Method, system, terminal and medium for real-time monitoring of cable temperature considering unsteady state

Abstract

The present invention discloses a real-time cable temperature monitoring method, system, terminal and medium considering unsteady state, which relates to the field of cable temperature monitoring. The key points of its technical solution are as follows: Based on the change trend of the cable surface temperature, the present invention can determine the amount and starting time of the ambient temperature and cable current changes through reverse coupling decomposition of the influence of ambient temperature and cable current changes on the surface temperature, without requiring the collected data to cover the starting time of the ambient temperature and / or cable current changes; and by coupling the predicted linear parameter sequence and the predicted discrete parameter sequence, the surface steady-state temperature of the target cable is solved, and the predicted temperature of the cable core is calculated using the cable steady-state conductor temperature calculation model, realizing the early monitoring of the final temperature of the cable core under unsteady state conditions and improving the reliability of real-time cable temperature monitoring.

Description

Technical Field

[0001] The present invention relates to the field of cable temperature monitoring, and more specifically, to a real-time cable temperature monitoring method, system, terminal and medium considering unsteady state. Background Art

[0002] The temperature of the cable core is an important parameter for the safe operation of power cables. For example, the allowable long-term maximum temperature of the cable core of a cross-linked polyethylene insulated power cable is 90 °C; the short-term overload operating temperature shall not exceed 130 °C, and the cumulative operating time throughout the year shall not exceed 100 hours; the short-circuit temperature of the core shall not exceed 250 °C, and the maximum duration shall not exceed 2 seconds.

[0003] Currently, the calculation methods of cable core temperature can be divided into two categories: steady-state calculation and unsteady-state calculation. (1) The steady-state calculation method is mainly based on the corresponding formulas in the IEC-60287 standard and the steady-state thermal circuit of the cable. This method assumes that the external environmental conditions are constant. When a single-core cable operates continuously under the rated current-carrying capacity, losses will occur in each part such as the core, insulation, metal sheath, and outer sheath, generating heat to form a steady-state temperature field. The principle of this method is to calculate the losses and thermal resistance of the cable according to the material structure parameters and laying conditions of the cable, and the temperature of the conductor is calculated layer by layer from the temperature rise of each layer of the cable. (2) The unsteady-state calculation method takes into account the temperature change of the cable under non-constant load or environmental conditions. These methods usually need to establish a transient thermal circuit model of the cable body and the surrounding medium, and introduce the concept of thermal time constant to study the calculation method of the transient conductor temperature of the cable under emergency load conditions. The unsteady-state calculation method can more accurately simulate the temperature change of the cable during actual operation, especially when the load changes greatly or the environmental conditions are unstable.

[0004] However, during the actual operation of the cable, the time under steady-state conditions accounts for a relatively small proportion. Therefore, the cable temperature monitoring technology considering unsteady state has become the current main research direction. Since the thermal time constant in the transient thermal circuit model determines the change rate of the cable core temperature, the existing unsteady-state calculation methods need to collect the starting moment of the change in load or environmental conditions, which requires the monitoring equipment for data collection to run in real time, such as fiber optic sensors, thermal effect temperature sensors, etc. If the monitoring equipment randomly collects data for unsteady-state calculation, it is easy to collect the cable surface temperature after a period of time when the load and / or environmental temperature has changed. At this time, the collected cable surface temperature has already had a thermal effect, so it is easy to cause a large deviation in the calculated cable core temperature. Therefore, how to research and design a real-time cable temperature monitoring method, system, terminal and medium considering unsteady state that can overcome the above defects is an urgent problem we need to solve currently. Summary of the Invention

[0005] To address the deficiencies in the existing technology, the objective of the present invention is to provide a real-time cable temperature monitoring method, system, terminal, and medium that consider unsteady states, which can determine the amounts and starting times of environmental temperature and cable current changes, without requiring the collected data to cover the starting times of environmental temperature and / or cable current changes, and realizes the early monitoring of the final temperature of the cable core under unsteady conditions, improving the reliability of real-time cable temperature monitoring.

[0006] The above technical objective of the present invention is achieved through the following technical solutions:

[0007] In the first aspect, a real-time cable temperature monitoring method that considers unsteady states is provided, including the following steps:

[0008] Collect the real-time current value of the target cable, as well as the surface temperature data and environmental temperature data within a preset time period;

[0009] Perform correction processing on the surface temperature data based on the environmental temperature data to obtain surface temperature correction data;

[0010] Using the surface temperature correction data as the coupling result, select a set of optimal linear parameter sequences and discrete parameter sequences from the pre-constructed linear parameter matrix and discrete parameter matrix;

[0011] Intercept the estimated linear parameter sequence from the linear parameter matrix according to the linear parameter sequence. The starting estimated linear parameter in the estimated linear parameter sequence is adjacent to the terminating linear parameter in the linear parameter sequence, and the terminating estimated linear parameter in the estimated linear parameter sequence represents that the influence of environmental temperature change on the surface temperature is in a steady state;

[0012] Intercept the estimated discrete parameter sequence from the discrete parameter matrix according to the discrete parameter sequence. The starting estimated discrete parameter in the estimated discrete parameter sequence is adjacent to the terminating discrete parameter in the discrete parameter sequence, and the terminating estimated discrete parameter in the estimated discrete parameter sequence represents that the influence of cable current change on the surface temperature is in a steady state;

[0013] Couple the estimated linear parameter sequence and the estimated discrete parameter sequence to solve for the surface steady-state temperature of the target cable;

[0014] Input the surface steady-state temperature, real-time environmental temperature, and real-time current value into the cable steady-state conductor temperature calculation model to calculate the estimated temperature of the cable core.

[0015] Furthermore, the specific calculation formula for the surface temperature correction data is:

[0016] ;

[0017] Wherein, represents in the surface temperature correction data The temperature value at a moment; Indicating in the surface temperature data The temperature value at a moment; Indicating in the ambient temperature data The temperature value at a moment; Indicating in the ambient temperature data The temperature value at a moment;

[0018] Or, the calculation formula of the surface temperature correction data is specifically:

[0019] ;

[0020] Wherein, Indicates the temperature value at the starting moment in the ambient temperature data.

[0021] Further, the linear parameters in the linear parameter matrix characterize the first temperature change ratio of the corresponding changing temperature causing the change of the cable surface temperature within the corresponding continuous change time;

[0022] Wherein, the first temperature change ratio is: the ratio of the final temperature of the cable surface to the starting temperature of the cable surface after the ambient temperature changes with the corresponding changing temperature and passes through the corresponding continuous change time;

[0023] And / or, the discrete parameters in the discrete parameter matrix characterize the second temperature change ratio of the corresponding changing current causing the change of the cable surface temperature within the corresponding continuous change time;

[0024] Wherein, the second temperature change ratio is: the ratio of the final temperature of the cable surface to the starting temperature of the cable surface after the cable current changes with the corresponding changing current and passes through the corresponding continuous change time.

[0025] Further, the expression of the linear parameter matrix is:

[0026] ;

[0027] Wherein, Indicates the changing temperature of the ambient temperature Causing the first temperature change ratio of the change of the cable surface temperature within the continuous change time ; Indicates the sampling time interval; Indicates the number of time samplings; Indicates the sampling temperature interval; Indicates the number of temperature samplings; Indicates that the ambient temperature changes with the changing temperature And after passing through the continuous change time The final temperature of the cable surface; Represents the starting temperature of the cable surface.

[0028] Furthermore, the expression of the discrete parameter matrix is specifically:

[0029] ;

[0030] Wherein, Represents the varying current of the cable current During the continuous change time The second temperature change ratio that causes the change of the cable surface temperature within; Represents the sampling time interval; Represents the number of time samplings; Represents the sampling current interval; Represents the number of current samplings; Represents that the cable current changes with the varying current And after passing through the continuous change time The final temperature of the cable surface; Represents the starting temperature of the cable surface.

