A photovoltaic power station cable fault location system

Abstract

The present invention belongs to the technical field of photovoltaic power station cable fault location, and discloses a photovoltaic power station cable fault location system, which includes a monitoring section division module, a preliminary fault location module, a time domain reflection location module, a pulse signal propagation correction module, and a fault point identification module. When locating a photovoltaic power station cable fault, the present invention analyzes the cable operation fault monitoring section and the cable operation fault position, and then comprehensively determines the abnormal monitoring section where each cable fault may exist. This analysis method can more comprehensively understand the fault situation and improve the accuracy of fault location. When analyzing the cable operation fault position, the present invention analyzes the pulse signal propagation correction index corresponding to each cable operation fault position and then corrects the cable operation fault position. This analysis method can more accurately consider the impact of these actual factors on signal propagation, thereby making a more accurate correction to the fault position.

Description

Technical Field

[0001] The invention belongs to the technical field of photovoltaic power station cable fault positioning, and relates to a photovoltaic power station cable fault positioning system. Background Art

[0002] Photovoltaic power station is a power generation system that uses the photovoltaic effect of photovoltaic cells to directly convert solar radiation energy into electrical energy. Cable failure in photovoltaic power stations will directly lead to a sharp drop in power generation efficiency, affect the stability of power supply, increase operation and maintenance costs, and may cause safety hazards such as fires due to short circuits and overheating, posing a dual threat to the economic benefits and operational safety of the power station. Traditional cable fault detection methods often require the entire cable line to be checked one by one, which is time-consuming and labor-intensive. Therefore, the analysis of cable fault location in photovoltaic power stations is of great significance.

[0003] On the one hand, the existing photovoltaic power station cable fault location analysis usually only involves one location analysis during the specific fault location analysis process, without comprehensive analysis through multiple methods. This analysis method may reduce the accuracy, comprehensiveness and efficiency of photovoltaic power station cable fault location, increase maintenance costs, extend power outage time, and affect the stability of power supply. Inaccurate location results may lead to unnecessary equipment disassembly and replacement, resulting in waste of resources.

[0004] On the other hand, the existing photovoltaic power station cable fault location analysis usually lacks corrective analysis of the location results during the specific fault location analysis process. This analysis method will reduce the accuracy of fault location, resulting in a large deviation between the location result and the actual fault location, which in turn affects the efficiency of fault detection and repair. Inaccurate location results may cause maintenance personnel to conduct troubleshooting at the wrong location, wasting a lot of time and energy, making it difficult to accurately assess the causes and influencing factors of the fault, and unable to provide an effective reference for subsequent fault prevention. Summary of the invention

[0005] In view of this, in order to solve the problems raised in the above background technology, a photovoltaic power station cable fault location system is now proposed.

[0006] The purpose of the present invention can be achieved through the following technical solutions: A photovoltaic power station cable fault location system, including: a monitoring section division module, which is used to divide the target cable of the target photovoltaic power station into monitoring sections to obtain each monitoring section, and record the center point of each monitoring section as a monitoring point.

[0007] The preliminary fault location module is used to monitor the cable operation data of each monitoring section, obtain the cable operation data of each monitoring section, analyze the abnormal cable operation of each monitoring section, and perform preliminary cable operation fault location to obtain each cable operation fault monitoring section.

[0008] The time domain reflection positioning module is used to perform time domain reflection method fault positioning detection on the target cable of the target photovoltaic power station, and to identify the cable running fault position to obtain the running fault position of each cable.

[0009] The pulse signal propagation correction module is used to obtain the pulse signal propagation correction data corresponding to each cable operation fault position, analyze the pulse signal propagation correction index corresponding to each cable operation fault position, and then determine whether it is necessary to correct each cable operation fault position, record the cable operation fault position that is determined to need to be corrected as the position to be corrected, and then perform cable operation fault position correction on each position to be corrected to obtain each corrected cable operation fault position. If not necessary, the cable operation fault position is recorded as the corrected cable operation fault position.

[0010] The fault point identification module is used to identify the target fault monitoring section and the risk fault monitoring section based on each cable operation fault monitoring section and each corrected cable operation fault position.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) When locating cable faults in photovoltaic power stations, the present invention analyzes the cable operation fault monitoring section and the cable operation fault position, and then comprehensively determines the abnormal monitoring section where each cable fault may exist. This analysis method can more comprehensively understand the fault situation and reduce the misjudgment that may be caused by a single factor, thereby improving the accuracy of fault location and more quickly determining the scope and severity of the fault.

