Cable core temperature calculation method, device and equipment of high-voltage cable and storage medium

Abstract

The invention discloses a cable core temperature calculation method and device of a high-voltage cable, equipment and a storage medium. A transient thermal circuit model of the high-voltage cable is constructed based on the structural composition of the high-voltage cable, the transient thermal circuit model of the high-voltage cable is equivalent to a first-order transient equivalent thermal circuit model, the equivalent thermal resistance and the equivalent thermal capacity of the first-order transient equivalent thermal circuit model are solved based on historical temperature data, and the cable surface temperature collected in real time is obtained. The cable core temperature of the high-voltage cable is calculated based on the cable surface temperature, the equivalent thermal resistance and the equivalent thermal capacity, a transient thermal circuit model of the high-voltage cable is equivalent to a first-order transient equivalent thermal circuit model, and the equivalent thermal resistance and the equivalent thermal capacity of the first-order transient equivalent thermal circuit model are solved based on historical temperature data. According to the cable surface temperature collected in real time and the solved first-order transient equivalent thermal circuit model, the cable core temperature of the high-voltage cable can be rapidly calculated, and the cable core temperature calculation efficiency is improved.

Description

Technical Field

[0001] The present invention relates to electric power technology, and in particular to a method, device, equipment and storage medium for calculating the cable core temperature of a high-voltage cable. Background Art

[0002] In the power system, high-voltage cables are responsible for current transmission. When current passes through the cable, a certain resistance is generated, causing the cable to heat up. If the cable temperature is too high, it may reduce the cable life, reduce the cable performance, and even cause safety accidents. Therefore, in order to ensure the safe and stable operation of the power system, it is crucial to solve the temperature of the high-voltage cable core.

[0003] The solution of cable core temperature mainly relies on the thermal circuit model. The thermal circuit model is proposed based on the electrothermal similarity theory. Analogous to the concepts of power supply, voltage and electrical parameters (resistance, capacitance, inductance) in the circuit, the thermal circuit model consists of three major elements: heat source, temperature and thermal parameters. Knowing the value of two of the three elements can determine the value of the other element. Generally speaking, the heat source can be calculated by the current flow of the cable and related electrical parameters. After knowing the thermal parameters of the cable, the solution of the cable core temperature can be realized.

[0004] At present, the thermal parameters of cables (including thermal resistance parameters and thermal capacitance parameters) are generally solved based on experimental results. For the thermal resistance parameters of cables, the cables need to be heated to a steady temperature before the obtained data values ​​can be used for calculation, which takes a long time. And only after the thermal resistance parameters are obtained can the transient data be used to calculate the thermal capacitance parameters of the cables. It can be seen that the existing methods take a long time and have low calculation efficiency. Summary of the invention

[0005] The present invention provides a method, device, equipment and storage medium for calculating the cable core temperature of a high-voltage cable, so as to improve the calculation efficiency of the cable core temperature.

[0006] In a first aspect, the present invention provides a method for calculating the cable core temperature of a high voltage cable, comprising:

[0007] Constructing a transient thermal circuit model of the high-voltage cable based on the structural composition of the high-voltage cable;

[0008] Equivalently converting the transient thermal circuit model of the high-voltage cable into a first-order transient equivalent thermal circuit model;

[0009] Solving the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent thermal circuit model based on the historical temperature data;

[0010] Get the real-time collected cable surface temperature;

[0011] The cable core temperature of the high-voltage cable is calculated based on the cable surface temperature, the equivalent thermal resistance and the equivalent thermal capacity.

[0012] Optionally, the high-voltage cable includes a cable core, an insulating layer wrapping the cable core, a buffer layer wrapping the insulating layer, an aluminum sheath wrapping the buffer layer, and an outer sheath wrapping the aluminum sheath. Constructing a transient thermal circuit model of the high-voltage cable based on the structural composition of the high-voltage cable includes:

[0013] Construct a transient thermal circuit model of the cable core heating power regarding the cable core temperature, cable core heat capacity, insulation heat loss, insulation layer temperature, insulation layer heat capacity, insulation layer thermal resistance, buffer layer heat loss, buffer layer thermal resistance, buffer layer heat capacity, aluminum sheath heat loss, aluminum sheath temperature, aluminum sheath heat capacity, outer sheath temperature, outer sheath thermal resistance and outer sheath thermal capacity.

[0014] Optionally, the transient thermal circuit model of the high-voltage cable is equivalent to a first-order transient equivalent thermal circuit model, including:

[0015] The transient thermal circuit model of the high-voltage cable is equivalent to a first-order transient equivalent thermal circuit model of the cable core heating power with respect to the cable core temperature, the temperature of the outer sheath, the equivalent heat capacity and the equivalent thermal resistance.

[0016] Optionally, the first-order transient equivalent thermal circuit model is as follows:

[0017]

[0018] Where Q is the heating power of the cable core, θ c is the cable core temperature, θ o is the temperature of the outer sheath, C is the equivalent heat capacity, and T is the equivalent thermal resistance.

[0019] Optionally, solving the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent thermal circuit model based on the historical temperature data includes:

[0020] Substituting the first historical cable core temperature and the first historical cable surface temperature at the first acquisition time into the first-order transient equivalent heat circuit model to obtain a first transient equivalent heat circuit equation;

[0021] Substituting the second historical cable core temperature and the second historical cable surface temperature at the second acquisition time into the first-order transient equivalent heat circuit model to obtain a second transient equivalent heat circuit equation;

[0022] The first transient equivalent heat circuit equation and the second transient equivalent heat circuit equation are combined to solve the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent heat circuit model.

[0023] Optionally, the first transient equivalent heat circuit equation and the second transient equivalent heat circuit equation are combined to solve the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent heat circuit model, including:

[0024] The transient temperature equation of the cable core is described by the fitting method, and the function of the transient temperature of the cable core with respect to time is determined;

[0025] Differentiating the function of the transient temperature of the cable core with respect to time to obtain a differential expression of the transient temperature of the cable core with respect to time;

[0026] Substitute the differential expression of the transient temperature of the cable core with respect to time into the first transient equivalent heat circuit equation and the second transient equivalent heat circuit equation to solve the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent heat circuit model.

[0027] Optionally, the transient temperature of the cable core as a function of time is:

[0028]

[0029] The differential expression of the transient temperature of the cable core with respect to time is:

[0030]

[0031] Among them, x1, x2, x3 are fitting coefficients, and t is time.

[0032] In a second aspect, the present invention further provides a device for calculating the cable core temperature of a high voltage cable, comprising:

[0033] A thermal circuit model building module, used to build a transient thermal circuit model of the high-voltage cable based on the structural composition of the high-voltage cable;

[0034] A model equivalent module, used for converting the transient thermal circuit model of the high-voltage cable into a first-order transient equivalent thermal circuit model;

[0035] A parameter solving module, used for solving the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent thermal circuit model based on the historical temperature data;

[0036] Real-time temperature acquisition module, used to obtain the real-time collected cable surface temperature;

[0037] A cable core temperature calculation module is used to calculate the cable core temperature of the high-voltage cable based on the cable surface temperature, the equivalent thermal resistance and the equivalent thermal capacity.

[0038] In a third aspect, the present invention further provides an electronic device, comprising:

[0039] one or more processors;

[0040] A storage device for storing one or more programs;

[0041] When the one or more programs are executed by the one or more processors, the one or more processors implement the method for calculating the cable core temperature of a high-voltage cable as provided in the first aspect of the present invention.

[0042] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for calculating the cable core temperature of a high-voltage cable as provided in the first aspect of the present invention.

[0043] The cable core temperature calculation method of the high-voltage cable provided by the present invention constructs a transient thermal circuit model of the high-voltage cable based on the structural composition of the high-voltage cable, equates the transient thermal circuit model of the high-voltage cable to a first-order transient equivalent thermal circuit model, solves the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent thermal circuit model based on historical temperature data, obtains the real-time collected cable surface temperature, and calculates the cable core temperature of the high-voltage cable based on the cable surface temperature, the equivalent thermal resistance and the equivalent thermal capacity. By equating the transient thermal circuit model of the high-voltage cable to a first-order transient equivalent thermal circuit model, and solving the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent thermal circuit model based on historical temperature data, in practical applications, the cable core temperature of the high-voltage cable can be quickly calculated according to the real-time collected cable surface temperature and the solved first-order transient equivalent thermal circuit model, thereby improving the efficiency of cable core temperature calculation.

