind of three cores system packet cable connector layering water-resisting ability certification test method | |
| WO2023072174A1 (en) | Method for determining insulation thermomechanical deterioration of vpi wire rod of pumped storage power generation motor | |
| CN111382531A (en) | Current-carrying capacity and temperature simulation method for high-voltage alternating-current submarine cable | |
| CN115758730A (en) | Aging detection method and device for self-melting type cable intermediate joint | |
| Marian et al. | Demonstration tests of a 320-kV-class DC superconducting cable for transmission of high powers | |
| Sutton | High stress wet aging of cable dielectrics-meeting new challenges | |
| Patel et al. | MV cable termination failure assessment in the context of increased use of power electronics | |
| CN109100621B (en) | Burn simulation test method and structure between outer semi-conducting layer of cable and aluminum sheath | |
| CN111060565A (en) | High-voltage direct-current cable material resistivity characteristic evaluation method | |
| Tzimas et al. | Qualitative analysis of PEA and TSM techniques on a 200kV extruded cable during a VSC ageing program | |
| CN110045247A (en) | A kind of bushing shell for transformer accelerates the experimental method of heat ageing | |
| CN104407247A (en) | Method and device for determining carrying capacity of two parallel direct-buried cables | |
| CN112731074B (en) | Oilpaper insulation aging test system | |
| Imburgia et al. | Effect of Space charge accumulation inside the thermoplastic insulation of a loaded HVDC model cable | |
| Soh et al. | Partial Discharge Simulation and Detection in 750V DC XLPE Cables | |
| Zhang et al. | Investigation on space charge behavior in water tree aged crosslinked polyethylene (XLPE) cable by experiment and simulation | |
| Liu et al. | Analysis of AC 500kV XLPE Submarine Cable Insulation Laboratory Aging Condition Based on Frequency Domain Dielectric Spectroscopy | |
| CN106706410A (en) | Aluminum alloy strip lock-armo cable flexibility test device and aluminum alloy strip lock-armo cable flexibility test method | |
| Shi et al. | Space Charge Distribution in Submarine Cable Factory Joint Insulation | |
| Mirebeau et al. | Review of HVDC insulated transmission cables technologies |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |