CN115758047A - Method for calculating temperature of directly-buried 10kV cable core based on electric heat conversion coefficient - Google Patents
Method for calculating temperature of directly-buried 10kV cable core based on electric heat conversion coefficient Download PDFInfo
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- CN115758047A CN115758047A CN202211444797.5A CN202211444797A CN115758047A CN 115758047 A CN115758047 A CN 115758047A CN 202211444797 A CN202211444797 A CN 202211444797A CN 115758047 A CN115758047 A CN 115758047A
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- 238000006243 chemical reaction Methods 0.000 title claims abstract description 17
- 238000000034 method Methods 0.000 title claims abstract description 10
- 239000002689 soil Substances 0.000 claims abstract description 20
- 238000009413 insulation Methods 0.000 claims abstract description 12
- 238000012937 correction Methods 0.000 claims abstract description 11
- 239000000463 material Substances 0.000 claims description 6
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 3
- 239000004020 conductor Substances 0.000 claims description 3
- 229910052739 hydrogen Inorganic materials 0.000 claims description 3
- 239000001257 hydrogen Substances 0.000 claims description 3
- 238000012544 monitoring process Methods 0.000 claims description 3
- 230000032683 aging Effects 0.000 abstract description 6
- 238000004364 calculation method Methods 0.000 abstract description 5
- 238000011156 evaluation Methods 0.000 abstract description 2
- 230000009286 beneficial effect Effects 0.000 abstract 1
- 230000002035 prolonged effect Effects 0.000 abstract 1
- 229920003020 cross-linked polyethylene Polymers 0.000 description 4
- 239000004703 cross-linked polyethylene Substances 0.000 description 4
- 238000010276 construction Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
Abstract
The invention discloses a method for calculating the temperature of a directly-buried 10kV cable core based on an electrothermal conversion coefficient, which comprises the following steps of: measuring the surface air temperature and the surface soil temperature of the laid part of the cable, measuring the temperature of the outer sheath of the cable, acquiring the working current information of the cable, calculating a temperature correction coefficient, calculating an electrothermal conversion coefficient and calculating the temperature of a cable core. The invention has the beneficial effects that: through the temperature correction coefficient and the electric heat conversion coefficient, the accurate calculation of the temperature of the buried 10kV cable core is realized, so that the evaluation of the insulation aging state inside the 10kV cable can be realized, the cable with serious aging is replaced in time, the service life of the low-load cable is prolonged, and the stable operation of power supply of a cable system is ensured.
Description
Technical Field
The invention belongs to the field of XLPE cable insulation state evaluation, and particularly relates to a calculation method for the temperature of a directly-buried 10kVXLPE cable core based on an electrothermal conversion coefficient.
Background
The cross-linked polyethylene (XLPE) cable has the advantages of simple structure, strong load capacity, high mechanical strength and the like, and is widely used in the transformation and new construction of urban power distribution networks in recent years. The laying mode of cable is various, and direct-burried cable laying, calandria cable laying, tunnel cable laying, slot cable laying, ladder frame cable laying, aerial [ insulated ] cable laying etc.. The direct-buried laying mode has the characteristics of less civil engineering quantity, convenience in laying, high construction progress and investment saving, and is widely applied to actual cable distribution projects. The insulation aging state of a high-voltage XLPE cable running in a power grid is closely related to the working temperature of a cable core, and if the cable runs under a high load condition for a long time, the working temperature of the cable core is continuously in a high position, so that the insulation aging of the cable is accelerated; if the cable runs under the low-load condition for a long time, the working temperature of the cable core is not greatly different from the ambient temperature of the cable, the temperature rise of the cable core has small influence on the insulation aging of the cable, and the service life expectancy of the cable is greatly improved. Therefore, the working temperature of the cable core of the cable is calculated, and the method has important significance for evaluating the insulation aging state in the cable, timely replacing the seriously aged cable, prolonging the service life of the low-load cable and ensuring the power supply stability of a cable system.
However, for the established cable power transmission network, since the sensor cannot be connected into the cable, the temperature of the cable core of the cable can only be indirectly calculated according to the temperature of the outer sheath of the cable and the working current of the cable, and therefore, a method for calculating the temperature of the cable core of the cable, which is accurate, efficient and convenient, is urgently needed. The method provides a cable core temperature calculation method based on the electrothermal conversion coefficient aiming at the directly-buried 10kV cable, corrects the cable core temperature calculation result by using the electrothermal conversion coefficient, is simple to operate and can realize accurate calculation of the core temperature of the directly-buried 10kV cable.
Disclosure of Invention
The invention discloses a method for calculating the temperature of a directly-buried 10kV cable core based on a temperature correction coefficient, which is used for calculating the temperature of the directly-buried 10kV cable core of a power distribution network in long-term operation.
The technical scheme of the invention is as follows:
the first step is as follows: measuring the surface air temperature and the surface soil temperature at the cable laying site
Measuring the surface air temperature and the surface soil temperature at the cable laying position five times at intervals of 30 seconds, and respectively recording the surface air temperature and the surface soil temperature as T i ，T j (1 ≦ i = j ≦ 5), and the average of the surface air temperatures measured five times is taken as the surface air temperature T a ：
Taking the surface soil temperature mean value of five measurements as the surface soil temperature T s ：
The second step is that: measuring the temperature of the outer sheath of a cable
Measuring the surface air temperature and the surface soil temperature at the cable laying position five times at intervals of 10 seconds, and respectively recording the surface air temperature and the surface soil temperature as T k (k is more than or equal to 1 and less than or equal to 5), and taking the average value of the surface air temperature measured five times as the surface air temperature T t ：
The third step: obtaining operating current information for a cable
Recording the working current I of the cable five times from the cable outlet end monitoring equipment at intervals of 10 seconds k (1 is more than or equal to k is less than or equal to 5), taking the average value of the five recorded working currents as the working current I of the cable at the moment:
the fourth step: calculating temperature correction coefficient of cable core
The temperature correction coefficient delta of the cable core can be calculated by the following formula (7):
the fifth step: calculating the electrothermal conversion coefficient sigma
The electric-to-thermal conversion coefficient of the cable can be calculated by equation (6):
where σ is the electrothermal conversion coefficient, unit: K/A 2 ；r c Radius for cable core, unit: m; r is x Is the outer radius of the cable insulation, unit: m; r is t Is the outer radius of the cable sheath layer, unit: m; ρ is a unit of a gradient x Is the thermal resistivity of the cable insulation layer material, the unit is: K.m/W; ρ is a unit of a gradient t Is the thermal resistivity of the cable sheath material, the unit is: K.m/W; tau. c Resistivity of the cable conductor, unit: omega m
And a sixth step: calculating the temperature of the cable core
Temperature T of cable core x Can be calculated by the following equation (8):
T x ＝δ(T g +σI 2 ) (7)
in the formula, T x For cable core temperature, unit: DEG C.
Drawings
Fig. 1 is a flow chart of a method for calculating the core temperature of a directly-buried 10kVXLPE cable based on a temperature correction coefficient.
Detailed Description
The invention is further described with reference to the accompanying drawings and the specific implementation procedures.
The first step is as follows: measuring the surface air temperature and the surface soil temperature at the cable laying site
Measuring the surface air temperature and the surface soil temperature at the cable laying position five times at intervals of 30 seconds, and respectively recording the surface air temperature and the surface soil temperature as T i ，T j (1I = j ≦ 5), and taking the average value of the surface air temperature measured for five times as the surface air temperature T a ：
The mean value of the surface soil temperature measured by five times is taken as the surface soil temperature T s ：
The second step is that: measuring the temperature of the outer sheath of a cable
Measuring the surface air temperature and the surface soil temperature at the cable laying part five times at intervals of 10 seconds, and respectively recording the surface air temperature and the surface soil temperature as T k (k is more than or equal to 1 and less than or equal to 5), and taking the average value of the surface air temperature measured five times as the surface air temperature T t ：
The third step: obtaining operating current information for a cable
Recording the working current I of the cable five times from the cable outlet end monitoring equipment at intervals of 10 seconds k (k is more than or equal to 1 and less than or equal to 5), taking the average value of the five recorded working currents as the working current I of the cable at the moment:
the fourth step: calculating temperature correction coefficient of cable core
The temperature correction coefficient delta of the cable core can be calculated by the following formula (7):
the fifth step: calculating the electrothermal conversion coefficient sigma
The electric-to-thermal conversion coefficient of the cable can be calculated by equation (6):
where σ is the electrothermal conversion coefficient, unit: K/A 2 ；r c Radius for cable core, unit: m; r is a radical of hydrogen x Is the outer radius of the cable insulation, unit: m; r is t The outer radius of the cable sheath layer, unit: m; rho x Is the thermal resistance coefficient of the cable insulation layer material, unit: K.m/W; rho t Is the thermal resistance coefficient of the cable sheath material, unit: K.m/W; tau. c Is the resistivity of the cable conductor, in units: omega m
And a sixth step: calculating the temperature of the cable core
Temperature T of cable core x Can be calculated by the following equation (8):
T x ＝δ(T g +σI 2 ) (7)
in the formula, T x For cable core temperature, unit: DEG C.
