Method and system for monitoring inter-core insulation of power secondary cable
By conducting real-time analysis of leakage current data of power secondary cables, calculating loop resistance, and judging abnormal insulation between cable cores, the problem of lack of effective monitoring methods in the existing technology is solved, and accurate inter-core insulation monitoring and early warning is achieved.
Patent Information
- Application Number
- CN202510395033.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2025-07-04
AI Technical Summary
The lack of effective monitoring means for the insulation between the core of the power secondary cable in the prior art, resulting in frequent failures in the power system.
By acquiring the leakage current sampling data of the cable based on the leakage current sensor, calculate the loop resistance data and determine whether the average resistance value of the continuous sampling period is within the preset threshold range. If it is within the range, it is determined that there is an abnormality in the core insulation and an alarm signal is issued.
It realizes efficient monitoring and early warning of the insulation between the core of the power secondary cable, solves the monitoring blind spot, is accurate in detection results, and is simple and efficient in methods.
Smart Images
Figure CN120254520A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of core - to - core insulation monitoring in power systems, and specifically provides a monitoring method and system for the core - to - core insulation of secondary power cables. Background Technique
[0002] As an important part of the power system, secondary cables carry functions such as equipment power supply, signal transmission, operation control, etc., and are closely related to the safe and reliable operation of the power system. During on - site operation, affected by factors such as temperature, humidity, over - current, over - voltage, and mechanical stress, secondary cables have a certain risk of aging and damage, which can easily cause problems such as insulation reduction and circuit short - circuit, affecting equipment operation and personal safety. To address the above problems, insulation monitoring equipment is usually equipped in engineering practice to monitor and give early warnings about the insulation status of secondary cables in real - time.
[0003] Currently, the insulation monitoring of secondary power cables usually adopts the differential principle. The positive and negative cables of the same circuit pass through the induction area of the sensor in pairs, and the induced current is detected in real - time and converted into insulation resistance through a certain proportional relationship. This method has certain limitations. It can only detect the insulation resistance to the ground and cannot detect the core - to - core insulation of the cable. In engineering practice, due to the lack of effective monitoring means for the core - to - core insulation of cables, related failures occur from time to time. Summary of the Invention
[0004] The purpose of the present invention is to provide a monitoring method and system for the core - to - core insulation of secondary power cables to solve at least one of the above - mentioned technical problems.
[0005] In a first aspect, an embodiment of the present invention provides a monitoring method for the core - to - core insulation of secondary power cables, including: obtaining a leakage current sampling data set of a target cable in a loop to be protected based on a leakage current sensor; the leakage current sampling data set includes leakage current sampling data in the current sampling period and leakage current sampling data in multiple historical sampling periods; the loop to be protected is a secondary cable loop of a power system; the target cable is the positive outgoing line or the negative outgoing line of the loop to be protected; the target cable passes through the induction area of the leakage current sensor; calculating a loop resistance data set of the loop to be protected based on the leakage current sampling data set; the loop resistance data set includes loop resistance data in the current sampling period and loop resistance data in multiple historical sampling periods; calculating the average value of the loop resistance data in the current sampling period and the loop resistance data in L historical sampling periods before the current sampling period to obtain the average resistance value corresponding to the current sampling period; L is a positive integer greater than 1; if the average resistance values in N consecutive sampling periods are all within a preset threshold range, it is determined that there is an abnormal core - to - core insulation in the loop to be protected; N is a positive integer greater than 1.
[0006] Further, based on the leakage current sampling data set, calculate the loop resistance data set of the loop to be protected, including: obtaining the loop voltage value of the loop to be protected; calculating the ratio of the loop voltage value to the leakage current sampling data corresponding to each sampling period to obtain the loop resistance data corresponding to each sampling period.
[0007] Further, the calculation formula for the average resistance value includes:
[0008]
[0009] In the formula, is the average resistance value corresponding to the k-th sampling period, and R k-L+i is the loop resistance data of the i-th historical sampling period among the loop resistance data of the L-1 historical sampling periods before the k-th sampling period or the loop resistance data of the current sampling period.
[0010] Further, the preset threshold range includes an upper threshold and a lower threshold; if the average resistance value is greater than the lower threshold and less than the upper threshold, it is determined that the average resistance value is within the preset threshold range.
[0011] Further, if it is determined that there is an abnormal inter-core insulation in the loop to be protected, an inter-core insulation alarm signal is issued.
[0012] In a second aspect, an embodiment of the present invention further provides a monitoring system for the inter-core insulation of a power secondary cable, including: a collection module, a first calculation module, a second calculation module, and a determination module; wherein, the collection module is used to obtain a leakage current sampling data set of the target cable of the loop to be protected based on a leakage current sensor; the leakage current sampling data set includes leakage current sampling data of the current sampling period and leakage current sampling data of multiple historical sampling periods; the loop to be protected is a power system secondary cable loop; the target cable is the positive outgoing line or the negative outgoing line of the loop to be protected; the target cable passes through the induction area of the leakage current sensor; the first calculation module is used to calculate the loop resistance data set of the loop to be protected based on the leakage current sampling data set; the loop resistance data set includes loop resistance data of the current sampling period and loop resistance data of multiple historical sampling periods; the second calculation module is used to calculate the average value of the loop resistance data of the current sampling period and the loop resistance data of the L historical sampling periods before the current sampling period to obtain the average resistance value corresponding to the current sampling period; L is a positive integer greater than 1; the determination module is used to determine that there is an abnormal inter-core insulation in the loop to be protected if the average resistance values of N consecutive sampling periods are all within the preset threshold range; N is a positive integer greater than 1.
[0013] Further, the first calculation module is further configured to: obtain the loop voltage value of the loop to be protected; calculate the ratio of the loop voltage value to the leakage current sampling data corresponding to each sampling period to obtain the loop resistance data corresponding to each sampling period.
[0014] Further, an alarm module is further included, configured to send an inter-core insulation alarm signal if it is determined that there is an abnormal inter-core insulation in the loop to be protected.
[0015] In a third aspect, an embodiment of the present invention further provides an electronic device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, where when the processor executes the computer program, the method provided by the embodiment of the present invention is implemented.
[0016] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium, where the computer-readable storage medium stores computer instructions, and when the computer instructions are executed by a processor, the method provided by the embodiment of the present invention is implemented.
[0017] The present invention provides a method and system for monitoring the inter-core insulation of power secondary cables. Through the real-time analysis of the leakage current data and loop resistance of a single cable in the secondary cable loop of the power system, inter-core insulation monitoring and early warning are realized, the insulation monitoring blind area is solved, and the method has the characteristics of simplicity, high efficiency, and accurate detection results, alleviating the technical problem in the prior art that power system-related failures occur frequently due to the lack of effective monitoring means for cable inter-core insulation. Description of the Drawings
[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0019] Figure 1 It is a flowchart of a method for monitoring the inter-core insulation of power secondary cables provided by an embodiment of the present invention;
[0020] Figure 2 It is a flowchart of another method for monitoring the inter-core insulation of power secondary cables provided by an embodiment of the present invention;
[0021] Figure 3 It is a schematic diagram of a system for monitoring the inter-core insulation of power secondary cables provided by an embodiment of the present invention. Detailed Embodiments
[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0023] Embodiment 1
[0024] Figure 1 is a flowchart of a method for monitoring the insulation between cores of a secondary power cable according to an embodiment of the present invention. As Figure 1 shown, the method specifically includes the following steps:
[0025] Step S102: Based on a leakage current sensor, obtain a leakage current sampling data set of the target cable in the loop to be protected; the leakage current sampling data set includes leakage current sampling data in the current sampling period and leakage current sampling data in multiple historical sampling periods; the loop to be protected is a secondary cable loop of a power system; the target cable is the positive outgoing line or negative outgoing line of the loop to be protected; the target cable passes through the induction area of the leakage current sensor.
[0026] Step S104: Based on the leakage current sampling data set, calculate a loop resistance data set of the loop to be protected; the loop resistance data set includes loop resistance data in the current sampling period and loop resistance data in multiple historical sampling periods.
[0027] Step S106: Calculate the average value of the loop resistance data in the current sampling period and the loop resistance data in the L historical sampling periods before the current sampling period to obtain the average resistance value corresponding to the current sampling period; L is a positive integer greater than 1.
[0028] Step S108: If the average resistance values in N consecutive sampling periods are all within a preset threshold range, it is determined that there is an abnormal insulation between cores in the loop to be protected; N is a positive integer greater than 1.
[0029] Specifically, the preset threshold range includes an upper threshold and a lower threshold; if the average resistance value is greater than the lower threshold and less than the upper threshold, it is determined that the average resistance value is within the preset threshold range.
[0030] Specifically, step S104 further includes the following steps:
[0031] Step S1041: Obtain the loop voltage value of the loop to be protected;
[0032] Step S1042: Calculate the ratio of the loop voltage value to the leakage current sampling data corresponding to each sampling period to obtain the loop resistance data corresponding to each sampling period.
[0033] Specifically, the calculation formula for loop resistance data is as follows:
[0034] R k = U / I k
[0035] In the formula, R k is the loop resistance data corresponding to the k-th sampling period, I k is the leakage current sampling data corresponding to the k-th sampling period, and U is the loop voltage value.
[0036] Specifically, the calculation formula for the average resistance value includes:
[0037]
[0038] In the formula, is the average resistance value corresponding to the k-th sampling period, and R k-L+i is the loop resistance data of the i-th historical sampling period among the loop resistance data of the L-1 historical sampling periods before the k-th sampling period or the loop resistance data of the current sampling period.
[0039] The method provided by the embodiment of the present invention further includes: if it is determined that there is abnormal insulation between cores in the loop to be protected, an alarm signal for insulation between cores is sent.
[0040] As can be seen from the above description, the present invention provides a method for monitoring the insulation between cores of a secondary power cable. By analyzing the leakage current data and loop resistance of a single cable in the secondary cable loop of the power system in real time, the insulation between cores is monitored and pre-warned, the insulation monitoring blind area is solved, and the method has the characteristics of simplicity, high efficiency, and accurate detection results, alleviating the technical problem in the prior art that due to the lack of effective monitoring means for the insulation between cores of the cable, related faults in the power system occur from time to time.
[0041] Embodiment 2
[0042] Figure 2 is a flowchart of another method for monitoring the insulation between cores of a secondary power cable provided by an embodiment of the present invention. As Figure 2 shown, it specifically includes the following steps, where step 1 is hardware preparation, steps 2-3 are parameter settings, steps 4-6 are leakage current acquisition and loop resistance calculation; steps 7-10 are insulation between cores discrimination; step 11 is data update.
[0043] Step 1, install a leakage current sensor, and pass the positive outgoing line or negative outgoing line of the loop to be protected through the sensing area of the sensor;
[0044] It should be noted that here it is a single cable passing through the sensing area of the sensor, and only one of the positive and negative outgoing lines needs to be selected, rather than passing through in pairs;
[0045] Step 2, set the upper threshold A H , the lower threshold A L , the data length L, and the holding coefficient N;
[0046] Among them, the upper threshold and the lower threshold should be set according to the specific situation of the on-site circuit, and the empirical value is A L = 250 kΩ, A H = 2 MΩ;
[0047] Step 3, initialize the counter C according to Equation (1)
[0048] C = 0 (1)
[0049] Step 4, obtain the leakage current sampling data I k , where the subscript k represents the current moment;
[0050] Step 5, calculate the loop resistance R according to Equation (2) k
[0051] R k = U / I k (2)
[0052] In the formula, U is the loop voltage, usually 110V or 220V;
[0053] Step 6, calculate the average value of the loop resistance according to Equation (3)
[0054]
[0055] Among them, i is the index;
[0056] Step 7, determine whether the average resistance satisfies Equation (4). If it is satisfied, go to Step 8. If it is not satisfied, set C = 0 and go to Step 11;
[0057]
[0058] Step 8, update the counter C according to Equation (5):
[0059] C = C + 1 (5)
[0060] Step 9, determine whether the counter satisfies Equation (6). If it is satisfied, go to Step 10. If it is not satisfied, go to Step 11;
[0061] C ≥ N (6)
[0062] Step 10, send an inter-core insulation alarm signal;
[0063] Step 11, update k, set k = k + 1, enter Step 4 to start the next analysis, or exit the algorithm.
[0064] Embodiment 3
[0065] Figure 3 It is a schematic diagram of a monitoring system for the insulation between cores of a secondary power cable according to an embodiment of the present invention. As Figure 3 shown, the system includes: an acquisition module 10, a first calculation module 20, a second calculation module 30, and a determination module 40.
[0066] Specifically, the acquisition module 10 is configured to obtain a leakage current sampling data set of the target cable of the circuit to be protected based on a leakage current sensor; the leakage current sampling data set includes leakage current sampling data of the current sampling period and leakage current sampling data of multiple historical sampling periods; the circuit to be protected is a secondary cable circuit of a power system; the target cable is the positive outgoing line or the negative outgoing line of the circuit to be protected; the target cable passes through the sensing area of the leakage current sensor.
[0067] The first calculation module 20 is configured to calculate a loop resistance data set of the circuit to be protected based on the leakage current sampling data set; the loop resistance data set includes loop resistance data of the current sampling period and loop resistance data of multiple historical sampling periods.
[0068] The second calculation module 30 is configured to calculate the average value of the loop resistance data of the current sampling period and the loop resistance data of the previous L historical sampling periods before the current sampling period to obtain the average resistance value corresponding to the current sampling period; L is a positive integer greater than 1.
[0069] The determination module 40 is configured to determine that there is an abnormal insulation between cores in the circuit to be protected if the average resistance values of N consecutive sampling periods are all within a preset threshold range; N is a positive integer greater than 1.
[0070] Specifically, the first calculation module 20 is further configured to:
[0071] Obtain the loop voltage value of the circuit to be protected;
[0072] Calculate the ratio of the loop voltage value to the leakage current sampling data corresponding to each sampling period to obtain the loop resistance data corresponding to each sampling period.
