CN111965044A - Transmission line creep calculation method and system based on lead tensile strength loss - Google Patents

Transmission line creep calculation method and system based on lead tensile strength loss Download PDF

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CN111965044A
CN111965044A CN202010830828.5A CN202010830828A CN111965044A CN 111965044 A CN111965044 A CN 111965044A CN 202010830828 A CN202010830828 A CN 202010830828A CN 111965044 A CN111965044 A CN 111965044A
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wire
tensile strength
composite
conductor
temperature
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CN111965044B (en
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廖如超
李国强
周华敏
周强辅
刘高
缪钟灵
翟瑞聪
郭启迪
陈赟
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Guangdong Power Grid Co Ltd
Machine Inspection Center of Guangdong Power Grid Co Ltd
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Guangdong Power Grid Co Ltd
Machine Inspection Center of Guangdong Power Grid Co Ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
    • G01N3/18—Performing tests at high or low temperatures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0014—Type of force applied
    • G01N2203/0016—Tensile or compressive
    • G01N2203/0017—Tensile
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/0058—Kind of property studied
    • G01N2203/0069—Fatigue, creep, strain-stress relations or elastic constants
    • G01N2203/0071—Creep
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/0202—Control of the test
    • G01N2203/0212—Theories, calculations
    • G01N2203/0218—Calculations based on experimental data
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/022—Environment of the test
    • G01N2203/0222—Temperature
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
    • G01N2203/02—Details not specific for a particular testing method
    • G01N2203/026—Specifications of the specimen
    • G01N2203/0262—Shape of the specimen
    • G01N2203/0278—Thin specimens
    • G01N2203/028—One dimensional, e.g. filaments, wires, ropes or cables
    • 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
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
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Abstract

According to the method and the system for calculating the creep of the power transmission line based on the tensile strength loss of the wire, provided by the invention, the tensile strength loss of the wire, the operating temperature of the wire and the corresponding operating time of the wire corresponding to the composite wire after temperature change are predicted through the initial tensile strength of the composite wire and the operating temperature of the composite wire in each operating time, so that the creep of the composite wire can be obtained after calculation is carried out through a creep calculation formula, the working efficiency is effectively improved, in addition, whether the composite wire has risks or not can be judged through the reasonable range of the creep, whether the composite wire needs to be replaced or not can be judged, and the maintenance work of the composite wire by working personnel is.

Description

Transmission line creep calculation method and system based on lead tensile strength loss
Technical Field
The invention relates to the technical field of power transmission conductors, in particular to a method and a system for calculating creep of a power transmission line based on tensile strength loss of a conductor.
Background
At present, the wire of the overhead transmission line can generate creep deformation under the action of tension in the operation process, and the creep deformation of the wire can cause the length increase and sag increase of the wire, so that the transmission quality and safety are influenced; moreover, as the wire is operated for a long time and at high temperature, the wire is permanently damaged, and when the wire exceeds the maximum current carrying capacity, the tensile strength is lost, and the creep of the wire is further increased.
In the prior art, the creep problem of the wire is mainly solved by means of test analysis, the results influenced by a plurality of factors are comprehensively considered, but the creep quantity of the wire can not be accurately obtained, so that whether the wire has risks or not and needs to be replaced or not can not be judged, and the working efficiency is reduced.
Disclosure of Invention
The invention aims to solve at least one of the technical defects, in particular to the technical defect that in the prior art, the creep of the lead cannot be accurately obtained, so that whether the lead has risks or not and whether the lead needs to be replaced or not cannot be judged, and the working efficiency is reduced.
The embodiment of the invention provides a power transmission line creep calculation method based on lead tensile strength loss, which comprises the following steps:
acquiring tension information and attribute information of the composite wire, and determining the initial tensile strength of the composite wire according to the tension information and the attribute information;
determining the operating temperature of the composite conductor in each operating time, predicting the tensile strength loss of the conductor after temperature change according to the operating temperature and the initial tensile strength, and determining the operating temperature and the operating time of the conductor corresponding to the tensile strength loss of the conductor;
calculating creep of the composite wire from the wire tensile strength loss, the wire operating temperature, and the wire operating time.
