CN107516870A - A kind of cable run automatic reclosing method based on short circuit current heat localization process - Google Patents

A kind of cable run automatic reclosing method based on short circuit current heat localization process Download PDF

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Publication number
CN107516870A
CN107516870A CN201710948475.7A CN201710948475A CN107516870A CN 107516870 A CN107516870 A CN 107516870A CN 201710948475 A CN201710948475 A CN 201710948475A CN 107516870 A CN107516870 A CN 107516870A
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China
Prior art keywords
cable
mrow
short circuit
circuit current
automatic reclosing
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CN201710948475.7A
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CN107516870B (en
Inventor
刘健
赵艾萱
徐龙
张志华
赵学风
陈曦
李嘉明
邓军波
张冠军
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State Grid Corp of China SGCC
Xian Jiaotong University
Electric Power Research Institute of State Grid Shaanxi Electric Power Co Ltd
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State Grid Corp of China SGCC
Xian Jiaotong University
Electric Power Research Institute of State Grid Shaanxi Electric Power Co Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/02—Details
    • H02H3/06—Details with automatic reconnection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current
    • H02H3/085—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current making use of a thermal sensor, e.g. thermistor, heated by the excess current

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  • Laying Of Electric Cables Or Lines Outside (AREA)

Abstract

The present invention provides a kind of cable run automatic reclosing method based on short circuit current heat localization process, including：Obtain cable laying type, the operation time limit and ambient parameter；The geometrical structure parameter of cable is measured, reads the resistance parameter of the corresponding thermal capacitance of cable above layers, thermal resistance and metal part, wherein ambient parameter, thermal capacitance, thermal resistance and resistance parameter are as calculating parameter；According to the calculating parameter and the geometrical structure parameter of cable, establish the mathematical modeling of cable dynamic heat localization process under short circuit current effect, and automatic reclosing strategy is formulated according to the temperature change during the heat localization of gained cable and laying type, the operation time limit, include the delay time and number of automatic reclosing.Pin of the present invention has filled up the blank of existing cable automatic reclosing strategy application, can formulate automatic reclosing strategy according to the running status of different cables, greatly reduce the workload and power off time of artificial reclosing, improve the reliability of power supply conscientiously.