[0031] Furthermore, the expression for screening out a set of optimal linear parameter sequences and discrete parameter sequences from the pre - constructed linear parameter matrix and discrete parameter matrix with the surface temperature correction data as the coupling result is specifically:

[0032] ;

[0033] Wherein, Respectively represent the temperature values at the starting time 0, time , and the end time In the surface temperature correction data; Represents the initial ambient temperature at the starting stage of the ambient temperature change, which is an unknown quantity and is eliminated by the ratio of different temperature values in the surface temperature correction data; Respectively represent the changing temperature of the ambient temperature During the continuous change time The first temperature change ratio that causes the change of the cable surface temperature within; Respectively represent the varying current of the cable current During the continuous change time The second temperature change ratio that causes the change of the cable surface temperature within; Respectively represent the coupling parameters for coupling the temperature values at the starting time 0, time , and the end time In the surface temperature correction data; Represents the optimal linear parameter sequence; Represents the optimal discrete parameter sequence.

[0034] Further, the specific process for solving the surface steady-state temperature of the target cable is as follows:

[0035] Perform fitting analysis on each coupling parameter during the screening process of the optimal linear parameter sequence and discrete parameter sequence to predict the prediction coupling parameters in the prediction stage when the influence of environmental temperature change and cable current change on the surface temperature tends to be steady state.

[0036] Combined with the predicted coupling parameters, the estimated linear parameter sequence, and the estimated discrete parameter sequence, perform coupling analysis to obtain the predicted surface temperature value in the prediction stage, and screen out the surface steady-state temperature from the predicted surface temperature values.

[0037] In a second aspect, a cable temperature real-time monitoring system considering unsteady state is provided. This system is used to implement the cable temperature real-time monitoring method considering unsteady state as described in any one of the first aspects, and includes:

[0038] A data acquisition module for collecting the real-time current value of the target cable, as well as the surface temperature data and environmental temperature data within a preset time period.

[0039] A data correction module for correcting the surface temperature data based on the environmental temperature data to obtain the surface temperature corrected data.

[0040] A parameter screening module for screening out a set of optimal linear parameter sequences and discrete parameter sequences from the pre-constructed linear parameter matrix and discrete parameter matrix with the surface temperature corrected data as the coupling result.

[0041] A linear intercepting module for intercepting the estimated linear parameter sequence from the linear parameter matrix according to the linear parameter sequence. The starting estimated linear parameter in the estimated linear parameter sequence is adjacent to the ending linear parameter in the linear parameter sequence, and the ending estimated linear parameter in the estimated linear parameter sequence represents that the influence of environmental temperature change on the surface temperature is in a steady state.

[0042] A discrete intercepting module for intercepting the estimated discrete parameter sequence from the discrete parameter matrix according to the discrete parameter sequence. The starting estimated discrete parameter in the estimated discrete parameter sequence is adjacent to the ending discrete parameter in the discrete parameter sequence, and the ending estimated discrete parameter in the estimated discrete parameter sequence represents that the influence of cable current change on the surface temperature is in a steady state.

[0043] A temperature coupling module for coupling the estimated linear parameter sequence and the estimated discrete parameter sequence to solve the surface steady-state temperature of the target cable.

[0044] A temperature prediction module for inputting the surface steady-state temperature, the real-time environmental temperature, and the real-time current value into the cable steady-state conductor temperature calculation model to calculate the estimated temperature of the cable core.

[0045] In a third aspect, a computer terminal is provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for real-time monitoring of cable temperature considering unsteady state as described in any one of the first aspects is implemented.

[0046] In a fourth aspect, a computer-readable medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method for real-time monitoring of cable temperature considering unsteady state as described in any one of the first aspects can be implemented.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The method for real-time monitoring of cable temperature considering unsteady state provided by the present invention is based on the change trend of the cable surface temperature. By performing reverse coupling decomposition on the influence of environmental temperature and cable current changes on the surface temperature, the amount and starting time of environmental temperature and cable current changes can be determined, without requiring the collected data to cover the starting time of environmental temperature and / or cable current changes. Moreover, by coupling the predicted linear parameter sequence and the predicted discrete parameter sequence, the surface steady-state temperature of the target cable is solved, and the predicted temperature of the cable core is calculated using the cable steady-state conductor temperature calculation model, realizing the early monitoring of the final temperature of the cable core under unsteady state conditions and improving the reliability of real-time cable temperature monitoring.

[0049] 2. The present invention corrects the surface temperature data based on the environmental temperature data, which can eliminate the influence of local changes in the environmental temperature data on the coupling analysis and effectively improve the accuracy of determining the amount and starting time of environmental temperature and cable current changes.

[0050] 3. When solving the surface steady-state temperature of the target cable, the present invention not only considers the continuous influence of a single environmental temperature and cable current changes on the surface temperature, but also considers the subsequent changes in the coupling parameters, making the calculation result of the surface steady-state temperature more accurate. Description of the Drawings

[0051] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the drawings:

[0052] Figure 1 is the flowchart in Embodiment 1 of the present invention;

[0053] Figure 2 is the system block diagram in Embodiment 2 of the present invention. Detailed Embodiments

[0054] To make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to embodiments and the accompanying drawings. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0055] Embodiment 1: Consider a real-time monitoring method for the unsteady cable temperature, as Figure 1 shown, which includes the following steps:

[0056] S1: Collect the real-time current value of the target cable, as well as the surface temperature data and ambient temperature data within a preset time period;

[0057] S2: Correct the surface temperature data based on the ambient temperature data to obtain the corrected surface temperature data;

[0058] S3: Using the corrected surface temperature data as the coupling result, select a set of optimal linear parameter sequences and discrete parameter sequences from the pre-constructed linear parameter matrix and discrete parameter matrix;

[0059] S4: Intercept the predicted linear parameter sequence from the linear parameter matrix according to the linear parameter sequence. The starting predicted linear parameter in the predicted linear parameter sequence is adjacent to the ending linear parameter in the linear parameter sequence. The ending predicted linear parameter in the predicted linear parameter sequence indicates that the influence of the ambient temperature change on the surface temperature is in a steady state;

[0060] S5: Intercept the predicted discrete parameter sequence from the discrete parameter matrix according to the discrete parameter sequence. The starting predicted discrete parameter in the predicted discrete parameter sequence is adjacent to the ending discrete parameter in the discrete parameter sequence. The ending predicted discrete parameter in the predicted discrete parameter sequence indicates that the influence of the cable current change on the surface temperature is in a steady state;

[0061] S6: Couple the predicted linear parameter sequence and the predicted discrete parameter sequence to solve for the surface steady-state temperature of the target cable;

[0062] S7: Input the surface steady-state temperature, the real-time ambient temperature, and the real-time current value into the cable steady-state conductor temperature calculation model to calculate the predicted temperature of the cable core.

[0063] In step S1, the preset time period can be 30 min, 60 min, 90 min, and can be flexibly set according to the load and the ambient temperature change frequency.

[0064] For example, the collection time range of the surface temperature data and the ambient temperature data on October 10, 2022 is [16:00, 17:00], and the real-time current value should be collected at 17:00 on October 10, 2022.

[0065] In step S2, considering that the influence of the change in ambient temperature on the surface temperature is linear, in order to eliminate the interference of the local change in ambient temperature on subsequent coupling, it is necessary to correct the surface temperature data.

[0066] As an alternative implementation, the calculation formula for the surface temperature correction data is specifically:

[0067] ;

[0068] where, represents the temperature value at the moment in the surface temperature correction data; represents the temperature value at the moment in the surface temperature data; represents the temperature value at the moment in the ambient temperature data; represents the temperature value at the moment in the ambient temperature data.

[0069] As another alternative implementation, the calculation formula for the surface temperature correction data is specifically:

[0070] ;

[0071] where, represents the temperature value at the starting moment in the ambient temperature data.

[0072] In step S3, the linear parameters in the linear parameter matrix represent the first temperature change ratio of the corresponding changing temperature causing the change in the cable surface temperature within the corresponding continuous change time; where the first temperature change ratio is: when the ambient temperature changes with the corresponding changing temperature and after the corresponding continuous change time, the ratio of the final temperature of the cable surface to the starting temperature of the cable surface.

[0073] The discrete parameters in the discrete parameter matrix represent the second temperature change ratio of the corresponding changing current causing the change in the cable surface temperature within the corresponding continuous change time; where the second temperature change ratio is: when the cable current changes with the corresponding changing current and after the corresponding continuous change time, the ratio of the final temperature of the cable surface to the starting temperature of the cable surface.

[0074] It should be noted that the first temperature change ratio can be obtained through experimental measurement with the ambient temperature as a single variable, and other conditions in the experiment can be taken as the average value of the actual working conditions within a certain period of time. Similarly, the second temperature change ratio can be obtained through experimental measurement with the cable current as a single variable, and other conditions in the experiment can be taken as the average value of the actual working conditions within a certain period of time. In addition, the first temperature change ratio and the second temperature change ratio can also be obtained through simulation, and there is no limitation here.

[0075] In this embodiment, the linear parameters and discrete parameters can be sampled at equal intervals, and the number of samples of the linear parameter matrix and the discrete parameter matrix can be kept consistent.

[0076] For example, the expression of the linear parameter matrix is:

[0077] ;

[0078] Wherein, ΔT represents the change temperature of the ambient temperature during the continuous change time and is the first temperature change ratio that causes the change of the cable surface temperature; Δt represents the sampling time interval; n represents the number of time samples; ΔTs represents the sampling temperature interval; m represents the number of temperature samples; T0 represents the ambient temperature changing at the change temperature ΔT, and after passing through the continuous change time is the final temperature of the cable surface; T1 represents the starting temperature of the cable surface.

[0079] It should be noted that when the influence of the change of the ambient temperature on the cable surface temperature is in a steady state, the value of the first temperature change ratio is 1.

[0080] For example, the expression of the discrete parameter matrix is specifically:

[0081] ;

[0082] Wherein, ΔI represents the change current of the cable current during the continuous change time and is the second temperature change ratio that causes the change of the cable surface temperature; Δt represents the sampling time interval; n represents the number of time samples; ΔIs represents the sampling current interval; p represents the number of current samples; I0 represents the cable current changing at the change current ΔI, and after passing through the continuous change time is the final temperature of the cable surface; T1 represents the starting temperature of the cable surface.

[0083] It should be noted that when the influence of the change of the cable current on the cable surface temperature is in a steady state, the value of the second temperature change ratio is 1.

[0084] In this embodiment, taking the surface temperature correction data as the coupling result, an optimal linear parameter sequence and a discrete parameter sequence corresponding to the minimum sum of a set of coupling parameters are selected from the pre-constructed linear parameter matrix and discrete parameter matrix. The specific expression is:

[0085] ;

[0086] Among them, respectively represent the temperature values at the starting time 0, time , and the end time in the surface temperature correction data; represents the initial ambient temperature in the initial stage of the ambient temperature change, which is an unknown quantity and is eliminated by the ratio of different temperature values in the surface temperature correction data; respectively represent the first temperature change ratio of the ambient temperature change temperature causing the surface temperature change of the cable within the continuous change time ; respectively represent the second temperature change ratio of the cable current change current causing the surface temperature change of the cable within the continuous change time ; respectively represent the coupling parameters for coupling the temperature values at the starting time 0, time , and the end time in the surface temperature correction data; represents the optimal linear parameter sequence; represents the optimal discrete parameter sequence.

[0087] In step S4, if a row of data in the linear parameter matrix is , where takes a value other than 1, takes a value of 1; when the selected linear parameter sequence is , the estimated linear parameter sequence is .

[0088] In step S5, if a row of data in the discrete parameter matrix is , where takes a value other than 1, takes a value of 1; when the selected discrete parameter sequence is , the estimated discrete parameter sequence is .