[0044] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 A flow chart of a method for calculating the cable core temperature of a high-voltage cable provided by the present invention;

[0047] Figure 2 A circuit diagram of a transient thermal circuit model of a high-voltage cable provided by the present invention;

[0048] Figure 3 A circuit diagram of a first-order transient equivalent thermal circuit model provided by the present invention;

[0049] Figure 4 A schematic diagram of the structure of a device for calculating the cable core temperature of a high-voltage cable provided by the present invention;

[0050] Figure 5 The present invention provides a schematic structural diagram of an electronic device.

[0051] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0053] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0054] Figure 1 This is a flow chart of a method for calculating the cable core temperature of a high-voltage cable provided by the present invention. This embodiment is applicable to the case of quickly calculating the cable core temperature of a high-voltage cable. The method can be executed by a device for calculating the cable core temperature of a high-voltage cable provided by an embodiment of the present invention. The device can be implemented by software and / or hardware, and is usually configured in an electronic device, such as Figure 1 As shown, the method for calculating the cable core temperature of a high-voltage cable specifically includes the following steps:

[0055] S101. Construct a transient thermal circuit model of the high-voltage cable based on the structural composition of the high-voltage cable.

[0056] In an embodiment of the present invention, a transient thermal circuit model of a high-voltage cable is constructed based on the structural composition of the high-voltage cable. In power cables, the transient thermal circuit model is used to describe the temperature distribution and heat flow changes of the cable under different working conditions. Exemplarily, the structural composition of a high-voltage cable refers to the layer structure of the high-voltage cable. Typically, a high-voltage cable includes a cable core and other layer structures covering the cable core, such as an insulating layer, a protective layer, etc., which are not limited in the embodiment of the present invention. The heat generated by the cable core of the high-voltage cable is transferred outward layer by layer through the layer structure, thereby constructing a transient thermal circuit model of the high-voltage cable.

[0057] Exemplarily, in some embodiments of the present invention, the high-voltage cable includes a cable core, an insulation layer wrapping the cable core, a buffer layer wrapping the insulation layer, an aluminum sheath wrapping the buffer layer, and an outer sheath wrapping the aluminum sheath, and a transient thermal circuit model of the cable core heating power is constructed with respect to the cable core temperature, cable core heat capacity, insulation heat loss, insulation layer temperature, insulation layer heat capacity, insulation layer thermal resistance, buffer layer heat loss, buffer layer thermal resistance, buffer layer heat capacity, aluminum sheath heat loss, aluminum sheath temperature, aluminum sheath heat capacity, outer sheath temperature, outer sheath thermal resistance and outer sheath thermal capacity.

[0058] Figure 2 A circuit diagram of a transient thermal circuit model of a high voltage cable provided by the present invention, such as Figure 2 As shown in the figure, the transient thermal circuit model circuit of the high-voltage cable includes the transient thermal circuit model circuit of the cable core, the transient thermal circuit model circuit of the insulation layer (usually cross-linked polyethylene (XLPE)), the transient thermal circuit model circuit of the buffer layer, the transient thermal circuit model circuit of the aluminum sheath and the transient thermal circuit model circuit of the outer sheath. These circuits are in parallel. c ,θ i ,θ s ,θ o They are respectively the cable core temperature, the insulation layer temperature, the aluminum sheath temperature, and the outer sheath temperature, in °C; T i 、T b 、T o They are the thermal resistance of the insulation layer, the thermal resistance of the buffer layer, and the thermal resistance of the outer sheath, in K·m / W; C c is the heat capacity of the cable core, in J / (m·K); C i1 , C i2 are the distributed heat capacity of the insulation layer, in J / (m·K); C b is the heat capacity of the buffer layer, in J / (m·K); C s is the heat capacity of the aluminum sheath, in J / (m·K); C o is the heat capacity of the outer sheath, in J / (m·K); Q1 is the heating power of the cable core, in W / m; Q2, Q3 are the heat loss of the insulation layer, in W / m; Q4 is the heat loss of the aluminum sheath, in W / m.