Optionally, the tension information includes a tension value corresponding to the composite conductor reaching a tension critical point;
the attribute information comprises the cross sectional area of the composite conductor, the type of the composite conductor, and the single-strand diameter and the strand number corresponding to each type of conductor;
the composite wire comprises an aluminum alloy wire and a steel core wire.
Optionally, the step of determining the initial tensile strength of the composite wire according to the tension information and the attribute information includes:
calculating to obtain the single-strand initial tensile strength of the composite conductor according to the corresponding tension value when the composite conductor reaches a tension critical point and the cross-sectional area of the composite conductor;
and calculating by utilizing the diameters and the number of the single strands corresponding to various types of wires and the initial tensile strength of the single strands to obtain the initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core and the overall initial tensile strength of the composite wire.
Optionally, the step of determining the operating temperature of the composite conductor for each operating time comprises:
acquiring current information and environmental information of the composite wire, wherein the environmental information comprises solar radiation heat, radiation loss heat dissipation and convection heat dissipation;
and calculating the operating temperature of the composite conductor in each operating time according to the current information and the solar radiation heat, radiation loss heat dissipation and convection heat dissipation.
Optionally, before the step of predicting the tensile strength loss of the wire after the temperature change according to the operating temperature and the initial tensile strength, the method further comprises:
determining an original operation temperature sequence corresponding to each operation time according to the operation temperature of the composite lead;
and performing primary accumulation operation on the original temperature sequence to obtain a primary accumulated temperature sequence, and determining a corresponding wire temperature predicted value according to the primary accumulated temperature sequence.
Optionally, the step of predicting the tensile strength loss of the wire after the temperature change according to the operating temperature and the initial tensile strength, and determining the operating temperature and the operating time of the wire corresponding to the tensile strength loss of the wire includes:
calculating the tensile strength loss of the wire after temperature change according to the predicted wire temperature value, the initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core and the overall initial tensile strength of the composite wire;
and determining the wire operating temperatures corresponding to different wire operating times according to the wire temperature predicted values.
Optionally, the step of calculating the creep of the composite wire from the wire tensile strength loss, the wire operating temperature, and the wire operating time comprises:
and calculating the creep of the composite wire at different temperatures by using a creep calculation formula of the steel-cored aluminum strand according to the tensile strength loss of the wire, the operating temperature of the wire and the operating time of the wire.
The invention also provides a power transmission line creep calculation system based on the tensile strength loss of the lead, which comprises the following steps:
the first confirming unit is used for acquiring tension information and attribute information of the composite conductor and determining the initial tensile strength of the composite conductor according to the tension information and the attribute information;
the second confirming unit is used for confirming the operating temperature of the composite conductor in each operating time, predicting the tensile strength loss of the conductor after temperature change according to the operating temperature and the initial tensile strength, and confirming the operating temperature of the conductor and the operating time of the conductor corresponding to the tensile strength loss of the conductor;
and the creep calculation unit is used for calculating the creep of the composite wire through the tensile strength loss of the wire, the wire operating temperature and the wire operating time.
Optionally, the tension information includes a tension value corresponding to the composite conductor reaching a tension critical point;
the attribute information comprises the cross sectional area of the composite conductor, the type of the composite conductor, and the single-strand diameter and the strand number corresponding to each type of conductor;
the composite wire comprises an aluminum alloy wire and a steel core wire.
Optionally, the first confirming unit includes:
the single-strand strength calculation unit is used for calculating and obtaining the single-strand initial tensile strength of the composite conductor through a corresponding tension value when the composite conductor reaches a tension critical point and the cross-sectional area of the composite conductor;
and the initial strength calculating unit is used for calculating by utilizing the diameters and the number of the single strands corresponding to various types of wires and the initial tensile strength of the single strands to obtain the initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core and the overall initial tensile strength of the composite wire.