[0089] From the above linear parameter sequence and discrete parameter sequence, it can be seen that this working condition is for the simultaneous change of current and ambient temperature. And from the estimated linear parameter sequence and the estimated discrete parameter sequence, it can be seen that the influence of current change on the surface temperature is initially in a steady state.

[0090] In step S6, the specific process of solving the surface steady-state temperature of the target cable is as follows: perform fitting analysis on each coupling parameter in the screening process of the optimal linear parameter sequence and discrete parameter sequence to predict the predicted coupling parameters in the prediction stage when the influence of environmental temperature change and cable current change on the surface temperature tends to be steady; combine the predicted coupling parameters, the estimated linear parameter sequence, and the estimated discrete parameter sequence for coupled analysis to obtain the predicted value of the surface temperature in the prediction stage, and screen out the surface steady-state temperature from the predicted values of the surface temperature.

[0091] Taking the estimated linear parameter sequence and the estimated discrete parameter sequence intercepted in steps S4 and S5 as an example, the estimated linear parameter sequence still needs three more data to reach a steady state, while the estimated discrete parameter sequence still needs two more data to reach a steady state. All reaching a steady state requires three data. Therefore, it is also necessary to fit and predict the subsequent three predicted coupling parameters based on the coupling parameters corresponding to the previous four data.

[0092] In step S7, the cable steady-state conductor temperature calculation model described in the present invention takes into account the surface temperature, environmental temperature, and current. The cable steady-state conductor temperature calculation model can also be replaced with a model that does not require the environmental temperature, which is not limited herein.

[0093] Embodiment 2: A cable temperature real-time monitoring system considering non-steady state, which is used to implement the cable temperature real-time monitoring method considering non-steady state as described in Embodiment 1. As Figure 2 shown, it includes a data acquisition module, a data correction module, a parameter screening module, a linear intercept module, a discrete intercept module, a temperature coupling module, and a temperature estimation module.

[0094] Among them, a data acquisition module is used to acquire the real-time current value of the target cable, as well as the surface temperature data and ambient temperature data within a preset time period; a data correction module is used to correct the surface temperature data based on the ambient temperature data to obtain surface temperature correction data; a parameter screening module is used to screen out a set of optimal linear parameter sequences and discrete parameter sequences from a pre-constructed linear parameter matrix and a discrete parameter matrix with the surface temperature correction data as the coupling result; a linear intercepting module is used to intercept an estimated linear parameter sequence from the linear parameter matrix according to the linear parameter sequence, where the starting estimated linear parameter in the estimated linear parameter sequence is adjacent to the ending linear parameter in the linear parameter sequence, and the ending estimated linear parameter in the estimated linear parameter sequence represents that the influence of ambient temperature change on the surface temperature is in a steady state; a discrete intercepting module intercepts an estimated discrete parameter sequence from the discrete parameter matrix according to the discrete parameter sequence, where the starting estimated discrete parameter in the estimated discrete parameter sequence is adjacent to the ending discrete parameter in the discrete parameter sequence, and the ending estimated discrete parameter in the estimated discrete parameter sequence represents that the influence of cable current change on the surface temperature is in a steady state; a temperature coupling module is used to couple the estimated linear parameter sequence and the estimated discrete parameter sequence to solve the surface steady-state temperature of the target cable; a temperature estimation module is used to input the surface steady-state temperature, the real-time ambient temperature, and the real-time current value into the cable steady-state conductor temperature calculation model to calculate the estimated temperature of the cable core.

[0095] The present invention also records a computer terminal, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the cable temperature real-time monitoring method considering non-steady state as recorded in Embodiment 1.

[0096] The present invention also records a computer-readable medium, on which a computer program is stored. When the computer program is executed by a processor, it can implement the cable temperature real-time monitoring method considering non-steady state as recorded in Embodiment 1.