Description

A kind of cable run automatic reclosing method based on short circuit current heat localization process
Technical field
The present invention relates to high voltage and insulation technology field, and in particular to a kind of cable run automatic reclosing method.
Background technology
With Process of Urbanization Construction continuous quickening and to power supply reliability requirement raising, overhead transmission line change cable into For a kind of inevitable trend.For a long time, automatic reclosing technology is widely used in overhead transmission line, is effectively improved power supply Reliability, but whether automatic reclosing is used containing cable run for power distribution network, unified understanding is not yet formed at present.State's household electrical appliances Regulation cable run does not use automatic reclosing in net company current design criteria, mainly considers that cable run occurs in running Failure be generally permanent fault, reclosing operation will bring serious short-circuit impact and switching overvoltage, to cable and change The equipment belts such as depressor damage, and accident is further expanded.But from the point of view of operation department distribution line failure analysis result, full electricity The transient fault on cable road still occupies certain proportion, can if can effectively improve power supply to pure cable run input automatic reclosing By property.
However, reclosing is blindly carried out to the cable in different conditions, it is possible to cause cable on fire, blast serious Consequence, can not only give full play to automatic reclosing improve power supply reliability effect, also exist failure propagation, harm the person and The hidden danger of equipment safety.Therefore, it is badly in need of the actual conditions according to each cable run and reclosing is decided whether by scientific method.
The content of the invention
It is an object of the invention to provide a kind of cable run automatic reclosing side based on short circuit current heat localization process Method, to solve above-mentioned technical problem.The present invention only needs existing current monitoring system collection cable that short circuit occurs due to its input quantity The electric current of fault moment, therefore the hardware requirement applied is relatively low, it is easy to spread.The present invention can be based on existing current monitoring system Cable status can be scored with account information, to determine reclosing number and delay time.The present invention can be carried effectively The power supply reliability of high cable run, low-impedance earthed system is particularly switched to by high resistance ground in distribution network systems neutral grounding mode There is extremely important theory and practice to be worth under overall background.
To achieve these goals, the present invention adopts the following technical scheme that：
A kind of cable run automatic reclosing method based on short circuit current heat localization process, comprises the following steps：
Step 1: monitoring obtains ambient parameter corresponding to respective cable line cord laying type, including：Heat convection system Number а, soil near-bottom temperature Tsoil, soil thermal resistivity ρ and air real time temperature Tamb；
Step 2: reading the geometric parameter of the construction of cable, and the corresponding thermal capacitance of each layer of cable, heat are solved according to geometric parameter Resistance and the resistance parameter of metal part；
Step 3: the limited element calculation model of short circuit current heat localization process is established, and according to the mode meter of iterative numerical Calculate cable temperature T (x, y, t) and time t under short circuit current effect variation relation；
Step 4: after obtaining temperature T (x, y, t) of each region of cable under short circuit current effect, by reading cable area Domain maximum temperature TmaxConfigure the automatic reclosing strategy of cable run.
Further, the geometric parameter of the construction of cable includes：Conductor diameter D1, conductor shielding thickness δ1, insulation thickness t1、 Insulation shielding thickness ti2, metallic shield thickness ts, sheath thickness t2, its thickness δ and outer jacket thickness t3。
Further, the step 3 is specially：
Each layer thermal capacitance of cable, the thermal resistance calculated according to step 2, thermal conductivity factor D is calculated, and utilizes thermal capacitance storage energy Make every effort to solve thermal diffusivity K；Meanwhile according to short circuit current IFThe endogenous pyrogen heating of each core is tried to achieve with cable core resistance parameter Rate
qv=IF 2R/S0 (1)
Wherein, S0For cable core region area；R is the D.C. resistance of cable；
Cable domain S is established according to the geometrical structure parameter of each Rotating fields, where it on cable domain S a bit Coordinate x, y must conduct heat formula, as shown in formula (2)：
Wherein T represents the temperature of cable core, and D is each region thermal conductivity factor, and K is each region thermal diffusivity, qvFor interior heat Source heat generation rate；
According to boundary condition of the ambient parameter that step 1 obtains as formula (2) domain S, in this, as basis to it Variation is carried out, is obtained shown in functional I such as formulas (3)：
Wherein, L is region S border；
Functional I is divided into limited individual unit in the S of region, and by its discretization, obtains formula (4)：
Wherein,For stiffness matrix,For heat source density matrix, NE is unit number, and the final extreme value for solving functional I is asked Obtain temperature T (x, y, t) and time t of each region of cable under short circuit current effect variation relation.
Further, according to temperature T (x, y, t) and the time t under short circuit current effect tried to achieve variation relation Scoring, system of laying scoring, run the time limit scoring, with reference to three's respective weights coefficient carry out calculate obtain overall score, Reclosing delay time and number are determined according to overall score.
Further, the ratio between weight coefficient corresponding to three is 40%：40%：20%.
Further, the variation relation of temperature T (x, y, t) and the time t under short circuit current effect, using desired Temperature T (x, y, t) and according to obtained temperature maximum T when delay time t solves the corresponding momentmaxThe corresponding scoring of inquiry：
TmaxTemperature range Scoring
(- ∞, 90 DEG C) 100
[90 DEG C, 135 DEG C) 80
[135 DEG C, 250 DEG C) 60
[250 DEG C ,+∞) 0
Further, scored accordingly according to different laying way of local type queries：
Further, according to the different corresponding scorings of operation time limit inquiry：
Run the time limit Scoring
Less than 5 years 100
More than 5 years, less than 15 years 80
More than 15 years, less than 25 years 60
More than 25 years 0
Further, delay time is voluntarily formulated according to relaying configuration strategy, and reclosing number, which is formulated, to be included：
Overall score Reclosing number
[90,100] 2
[80,90) 1
[0,80) Forbid to configure automatic reclosing
Relative to prior art, the invention has the advantages that：
The present invention gathers electric current when short trouble occurs for cable run by monitoring system, not only avoid additional monitoring Equipment belt comes cost and potential safety hazard, but also can effectively avoid traditional on-line monitoring from gathering weak current by outside The problem of interference.In the case where distribution network systems neutral grounding mode is changed to the overall background of low-impedance earthed system by high resistance ground, cable tripping operation Probability certainly will be greatly improved, and a line maintenance work efficiency and power supply reliability can be effectively improved using the present invention, existing each Do not related in class reclosing configuration strategy.
Brief description of the drawings
Fig. 1 is the schematic flow sheet of the configuration reclosing method of the invention based on short circuit current heat localization process；
Embodiment
Below in conjunction with the accompanying drawing in the present invention, the technical scheme in the present invention is clearly and completely described.
Reference picture 1, a kind of cable run automatic reclosing side based on short circuit current heat localization process of offer of the invention Method, comprise the following steps：
Step 1: monitoring obtains ambient parameter corresponding to respective cable laying type, including：Convection transfer rate а, soil Near-bottom temperature Tsoil, soil thermal resistivity ρ, air real time temperature Tamb；
Step 2: read the geometric parameter of the construction of cable, and according to geometric parameter solve the corresponding thermal capacitance of each layer, thermal resistance with And the resistance parameter of metal part；
Step 3: the limited element calculation model of short circuit current heat localization process is established according to above-mentioned parameter, and according to numerical value The mode of iteration calculates cable temperature T (x, y, t) and time t under short circuit current effect variation relation；
Step 4: after temperature T (x, y, t) of each region of cable under short circuit current effect is obtained, by reading cable Region maximum temperature TmaxConfigure the automatic reclosing strategy of cable run.
In step 2, the geometric parameter of the construction of cable includes conductor diameter D1, conductor shielding thickness δ1, insulation thickness t1, absolutely Edge shielding thickness ti2, metallic shield thickness ts, sheath thickness t2, its thickness δ, outer jacket thickness t3。
The step 3 is specially：
Each layer thermal capacitance of cable, the thermal resistance calculated according to step 2, thermal conductivity factor D is calculated, and utilizes thermal capacitance storage energy Make every effort to solve thermal diffusivity K.Meanwhile according to short circuit current IFThe endogenous pyrogen heating of each core is tried to achieve with cable core resistance parameter Rate
qv=IF 2R/S0 (1)
Wherein, S0For cable core region area；R is the D.C. resistance of cable.
Cable domain S is established according to the geometrical structure parameter of each Rotating fields, where it on cable domain S a bit Coordinate x, y must can conduct heat formula, as shown in formula (2)：
Wherein T represents the temperature of cable core, and D is each region thermal conductivity factor, and K is each region thermal diffusivity, qvFor interior heat Source heat generation rate；
According to boundary condition of the ambient parameter that step 1 obtains as formula (2) domain S, in this, as basis to it Variation is carried out, is obtained shown in functional I such as formulas (3)：
Wherein, L is region S border；
Functional I is divided into limited individual unit in the S of region, and by its discretization, obtains formula (4)：
Wherein,For stiffness matrix,For heat source density matrix, NE is unit number, and final solution functional I extreme value is Temperature T (x, y, t) and time t of each region of cable under short circuit current effect variation relation can be tried to achieve.
Hereafter, according to the variation relation for being tried to achieve temperature T (x, y, t) and the time t under short circuit current effect and System of laying, the weight coefficient of the operation time limit are calculated, and determine that reclosing delay time and the ratio between number, the weight of three are 40%：40%：20%.
Specifically, the variation relation of temperature T (x, y, t) and the time t under short circuit current effect, is prolonged using desired When time t temperature T (x, y, t) and according to obtained temperature maximum T when solving the corresponding momentmaxThe corresponding scoring of inquiry.Its In, scoring includes：
Foregoing system of laying, scored accordingly according to different laying way of local type queries, including：
Lay type Scoring
Direct-burried/aerial 100
Comb 80
Groove 60
Tunnel 0
The foregoing operation time limit, according to the different corresponding scorings of operation time limit inquiry, including：
Run the time limit Scoring
Less than 5 years 100
More than 5 years, less than 15 years 80
More than 15 years, less than 25 years 60
More than 25 years 0
Foregoing reclosing delay time and number：Delay time is voluntarily formulated according to relaying configuration strategy, is overlapped Lock number, which is formulated, to be included：
Overall score Reclosing number
[90,100] 2
[80,90) 1
[0,80) Forbid to configure automatic reclosing
Corresponding weight is multiplied by the scoring of three, is then added and is obtained final scoring, and scoring is more than or equal to 90, overlaps Lock number is 2；Less than 90 and more than or equal to 80, reclosing number is 1；Less than 80, forbid to configure automatic reclosing.
The foregoing is only a specific embodiment of the invention, but protection scope of the present invention is not limited thereto, any Belong to those skilled in the art the invention discloses technical scope in, the change or replacement that can readily occur in, all should It is included within the scope of the present invention.Therefore, protection scope of the present invention should be defined by scope of the claims.