According to the technical scheme, the embodiment of the invention has the following advantages:
according to the method and the system for calculating the creep of the power transmission line based on the tensile strength loss of the wire, the tensile force information and the attribute information of the composite wire are obtained, and the initial tensile strength of the composite wire is determined according to the tensile force information and the attribute information; determining the operating temperature of the composite conductor in each operating time, predicting the tensile strength loss of the conductor after temperature change according to the operating temperature and the initial tensile strength, and determining the operating temperature and the operating time of the conductor corresponding to the tensile strength loss of the conductor; calculating creep of the composite wire from the wire tensile strength loss, the wire operating temperature, and the wire operating time.
According to the method, the tensile strength loss of the wire, the wire operating temperature and the corresponding wire operating time of the composite wire after temperature change are predicted through the initial tensile strength of the composite wire and the operating temperature of the composite wire in each operating time, so that the creep of the composite wire can be obtained after calculation is performed through a creep calculation formula, the working efficiency is effectively improved, in addition, whether the composite wire has risks or not and needs to be replaced or not can be judged through the reasonable range of the creep, and the maintenance work of the composite wire by a worker is facilitated.
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.
Fig. 1 is a schematic flowchart of a method for calculating creep of a power transmission line based on a tensile strength loss of a wire according to an embodiment of the present invention;
FIG. 2 is a schematic structural diagram of a system for calculating creep of a power transmission line based on a tensile strength loss of a wire according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of a first verification unit according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
It will be understood by those within the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
Referring to fig. 1, fig. 1 is a schematic flow chart of a method for calculating creep of a power transmission line based on tensile strength loss of a wire according to an embodiment of the present invention; as shown in fig. 1, an embodiment of the present invention provides a method for calculating a creep of a power transmission line based on a tensile strength loss of a wire, which specifically includes the following steps:
s110: and acquiring tension information and attribute information of the composite wire, and determining the initial tensile strength of the composite wire according to the tension information and the attribute information.
In this step, in order to obtain the initial tensile strength of the composite conductor, it is necessary to obtain relevant information of the composite conductor, such as tensile force information including, but not limited to, the stress value of the composite conductor in a critical state, and attribute information including, but not limited to, the type of conductor, the number of strands, and the diameter of a single strand compounded in the composite conductor.
It is understood that tensile strength herein refers to the stress value at a given state point in the overall process of the material being stretched; taking the composite wire drawing process as an example, when the stress of the material reaches the breaking limit, the breaking limit stress is called tensile limit strength; a composite wire herein refers to a wire structure formed by bonding at least two materials.
S120: determining the operating temperature of the composite conductor in each operating time, predicting the tensile strength loss of the conductor after temperature change according to the operating temperature and the initial tensile strength, and determining the operating temperature of the conductor and the operating time of the conductor corresponding to the tensile strength loss of the conductor.
In this step, since the creep of the composite wire is closely related to the operating time, the operating temperature, the wire stress, and the like of the power transmission line, if the creep of the composite wire is required, the operating temperature of the composite wire in each operating time needs to be obtained in advance, and the tensile strength loss of the wire after the temperature change is predicted by combining the initial tensile strength of the composite wire obtained in step S110.
For example, in the case that the operating temperature of the composite wire is known in each operating time, the operating temperature of the composite wire after the temperature change in each operating time can be predicted by a first addition method, and then the wire tensile strength loss of the composite wire, which includes the corresponding wire operating temperatures of the composite wire in different wire operating times, can be predicted according to the predicted operating temperature and the initial tensile strength.
S130: calculating creep of the composite wire from the wire tensile strength loss, the wire operating temperature, and the wire operating time.
In this step, the creep of the composite wire can be calculated according to the creep prediction equation of the composite wire after the wire tensile strength loss predicted by the composite wire after the temperature change is obtained in step S120, and the wire operating temperature and the wire operating time corresponding to the wire tensile strength loss are determined.