[0097] Working principle: Based on the change trend of the cable surface temperature, the present invention can determine the amount and starting time of the ambient temperature and cable current changes by performing reverse coupling decomposition on the influence of ambient temperature and cable current changes on the surface temperature, without requiring the collected data to cover the starting time of the ambient temperature and / or cable current changes; and by coupling the estimated linear parameter sequence and the estimated discrete parameter sequence, the surface steady-state temperature of the target cable is solved, and the cable steady-state conductor temperature calculation model is used to calculate the estimated temperature of the cable core, realizing the early monitoring of the final temperature of the cable core under non-steady state conditions and improving the reliability of cable temperature real-time monitoring.

[0098] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0099] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram can be implemented by computer program instructions, and the combination of the flows and / or blocks in the flowchart and / or block diagram can also be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0100] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device implements the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0101] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Therefore, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0102] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A real-time cable temperature monitoring method considering non-steady state is characterized by: The following steps are involved: Collect the real-time current value of the target cable and the surface temperature data and ambient temperature data within a preset time period; Correcting the surface temperature data according to the ambient temperature data to obtain surface temperature correction data; Taking the surface temperature correction data as the coupling result, a set of optimal linear parameter sequences and discrete parameter sequences are screened out from the pre-constructed linear parameter matrix and discrete parameter matrix; According to the linear parameter sequence, an estimated linear parameter sequence is intercepted from the linear parameter matrix, wherein the starting estimated linear parameter in the estimated linear parameter sequence is adjacent to the terminating linear parameter in the linear parameter sequence, and the terminating estimated linear parameter in the estimated linear parameter sequence represents that the influence of the ambient temperature change on the surface temperature is in a steady state; According to the discrete parameter sequence, an estimated discrete parameter sequence is intercepted from the discrete parameter matrix, the estimated discrete parameter at the beginning of the estimated discrete parameter sequence is adjacent to the discrete parameter at the end of the discrete parameter sequence, and the estimated discrete parameter at the end of the estimated discrete parameter sequence represents that the influence of the cable current change on the surface temperature is in a steady state; The estimated linear parameter sequence and the estimated discrete parameter sequence are coupled to solve the surface steady-state temperature of the target cable; The surface steady-state temperature, real-time ambient temperature and real-time current value are input into the cable steady-state conductor temperature calculation model to calculate the estimated temperature of the cable core; The linear parameters in the linear parameter matrix represent the first temperature change ratio of the cable surface temperature caused by the corresponding change temperature within the corresponding continuous change time; The first temperature change ratio is: the ratio of the final temperature of the cable surface to the initial temperature of the cable surface after the ambient temperature changes at a corresponding change temperature and after a corresponding continuous change time; The discrete parameters in the discrete parameter matrix represent a second temperature change ratio of the cable surface temperature caused by the corresponding changing current within the corresponding continuous changing time; The second temperature change ratio is: the ratio of the final temperature of the cable surface to the initial temperature of the cable surface after the cable current changes with a corresponding change current and a corresponding continuous change time has passed.

2. The real-time cable temperature monitoring method considering non-steady state according to claim 1 is characterized in that: The calculation formula of the surface temperature correction data is specifically: ； in, Indicates surface temperature correction data Temperature value at the moment; Indicates surface temperature data Temperature value at the moment; Indicates the ambient temperature data Temperature value at the moment; Indicates the ambient temperature data Temperature value at the moment; Or, the calculation formula of the surface temperature correction data is specifically: ； in, Indicates the temperature value at the starting time in the ambient temperature data; Indicates surface temperature correction data Temperature value at the moment; Indicates surface temperature data Temperature value at the moment; Indicates the ambient temperature data The temperature value at the moment.

3. The real-time cable temperature monitoring method considering non-steady state according to claim 1 is characterized in that: The expression of the linear parameter matrix is: ； in, Indicates the change in ambient temperature In the continuous change time The first temperature ratio causing the cable surface temperature change; Indicates the sampling time interval; Indicates the number of time sampling; Indicates the sampling temperature interval; Indicates the number of temperature sampling times; Indicates the ambient temperature as a function of the temperature change Changes, and after a period of continuous change Final temperature of the rear cable surface; Indicates the starting temperature of the cable surface.