[0073] Specifically, as Figure 3 shown, the system provided by the embodiment of the present invention further includes an alarm module 50, configured to send an inter-core insulation alarm signal if it is determined that there is an abnormal insulation between cores in the circuit to be protected.
[0074] The present invention also provides an electronic device, including: a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the computer program, the method provided by the embodiment of the present invention is implemented.
[0075] The present invention also provides a computer-readable storage medium storing computer instructions, which, when executed by a processor, implement the method provided by the embodiments of the present invention.
[0076] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced by the present invention. Any reference signs in the claims should not be construed as limiting the claimed invention.
[0077] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A monitoring method for the insulation between cores of secondary power cables, characterized in that, Including: Based on a leakage current sensor, obtaining a leakage current sampling data set of a target cable of a circuit to be protected; The leakage current sampling data set includes leakage current sampling data of the current sampling period and leakage current sampling data of multiple historical sampling periods; the circuit to be protected is a secondary cable circuit of a power system; The target cable is the positive outgoing line or the negative outgoing line of the circuit to be protected; The target cable passes through the induction area of the leakage current sensor; Based on the leakage current sampling data set, calculating a loop resistance data set of the circuit to be protected; the loop resistance data set includes loop resistance data of the current sampling period and loop resistance data of multiple historical sampling periods; Calculating the average value of the loop resistance data of the current sampling period and the loop resistance data of L historical sampling periods before the current sampling period to obtain the average resistance value corresponding to the current sampling period; L is a positive integer greater than 1; If the average resistance values of N consecutive sampling periods are all within a preset threshold range, it is determined that there is an inter-core insulation abnormality in the circuit to be protected; N is a positive integer greater than 1.
2. The method according to claim 1, wherein: Based on the leakage current sampling data set, calculating the loop resistance data set of the circuit to be protected, including: Obtaining the loop voltage value of the circuit to be protected; Calculating the ratio of the loop voltage value to the leakage current sampling data corresponding to each sampling period to obtain the loop resistance data corresponding to each sampling period.
3. The method according to claim 1, wherein: The calculation formula of the average resistance value includes: Wherein, is the average resistance value corresponding to the k-th sampling period, and R k-L+i is the i-th historical sampling period loop resistance data among the loop resistance data of the L-1 historical sampling periods before the k-th sampling period or the loop resistance data of the current sampling period.
4. The method according to claim 1, wherein: The preset threshold range includes an upper threshold and a lower threshold; if the average resistance value is greater than the lower threshold and less than the upper threshold, it is determined that the average resistance value is within the preset threshold range.
5. The method according to claim 1, wherein: If it is determined that there is an inter-core insulation abnormality in the circuit to be protected, an inter-core insulation alarm signal is issued.
6. A monitoring system for the insulation between cores of secondary power cables, characterized in that, Including: A collection module, a first calculation module, a second calculation module, and a determination module; wherein, The collection module is used to obtain a leakage current sampling data set of a target cable of a circuit to be protected based on a leakage current sensor; the leakage current sampling data set includes leakage current sampling data of the current sampling period and leakage current sampling data of multiple historical sampling periods; the circuit to be protected is a secondary cable circuit of a power system; the target cable is the positive outgoing line or the negative outgoing line of the circuit to be protected; the target cable passes through the induction area of the leakage current sensor; The first calculation module is used to calculate a loop resistance data set of the circuit to be protected based on the leakage current sampling data set; the loop resistance data set includes loop resistance data of the current sampling period and loop resistance data of multiple historical sampling periods; The second calculation module is used to calculate the average value of the loop resistance data of the current sampling period and the loop resistance data of L historical sampling periods before the current sampling period to obtain the average resistance value corresponding to the current sampling period; L is a positive integer greater than 1; The determination module is used to determine that there is an inter-core insulation abnormality in the circuit to be protected if the average resistance values of N consecutive sampling periods are all within a preset threshold range; N is a positive integer greater than 1.
7. The system according to claim 6, characterized in that: The first calculation module is further used to: Obtain the loop voltage value of the circuit to be protected; Calculate the ratio of the loop voltage value to the leakage current sampling data corresponding to each sampling period to obtain the loop resistance data corresponding to each sampling period.
8. The system according to claim 6, wherein: It further includes an alarm module for sending an inter-core insulation alarm signal if it is determined that there is an inter-core insulation abnormality in the loop to be protected.
9. An electronic device, characterized in that, It includes: A memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the computer program, the method described in any one of claims 1-5 is implemented.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions, and when the computer instructions are executed by the processor, the method described in any one of claims 1-5 is implemented.