In the above embodiment, through the initial tensile strength of the composite conductor and the operating temperature of the composite conductor in each operating time, the tensile strength loss of the conductor, the operating temperature of the conductor and the operating time of the conductor corresponding to the composite conductor after the temperature change are predicted, and thus, after calculation is performed through a creep calculation formula, the creep of the composite conductor can be obtained, the working efficiency is effectively improved, and whether the composite conductor has risks or not can be judged through the reasonable range of the creep, and whether the composite conductor needs to be replaced or not, so that the composite conductor is beneficial to maintenance of a worker on the composite conductor.
In one embodiment, the tension information may include a corresponding tension value when the composite conductor reaches a tension critical point; the attribute information may include a cross-sectional area of the composite wire, a type of the composite wire, and a single strand diameter and a strand number corresponding to each type of wire; the composite wire type may include an aluminum alloy wire and a steel core wire.
In one embodiment, the step of determining the initial tensile strength of the composite wire according to the tension information and the property information in step S110 may include:
s111: calculating to obtain the single-strand initial tensile strength of the composite conductor according to the corresponding tension value when the composite conductor reaches a tension critical point and the cross-sectional area of the composite conductor;
s112: and calculating by utilizing the diameters and the number of the single strands corresponding to various types of wires and the initial tensile strength of the single strands to obtain the initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core and the overall initial tensile strength of the composite wire.
In this embodiment, the single-strand initial tensile strength of the composite wire can be obtained by calculating a tensile force value corresponding to when the composite wire reaches the tensile force critical point and a cross-sectional area of the composite wire, and if the tensile force value corresponding to when the composite wire reaches the tensile force critical point is F and the cross-sectional area of the composite wire is L, the single-strand initial tensile strength S of the composite wire is:
Figure BDA0002637902160000071
after the initial tensile strengths of the individual strands of the composite wire are obtained, if it is necessary to calculate the initial tensile strengths corresponding to the respective constituent components in the composite wire and the initial tensile strength of the entire composite wire, it is necessary to obtain the constituent type of the composite wire, the number of strands and the diameter of the individual strands corresponding to the constituent type, and calculate the initial tensile strengths of the individual strands by using the above-described calculation.
For example, when the composite wire is an aluminum-steel-cored wire formed by an aluminum alloy wire and a steel-cored wire, the initial tensile strength of the aluminum alloy and the initial tensile strength of the steel core can be calculated respectively, and then the overall initial tensile strength of the composite wire is calculated, as follows:
Figure BDA0002637902160000072
Figure BDA0002637902160000073
Figure BDA0002637902160000074
wherein d isAl、dStDiameter of single-stranded wire of aluminum alloy and steel core, SAl、SStSingle strand initial tensile strength, n, of aluminium alloy, steel core respectivelyAl、nStNumber of strands of wire, STR, of aluminium alloy, steel core respectivelyAl、STRSt、STRTThe initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core and the overall initial tensile strength of the composite wire are respectively.
In one embodiment, the step of determining the operating temperature of the composite conductor in the step S120 during the respective operating time may include:
s121: acquiring current information and environmental information of the composite wire, wherein the environmental information comprises solar radiation heat, radiation loss heat dissipation and convection heat dissipation;
s122: and calculating the operating temperature of the composite conductor in each operating time according to the current information and the solar radiation heat, radiation loss heat dissipation and convection heat dissipation.
In this embodiment, in order to obtain the operating temperature of the composite conductor in each operating time, the environment information and the current information of the composite conductor may be obtained first, and then the operating temperature of the power transmission line is obtained according to a thermal balance equation, where the thermal balance equation is as follows:
qs-qr-qc+I2R(Tc)＝0
wherein q issFor solar radiant heat, qrFor radiation loss heat dissipation, qcFor heat dissipation by convection, I2R(Tc) Joule heat of the composite wire.
After the joule heat of the composite wire is obtained, the operating temperature of the composite wire in each operating time can be determined.
In one embodiment, before the step of predicting the tensile strength loss of the wire after the temperature change according to the operating temperature and the initial tensile strength in step S120, the method may further include:
s123: determining an original operation temperature sequence corresponding to each operation time according to the operation temperature of the composite lead;
s124: and performing primary accumulation operation on the original temperature sequence to obtain a primary accumulated temperature sequence, and determining a corresponding wire temperature predicted value according to the primary accumulated temperature sequence.