[0059] S102. Equivalent the transient thermal circuit model of the high-voltage cable to a first-order transient equivalent thermal circuit model.

[0060] Exemplarily, the transient thermal circuit model of the high-voltage cable is equivalent to a first-order transient equivalent thermal circuit model of the cable core heating power with respect to the cable core temperature, the temperature of the outer sheath, the equivalent heat capacity and the equivalent thermal resistance. Figure 3 A circuit diagram of a first-order transient equivalent thermal circuit model provided by the present invention, such as Figure 3 As shown, the simplified principle of analog circuit can simplify the circuit of the transient thermal circuit model of the cable into a first-order thermal circuit model. In the figure: C is the equivalent heat capacitance, T is the equivalent thermal resistance, and Q is the equivalent heat source.

[0061] The corresponding relationship between the three equivalent parameters and the parameters in the original transient thermal circuit model can be characterized according to equations (1)-(3):

[0062] Q=Q1 (1)

[0063] T=T i +T b +T o (2)

[0064]

[0065] It can be seen that the equivalent parameters of the cable have a corresponding relationship with the original transient thermal circuit model. Solving the equivalent parameters of the first-order transient equivalent thermal circuit can also characterize the transient thermal process of the cable.

[0066] according to Figure 3 The circuit diagram of the first-order transient equivalent thermal circuit model is shown in FIG. 4 , and the mathematical expression of the first-order transient equivalent thermal circuit model of the cable can be written as shown in (4):

[0067]

[0068] Where Q is the heating power of the cable core, θ c is the cable core temperature, θ o is the temperature of the outer sheath, C is the equivalent heat capacity, and T is the equivalent thermal resistance. The cable core heating power Q can be calculated according to the IEC 60287 standard, while the equivalent heat capacity C and the equivalent thermal resistance T are unknown quantities.

[0069] S103. Solve the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent thermal circuit model based on historical temperature data.

[0070] Since the first-order transient equivalent thermal circuit model of the cable can be written at any time during the temperature change of the cable, two temperature points in the cable temperature change process can be taken to write the equivalent thermal parameter solution equation group. Take the first historical cable core temperature and the first historical cable surface temperature at the first acquisition time numbered N1 and N2 in the historical acquisition data, and the second historical cable core temperature and the second historical cable surface temperature at the second acquisition time for analysis. The written equation group is shown in formula (5):

[0071]

[0072] Where: θ cN1 is the cable core temperature data numbered N1; θ oN1 is the surface temperature data of the outer sheath numbered N1; θ cN2 is the cable core temperature data numbered N2; θ oN2 is the temperature data of the outer sheath numbered N2; Q N1 is the heating power of the cable numbered N1 at the corresponding time; Q N2 It is the heating power of the cable numbered N2 at the corresponding time.

[0073] Since the temperature differential term of the cable core cannot be measured directly, the present invention considers using an analytical derivation method to solve the temperature differential term. During the processing, a fitting method is used to describe the transient temperature equation of the cable core, and the fitted transient equation of the cable core satisfies formula (6):

[0074]

[0075] It is a function of time, x1, x2, x3 are fitting coefficients, and t is time.

[0076] The three fitting coefficients can be solved according to the actual temperature rise data of the cable collected, and then the differential term of the cable core can be expressed as follows:

[0077]

[0078] Therefore, as long as the time corresponding to a certain temperature point is obtained, the temperature differential term corresponding to the temperature point can also be solved.

[0079] Therefore, by substituting the first acquisition time numbered N1 into formula (7) and the second acquisition time numbered N2 into formula (7), we can obtain formula (8):

[0080]

[0081] Among them, k 1_N1 Substituting the first acquisition time numbered N1 into equation (7) to calculate the temperature differential term at the first acquisition time, k2_N1 is the difference between the cable core temperature and the outer sheath temperature at the first acquisition time numbered N1, k 1_N2 Substituting the second acquisition time numbered N2 into equation (7) to calculate the temperature differential term at the second acquisition time, k 2_N2 is the difference between the cable core temperature and the outer sheath temperature at the second acquisition moment numbered N2.

