CN113468841B - Distribution cable thermal defect detection method, distribution cable thermal defect detection device, computer equipment and storage medium - Google Patents
Distribution cable thermal defect detection method, distribution cable thermal defect detection device, computer equipment and storage medium Download PDFInfo
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Abstract
The application relates to a distribution cable thermal defect detection method, a distribution cable thermal defect detection device, computer equipment and a storage medium. The method comprises the following steps: determining a section temperature unit of the distribution cable; acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment; respectively obtaining a first radial heat transfer parameter between the conductor layer and the guard layer of each section temperature unit, a second radial heat transfer parameter between the conductor layer of each section temperature unit and an external environment layer, and an axial heat transfer parameter of each layer between the section temperature units; inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment; and determining the thermal defect level of the distribution cable according to the temperature of each distribution point. By adopting the method, the grading identification accuracy of the thermal defects of the distribution cable can be improved.
Description
Technical Field
The present application relates to the field of power technologies, and in particular, to a method and an apparatus for detecting thermal defects of a distribution cable, a computer device, and a storage medium.
Background
With the development of science and technology, electric energy has become one of indispensable energy sources in production, development and life. The electric energy application can not be separated from the corresponding electric energy transmission, and the distribution cable is one of the most important devices in the electric energy transmission process. The main surrounding environment of economic nature, the reliability of distribution cable operation, the influence of running condition and laying mode, if it has the problem, will influence distribution cable's current-carrying capacity to appear the transmission of electricity bottleneck, influence the normal use of electric energy. The existing research on cable monitoring and state evaluation mainly focuses on the research on the aspects of insulation, aging and the like of the cable.
However, with the development of modern power systems, the load capacity of a power distribution network gradually increases, and the temperature of a power distribution cable is closely related to the magnitude of the current-carrying capacity that the power distribution cable can carry, so that in order to avoid sudden grid faults, the development rule of the thermal defects of the cable needs to be researched. At present, in actual operation, the temperature of the cable is monitored on line or is inspected on line through infrared imaging, so that the temperature of the cable is monitored and calculated inaccurately, and the thermal defect of the cable cannot be identified accurately in a grading way.
Disclosure of Invention
In view of the foregoing, it is desirable to provide a distribution cable thermal defect detection method, apparatus, computer device and storage medium capable of improving classification identification accuracy of distribution cable thermal defects.
A method of distribution cable thermal defect detection, the method comprising:
determining a section temperature unit of the distribution cable;
acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment;
respectively acquiring a first radial heat transfer parameter between each section temperature unit conductor layer and the protective layer, a second radial heat transfer parameter between each section temperature unit conductor layer and the external environment layer, and an axial heat transfer parameter of each layer between the section temperature units;
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of a constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment;
determining a thermal defect level of the distribution cable based on each of the distribution point temperatures.
In one embodiment, the constructing of the equivalent thermal circuit model of the section temperature unit includes:
acquiring structural parameters of the distribution cable; the structural parameters comprise heat capacity, thermal resistance and conductor resistance of each layer in a cable conductor layer, an insulating layer and a shielding layer of the distribution cable;
based on a thermoelectric analogy method, the temperature and the voltage of the distribution cable, the thermal resistance and the resistance of each layer of the conductor layer, the insulating layer and the shielding layer of the cable, and the thermal capacity and the capacitance are analogized, and an equivalent thermal circuit model on two radial and axial heat transfer paths of the distribution cable is constructed in a circuit mode.
In one embodiment, before the constructing the equivalent thermal circuit model of the distribution cable on both the radial and axial heat transfer paths in the form of an electrical circuit, the method further comprises:
based on a thermoelectric comparison method, heat capacities among all layers of the distribution cable are connected in parallel and heat resistances are connected in series to optimize the equivalent thermal circuit model, and the equivalent thermal circuit model on two heat transfer paths in the radial direction and the axial direction of the distribution cable is constructed in a circuit mode.
In one embodiment, the first radial heat transfer parameter includes an equivalent heat capacity and an equivalent heat resistance of radial heat transfer between each of the section temperature unit conductor layers and the guard layer; the second radial heat transfer parameters comprise equivalent heat capacity and equivalent heat resistance of radial heat transfer between each section temperature unit conductor layer and an external environment layer; the axial heat transfer parameters comprise equivalent heat capacity and equivalent thermal resistance of the sheath axial heat transfer among the section temperature units, and equivalent heat capacity and equivalent thermal resistance of the conductor layer axial heat transfer.
In one embodiment, the inputting the environment temperature, the thermal data, the first radial heat transfer parameter, the second radial heat transfer parameter, and the axial heat transfer data into an equivalent thermal circuit model of a constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current time includes:
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature units to obtain the conductor layer temperature and the sheath layer temperature of each section temperature unit at the current moment;
and taking the conductor layer temperature and the sheath layer temperature as distribution point temperatures.
In one embodiment, the determining the thermal defect level of the distribution cable according to each distribution point temperature includes:
performing combined coding on the temperatures of the distribution points according to a specified sequence to obtain coding information of a target data format;
and determining the thermal defect grade corresponding to the coding information of the target data format according to the corresponding relation between the pre-established coding information and the thermal defect grade to obtain the thermal defect grade of the distribution cable.
In one embodiment, the performing combined encoding on the temperatures of the distribution points according to a specified order to obtain the encoded information in the target data format includes:
performing combined coding on the temperatures of the distribution points according to a specified sequence to obtain first system coding information;
converting the first binary code information into second binary code information;
the determining the thermal defect grade corresponding to the coding information of the target data format according to the pre-established corresponding relationship between the coding information and the thermal defect grade to obtain the thermal defect grade of the distribution cable comprises:
and determining the thermal defect grade corresponding to the second binary coded information according to the corresponding relation between the pre-established coded information and the thermal defect grade to obtain the thermal defect grade of the distribution cable.
An apparatus for detecting thermal defects in a distribution cable, the apparatus comprising:
the determining module is used for determining a section temperature unit of the distribution cable;
the first acquisition module is used for acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment;
the second acquisition module is used for respectively acquiring a first radial heat transfer parameter between each section temperature unit conductor layer and the protective layer, a second radial heat transfer parameter between each section temperature unit conductor layer and the external environment layer and an axial heat transfer parameter of each layer between the section temperature units;
the temperature processing module is used for inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of a constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment;
and the thermal defect determining module is used for determining the thermal defect level of the distribution cable according to the temperature of each distribution point.
A computer device comprising a memory and a processor, the memory storing a computer program, the processor implementing the following steps when executing the computer program:
determining a section temperature unit of the distribution cable;
acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment;
respectively acquiring a first radial heat transfer parameter between each section temperature unit conductor layer and the protective layer, a second radial heat transfer parameter between each section temperature unit conductor layer and the external environment layer, and an axial heat transfer parameter of each layer between the section temperature units;
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of a constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment;
determining a thermal defect level of the distribution cable based on each of the distribution point temperatures.
A computer-readable storage medium, on which a computer program is stored which, when executed by a processor, carries out the steps of:
determining a section temperature unit of the distribution cable;
acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment;
respectively acquiring a first radial heat transfer parameter between each section temperature unit conductor layer and the protective layer, a second radial heat transfer parameter between each section temperature unit conductor layer and the external environment layer, and an axial heat transfer parameter of each layer between the section temperature units;
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of a constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment;
determining a thermal defect level of the distribution cable based on each of the distribution point temperatures.
According to the distribution cable thermal defect detection method, the distribution cable thermal defect detection device, the computer equipment and the storage medium, the thermal data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment are determined and obtained; inputting a first radial heat transfer parameter between each section temperature unit conductor layer and a guard layer, a second radial heat transfer parameter between each section temperature unit conductor layer and an external environment layer and an axial heat transfer parameter of each layer between the section temperature units into an equivalent thermal circuit model of the constructed section temperature units to obtain the temperature of each distribution point in the section temperature units at the current moment; the thermal defect grade of the distribution cable is determined according to the temperatures of the distribution points, namely, a radial and axial equivalent thermal circuit model of the section temperature unit is constructed by combining radial and axial heat dissipation rules of the cable, the cable is equivalently represented by the sectional section temperature unit, the temperature calculation mode is simplified, the temperatures of the distribution points which meet the requirement of cable thermal defect identification accuracy are calculated, and the identification accuracy of the cable thermal defects is improved.
Drawings
FIG. 1 is a schematic flow chart diagram of a method for thermal defect detection of a distribution cable in one embodiment;
FIG. 2 is a schematic sectional series connection of a distribution cable in one embodiment;
FIG. 3 is a schematic flow chart illustrating a method for constructing an equivalent thermal circuit model according to an embodiment;
FIG. 4 is a schematic diagram of an equivalent thermal circuit model in one embodiment;
FIG. 5 is a diagram of an exemplary application of a method for detecting thermal defects in a distribution cable;
FIG. 6 is a block diagram of an embodiment of an apparatus for thermal defect detection of a distribution cable;
FIG. 7 is a diagram of the internal structure of a computer device in one embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
In one embodiment, as shown in fig. 1, a distribution cable thermal defect detection method is provided, and this embodiment is illustrated by applying the method to a terminal, and it is to be understood that the method may also be applied to a server, and may also be applied to a system including a terminal and a server, and is implemented by interaction between the terminal and the server. In this embodiment, the method includes the steps of:
The section temperature units of the distribution cables are determined by equivalently using each section of the distribution cables as a circuit connection diagram for connecting electrical elements according to structural parameters of the distribution cables, and the section temperature units are connected in series. The structure of the power distribution cable comprises a cable protective layer, a cable conductor layer, a shielding layer and the like, wherein the cable protective layer comprises a cable protective layer on the surface side and a cable protective layer on the soil side. The structural parameters of the distribution cable include equivalent heat capacity and heat resistance of each layer such as a cable conductor layer, an insulating layer and a shielding layer, and conductor resistance. As shown in fig. 2, which is a schematic diagram of a sectional series connection of a distribution cable in an embodiment, each sectional temperature unit has the same circuit connection mode and the same cable structure parameters, and includes a ground surface, a cable sheath layer located on the ground surface side, a cable conductor layer located between the ground surface and the soil, and a cable sheath layer located on the soil below the ground surface in the radial direction, and each sectional temperature unit includes thermal resistance, thermal capacity, conductor resistance and the like of each layer.
Specifically, according to a temperature monitoring instruction of the power distribution cable, determining a monitoring power distribution cable to be monitored and determining a section temperature unit of the monitoring power distribution cable according to a monitoring requirement; at least two profile temperature units are defined based on the distribution cable's heat transfer paths including a radial heat transfer path and an axial heat transfer path. Optionally, the number of the section temperature units can be determined in a user-defined manner according to the operation and maintenance requirements of the actual power distribution grid. In this embodiment, two section temperature units, i.e., a first section temperature unit and a second section temperature unit, are obtained as an example for explanation.
And 104, acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment.
The heat data refers to a heat source of the section temperature unit, and comprises cable conductor heating related to current-carrying capacity and heating and heat dissipation capacity determined by real-time weather and environmental conditions. The ambient temperature of the section temperature unit is acquired by a temperature measuring device.
The radial direction of the distribution cable refers to the direction from the cable conductor to the external environment (earth surface and soil) through the sheath; the axial direction of the distribution cable refers to the radial perpendicular direction of the distribution cable. The first radial heat transfer parameter comprises equivalent heat capacity and equivalent thermal resistance of radial heat transfer between the conductor layer and the sheath of the section temperature unit, the second radial heat transfer parameter comprises equivalent heat capacity and equivalent thermal resistance of radial heat transfer between the sheath of the section temperature unit and an external environment layer, and the axial heat transfer parameter comprises axial heat transfer parameters (comprising equivalent heat capacity and equivalent thermal resistance) of axial heat transfer of the sheath between the section temperature unit and the conductor layer (comprising equivalent heat capacity and equivalent thermal resistance).
For example, when the determined section temperature units are the first section temperature unit and the second section temperature unit, the equivalent heat capacity and the equivalent thermal resistance of the radial heat transfer between the conductor layer and the sheath of the first section temperature unit and the second section temperature unit, the equivalent heat capacity and the equivalent thermal resistance of the radial heat transfer between the conductor layer of each section temperature unit and the external environment layer, the equivalent heat capacity and the equivalent thermal resistance of the axial heat transfer of the sheath of the first section temperature unit and the second section temperature unit, and the equivalent heat capacity and the equivalent thermal resistance of the axial heat transfer of the conductor layer are respectively obtained.
And step 108, inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment.
The distribution point temperature refers to the temperature of the distribution point of each section temperature unit, and the distribution points comprise distribution cable conductor layers and protective layers. The equivalent thermal circuit model is a radial and axial equivalent thermal circuit model of each section temperature unit established by adopting a thermoelectric analog method according to the structural parameters of the distribution cable.
Specifically, the ambient temperature, the thermal data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data are input into an equivalent thermal circuit model of the constructed section temperature unit, so that the distribution point temperature of the first section temperature unit and the distribution point temperature of the second section temperature unit are obtained, and the two groups of distribution point temperatures are obtained.
The thermal defect level is determined according to the operation safety of the distribution cable, the defect level can be determined according to the heating level of the cable, the heating level comprises four heating levels which are normal, I-level heating, II-level heating and III-level heating and respectively correspond to binary codes 00, 01, 10 and 11, and the larger the binary code is, the higher the heating level of the cable is, and the more serious the heating condition is.
The corresponding relation exists between the thermal defect level and the coding information, and in order to obtain the corresponding relation after pre-establishment, the thermal defect is divided into I-X levels, wherein the code 00 is normal operation, the codes 01-19 are I-level defects, the codes 1A-32 are II-level defects, the codes 33-4B are III-level defects, the codes 4C-64 are IV-level defects, the codes 65-7D are V-level defects, the codes 7E-96 are VI-level defects, the codes 97-AF are VII-level defects, the codes B0-C8 are VIII-level defects, the codes C9-E1 are IX-level defects, and the codes E2-FF are X-level defects.
Specifically, according to the distribution point temperatures of a first section temperature unit and a second section temperature unit, determining the heating levels of the section temperature units, performing combined coding on the obtained heating levels of the first section temperature unit and the second section temperature unit according to a specified sequence to obtain coding information in a target format, and according to a pre-established corresponding relation between the coding information and the thermal defect levels, determining the thermal defect level corresponding to the coding information in the target data format to obtain the thermal defect level of the distribution cable; the target data format may be, but is not limited to, 16-ary encoding. For example, the obtained binary code is converted into a 16-system code, and the thermal defect level of the distribution cable is determined according to the corresponding relation between the thermal defect level and the coded information, namely the thermal defect level of the distribution cable is accurately determined from the two axial and radial heating paths by acquiring the distribution point temperatures of the two section temperature units.
In the distribution cable thermal defect detection method, the heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment are determined and obtained; inputting a first radial heat transfer parameter between the conductor layer and the protective layer of each section temperature unit, a second radial heat transfer parameter between the conductor layer of each section temperature unit and an external environment layer and an axial heat transfer parameter of the protective layer between the section temperature units into an equivalent thermal circuit model of the constructed section temperature units to obtain the temperature of each distribution point in the section temperature units at the current moment; the thermal defect grade of the distribution cable is determined according to the temperatures of the distribution points, namely, a radial and axial equivalent thermal circuit model of the section temperature unit is constructed by combining radial and axial heat dissipation rules of the cable, the cable is equivalently represented by the sectional section temperature unit, the temperature calculation mode is simplified, the temperatures of the distribution points which meet the requirement of the identification accuracy of the thermal defects of the cable are calculated, and the identification accuracy of the thermal defects of the cable is improved.
In an embodiment, as shown in fig. 3, a method for constructing an equivalent thermal circuit model is provided, and this embodiment is illustrated by applying the method to a terminal, it is to be understood that the method may also be applied to a server, and may also be applied to a system including a terminal and a server, and is implemented by interaction between the terminal and the server. In this embodiment, the method includes the steps of:
Specifically, the distribution cable is segmented and equivalently represented by a section temperature unit, and the structural parameters of the distribution cable corresponding to the section temperature unit are obtained.
And 304, based on a thermoelectric analogy method, analogy is carried out on the temperature and the voltage of the distribution cable, the thermal resistance and the resistance of each layer of the conductor layer, the insulating layer and the shielding layer of the cable, and the thermal capacity and the capacitance, so as to construct an equivalent thermal circuit model on two heat transfer paths of the radial direction and the axial direction of the distribution cable in a circuit mode.
Specifically, the cable heat transfer path includes two directions, namely a radial direction and an axial direction, the radial direction is from the cable conductor to the external environment (earth surface and soil) through the sheath, and each layer is along the axial direction, the axial direction is along the direction of the central axis of the distribution cable, the temperature and the voltage of the distribution cable, the thermal resistance and the resistance of each layer of the cable conductor layer, the insulation layer and the shielding layer, and the thermal capacitance and the capacitance are analogized, the thermal capacitances between the layers of the distribution cable are connected in parallel and the thermal resistances are connected in series to optimize the equivalent heat circuit model, and the equivalent heat circuit model on the two heat transfer paths, namely the radial direction and the axial direction of the distribution cable is constructed in a circuit mode. The thermoelectric analogy method in the present application can be realized by a conventional thermoelectric analogy method. As shown in fig. 4, in an embodiment, to construct an equivalent thermal circuit model on two heat transfer paths, radial and axial, of a distribution cable in the form of a circuit, according to the conductor layer temperature and the sheath temperature of a section temperature unit, i.e. 4 distribution point temperatures, the temperature calculation expression of the distribution points can be determined as follows:
θ c1 、θ s1 the distribution point temperature of the first section temperature unit, i.e. the conductor layer temperature and the sheath layer temperature, theta c2 、θ s2 The distribution point temperature of the second section temperature unit, i.e. the conductor layer temperature and the sheath layer temperature, theta a1 、θ a2 The temperature measured directly for the outermost layer of the two section temperature units is taken as the ambient temperature, C c1 、C c2 And R c1 、R c2 Equivalent heat capacity and equivalent thermal resistance C of radial heat transfer between the conductor layer and the sheath layer of the two temperature units s1 、C s2 And R s1 、R s2 Equivalent heat capacity and equivalent thermal resistance C of radial heat transfer between the two section temperature unit sheaths and the external environment layer ac 、R ac Equivalent heat capacity and equivalent thermal resistance for axial heat transfer of the sheath between two section temperature units, C as 、R as Equivalent heat capacity and equivalent thermal resistance W for axial heat transfer of the sheath between two section temperature units 1 、W 2 The heat source for the two section temperature units comprises cable conductor heating related to current-carrying capacity and heating and heat dissipation capacity determined by real-time meteorological and environmental conditions.
According to the method for constructing the equivalent thermal circuit model, the structural parameters of the distribution cable are obtained, the thermal resistance and the resistance of each layer of the distribution cable, the conductor layer of the cable, the insulating layer and the shielding layer and the thermal capacity and the capacitance of each layer of the cable are compared based on a thermoelectric comparison method, the equivalent thermal circuit model on the radial and axial heat transfer paths of the distribution cable is constructed in a circuit mode, namely the cable is equivalently represented by a segmented section temperature unit, the calculation of the distribution temperature of the cable in the radial and axial directions is simplified, the temperature calculation formula can be popularized to a plurality of distribution points in a multi-segment series mode, the number of the distribution points can be selected according to the requirement of cable thermal defect identification accuracy, and the accuracy of cable temperature monitoring and calculation is improved.
In one embodiment, as shown in fig. 5, a distribution cable thermal defect detection method is provided, and this embodiment is illustrated by applying the method to a terminal, and it is to be understood that the method may also be applied to a server, and may also be applied to a system including a terminal and a server, and is implemented by interaction between the terminal and the server. In this embodiment, the method includes the steps of:
And step 504, constructing equivalent thermal circuit models on two radial and axial heat transfer paths of the distribution cable in a circuit mode according to the structural parameters of the distribution cable based on a thermoelectric analogy method.
At step 506, a cross-sectional temperature unit of the distribution cable is determined.
Step 510, respectively obtaining a first radial heat transfer parameter between the conductor layer and the guard layer of each section temperature unit, a second radial heat transfer parameter between the conductor layer and the external environment layer of each section temperature unit, and an axial heat transfer parameter of each layer between the section temperature units.
And step 512, inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment.
Specifically, the ambient temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data are input into an equivalent thermal circuit model of the constructed section temperature units, and the temperature of each distribution point in each section unit at the current moment is calculated by determining a temperature calculation formula of each distribution point, namely the conductor layer temperature and the sheath layer temperature in each section temperature unit are calculated.
And 514, performing combined coding on the temperatures of the distribution points according to a specified sequence to obtain coding information in a target data format.
And 516, determining the thermal defect grade corresponding to the coded information in the target data format according to the pre-established corresponding relation between the coded information and the thermal defect grade to obtain the thermal defect grade of the distribution cable.
Specifically, the temperature of each distribution point is combined and coded according to a specified sequence to obtain first system coding information; converting the first binary coded information into second binary coded information; and determining the thermal defect grade corresponding to the second binary coded information according to the corresponding relation between the pre-established coded information and the thermal defect grade to obtain the thermal defect grade of the distribution cable. The first binary system may be, but is not limited to, a binary system, and the second binary system may be, but is not limited to, a hexadecimal system. The method can accurately and comprehensively determine the thermal defect level of the distribution cable according to the combination of the coding rules of the heating levels corresponding to the temperatures of the distribution points, and the combination coding mode for representing the thermal defect level is favorable for the real-time visual judgment of the cable thermal defect state by the operation and maintenance personnel of the distribution network.
In the distribution cable thermal defect detection method, equivalent thermal circuit models on two radial and axial heat transfer paths of the distribution cable are constructed in a circuit mode according to structural parameters of the distribution cable based on a thermoelectric comparison method, namely radial and axial heat dissipation rules of the cable, radial and axial temperatures of the section units are modeled, and thermal data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment are obtained by determining; inputting a first radial heat transfer parameter between the conductor layer and the protective layer of each section temperature unit, a second radial heat transfer parameter between the conductor layer of each section temperature unit and an external environment layer and an axial heat transfer parameter of the protective layer between the section temperature units into an equivalent thermal circuit model of the constructed section temperature units to obtain the temperature of each distribution point in the section temperature units at the current moment; the thermal defect level of the distribution cable is determined according to the temperature of each distribution point, namely the cable is equivalently represented by a segmented section temperature unit, the calculation of the radial and axial distribution temperature of the cable is simplified, the temperature of the distribution points is accurately calculated, the identification accuracy of the thermal defect of the cable is improved, the thermal defect level of the distribution cable is determined in a combined coding mode, operation and maintenance personnel can conveniently and visually judge the thermal defect state of the cable in real time, the power grid fault can be timely overhauled, and the safety of the power grid is improved.
It should be understood that although the steps in the flowcharts of fig. 1, 3 and 5 are shown in order as indicated by the arrows, the steps are not necessarily performed in order as indicated by the arrows. The steps are not performed in the exact order shown and described, and may be performed in other orders, unless explicitly stated otherwise. Moreover, at least some of the steps in fig. 1, 3 and 5 may include multiple steps or multiple stages, which are not necessarily performed at the same time, but may be performed at different times, which are not necessarily performed in sequence, but may be performed alternately or alternately with other steps or at least some of the other steps.
In one embodiment, as shown in fig. 6, there is provided a distribution cable thermal defect detection apparatus comprising: a determination module 602, a first acquisition module 604, a second acquisition module 606, a temperature processing module 608, and a thermal defect determination module 610, wherein:
a determination module 602 for determining a section temperature unit of a distribution cable.
The first obtaining module 604 is configured to obtain heat data of at least two section temperature units and an ambient temperature of an environment where each section temperature unit is located at a current time.
A second obtaining module 606, configured to obtain a first radial heat transfer parameter between the conductor layer and the guard layer of each section temperature unit, a second radial heat transfer parameter between the conductor layer and the external environment layer of each section temperature unit, and an axial heat transfer parameter of each layer between the section temperature units.
The temperature processing module 608 is configured to input the ambient temperature, the thermal data, the first radial heat transfer parameter, the second radial heat transfer parameter, and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature unit, so as to obtain the temperature of each distribution point in the section temperature unit at the current time.
A thermal defect determination module 610 for determining a thermal defect level of the distribution cable based on the distribution point temperatures.
The distribution cable thermal defect detection device obtains the heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment by determining; inputting a first radial heat transfer parameter between the conductor layer and the guard layer of each section temperature unit, a second radial heat transfer parameter between the conductor layer of each section temperature unit and an external environment layer and an axial heat transfer parameter of each layer between the section temperature units into an equivalent thermal circuit model of the constructed section temperature units to obtain the temperature of each distribution point in the section temperature unit at the current moment; the thermal defect grade of the distribution cable is determined according to the temperatures of the distribution points, namely, a radial and axial equivalent thermal circuit model of the section temperature unit is constructed by combining radial and axial heat dissipation rules of the cable, the cable is equivalently represented by the sectional section temperature unit, the temperature calculation mode is simplified, the temperatures of the distribution points which meet the requirement of the identification accuracy of the thermal defects of the cable are calculated, and the identification accuracy of the thermal defects of the cable is improved.
In another embodiment, a distribution cable apparatus is provided that includes, in addition to the determination module 602, the first acquisition module 604, the second acquisition module 606, the temperature processing module 608, and the thermal defect determination module 610: the system comprises an analogy submodule, an optimization processing submodule, an encoding submodule and a transcoding submodule, wherein:
in one embodiment, the first obtaining module 604 is further configured to obtain structural parameters of the distribution cable; the structural parameters include heat capacity, thermal resistance and conductor resistance of each of the cable conductor, insulation and shielding layers of the distribution cable.
The temperature processing module 608 includes an analog sub-module for performing an analog operation on the temperature and voltage of the distribution cable, the thermal resistance and resistance of each of the conductor layer, the insulating layer, and the shielding layer, and the thermal capacitance and capacitance of the distribution cable based on a thermoelectric analog method, so as to construct an equivalent thermal circuit model on two heat transfer paths, i.e., the radial and axial directions of the distribution cable, in a circuit form.
The temperature processing module 608 further includes an optimization processing sub-module, which is configured to perform optimization processing on the equivalent thermal circuit model by connecting the heat capacities between the layers of the distribution cable in parallel and connecting the heat resistances in series based on a thermoelectric analog method, and construct the equivalent thermal circuit model on two heat transfer paths, i.e., the radial and axial directions, of the distribution cable in a circuit form.
In one embodiment, the temperature processing module 608 is further configured to input the ambient temperature, the thermal data, the first radial heat transfer parameter, the second radial heat transfer parameter, and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature units, so as to obtain the conductor layer temperature and the sheath layer temperature of each section temperature unit at the current time; the conductor layer temperature and the sheath temperature are taken as distribution point temperatures.
The first radial heat transfer parameter comprises equivalent heat capacity and equivalent heat resistance of radial heat transfer between the conductor layer and the guard layer of each section temperature unit; the second radial heat transfer parameters comprise equivalent heat capacity and equivalent heat resistance of radial heat transfer between each section temperature unit conductor layer and an external environment layer; the axial heat transfer parameters comprise equivalent heat capacity and equivalent heat resistance of the sheath axial heat transfer among the section temperature units.
The thermal defect determining module 610 includes an encoding sub-module, which is configured to perform combined encoding on the temperatures of the distribution points according to a specified sequence to obtain encoded information of a target data format.
In an embodiment, the thermal defect determining module 610 is further configured to determine a thermal defect level corresponding to the encoded information in the target data format according to a pre-established correspondence between the encoded information and the thermal defect level, so as to obtain the thermal defect level of the distribution cable.
In one embodiment, the encoding sub-module is further configured to perform combined encoding on the temperatures of the distribution points according to a specified sequence to obtain the first binary coded information.
The thermal defect determining module 610 further includes a transcoding sub-module for converting the first binary coded information into the second binary coded information.
In an embodiment, the thermal defect determining module 610 is further configured to determine a thermal defect level corresponding to the second binary coded information according to a pre-established correspondence between the coded information and the thermal defect level, so as to obtain the thermal defect level of the distribution cable.
