Running state evaluation and fault diagnosis method of cable tunnel pipe gallery power distribution system

Abstract

The invention relates to an operation state evaluation and fault diagnosis method for a cable tunnel pipe gallery power distribution system, and the system comprises an open-close type current transformer, an open-close type electric leakage transformer, and a temperature sensor. Parameters such as cable temperature, electric leakage, voltage, current, power, harmonic wave, electric energy quality and electric power metering of a protected power distribution loop can be monitored, electric leakage, temperature, overvoltage, undervoltage and other alarms are realized, the power supply condition of each path is analyzed in real time, and the operation state is researched and judged. Compared with the prior art, normal and stable operation of online monitoring equipment for partial discharge, circulation, fault area judgment and the like of a 500kV cable line and auxiliary control equipment for fire fighting, video, illumination, drainage and the like in a 500kV cable tunnel can be guaranteed; meanwhile, data of the monitoring device, the inspection device and the host are summarized and analyzed, faults and hidden dangers of the power supply equipment are found in time, and manual operation is replaced to achieve remote inspection.

Description

Technical Field

[0001] The present invention relates to the technical field of cable tunnel monitoring, and in particular to an operating status evaluation and fault diagnosis method for a cable tunnel corridor power distribution system. Background Art

[0002] The current operating status of the power supply and distribution system in high-voltage cable tunnels is as follows:

[0003] With the rapid development of urban economy and the annual increase in electricity load, cable tunnels and corridors are increasingly used to lay power cables in urban construction, and the construction mileage of cable tunnels and corridors is also increasing rapidly. The proportion of cable transmission in urban power tunnels is increasing rapidly: higher voltage, larger capacity, and longer distance. In order to meet the normal operation of electrical equipment in cable tunnels, it is necessary to set up a power supply and distribution system along the tunnel. Due to the high load level requirements of the tunnel, the reliability of the power supply and distribution system is related to the safe, reliable, and efficient operation of facilities such as power cables in the tunnel. It is of great significance to ensure the safety of the power transmission channel of the power grid. At the same time, it is also related to the stable development of the city to a certain extent.

[0004] The power load in the cable tunnel includes lighting, fans, water pumps, monitoring systems, maintenance equipment, etc., which are characterized by large number and scattered distribution. Among them, the largest number is lighting fixtures, about 8,000 sets. The lighting load is distributed linearly along the cable tunnel, which is a dispersed load; the fans and water pumps with relatively large capacity are relatively concentrated in the working shaft, which is a concentrated load. The concentrated load accounts for about 70% of the total capacity of the entire tunnel power load. The operation and maintenance are very difficult. In order to improve the power supply reliability of the distribution network cable and strengthen the operation status monitoring, it is necessary to evaluate and judge the operation status of the distribution network cable. However, the existing health status assessment work is complicated and cumbersome, with many indicators such as online monitoring, electrical inspection, and offline detection. How to fully integrate these indicators and conduct a comprehensive and accurate health status assessment of power cables requires in-depth research. In addition, the existing health status assessment requires a lot of professional knowledge, which is not conducive to the accurate grasp of non-professionals in this field.

[0005] Common status assessment methods include fuzzy mathematical evaluation, grey clustering evaluation, neural network, etc. The fuzzy mathematical evaluation of cable tunnel distribution system is to establish the risk factor set and impact list of cable distribution system according to the different risk status of cable channel distribution system components, and to fuzzify the precise mathematical evaluation according to the different evaluation opinions of different maintenance personnel. The multi-level fuzzy algorithm is further improved and perfected by using the weighted average model. In the application of evaluating the health status of system equipment, for the case where there is no significant difference in grayscale clustering, the normalized clustering coefficient of the equipment health status is first calculated, and then a more reasonable definition of no significant difference in clustering coefficient is given. Then, the idea of ​​grey correlation analysis is used to improve the grey clustering evaluation model. For the lighting line problem, the cross optimization (CSO) algorithm-back propagation (BP) neural network is adopted, and the weights and thresholds optimized by CSO are introduced into the neural network for training, which realizes accurate and efficient fault diagnosis.

[0006] The current state assessment method, on the one hand, has a single assessment indicator and cannot conduct a comprehensive assessment of the power supply and distribution system as a whole. On the other hand, it is very subjective. Due to the different subjectivity of each expert, the assessment results are also different, which in turn affects the accuracy of the system state assessment. Summary of the invention

[0007] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method for evaluating the operating status and diagnosing faults of a cable tunnel corridor power distribution system, thereby reducing the reliance on expert knowledge and facilitating on-site operation and maintenance personnel to quickly and accurately grasp the health status of the cable and perform targeted status maintenance.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] A method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system, wherein the cable tunnel and pipe gallery power distribution system is provided with an open-close current transformer, an open-close leakage transformer, a temperature sensor and a sensing module, which are used to sense the basic characteristics and operating parameters of equipment in a cable tunnel of a distribution network, and the method comprises the following steps:

[0010] According to the basic characteristics and operating parameters of the equipment in the distribution network cable tunnel, the influencing factor set of the state evaluation is determined;

[0011] According to the influencing factor set, the probability of equipment hidden danger under each influencing factor in the influencing factor set and the conditional probability of system failure and normal operation under the action of each influencing factor are calculated;

[0012] According to the acquired equipment hidden danger probability and conditional probability, the influence degree of each influencing factor in the influencing factor set on the cable fault and the degree of change of each influencing factor itself are calculated based on the information entropy theory, and a weight set composed of the weights of each influencing factor in the influencing factor set is obtained;

[0013] Normalizing each influencing factor in the influencing factor set, establishing a membership function of each influencing factor in the influencing factor set to each element in the preset judgment set, and obtaining a judgment matrix of the influencing factor set to which the judgment set belongs;

[0014] The weight of each influencing factor in the influencing factor set is fuzzy operated with the judgment matrix to obtain an evaluation set; the evaluation set is quantified to obtain the corresponding relationship between the evaluation set and the judgment set, and the evaluation result of the cable operation status is obtained.

[0015] Furthermore, the calculation process of the equipment hidden danger probability and conditional probability is specifically as follows:

[0016] Obtain the statistical information of the equipment in the distribution network cable tunnel to calculate the failure probability of the distribution system equipment in the evaluation area, and further determine the probability of equipment hidden dangers under each influencing factor in the influencing factor concentration and the conditional probability of system failure and normal operation under each influencing factor.

[0017] Further, the split current transformer is used to provide power parameters and power quality parameters;

[0018] The open-close leakage transformer is used to provide a leakage current value;

[0019] The temperature sensor is used to provide a temperature value;

[0020] The method evaluates the cable operation status according to the power parameters, power quality parameters, leakage current values ​​and temperature values, and obtains leakage, temperature, overvoltage, undervoltage, phase loss and overcurrent alarms.

[0021] Furthermore, the process of obtaining the real leakage current value by the open-close leakage transformer is specifically as follows:

[0022] By measuring the phase of the primary current in the line, the magnitude and phase of the mixed residual current, and based on the principle that the phase of the primary current is opposite to the phase of the false residual current, the phase difference between the false residual current and the mixed residual current is calculated, so as to predict the magnitude of the false residual current in combination with the magnitude of the mixed residual current;

[0023] Finally, according to the relationship between the vector sum of the false residual current, the real leakage current and the mixed residual current, the real leakage current value is calculated.

[0024] Furthermore, the method also includes experimental verification of the process of obtaining the real leakage current value, specifically:

[0025] Divide the line into two paths, one path is connected to the split leakage transformer, and the other path is connected to the leakage current clamp;

[0026] By changing the resistance in the circuit of the split leakage transformer to change the magnitude of the real leakage current, increasing the inductance to change the current phase in the circuit, and calculating the corresponding pseudo residual current magnitude, the predicted value of the real leakage current value is obtained;

[0027] The actual leakage current value is measured by a leakage current clamp, and then compared with the corresponding predicted value to verify the error.

[0028] Furthermore, the split-type leakage transformer is installed in the lines of fire-fighting, video, lighting and drainage equipment in the cable tunnel.

[0029] Furthermore, the power parameters include single-phase / three-phase voltage, current, active power, reactive power and power factor.

[0030] Furthermore, the power quality parameters include voltage / current deviation and total harmonic content.

[0031] Furthermore, the perception module is respectively connected to an open-and-close current transformer, an open-and-close leakage transformer and a temperature sensor, and is also connected to an analysis host for executing an operation status evaluation and fault diagnosis method of the cable tunnel corridor power distribution system through the analysis host.

[0032] Furthermore, the method further includes obtaining basic characteristics and operating parameters of the power load in the cable tunnel, the power load including lighting, fans, water pumps, monitoring systems and maintenance equipment, scoring the mutual influence between the basic characteristics of the power load and the indicators of the operating parameters by an expert method, constructing an initial influence matrix, and performing normalization and comprehensive processing to obtain a comprehensive influence matrix;

[0033] The centrality and causal degree of each element are calculated according to the comprehensive influence matrix, so as to calculate the entropy of each indicator to determine the weight of each indicator and thus evaluate the operating status of the power load.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] (1) The cable tunnel corridor power distribution system of the present invention is provided with an open-and-close current transformer, an open-and-close leakage transformer and a temperature sensor. The data obtained by the sensing module can monitor the cable temperature, leakage, voltage, current, power, harmonics, power quality, power metering and other parameters of the protected distribution circuit. By analyzing the leakage, temperature, overvoltage, undervoltage, phase loss and overcurrent, alarms are issued, the power supply of each line is analyzed in real time, the operating status is judged, and the online monitoring equipment such as partial discharge, circulating current and fault zone judgment of the 500kV cable line and the auxiliary control equipment such as fire protection, video, lighting and drainage in the 500kV cable tunnel are guaranteed to operate normally and stably.

[0036] (2) The present invention considers the impact of different indicator parameters on the system status, and refers to various maintenance test procedures. It adopts the equipment basic characteristics-operation element theory to establish a characteristic-element extended information entropy model for the health status evaluation of the cable tunnel power supply and distribution system. Through the logical relationship and direct influence matrix between the factors in the system, the influence of each factor on other factors and the degree of change of each influencing factor itself are calculated, so as to determine the weight of each influencing factor, which is equivalent to determining the causal relationship between these elements and the position of each element in the system. The evaluation method proposed on this basis is less affected by subjectivity and does not rely on a large amount of expert knowledge. It is beneficial for on-site operation and maintenance personnel to quickly and accurately grasp the health status of the cable and perform targeted status maintenance. It has a strong engineering practical advantage.

[0037] (3) The present invention aims to solve the problem of false residual current generated by open-type leakage transformers, and proposes a calculation method for solving the true leakage current size. By setting the open-type current transformer, the open-type leakage transformer, and the temperature sensor in the cable tunnel, the analysis host can transmit the status information data to the monitoring terminal, and timely discover the faults and hidden dangers of the power supply equipment by summarizing and analyzing the monitoring, inspection device and host data. When the equipment has abnormal alarm or alarm recovery and other changes, the record is recorded and reported, and the current equipment status information is tracked and processed to ensure real-time response in emergencies, replacing manual remote inspections. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A monitoring flow chart of an operating status evaluation and fault diagnosis method for a cable tunnel corridor power distribution system provided in an embodiment of the present invention;

[0039] Figure 2 A diagram of an electric box power distribution system of a cable tunnel corridor power distribution system provided in an embodiment of the present invention;

[0040] Figure 3 The present invention provides a flow chart of a method for evaluating the operating status and diagnosing faults of a cable tunnel and corridor power distribution system in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions 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 part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0044] Example 1

[0045] like Figure 1 and Figure 3 As shown, this embodiment provides an operation status evaluation and fault diagnosis method for a cable tunnel corridor power distribution system. The cable tunnel corridor power distribution system is provided with an open-close current transformer, an open-close leakage transformer, a temperature sensor and a sensing module, which are used to sense the basic characteristics and operation parameters of the equipment in the cable tunnel of the distribution network. The method includes the following steps:

[0046] S1: Collect and obtain the account statistics and basic characteristic elements of each branch equipment in the distribution network to be evaluated, and determine the influencing factor set U of the state evaluation based on the obtained account statistics and basic characteristics;

[0047] S2: Calculate the probability of failure of the power distribution system equipment in the area to be evaluated based on the account statistical information obtained in step S1, and obtain the probability of equipment hidden dangers under each influencing factor in the influencing factor set U determined in step S1 and the conditional probability of system failure and normal operation under each influencing factor;

[0048] S3: Taking the fault probability and conditional probability calculated in step S2 as basic data, based on the information entropy theory, calculate the influence of each influencing factor in the influencing factor set U in step S1 on the cable fault and the degree of change of each influencing factor itself, and obtain a weight set A composed of the weights of each influencing factor in the influencing factor set U;

[0049] S4: normalize each influencing factor in the influencing factor set, establish a membership function μ(x) that represents each element in the influencing factor set U in step S1 and each element in the preset judgment set V, and obtain a judgment matrix R that reflects the influencing factor set U's membership to the judgment set V through the membership function μ(x);

[0050] S5: Perform fuzzy operation on the weight of each influencing factor in the influencing factor set U and the judgment matrix R to obtain the evaluation set D; quantify the evaluation set D to obtain the corresponding relationship between the evaluation set D and the judgment set V, and make a status evaluation on the cable operation status through the obtained corresponding relationship.

[0051] Among them, Figure 2 As shown, the entire cable tunnel corridor power distribution system includes open-close current transformers, open-close leakage transformers, and temperature sensors. The open-close current transformers provide the analysis host with power parameters such as single-phase / three-phase voltage, current, active power, reactive power, power factor, and power quality parameters such as voltage / current deviation and total harmonic content.

[0052] Open-and-close leakage transformers and temperature sensors provide electrical protection monitoring parameters such as leakage fluctuations and temperature.

[0053] The analysis host is connected to the sensing module via a single bus. The data obtained through the sensing module can monitor the cable temperature, leakage, voltage, current, power, harmonics, power quality, power metering and other parameters of the protected distribution circuit. By analyzing the leakage, temperature, overvoltage, undervoltage, phase loss and overcurrent, alarms are issued, and the power supply of each line is analyzed in real time to determine the operating status.

[0054] The open-close leakage transformer will generate a false residual current. The false residual current, true leakage current, and mixed residual current value signals are in a vector sum relationship. In the absence of true leakage, the false residual current is affected by the balance characteristic. The current induced on the secondary side generates magnetic flux according to Lenz's law when the primary current changes. The magnetic field of the secondary induced current will hinder the change of the primary current. The two directions are theoretically opposite, and the phase difference is about 180°. The phase of the false residual current can be obtained based on the primary current phase. The magnitude of the false residual current is obtained through prediction;

[0055] Two circuits are set up in the laboratory, one is connected to the open-type leakage transformer, and the other is connected to the leakage current clamp. The actual leakage size is changed by changing the resistance in the open-type leakage transformer circuit. Adding inductance can change the current phase in the circuit and obtain the corresponding false residual current size. The leakage current clamp measures the actual leakage size to verify the error.

[0056] The phase of the mixed residual current value signal is affected by the load characteristics. When the real leakage is a resistive current, it is in phase with the false residual current. When it is a capacitive leakage or inductive leakage, it is different from the false residual current phase. The phase of the primary current and the phase of the mixed leakage can be measured. Therefore, the phase difference between the false residual current and the mixed residual current can be calculated based on the phase of the primary current and the phase of the mixed leakage. By monitoring the mixed residual current value, the phase difference between the false residual current and the mixed residual current, and predicting the size of the false residual current, the size of the real leakage current can be finally calculated.