Claims (9)

  1. A kind of 1. cable run automatic reclosing method based on short circuit current heat localization process, it is characterised in that including as follows Step：
    Step 1: monitoring obtains ambient parameter corresponding to respective cable line cord laying type, including：Convection transfer rate а, Soil near-bottom temperature Tsoil, soil thermal resistivity ρ and air real time temperature Tamb；
    Step 2: read the geometric parameter of the construction of cable, and according to geometric parameter solve the corresponding thermal capacitance of each layer of cable, thermal resistance with And the resistance parameter of metal part；
    Step 3: establishing the limited element calculation model of short circuit current heat localization process, and electricity is calculated according to the mode of iterative numerical Cable temperature T (x, y, t) and time t under short circuit current effect variation relation；
    Step 4: after obtaining temperature T (x, y, t) of each region of cable under short circuit current effect, by reading cable area most High-temperature TmaxConfigure the automatic reclosing strategy of cable run.
  2. 2. a kind of cable run automatic reclosing method based on short circuit current heat localization process according to claim 1, It is characterized in that：The geometric parameter of the construction of cable includes：Conductor diameter D1, conductor shielding thickness δ1, insulation thickness t1, insulation screen Cover thickness ti2, metallic shield thickness ts, sheath thickness t2, its thickness δ and outer jacket thickness t3。
  3. 3. a kind of cable run automatic reclosing method based on short circuit current heat localization process according to claim 1, It is characterized in that：The step 3 is specially：
    Each layer thermal capacitance of cable, the thermal resistance calculated according to step 2, is calculated thermal conductivity factor D, and ask using thermal capacitance storage capacity Solve thermal diffusivity K；Meanwhile according to short circuit current IFThe endogenous pyrogen heat generation rate of each core is tried to achieve with cable core resistance parameter
    qv=IF 2R/S0 (1)
    Wherein, S0For cable core region area；R is the D.C. resistance of cable；
    Cable domain S is established according to the geometrical structure parameter of each Rotating fields, the seat of any on cable domain S where it X is marked, y must conduct heat formula, as shown in formula (2)：
    <mrow> <mfrac> <mrow> <msup> <mo>&amp;part;</mo> <mn>2</mn> </msup> <mi>T</mi> </mrow> <mrow> <mo>&amp;part;</mo> <msup> <mi>x</mi> <mn>2</mn> </msup> </mrow> </mfrac> <mo>+</mo> <mfrac> <mrow> <msup> <mo>&amp;part;</mo> <mn>2</mn> </msup> <mi>T</mi> </mrow> <mrow> <mo>&amp;part;</mo> <msup> <mi>y</mi> <mn>2</mn> </msup> </mrow> </mfrac> <mo>+</mo> <mfrac> <msub> <mi>q</mi> <mi>v</mi> </msub> <mi>D</mi> </mfrac> <mo>=</mo> <mi>K</mi> <mfrac> <mrow> <mo>&amp;part;</mo> <mi>T</mi> </mrow> <mrow> <mo>&amp;part;</mo> <mi>t</mi> </mrow> </mfrac> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </mrow>
    Wherein T represents the temperature of cable core, and D is each region thermal conductivity factor, and K is each region thermal diffusivity, qvGenerated heat for endogenous pyrogen Rate；
    According to boundary condition of the ambient parameter that step 1 obtains as formula (2) domain S, it is carried out in this, as basis Variation, obtain shown in functional I such as formulas (3)：
    Wherein, L is region S border；
    Functional I is divided into limited individual unit in the S of region, and by its discretization, obtains formula (4)：
    <mrow> <mi>I</mi> <mrow> <mo>(</mo> <mi>T</mi> <mo>)</mo> </mrow> <mo>=</mo> <munderover> <mo>&amp;Sigma;</mo> <mrow> <mi>e</mi> <mo>=</mo> <mn>1</mn> </mrow> <mrow> <mi>N</mi> <mi>E</mi> </mrow> </munderover> <msub> <mi>I</mi> <mi>e</mi> </msub> <mo>=</mo> <msup> <mover> <mi>T</mi> <mo>&amp;OverBar;</mo> </mover> <mi>T</mi> </msup> <mover> <mi>K</mi> <mo>&amp;OverBar;</mo> </mover> <mover> <mi>T</mi> <mo>&amp;OverBar;</mo> </mover> <mo>-</mo> <mn>2</mn> <msup> <mover> <mi>T</mi> <mo>&amp;OverBar;</mo> </mover> <mi>T</mi> </msup> <mover> <mi>P</mi> <mo>&amp;OverBar;</mo> </mover> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>4</mn> <mo>)</mo> </mrow> </mrow>