In one embodiment, based on a thermoelectric analog method, equivalent thermal circuit models on two radial and axial heat transfer paths of a distribution cable are constructed in a circuit mode according to structural parameters of the distribution cable, namely radial and axial heat dissipation rules of the cable, radial and axial temperatures of section units are modeled, and heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment are obtained through determination; inputting a first radial heat transfer parameter between the conductor layer and the protective layer of each section temperature unit, a second radial heat transfer parameter between the conductor layer of each section temperature unit and an external environment layer and an axial heat transfer parameter of the protective layer between the section temperature units into an equivalent thermal circuit model of the constructed section temperature units to obtain the temperature of each distribution point in the section temperature units at the current moment; the thermal defect level of the distribution cable is determined according to the temperature of each distribution point, namely the cable is equivalently represented by a segmented section temperature unit, the calculation of the radial and axial distribution temperature of the cable is simplified, the temperature of the distribution points is accurately calculated, the identification accuracy of the thermal defect of the cable is improved, the thermal defect level of the distribution cable is determined in a combined coding mode, operation and maintenance personnel can conveniently and visually judge the thermal defect state of the cable in real time, the power grid fault can be timely overhauled, and the safety of the power grid is improved.
For specific limitations of the distribution cable thermal defect detection apparatus, reference may be made to the above limitations of the distribution cable thermal defect detection method, which are not described herein again. The modules in the distribution cable thermal defect detection apparatus may be implemented in whole or in part by software, hardware, and combinations thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as shown in fig. 7. The computer device includes a processor, a memory, a communication interface, a display screen, and an input device connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device comprises a nonvolatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of an operating system and computer programs in the non-volatile storage medium. The communication interface of the computer device is used for carrying out wired or wireless communication with an external terminal, and the wireless communication can be realized through WIFI, an operator network, NFC (near field communication) or other technologies. The computer program is executed by a processor to implement a method of distribution cable thermal defect detection. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, a key, a track ball or a touch pad arranged on the shell of the computer equipment, an external keyboard, a touch pad or a mouse and the like.
Those skilled in the art will appreciate that the architecture shown in fig. 7 is merely a block diagram of some of the structures associated with the disclosed aspects and is not intended to limit the computing devices to which the disclosed aspects apply, as particular computing devices may include more or less components than those shown, or may combine certain components, or have a different arrangement of components.
In one embodiment, a computer device is provided, comprising a memory having a computer program stored therein and a processor that when executing the computer program performs the steps of:
determining a section temperature unit of the distribution cable;
acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment;
respectively acquiring a first radial heat transfer parameter between each section temperature unit conductor layer and the protective layer, a second radial heat transfer parameter between each section temperature unit conductor layer and the external environment layer, and an axial heat transfer parameter of each layer between the section temperature units;
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment;
the thermal defect level of the distribution cable is determined based on the distribution point temperatures.
In one embodiment, the processor, when executing the computer program, further performs the steps of:
acquiring structural parameters of a distribution cable; the structural parameters comprise heat capacity, thermal resistance and conductor resistance of each layer in a cable conductor layer, an insulating layer and a shielding layer of the distribution cable;
based on a thermoelectric analogy method, the temperature and the voltage of the distribution cable, the thermal resistance and the resistance of each layer of the conductor layer, the insulating layer and the shielding layer of the cable, and the thermal capacity and the capacitance are analogized, and an equivalent thermal circuit model on two heat transfer paths of the radial direction and the axial direction of the distribution cable is constructed in a circuit mode.
In one embodiment, the processor when executing the computer program further performs the steps of:
based on a thermoelectric comparison method, heat capacities among all layers of the distribution cable are connected in parallel and heat resistances are connected in series to optimize an equivalent thermal circuit model, and the equivalent thermal circuit model on two heat transfer paths in the radial direction and the axial direction of the distribution cable is constructed in a circuit mode.
In one embodiment, the processor, when executing the computer program, further implements the following:
the first radial heat transfer parameter comprises equivalent heat capacity and equivalent heat resistance of radial heat transfer between the conductor layer and the guard layer of each section temperature unit; the second radial heat transfer parameter comprises equivalent heat capacity and equivalent thermal resistance of radial heat transfer between each section temperature unit conductor layer and the external environment layer; the axial heat transfer parameters comprise equivalent heat capacity and equivalent thermal resistance of the sheath axial heat transfer among the section temperature units and equivalent heat capacity and equivalent thermal resistance of the conductor layer axial heat transfer.
In one embodiment, the processor, when executing the computer program, further performs the steps of:
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature units to obtain the conductor layer temperature and the sheath layer temperature of each section temperature unit at the current moment;
the conductor layer temperature and the sheath temperature were taken as the distribution point temperatures.
In one embodiment, the processor, when executing the computer program, further performs the steps of:
performing combined coding on the temperatures of the distribution points according to a specified sequence to obtain coding information of a target data format;
and determining the thermal defect grade corresponding to the coded information in the target data format according to the pre-established corresponding relation between the coded information and the thermal defect grade to obtain the thermal defect grade of the distribution cable.
In one embodiment, the processor, when executing the computer program, further performs the steps of:
carrying out combined coding on the temperatures of all distribution points according to a specified sequence to obtain first system coding information;
converting the first binary code information into second binary code information;
determining the thermal defect grade corresponding to the coding information of the target data format according to the corresponding relation between the pre-established coding information and the thermal defect grade to obtain the thermal defect grade of the distribution cable, wherein the thermal defect grade comprises the following steps:
and determining the thermal defect grade corresponding to the second binary coded information according to the corresponding relation between the pre-established coded information and the thermal defect grade to obtain the thermal defect grade of the distribution cable.
In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored which, when executed by a processor, performs the steps of:
determining a section temperature unit of the distribution cable;
acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment;
respectively acquiring a first radial heat transfer parameter between each section temperature unit conductor layer and the protective layer, a second radial heat transfer parameter between each section temperature unit conductor layer and the external environment layer, and an axial heat transfer parameter of each layer between the section temperature units;
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment;
and determining the thermal defect level of the distribution cable according to the temperature of each distribution point.