[0082] Substituting the above (8) into formula (5) to solve the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent thermal circuit model, the expressions of the equivalent thermal resistance T and equivalent heat capacity C are obtained as follows:

[0083]

[0084] Among them, Q N1 is the heating power of the cable at the first acquisition moment numbered N1, Q N2 It is the heating power of the cable at the second collection moment numbered N2.

[0085] S104: Acquire the cable surface temperature collected in real time.

[0086] In actual application, the cable surface temperature, that is, the temperature of the outer sheath, is collected in real time. For example, a temperature sensor may be provided on the outer sheath to collect the temperature of the outer sheath.

[0087] S105. Calculate the cable core temperature of the high voltage cable based on the cable surface temperature, equivalent thermal resistance and equivalent thermal capacity.

[0088] For example, the cable surface temperature collected in real time is substituted into the first-order transient equivalent heat circuit model for calculation to obtain the cable core temperature of the high-voltage cable. Since the equivalent thermal resistance T, equivalent heat capacity C, and temperature differential terms of the first-order transient equivalent heat circuit model have been solved, the cable core heating power Q can be calculated according to the IEC 60287 standard. Therefore, only the cable core temperature θ c An unknown quantity, therefore, the cable core temperature θ can be directly calculated c .

[0089] The cable core temperature calculation method of the high-voltage cable provided by the present invention constructs a transient thermal circuit model of the high-voltage cable based on the structural composition of the high-voltage cable, equates the transient thermal circuit model of the high-voltage cable to a first-order transient equivalent thermal circuit model, solves the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent thermal circuit model based on historical temperature data, obtains the real-time collected cable surface temperature, and calculates the cable core temperature of the high-voltage cable based on the cable surface temperature, the equivalent thermal resistance and the equivalent thermal capacity. By equating the transient thermal circuit model of the high-voltage cable to a first-order transient equivalent thermal circuit model, and solving the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent thermal circuit model based on historical temperature data, in practical applications, the cable core temperature of the high-voltage cable can be quickly calculated according to the real-time collected cable surface temperature and the solved first-order transient equivalent thermal circuit model, thereby improving the efficiency of cable core temperature calculation.

[0090] Figure 4 A schematic diagram of the structure of a cable core temperature calculation device for a high-voltage cable provided by the present invention, such as Figure 4 As shown, the cable core temperature calculation device of the high voltage cable includes:

[0091] A thermal circuit model building module 201 is used to build a transient thermal circuit model of the high-voltage cable based on the structural composition of the high-voltage cable;

[0092] A model equivalent module 202, used to convert the transient thermal circuit model of the high-voltage cable into a first-order transient equivalent thermal circuit model;

[0093] A parameter solving module 203, used for solving the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent thermal circuit model based on the historical temperature data;

[0094] A real-time temperature acquisition module 204 is used to acquire the cable surface temperature collected in real time;

[0095] The cable core temperature calculation module 205 is used to calculate the cable core temperature of the high voltage cable based on the cable surface temperature, the equivalent thermal resistance and the equivalent thermal capacity.

[0096] In some embodiments of the present invention, the high-voltage cable includes a cable core, an insulating layer wrapping the cable core, a buffer layer wrapping the insulating layer, an aluminum sheath wrapping the buffer layer, and an outer sheath wrapping the aluminum sheath, and the thermal circuit model building module 201 includes:

[0097] The thermal circuit model construction submodule is used to construct a transient thermal circuit model of the cable core heating power regarding the cable core temperature, cable core heat capacity, insulation heat loss, insulation layer temperature, insulation layer heat capacity, insulation layer thermal resistance, buffer layer heat loss, buffer layer thermal resistance, buffer layer heat capacity, aluminum sheath heat loss, aluminum sheath temperature, aluminum sheath heat capacity, outer sheath temperature, outer sheath thermal resistance and outer sheath thermal capacity.