In this embodiment, before predicting the tensile strength loss of the conductor after the temperature change, the conductor operating temperature of the composite conductor after the temperature change in the conductor operating time may be predicted, and the conductor operating temperature may be obtained by performing one-time accumulation operation on the original operating temperature sequence.
For example, in the present application, where the operating temperatures for all operating times of the composite conductor are known, the original operating temperature sequence for each operating time may be determined as follows:
q(0)＝{q(0)(1),q(0)(2),...,q(0)(n)}
wherein q is(0)Is the original running temperature sequence under all running time, n is the number of sequence values, q(0)(n) is an operation temperature series value corresponding to the nth operation hour.
Through one accumulation operation, the obtained one-time accumulation temperature sequence is as follows:
q(1)＝q(0)d{q(1)(1),q(1)(2),...,q(1)(n)}
wherein q is(1)Is a once-accumulated temperature sequence, d is a once-accumulated generation operator, q(1)(n) is the predicted wire temperature value, which is the running temperature sequence value accumulated once for the nth running hour.
For the one-time accumulation generation operator d, the conversion formula is as follows:
Figure BDA0002637902160000091
for a once-accumulated temperature sequence q(1)The predicted value of the once accumulated generation sequence, which is expressed as
Figure BDA0002637902160000092
The predicted value of the original operating temperature sequence is obtained by carrying out one-time accumulation reduction on the predicted value of the wire temperature of the one-time accumulation temperature sequence, and the formula is as follows:
Figure BDA0002637902160000093
in one embodiment, the step of predicting the tensile strength loss of the wire after the temperature change according to the operating temperature and the initial tensile strength in step S120, and determining the operating temperature and the operating time of the wire corresponding to the tensile strength loss of the wire may include:
s125: calculating the tensile strength loss of the wire after temperature change according to the predicted wire temperature value, the initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core and the overall initial tensile strength of the composite wire;
s126: and determining the wire operating temperatures corresponding to different wire operating times according to the wire temperature predicted values.
In this embodiment, after obtaining the predicted value of the temperature of the wire, the initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core, and the overall initial tensile strength of the composite wire, the loss of the tensile strength of the wire after the temperature change of the steel core aluminum wire can be calculated according to the empirical loss formula of the tensile strength, where the formula is as follows:
Figure BDA0002637902160000094
Figure BDA0002637902160000095
wherein, RSAlIs the percentage of the residual strength of the aluminum alloy in the initial tensile strength, RSCOMIs the percentage of the composite wire residual strength in the initial tensile strength, T is the wire operating temperature, and T is the wire operating time.
In one embodiment, the step of calculating the creep of the composite wire from the wire tensile strength loss, the wire operating temperature and the wire operating time in step S130 may include:
and calculating the creep of the composite wire at different temperatures by using a creep calculation formula of the steel-cored aluminum strand according to the tensile strength loss of the wire, the operating temperature of the wire and the operating time of the wire.
In this embodiment, the creep of the power transmission line is closely related to the operating time, the temperature and the wire stress of the line, and the creep of the composite wire can be calculated according to the creep prediction equation of the composite wire.
For All Aluminum Conductor (AAC), the creep calculation formula at ambient temperature is:
＝Kσ1.3t0.16
where is the initial wire creep, K is a constant, σ is the wire stress, and t is the number of hours of operation of the wire.
For Aluminum Conductor Steel Reinforced (ACSR), the creep calculation at ambient temperature is:
＝2.4(RS％)1.3t0.16
wherein, the creep of the composite wire is shown, RS% is the tensile strength loss of the composite wire, and t is the wire running time of the composite wire.