In one embodiment, the computer program when executed by the processor further performs the steps of:
acquiring structural parameters of a distribution cable; the structural parameters comprise heat capacity, thermal resistance and conductor resistance of each layer in a cable conductor layer, an insulating layer and a shielding layer of the distribution cable;
based on a thermoelectric analogy method, the temperature and the voltage of the distribution cable, the thermal resistance and the resistance of each layer of the conductor layer, the insulating layer and the shielding layer of the cable, and the thermal capacity and the capacitance are analogized, and an equivalent thermal circuit model on two heat transfer paths of the radial direction and the axial direction of the distribution cable is constructed in a circuit mode.
In one embodiment, the computer program when executed by the processor further performs the steps of:
based on a thermoelectric comparison method, heat capacities among all layers of the distribution cable are connected in parallel and heat resistances are connected in series to optimize an equivalent thermal circuit model, and the equivalent thermal circuit model on two heat transfer paths in the radial direction and the axial direction of the distribution cable is constructed in a circuit mode.
In one embodiment, the computer program when executed by the processor further implements the following:
the first radial heat transfer parameter comprises equivalent heat capacity and equivalent heat resistance of radial heat transfer between the conductor layer and the guard layer of each section temperature unit; the second radial heat transfer parameters comprise equivalent heat capacity and equivalent heat resistance of radial heat transfer between each section temperature unit conductor layer and an external environment layer; the axial heat transfer parameters comprise equivalent heat capacity and equivalent thermal resistance of the sheath axial heat transfer among the section temperature units and equivalent heat capacity and equivalent thermal resistance of the conductor layer axial heat transfer.
In one embodiment, the computer program when executed by the processor further performs the steps of:
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature units to obtain the conductor layer temperature and the sheath layer temperature of each section temperature unit at the current moment;
the conductor layer temperature and the sheath temperature were taken as the distribution point temperatures.
In one embodiment, the computer program when executed by the processor further performs the steps of:
performing combined coding on the temperatures of the distribution points according to a specified sequence to obtain coding information of a target data format;
and determining the thermal defect grade corresponding to the coded information in the target data format according to the pre-established corresponding relation between the coded information and the thermal defect grade to obtain the thermal defect grade of the distribution cable.
In one embodiment, the computer program when executed by the processor further performs the steps of:
carrying out combined coding on the temperatures of all distribution points according to a specified sequence to obtain first system coding information;
converting the first binary code information into second binary code information;
determining the thermal defect grade corresponding to the coding information of the target data format according to the corresponding relation between the pre-established coding information and the thermal defect grade to obtain the thermal defect grade of the distribution cable, wherein the thermal defect grade comprises the following steps:
and determining the thermal defect grade corresponding to the second binary coded information according to the corresponding relation between the pre-established coded information and the thermal defect grade to obtain the thermal defect grade of the distribution cable.
It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by hardware instructions of a computer program, which can be stored in a non-volatile computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. Any reference to memory, storage, database or other medium used in the embodiments provided herein can include at least one of non-volatile and volatile memory. Non-volatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical storage, or the like. Volatile Memory can include Random Access Memory (RAM) or external cache Memory. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM), among others.
The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A method of distribution cable thermal defect detection, the method comprising:
determining a section temperature unit of the distribution cable; the section temperature units of the distribution cable are determined by dividing the distribution cable according to a preset length to obtain a plurality of sections of distribution cables, and equivalently setting each section of distribution cable as a circuit connection diagram for connecting electrical elements according to structural parameters of the distribution cable, wherein the section temperature units are connected in series; the structure of the distribution cable comprises a cable sheath layer on the surface side, a cable sheath layer on the soil side, a cable conductor layer and a shielding layer; the structural parameters comprise heat capacity, thermal resistance and conductor resistance of each layer in a cable conductor layer, an insulating layer and a shielding layer of the distribution cable;
acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment;
respectively acquiring a first radial heat transfer parameter between each section temperature unit conductor layer and the protective layer, a second radial heat transfer parameter between each section temperature unit conductor layer and the external environment layer, and an axial heat transfer parameter of each layer between the section temperature units; wherein, the radial direction of the distribution cable refers to the direction of the cable conductor radiating to the external environment through the sheath; the axial direction of the distribution cable refers to the radial vertical direction of the distribution cable; the axial heat transfer parameters comprise equivalent heat capacity and equivalent thermal resistance of the sheath axial heat transfer among the section temperature units and equivalent heat capacity and equivalent thermal resistance of the conductor layer axial heat transfer;
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of a constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment; the equivalent thermal circuit model is obtained by adopting a thermoelectric analog method to establish a radial equivalent thermal circuit model and an axial equivalent thermal circuit model of each section temperature unit according to structural parameters of the distribution cable, and performing parallel connection on heat capacities among all layers of the distribution cable and performing series connection on the heat resistances to optimize the equivalent thermal circuit model; the calculation expression of the temperature of the distribution point is as follows:
wherein,
、
is the distribution point temperature of the first section temperature unit,
、
is the distribution point temperature of the second section temperature unit,
、
the temperature directly measured by the outermost layer of the two section temperature units is regarded as the ambient temperature,
、
and
、
respectively the equivalent heat capacity and the equivalent heat resistance of the radial heat transfer between the conductor layer and the sheath layer of the two temperature units with cross sections,
、
and
、
respectively the equivalent heat capacity and the equivalent heat resistance of the radial heat transfer between the two section temperature unit protective layers and the external environment layer,
、
is equivalent thermal resistance of axial heat transfer of the sheath between the two section temperature units,
、
the heat source is a heat source of two section temperature units, and comprises cable conductor heating related to current-carrying capacity and heating and heat dissipation capacity determined by real-time meteorological and environmental conditions;
determining a thermal defect level of the distribution cable based on each of the distribution point temperatures.