[0057] By installing the open-and-close leakage transformer on auxiliary control equipment such as fire protection, video, lighting, and drainage in the 500kV cable tunnel, the analysis host transmits the status information data to the monitoring terminal, and collects and analyzes the monitoring, inspection device and host data to timely discover the faults and hidden dangers of the power supply equipment. When the equipment has abnormal alarms or alarm recovery and other changes, the record and report are started, and the current equipment status information is tracked and processed to ensure real-time response in emergencies and replace manual remote inspections.

[0058] Preferably, the method further comprises obtaining basic characteristics and operating parameters of the power load in the cable tunnel, wherein the power load includes lighting, fans, water pumps, monitoring systems and maintenance equipment, scoring the mutual influence between the basic characteristics of the power load and the indicators of the operating parameters by an expert method, constructing an initial influence matrix, and performing normalization and comprehensive processing to obtain a comprehensive influence matrix;

[0059] The centrality and causal degree of each element are calculated according to the comprehensive influence matrix, so as to calculate the entropy of each indicator to determine the weight of each indicator and thus evaluate the operating status of the power load.

[0060] The specific process is as follows:

[0061] S101: Invite N experts to construct the basic characteristics and operating parameters of the power load in the system cable tunnel, including lighting, fans, water pumps, monitoring systems, and maintenance equipment, score the degree of mutual influence between each indicator, and construct the initial influence matrix M:

[0062]

[0063] Among them, mij shows the direct impact level of risk index mi on mj;

[0064] S102: Obtain the normalized matrix N from formula (2):

[0065]

[0066] S103: The comprehensive influence matrix T is obtained from formula (3):

[0067]

[0068] S104: Calculate the degree of center, cause, hidden danger and fault:

[0069]

[0070] S105: Calculate the entropy of each indicator based on the impact of the value change of each information entropy indicator on the whole, and then determine the weight. The target weight can eliminate the result deviation caused by subjective evaluation and improve its objectivity and accuracy.

[0071] The decision matrix B = (blk)m×n is used to represent the evaluation index set (l = 1, 2..m; K = 1, 2..n), where m and n represent the number of experts and the number of indicators respectively.

[0072] S106: Standardize the index using formula (5) to obtain a standardized matrix P = (plk)m×n:

[0073]

[0074] S107: Calculate the ratio rlk of each index:

[0075]

[0076] S108: Calculate the information entropy Hk of each index, where if rlk=0, lnrlk=0, then 0≤Hk≤1:

[0077]

[0078] Example 2

[0079] This embodiment provides an operating status evaluation and fault diagnosis method device for a cable tunnel and pipe gallery power distribution system, characterized in that it includes a memory and a processor, the memory stores a computer program, and the processor calls the computer program to execute the steps of the operating status evaluation and fault diagnosis method for the cable tunnel and pipe gallery power distribution system as described in Example 1.

[0080] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for evaluating the operating status and diagnosing faults of a power distribution system in a cable tunnel and pipe gallery, characterized in that: The cable tunnel corridor power distribution system is provided with an open-and-close current transformer, an open-and-close leakage transformer, a temperature sensor and a sensing module, which are used to sense the basic characteristics and operating parameters of the equipment in the cable tunnel of the distribution network. The method comprises the following steps: According to the basic characteristics and operating parameters of the equipment in the distribution network cable tunnel, the influencing factor set of the state evaluation is determined; According to the influencing factor set, the probability of equipment hidden danger under each influencing factor in the influencing factor set and the conditional probability of system failure and normal operation under the action of each influencing factor are calculated; According to the acquired equipment hidden danger probability and conditional probability, the influence degree of each influencing factor in the influencing factor set on the cable fault and the degree of change of each influencing factor itself are calculated based on the information entropy theory, and a weight set composed of the weights of each influencing factor in the influencing factor set is obtained; Normalizing each influencing factor in the influencing factor set, establishing a membership function of each influencing factor in the influencing factor set to each element in the preset judgment set, and obtaining a judgment matrix of the influencing factor set to which the judgment set belongs; The weight of each influencing factor in the influencing factor set is fuzzy operated with the judgment matrix to obtain an evaluation set; the evaluation set is quantified to obtain the corresponding relationship between the evaluation set and the judgment set, and the evaluation result of the cable operation status is obtained.