Claims (1)
1. A method for calculating the temperature of a directly-buried 10kV cable core based on a temperature correction coefficient is characterized by comprising the following steps:
the first step is as follows: measuring the surface air temperature and the surface soil temperature at the cable laying site
Measuring the surface air temperature and the surface soil temperature at the cable laying position five times at intervals of 30 seconds, and respectively recording the surface air temperature and the surface soil temperature as T i ，T j (unit: K, kelvin; i = {1,2,3,4,5}, j = {1,2,3,4,5 }), and the average value of the surface air temperatures measured five times is taken as the surface air temperature T a (unit: K):
five measurementsThe mean value of the earth surface soil temperature is taken as the earth surface soil temperature T s (unit: K):
the second step is that: measuring the temperature of the outer sheath of a cable
Measuring the temperature of the outer sheath of the cable five times at intervals of 10 seconds, and respectively recording the temperature as T k (k = {1,2,3,4,5 }), and the average value of the surface air temperatures measured five times is taken as the surface air temperature T t (unit: K):
the third step: obtaining operating current information for a cable
Recording the working current I of the cable five times from the cable outlet end monitoring equipment at intervals of 10 seconds k (k = {1,2,3,4,5 }), the average value of the five recorded operating currents is taken as the operating current I of the cable at this time:
the fourth step: calculating temperature correction coefficient of cable core
The temperature correction coefficient delta of the cable core can be calculated by the following formula (7):
the fifth step: calculating the electrothermal conversion coefficient sigma
The electric-to-thermal conversion coefficient of the cable can be calculated by equation (6):
wherein σ is the electrothermal conversion coefficient in units: K/A 2 ；r c Radius of the cable core, unit: m; r is a radical of hydrogen x Outer radius of cable insulation, unit: m; r is a radical of hydrogen t The outer radius of the cable sheath layer, unit: m; rho x Is the thermal resistance coefficient of the cable insulation layer material, unit: K.m/W; rho t Is the thermal resistivity of the cable sheath material, the unit is: K.m/W; tau. c Resistivity of the cable conductor, unit: omega m
And a sixth step: calculating the temperature of the cable core
Temperature T of cable core x Can be calculated by the following equation (8):
T x ＝δ(T g +σI 2 ) (7)
in the formula, T x For cable core temperature, unit: K.
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001165781A (en) * | 1999-12-13 | 2001-06-22 | Hitachi Cable Ltd | Method for estimating conductor temperature of power cable |
| CN1982859A (en) * | 2005-12-13 | 2007-06-20 | 李志坚 | Electric-cable core temperature on-line monitoring system |
| CN103048568A (en) * | 2012-12-21 | 2013-04-17 | 广东电网公司佛山供电局 | Method and system for determining current-carrying capacity of three-core cable laid in cable duct |
| CN103226172A (en) * | 2013-04-02 | 2013-07-31 | 国家电网公司 | Cable ampacity analysis system based on linear temperature-sensitive technology and calculation method for cable ampacity |
| CN103336023A (en) * | 2013-06-04 | 2013-10-02 | 华南理工大学 | Calculation method of thermal resistance of power cable |
| CN105808830A (en) * | 2016-03-03 | 2016-07-27 | 国家电网公司 | Method for calculating thermal ageing states of cables by utilizing load current of cables |
| CN105866564A (en) * | 2016-03-17 | 2016-08-17 | 南京电力工程设计有限公司 | Cable core temperature inversion formula examination method and apparatus thereof |
| CN110083908A (en) * | 2019-04-19 | 2019-08-02 | 陕西科技大学 | Cable conductor temperature predicting method based on finite element analysis |
| CN115204000A (en) * | 2022-06-06 | 2022-10-18 | 国网湖北省电力有限公司电力科学研究院 | Method for calculating rated current-carrying capacity of cable based on soil thermal resistivity change |
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- 2022-11-18 CN CN202211444797.5A patent/CN115758047B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001165781A (en) * | 1999-12-13 | 2001-06-22 | Hitachi Cable Ltd | Method for estimating conductor temperature of power cable |
| CN1982859A (en) * | 2005-12-13 | 2007-06-20 | 李志坚 | Electric-cable core temperature on-line monitoring system |
| CN103048568A (en) * | 2012-12-21 | 2013-04-17 | 广东电网公司佛山供电局 | Method and system for determining current-carrying capacity of three-core cable laid in cable duct |
| CN103226172A (en) * | 2013-04-02 | 2013-07-31 | 国家电网公司 | Cable ampacity analysis system based on linear temperature-sensitive technology and calculation method for cable ampacity |
| CN103336023A (en) * | 2013-06-04 | 2013-10-02 | 华南理工大学 | Calculation method of thermal resistance of power cable |
| CN105808830A (en) * | 2016-03-03 | 2016-07-27 | 国家电网公司 | Method for calculating thermal ageing states of cables by utilizing load current of cables |
| CN105866564A (en) * | 2016-03-17 | 2016-08-17 | 南京电力工程设计有限公司 | Cable core temperature inversion formula examination method and apparatus thereof |
| CN110083908A (en) * | 2019-04-19 | 2019-08-02 | 陕西科技大学 | Cable conductor temperature predicting method based on finite element analysis |
| CN115204000A (en) * | 2022-06-06 | 2022-10-18 | 国网湖北省电力有限公司电力科学研究院 | Method for calculating rated current-carrying capacity of cable based on soil thermal resistivity change |
Non-Patent Citations (3)
| Title |
|---|
| 姜小兵: "XLPE 电缆线芯温度计算方法研究", 东北电力技术, no. 3, 31 March 2014 (2014-03-31), pages 1 - 3 * |
| 李好: "直埋电缆缆芯温度的反演计算", 通信电源技术, vol. 36, no. 5, pages 116 - 119 * |
| 薛强 等: "电缆导体温度的推算方法及应用", 电线电缆, no. 2, pages 23 - 25 * |
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