[0098] In some embodiments of the present invention, the model equivalence module 202 includes:

[0099] The model equivalent submodule is used to equate the transient thermal circuit model of the high-voltage cable to a first-order transient equivalent thermal circuit model of the cable core heating power with respect to the cable core temperature, the temperature of the outer sheath, the equivalent heat capacity and the equivalent thermal resistance.

[0100] In some embodiments of the present invention, the first-order transient equivalent thermal circuit model is as follows:

[0101]

[0102] Where Q is the heating power of the cable core, θ c is the cable core temperature, θ o is the temperature of the outer sheath, C is the equivalent heat capacity, and T is the equivalent thermal resistance.

[0103] In some embodiments of the present invention, the parameter solving module 203 includes:

[0104] A first heat circuit equation construction submodule, used for substituting the first historical cable core temperature and the first historical cable surface temperature at the first acquisition moment into the first-order transient equivalent heat circuit model to obtain a first transient equivalent heat circuit equation;

[0105] A second heat circuit equation construction submodule is used to substitute the second historical cable core temperature and the second historical cable surface temperature at the second acquisition moment into the first-order transient equivalent heat circuit model to obtain a second transient equivalent heat circuit equation;

[0106] The joint solving submodule is used to jointly solve the first transient equivalent thermal circuit equation and the second transient equivalent thermal circuit equation to solve the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent thermal circuit model.

[0107] In some embodiments of the present invention, the simultaneous solution submodule includes:

[0108] A fitting unit, used to describe the transient temperature equation of the cable core by using a fitting method, and determine the function of the transient temperature of the cable core with respect to time;

[0109] A differential unit, used for differentiating the function of the transient temperature of the cable core with respect to time to obtain a differential expression of the transient temperature of the cable core with respect to time;

[0110] A solving unit is used to substitute the differential expression of the transient temperature of the cable core with respect to time into the first transient equivalent heat circuit equation and the second transient equivalent heat circuit equation to solve the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent heat circuit model.

[0111] In some embodiments of the present invention, the transient temperature of the cable core as a function of time is:

[0112]

[0113] The differential expression of the transient temperature of the cable core with respect to time is:

[0114]

[0115] Among them, x1, x2, x3 are fitting coefficients, and t is time.

[0116] The above-mentioned device for calculating the cable core temperature of a high-voltage cable can execute the method for calculating the cable core temperature of a high-voltage cable provided in the above-mentioned embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the method for calculating the cable core temperature of a high-voltage cable.

[0117] Figure 5 A schematic diagram of the structure of an electronic device provided by the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0118] like Figure 5 As shown, the electronic device includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0119] A number of components in the electronic device are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0120] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a method for calculating the cable core temperature of a high-voltage cable.

[0121] In some embodiments, the cable core temperature calculation method of the high-voltage cable can be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program can be loaded and / or installed on the electronic device via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the cable core temperature calculation method of the high-voltage cable described above can be performed. Alternatively, in other embodiments, the processor 11 can be configured to execute the cable core temperature calculation method of the high-voltage cable by any other appropriate means (for example, by means of firmware).

[0122] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0123] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0124] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0125] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0126] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0127] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0128] An embodiment of the present invention further provides a computer program product, including a computer program, which, when executed by a processor, implements the method for calculating the cable core temperature of a high-voltage cable as provided in any embodiment of the present application.

[0129] In the process of implementation, the computer program product can be written in one or more programming languages ​​or a combination thereof to perform the computer program code of the present invention, including object-oriented programming languages, such as Java, Smalltalk, C++, and conventional procedural programming languages, such as "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0130] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0131] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for calculating the cable core temperature of a high voltage cable, characterized in that: include: Constructing a transient thermal circuit model of the high-voltage cable based on the structural composition of the high-voltage cable; Equivalently converting the transient thermal circuit model of the high-voltage cable into a first-order transient equivalent thermal circuit model; Solving the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent thermal circuit model based on the historical temperature data; Get the real-time collected cable surface temperature; The cable core temperature of the high-voltage cable is calculated based on the cable surface temperature, the equivalent thermal resistance and the equivalent thermal capacity.