2. The method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system according to claim 1 is characterized in that: The calculation process of the equipment hidden danger probability and conditional probability is specifically as follows: Obtain the statistical information of the equipment in the distribution network cable tunnel to calculate the failure probability of the distribution system equipment in the evaluation area, and further determine the probability of equipment hidden dangers under each influencing factor in the influencing factor set and the conditional probability of system failure and normal operation under each influencing factor.

3. The method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system according to claim 1 is characterized in that: The split current transformer is used to provide power parameters and power quality parameters; The open-close leakage transformer is used to provide a leakage current value; The temperature sensor is used to provide a temperature value; The method evaluates the cable operation status according to the power parameters, power quality parameters, leakage current values ​​and temperature values, and obtains leakage, temperature, overvoltage, undervoltage, phase loss and overcurrent alarms.

4. The method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system according to claim 3 is characterized in that: The process of obtaining the real leakage current value by the split leakage transformer is specifically as follows: By measuring the phase of the primary current in the line, the magnitude and phase of the mixed residual current, and based on the principle that the phase of the primary current is opposite to the phase of the false residual current, the phase difference between the false residual current and the mixed residual current is calculated, so as to predict the magnitude of the false residual current in combination with the magnitude of the mixed residual current; Finally, according to the relationship between the vector sum of the false residual current, the real leakage current and the mixed residual current, the real leakage current value is calculated.

5. The method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system according to claim 4 is characterized in that: The method also includes experimental verification of the process of obtaining the real leakage current value, specifically: Divide the line into two paths, one path is connected to the split leakage transformer, and the other path is connected to the leakage current clamp; By changing the resistance in the circuit of the split leakage transformer to change the magnitude of the real leakage current, increasing the inductance to change the current phase in the circuit, and calculating the corresponding pseudo residual current magnitude, the predicted value of the real leakage current value is obtained; The actual leakage current value is measured by a leakage current clamp, and then compared with the corresponding predicted value to verify the error.

6. The method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system according to claim 3 is characterized in that: The split-type leakage transformer is installed in the lines of fire-fighting, video, lighting and drainage equipment in the cable tunnel.

7. The method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system according to claim 3 is characterized in that: The power parameters include single-phase / three-phase voltage, current, active power, reactive power and power factor.

8. The method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system according to claim 3 is characterized in that: The power quality parameters include voltage / current deviation and total harmonic content.

9. The method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system according to claim 1, characterized in that: The sensing module is respectively connected to an open-and-close current transformer, an open-and-close leakage transformer and a temperature sensor, and is also connected to an analysis host, for executing an operation status evaluation and fault diagnosis method of the cable tunnel corridor power distribution system through the analysis host.

10. The method for evaluating the operating status and diagnosing faults of a cable tunnel and pipe gallery power distribution system according to claim 1, characterized in that: The method further includes obtaining basic characteristics and operating parameters of the power load in the cable tunnel, wherein the power load includes lighting, fans, water pumps, monitoring systems and maintenance equipment, scoring the mutual influence between the basic characteristics of the power load and the indicators of the operating parameters by an expert method, constructing an initial influence matrix, and performing normalization and comprehensive processing to obtain a comprehensive influence matrix; The centrality and causal degree of each element are calculated according to the comprehensive influence matrix, so as to calculate the entropy of each indicator to determine the weight of each indicator and thus evaluate the operating status of the power load.

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