4. The real-time cable temperature monitoring method considering non-steady state according to claim 1 is characterized in that: The expression of the discrete parameter matrix is ​​specifically: ； in, Indicates the changing current of the cable current In the continuous change time The second temperature ratio causing the cable surface temperature change; Indicates the sampling time interval; Indicates the number of time sampling; Indicates the sampling current interval; Indicates the number of current sampling times; Indicates cable current as variable current Changes, and after a period of continuous change Final temperature of the rear cable surface; Indicates the starting temperature of the cable surface.

5. The real-time cable temperature monitoring method considering non-steady state according to claim 1 is characterized in that: The specific expression of selecting a set of optimal linear parameter sequences and discrete parameter sequences from the pre-constructed linear parameter matrix and discrete parameter matrix using the surface temperature correction data as the coupling result is: ； in, Respectively represent the starting time 0 and time in the surface temperature correction data , the end time Temperature value; The initial ambient temperature at the beginning of the ambient temperature change is an unknown quantity, which is eliminated by the ratio of different temperature values ​​in the surface temperature correction data; Respectively represent the change of ambient temperature In the continuous change time The first temperature ratio causing the cable surface temperature change; Represents the change of cable current In the continuous change time The second temperature ratio causing the cable surface temperature change; Respectively represent the starting time 0 and time in the surface temperature correction data , the end time Coupling parameters for coupling the temperature value; represents the optimal linear parameter sequence; represents the optimal discrete parameter sequence.

6. The real-time cable temperature monitoring method considering non-steady state according to claim 1 is characterized in that: The specific process of solving the surface steady-state temperature of the target cable is as follows: Fitting analysis is performed on each coupling parameter in the process of selecting the optimal linear parameter sequence and discrete parameter sequence, and the coupling parameters are predicted in the prediction stage when the influence of ambient temperature change and cable current change on surface temperature tends to be steady state; The predicted coupled parameters, estimated linear parameter sequence and estimated discrete parameter sequence are coupled to analyze the predicted surface temperature value in the prediction stage, and the surface steady-state temperature is screened out from the predicted surface temperature value.

7. Considering the non-steady-state cable temperature real-time monitoring system, its characteristics are: The system is used to implement the real-time cable temperature monitoring method considering non-steady state as described in any one of claims 1 to 6, comprising: A data acquisition module is used to collect the real-time current value of the target cable and the surface temperature data and ambient temperature data within a preset time period; A data correction module is used to correct the surface temperature data according to the ambient temperature data to obtain surface temperature correction data; A parameter screening module is used to screen out a set of optimal linear parameter sequences and discrete parameter sequences from pre-built linear parameter matrices and discrete parameter matrices using surface temperature correction data as coupling results; A linear interception module is used to intercept an estimated linear parameter sequence from a linear parameter matrix according to a linear parameter sequence, wherein the starting estimated linear parameter in the estimated linear parameter sequence is adjacent to the terminating linear parameter in the linear parameter sequence, and the terminating estimated linear parameter in the estimated linear parameter sequence represents that the influence of the ambient temperature change on the surface temperature is in a steady state; A discrete interception module intercepts an estimated discrete parameter sequence from a discrete parameter matrix according to a discrete parameter sequence, wherein the estimated discrete parameter at the beginning of the estimated discrete parameter sequence is adjacent to the discrete parameter at the end of the estimated discrete parameter sequence, and the estimated discrete parameter at the end of the estimated discrete parameter sequence represents that the influence of the cable current change on the surface temperature is in a steady state; The temperature coupling module is used to couple the estimated linear parameter sequence and the estimated discrete parameter sequence to solve the surface steady-state temperature of the target cable; The temperature estimation module is used to input the surface steady-state temperature, real-time ambient temperature and real-time current value into the cable steady-state conductor temperature calculation model to calculate the estimated temperature of the cable core.

8. A computer terminal comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the real-time cable temperature monitoring method taking non-steady state into consideration as described in any one of claims 1 to 6 is implemented.

9. A computer readable medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement the real-time cable temperature monitoring method taking non-steady state into consideration as described in any one of claims 1 to 6.

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