    Wherein,For stiffness matrix,For heat source density matrix, NE is unit number, and the final extreme value for solving functional I tries to achieve electricity Temperature T (x, y, t) and time t of each region of cable under short circuit current effect variation relation.
  4. 4. a kind of cable run automatic reclosing method based on short circuit current heat localization process according to claim 3, It is characterized in that：According to the scoring for the variation relation for being tried to achieve temperature T (x, y, t) and the time t under short circuit current effect, The scoring of system of laying, the scoring for running the time limit, carry out calculating acquisition overall score with reference to three's respective weights coefficient, according to general comment Divide determination reclosing delay time and number.
  5. 5. a kind of cable run automatic reclosing method based on short circuit current heat localization process according to claim 4, It is characterized in that：The ratio between weight coefficient corresponding to three is 40%：40%：20%.
  6. 6. a kind of cable run automatic reclosing method based on short circuit current heat localization process according to claim 4, It is characterized in that：The variation relation of temperature T (x, y, t) and time t under short circuit current effect, during using desired delay Between t temperature T (x, y, t) and according to obtained temperature maximum T when solving the corresponding momentmaxThe corresponding scoring of inquiry：
    TmaxTemperature range Scoring (- ∞, 90 DEG C) 100 [90 DEG C, 135 DEG C) 80 [135 DEG C, 250 DEG C) 60 [250 DEG C ,+∞) 0
  7. 7. a kind of cable run automatic reclosing method based on short circuit current heat localization process according to claim 4, It is characterized in that：Scored accordingly according to different laying way of local type queries：
    Lay type Scoring Direct-burried/aerial 100 Comb 80 Groove 60 Tunnel 0
  8. 8. a kind of cable run automatic reclosing method based on short circuit current heat localization process according to claim 4, It is characterized in that：According to the different corresponding scorings of operation time limit inquiry：
    Run the time limit Scoring Less than 5 years 100 More than 5 years, less than 15 years 80 More than 15 years, less than 25 years 60 More than 25 years 0
  9. 9. a kind of cable run automatic reclosing method based on short circuit current heat localization process according to claim 4, It is characterized in that：Delay time is voluntarily formulated according to relaying configuration strategy, and reclosing number, which is formulated, to be included：
CN201710948475.7A 2017-10-12 2017-10-12 A kind of cable run automatic reclosing method based on short circuit current heat localization process Active CN107516870B (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1780858A1 (en) * 2005-10-31 2007-05-02 ABB Technology AG Arrangement and method for protecting an electric power system
CN101789587A (en) * 2010-01-08 2010-07-28 黄震 Automatic reclosing method of A type overhead line- cable hybrid line
CN102749554A (en) * 2012-06-19 2012-10-24 张忠华 Electric power circuit fault detecting system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1780858A1 (en) * 2005-10-31 2007-05-02 ABB Technology AG Arrangement and method for protecting an electric power system
CN101789587A (en) * 2010-01-08 2010-07-28 黄震 Automatic reclosing method of A type overhead line- cable hybrid line
CN102749554A (en) * 2012-06-19 2012-10-24 张忠华 Electric power circuit fault detecting system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
杨军: ""高温超导电缆保护理论与技术研究"", 《中国优秀博士学位论文全文数据库》 *

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