For all aluminum wire (AAC), the creep calculation formula at high temperature is:
＝MT1.4σ1.3t0.16
wherein T is the operating temperature of the wire, M is a constant, and the values of K and M are shown in the following table:
constant number 7 ply 19 strands 37 shares of 61 ply
K 0.84 0.77 0.77 0.71
M 0.0090 0.0090 0.0084 0.0077
For Aluminum Conductor Steel Reinforced (ACSR), the creep calculation at high temperature is:
＝0.24(RS％)Tt0.16
the creep of the composite wire is shown, RS% is the tensile strength loss of the composite wire, T is the wire operating temperature of the composite wire, and T is the wire operating time of the composite wire.
In an embodiment, as shown in fig. 2, fig. 2 is a schematic structural diagram of a system for calculating creep of a power transmission line based on a tensile strength loss of a wire according to the present invention, and the system for calculating creep of a power transmission line based on a tensile strength loss of a wire according to the present invention further includes a first confirming unit 110, a first confirming unit 120, and a creep calculating unit 130, and specifically includes the following components:
the first confirming unit 110 is configured to obtain tension information and attribute information of the composite conductor, and determine an initial tensile strength of the composite conductor according to the tension information and the attribute information;
a second determining unit 120, configured to determine an operating temperature of the composite conductor during each operating time, predict a conductor tensile strength loss after a temperature change according to the operating temperature and the initial tensile strength, and determine a conductor operating temperature and a conductor operating time corresponding to the conductor tensile strength loss;
a creep calculation unit 130 for calculating a creep of the composite wire from the wire tensile strength loss, the wire operating temperature, and the wire operating time.
In the above embodiment, through the initial tensile strength of the composite conductor and the operating temperature of the composite conductor in each operating time, the tensile strength loss of the conductor, the operating temperature of the conductor and the operating time of the conductor corresponding to the composite conductor after the temperature change are predicted, and thus, after calculation is performed through a creep calculation formula, the creep of the composite conductor can be obtained, the working efficiency is effectively improved, and whether the composite conductor has risks or not can be judged through the reasonable range of the creep, and whether the composite conductor needs to be replaced or not, so that the composite conductor is beneficial to maintenance of a worker on the composite conductor.
In one embodiment, the tension information in the first confirmation unit 110 may include a corresponding tension value when the composite conductor reaches a tension critical point; the attribute information may include a cross-sectional area of the composite wire, a type of the composite wire, and a single strand diameter and a strand number corresponding to each type of wire; the composite wire type may include an aluminum alloy wire and a steel core wire.
In an embodiment, as shown in fig. 3, fig. 3 is a schematic structural diagram of a first confirming unit provided by the present invention, and the first confirming unit 110 may include:
the single-strand strength calculation unit 111 is configured to calculate a single-strand initial tensile strength of the composite wire according to a corresponding tension value when the composite wire reaches a tension critical point and a cross-sectional area of the composite wire;
the initial strength calculating unit 112 is configured to calculate by using the diameters of the single strands, the number of strands, and the initial tensile strength of the single strands corresponding to the various types of wires, so as to obtain an initial tensile strength of the aluminum alloy, an initial tensile strength of the steel core, and an overall initial tensile strength of the composite wire.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims (10)

1. A transmission line creep calculation method based on lead tensile strength loss is characterized by comprising the following steps:
acquiring tension information and attribute information of the composite wire, and determining the initial tensile strength of the composite wire according to the tension information and the attribute information;
determining the operating temperature of the composite conductor in each operating time, predicting the tensile strength loss of the conductor after temperature change according to the operating temperature and the initial tensile strength, and determining the operating temperature and the operating time of the conductor corresponding to the tensile strength loss of the conductor;
calculating creep of the composite wire from the wire tensile strength loss, the wire operating temperature, and the wire operating time.
2. The electric transmission line creep calculation method based on the lead tensile strength loss according to claim 1, wherein the tension information includes a corresponding tension value when the composite lead reaches a tension critical point;
the attribute information comprises the cross sectional area of the composite conductor, the type of the composite conductor, and the single-strand diameter and the strand number corresponding to each type of conductor;
the composite wire comprises an aluminum alloy wire and a steel core wire.