2. The method for calculating the cable core temperature of a high-voltage cable according to claim 1, characterized in that: The high-voltage cable comprises a cable core, an insulating layer wrapping the cable core, a buffer layer wrapping the insulating layer, an aluminum sheath wrapping the buffer layer, and an outer sheath wrapping the aluminum sheath. A transient thermal circuit model of the high-voltage cable is constructed based on the structural composition of the high-voltage cable, including: Construct a transient thermal circuit model of the cable core heating power regarding the cable core temperature, cable core heat capacity, insulation heat loss, insulation layer temperature, insulation layer heat capacity, insulation layer thermal resistance, buffer layer heat loss, buffer layer thermal resistance, buffer layer heat capacity, aluminum sheath heat loss, aluminum sheath temperature, aluminum sheath heat capacity, outer sheath temperature, outer sheath thermal resistance and outer sheath thermal capacity.

3. The method for calculating the cable core temperature of a high-voltage cable according to claim 2, characterized in that: The transient thermal circuit model of the high-voltage cable is equivalent to a first-order transient equivalent thermal circuit model, including: The transient thermal circuit model of the high-voltage cable is equivalent to a first-order transient equivalent thermal circuit model of the cable core heating power with respect to the cable core temperature, the temperature of the outer sheath, the equivalent heat capacity and the equivalent thermal resistance.

4. The method for calculating the cable core temperature of a high-voltage cable according to claim 3, characterized in that: The first-order transient equivalent thermal circuit model is as follows: Where Q is the heating power of the cable core, θ c is the cable core temperature, θ o is the temperature of the outer sheath, C is the equivalent heat capacity, and T is the equivalent thermal resistance.

5. The method for calculating the cable core temperature of a high voltage cable according to claim 4, characterized in that: Solving the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent thermal circuit model based on the historical temperature data includes: Substituting the first historical cable core temperature and the first historical cable surface temperature at the first acquisition time into the first-order transient equivalent heat circuit model to obtain a first transient equivalent heat circuit equation; Substituting the second historical cable core temperature and the second historical cable surface temperature at the second acquisition time into the first-order transient equivalent heat circuit model to obtain a second transient equivalent heat circuit equation; The first transient equivalent heat circuit equation and the second transient equivalent heat circuit equation are combined to solve the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent heat circuit model.

6. The method for calculating the cable core temperature of a high voltage cable according to claim 5, characterized in that: The first transient equivalent heat circuit equation and the second transient equivalent heat circuit equation are combined to solve the equivalent thermal resistance and equivalent heat capacity of the first-order transient equivalent heat circuit model, including: The transient temperature equation of the cable core is described by the fitting method, and the function of the transient temperature of the cable core with respect to time is determined; Differentiating the function of the transient temperature of the cable core with respect to time to obtain a differential expression of the transient temperature of the cable core with respect to time; Substitute the differential expression of the transient temperature of the cable core with respect to time into the first transient equivalent heat circuit equation and the second transient equivalent heat circuit equation to solve the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent heat circuit model.

7. The method for calculating the cable core temperature of a high-voltage cable according to claim 6, characterized in that: The transient temperature of the cable core as a function of time is: The differential expression of the transient temperature of the cable core with respect to time is: Among them, x1, x2, x3 are fitting coefficients, and t is time.

8. A device for calculating the cable core temperature of a high voltage cable, characterized in that: include: A thermal circuit model building module, used to build a transient thermal circuit model of the high-voltage cable based on the structural composition of the high-voltage cable; A model equivalent module, used for converting the transient thermal circuit model of the high-voltage cable into a first-order transient equivalent thermal circuit model; A parameter solving module, used for solving the equivalent thermal resistance and equivalent thermal capacity of the first-order transient equivalent thermal circuit model based on the historical temperature data; Real-time temperature acquisition module, used to obtain the real-time collected cable surface temperature; A cable core temperature calculation module is used to calculate the cable core temperature of the high-voltage cable based on the cable surface temperature, the equivalent thermal resistance and the equivalent thermal capacity.

9. An electronic device, characterized in that: include: one or more processors; A storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method for calculating the cable core temperature of a high-voltage cable as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for calculating the cable core temperature of a high-voltage cable as described in any one of claims 1 to 7 is implemented.

Images