2. The method of claim 1, wherein the constructing of the equivalent thermal circuit model of the cross-sectional temperature unit comprises:
acquiring structural parameters of the distribution cable;
based on a thermoelectric analogy method, the temperature and the voltage of the distribution cable, the thermal resistance and the resistance of each layer of the conductor layer, the insulating layer and the shielding layer of the cable, and the thermal capacity and the capacitance are analogized, and an equivalent thermal circuit model on two radial and axial heat transfer paths of the distribution cable is constructed in a circuit mode.
3. The method of claim 2, wherein prior to said constructing an equivalent thermal circuit model of said distribution cable in the form of an electrical circuit over both radial and axial heat transfer paths, said method further comprises:
based on a thermoelectric comparison method, heat capacities among all layers of the distribution cable are connected in parallel and heat resistances are connected in series to optimize the equivalent thermal circuit model, and the equivalent thermal circuit model on two heat transfer paths in the radial direction and the axial direction of the distribution cable is constructed in a circuit mode.
4. The method of claim 1 wherein said first radial heat transfer parameter comprises an equivalent heat capacity and an equivalent thermal resistance for radial heat transfer between each of said temperature profile cell conductor layers and sheaths; the second radial heat transfer parameter comprises equivalent heat capacity and equivalent thermal resistance of radial heat transfer between each section temperature unit conductor layer and an external environment layer.
5. The method of claim 1, wherein inputting the ambient temperature, the thermal data, the first radial heat transfer parameter, the second radial heat transfer parameter, and the axial heat transfer data into an equivalent thermal circuit model of a constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment comprises:
inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of the constructed section temperature units to obtain the conductor layer temperature and the sheath layer temperature of each section temperature unit at the current moment;
and taking the conductor layer temperature and the sheath layer temperature as distribution point temperatures.
6. The method of claim 1, wherein said determining a thermal defect level of said distribution cable based on each of said distribution point temperatures comprises:
performing combined coding on the temperatures of the distribution points according to a specified sequence to obtain coding information of a target data format;
and determining the thermal defect grade corresponding to the coding information of the target data format according to the corresponding relation between the pre-established coding information and the thermal defect grade to obtain the thermal defect grade of the distribution cable.
7. The method as claimed in claim 6, wherein the step of performing combined encoding on the temperatures of the distribution points according to a specified sequence to obtain encoded information in a target data format comprises:
performing combined coding on the temperatures of the distribution points according to a specified sequence to obtain first system coding information;
converting the first binary code information into second binary code information;
the determining the thermal defect grade corresponding to the coding information of the target data format according to the pre-established corresponding relationship between the coding information and the thermal defect grade to obtain the thermal defect grade of the distribution cable comprises the following steps:
and determining the thermal defect grade corresponding to the second binary coded information according to the corresponding relation between the pre-established coded information and the thermal defect grade to obtain the thermal defect grade of the distribution cable.
8. An apparatus for detecting thermal defects in a distribution cable, the apparatus comprising:
the determining module is used for determining a section temperature unit of the distribution cable; the section temperature units of the distribution cable are determined by dividing the distribution cable according to a preset length to obtain a plurality of sections of distribution cables, and equivalently setting each section of distribution cable as a circuit connection diagram for connecting electrical elements according to structural parameters of the distribution cable, wherein the section temperature units are connected in series; the structure of the distribution cable comprises a cable sheath layer on the surface side, a cable sheath layer on the soil side, a cable conductor layer and a shielding layer; the structural parameters comprise heat capacity, thermal resistance and conductor resistance of each layer in a cable conductor layer, an insulating layer and a shielding layer of the distribution cable;
the first acquisition module is used for acquiring heat data of at least two section temperature units and the environmental temperature of the environment where each section temperature unit is located at the current moment;
the second acquisition module is used for respectively acquiring a first radial heat transfer parameter between each section temperature unit conductor layer and the protective layer, a second radial heat transfer parameter between each section temperature unit conductor layer and the external environment layer and an axial heat transfer parameter of each layer between the section temperature units; wherein, the radial direction of the distribution cable refers to the direction of the cable conductor radiating to the external environment through the sheath; the axial direction of the distribution cable refers to the radial vertical direction of the distribution cable; the axial heat transfer parameters comprise equivalent heat capacity and equivalent thermal resistance of the sheath axial heat transfer among the section temperature units and equivalent heat capacity and equivalent thermal resistance of the conductor layer axial heat transfer;
the temperature processing module is used for inputting the environment temperature, the heat data, the first radial heat transfer parameter, the second radial heat transfer parameter and the axial heat transfer data into an equivalent thermal circuit model of a constructed section temperature unit to obtain the temperature of each distribution point in the section temperature unit at the current moment; the equivalent thermal circuit model is a radial and axial equivalent thermal circuit model of each section temperature unit established by adopting a thermoelectric analog method according to the structural parameters of the distribution cable; the heat capacity among all layers of the distribution cable is connected in parallel and the heat resistance is connected in series, and the equivalent heat circuit model is optimized to obtain the equivalent heat circuit model; the calculation expression of the temperature of the distribution point is as follows:
wherein,
、
is the distribution point temperature of the first section temperature unit,
、
is the distribution point temperature of the second section temperature unit,
、
the temperature directly measured by the outermost layer of the two section temperature units is regarded as the ambient temperature,
、
and with
、
Respectively the equivalent heat capacity and the equivalent heat resistance of the radial heat transfer between the conductor layer and the sheath layer of the two temperature units with cross sections,
、
and
、
respectively the equivalent heat capacity and the equivalent heat resistance of the radial heat transfer between the two section temperature unit protective layers and the external environment layer,
、
is equivalent thermal resistance of axial heat transfer of the sheath between the two section temperature units,
、
the heat source is a heat source of two section temperature units, and comprises cable conductor heating related to current-carrying capacity and heating and heat dissipation capacity determined by real-time meteorological and environmental conditions;
and the thermal defect determining module is used for determining the thermal defect level of the distribution cable according to the temperature of each distribution point.
9. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the method of any of claims 1 to 7.
10. A computer-readable storage medium, on which a computer program is stored which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 7.
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