3. The wire tensile strength loss-based power transmission line creep calculation method according to claim 2, wherein the step of determining the initial tensile strength of the composite wire according to the tension information and the attribute information comprises:
calculating to obtain the single-strand initial tensile strength of the composite conductor according to the corresponding tension value when the composite conductor reaches a tension critical point and the cross-sectional area of the composite conductor;
and calculating by utilizing the diameters and the number of the single strands corresponding to various types of wires and the initial tensile strength of the single strands to obtain the initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core and the overall initial tensile strength of the composite wire.
4. The wire tensile strength loss based power transmission line creep calculation method of claim 1, wherein the step of determining the operating temperature of the composite wire at each operating time comprises:
acquiring current information and environmental information of the composite wire, wherein the environmental information comprises solar radiation heat, radiation loss heat dissipation and convection heat dissipation;
and calculating the operating temperature of the composite conductor in each operating time according to the current information and the solar radiation heat, radiation loss heat dissipation and convection heat dissipation.
5. The method for calculating transmission line creep based on lead tensile strength loss according to claim 3, wherein before the step of predicting the lead tensile strength loss after temperature change according to the operating temperature and the initial tensile strength, the method further comprises:
determining an original operation temperature sequence corresponding to each operation time according to the operation temperature of the composite lead;
and performing primary accumulation operation on the original temperature sequence to obtain a primary accumulated temperature sequence, and determining a corresponding wire temperature predicted value according to the primary accumulated temperature sequence.
6. The wire tensile strength loss-based power transmission line creep calculation method according to claim 5, wherein the step of predicting the wire tensile strength loss after temperature change according to the operating temperature and the initial tensile strength, and determining the wire operating temperature and the wire operating time corresponding to the wire tensile strength loss comprises the steps of:
calculating the tensile strength loss of the wire after temperature change according to the predicted wire temperature value, the initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core and the overall initial tensile strength of the composite wire;
and determining the wire operating temperatures corresponding to different wire operating times according to the wire temperature predicted values.
7. The wire tensile strength loss-based power transmission line creep calculation method according to claim 6, wherein the step of calculating the creep of the composite wire through the wire tensile strength loss, the wire operating temperature and the wire operating time comprises:
and calculating the creep of the composite wire at different temperatures by using a creep calculation formula of the steel-cored aluminum strand according to the tensile strength loss of the wire, the operating temperature of the wire and the operating time of the wire.
8. A transmission line creep calculation system based on wire tensile strength loss, comprising:
the first confirming unit is used for acquiring tension information and attribute information of the composite conductor and determining the initial tensile strength of the composite conductor according to the tension information and the attribute information;
the second confirming unit is used for confirming the operating temperature of the composite conductor in each operating time, predicting the tensile strength loss of the conductor after temperature change according to the operating temperature and the initial tensile strength, and confirming the operating temperature of the conductor and the operating time of the conductor corresponding to the tensile strength loss of the conductor;
and the creep calculation unit is used for calculating the creep of the composite wire through the tensile strength loss of the wire, the wire operating temperature and the wire operating time.
9. The wire tensile strength loss-based power transmission line creep calculation system according to claim 8, wherein the tension information includes a corresponding tension value when the composite wire reaches a tension critical point;
the attribute information comprises the cross sectional area of the composite conductor, the type of the composite conductor, and the single-strand diameter and the strand number corresponding to each type of conductor;
the composite wire comprises an aluminum alloy wire and a steel core wire.
10. The wire tensile strength loss based power transmission line creep calculation system of claim 9, wherein the first confirmation unit comprises:
the single-strand strength calculation unit is used for calculating and obtaining the single-strand initial tensile strength of the composite conductor through a corresponding tension value when the composite conductor reaches a tension critical point and the cross-sectional area of the composite conductor;
and the initial strength calculating unit is used for calculating by utilizing the diameters and the number of the single strands corresponding to various types of wires and the initial tensile strength of the single strands to obtain the initial tensile strength of the aluminum alloy, the initial tensile strength of the steel core and the overall initial tensile strength of the composite wire.
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