[0012] (2) When analyzing the cable operation fault location, the present invention corrects the cable operation fault location by analyzing the pulse signal propagation correction index corresponding to each cable operation fault location. This analysis method can more accurately consider the impact of these actual factors on signal propagation, thereby making a more accurate correction to the fault location. Accurate fault location correction can help maintenance personnel find the fault point faster and reduce the time and workload of troubleshooting. Maintenance personnel can perform detection and maintenance more targetedly, improving the efficiency of troubleshooting and repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0014] Figure 1 It is a schematic diagram of the connection of each module of the system of the present invention.

[0015] Figure 2The present invention is a flowchart of the implementation steps of the time domain reflectometry fault location detection.

[0016] Figure 3 This is a schematic diagram of the monitoring section division of the present invention.

[0017] Figure numerals: 1 - target cable, 2 - monitoring section, 3 - monitoring point. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 1 As shown, the present invention provides a photovoltaic power station cable fault location system, the system includes a monitoring section division module, a preliminary fault location module, a time domain reflection location module, a pulse signal propagation correction module and a fault point identification module, wherein the monitoring section division module is respectively connected to the preliminary fault location module and the time domain reflection location module, the time domain reflection location module is connected to the pulse signal propagation correction module, and the preliminary fault location module and the pulse signal propagation correction module are both connected to the fault point identification module.

[0020] See also Figure 3 As shown, the monitoring section division module is used to divide the target cable of the target photovoltaic power station into monitoring sections to obtain each monitoring section, and the center point of each monitoring section is recorded as a monitoring point.

[0021] It should be explained that the reasons for dividing the monitoring sections are: 1. Narrowing the scope of troubleshooting: After dividing the target cable into multiple monitoring sections, once a fault occurs, the section where the fault is located can be quickly determined, thereby greatly narrowing the scope of troubleshooting. Compared with indiscriminate troubleshooting of the entire cable, this method can save a lot of time and labor costs and improve the efficiency of fault detection. 2. Optimizing maintenance strategies: Different maintenance strategies can be formulated according to the importance and failure risks of different monitoring sections. For key sections, monitoring and maintenance efforts can be strengthened, inspection frequency and maintenance investment can be increased; while for relatively stable sections, maintenance costs can be appropriately reduced. This can achieve optimal allocation of resources and improve the overall management level of the power station.

[0022] The preliminary fault location module is used to monitor the cable operation data of each monitoring section, obtain the cable operation data of each monitoring section, analyze the abnormal cable operation of each monitoring section, and perform preliminary cable operation fault location to obtain each cable operation fault monitoring section.

[0023] It should be further explained that the cable operation data includes a current anomaly index, a voltage anomaly index and a temperature anomaly index.

[0024] It should be explained that the reasons for selecting the current anomaly index, voltage anomaly index and temperature anomaly index as cable operation data are as follows: 1. Current is an important parameter for the transmission of electrical energy by cables, and its size directly reflects the load of the cables. When a cable fails, the current often changes abnormally. 2. Voltage is one of the key factors to ensure the normal operation of the power system. Faults such as decreased insulation performance and poor contact of the cable may lead to abnormal voltage. For example, insulation aging will increase the leakage current of the cable, resulting in a drop in voltage; poor contact will cause voltage fluctuations. 3. The cable will generate heat during operation. Under normal circumstances, the temperature should fluctuate within a certain range. When the cable fails such as overload, short circuit, poor contact, etc., the temperature will rise sharply. In addition, changes in ambient temperature will also affect the cable temperature.

[0025] It should be further explained that the specific analysis method of the cable operation abnormality index of each monitoring section needs to be constructed to analyze the cable operation abnormality of each monitoring section as follows: extract the current abnormality index, voltage abnormality index and temperature abnormality index of each monitoring section, which are recorded as , , ,in Indicates the number of the monitoring section. , Indicates the number of the monitoring section.

[0026] It should be added that the analysis method of the temperature anomaly index of each monitoring section is as follows: the temperature of each monitoring point is obtained by using the temperature monitoring equipment , using the formula The temperature anomaly index of each monitoring section is obtained by analysis ,in Indicates the preset reference temperature. Indicates the allowable deviation value between the preset temperature and the reference temperature. Represents a natural constant.

[0027] It should be added that the voltage anomaly index of each monitoring section is analyzed as follows: the voltage of each monitoring point is obtained by using an ammeter , using the formula The voltage anomaly index of each monitoring section is obtained by analysis ,in Indicates the preset reference voltage. Indicates the allowable deviation value between the preset voltage and the reference voltage.

[0028] It should be noted that the analysis method of the current anomaly index of each monitoring section refers to the analysis method of the voltage anomaly index of each monitoring section.

[0029] Using the formula Analyze and obtain the cable operation abnormality index of each monitoring section ,in Indicates the preset current abnormality index threshold. Indicates the preset voltage anomaly index threshold. Indicates the preset temperature anomaly index threshold. They respectively represent the influence weight factors corresponding to the preset current anomaly index, voltage anomaly index and temperature anomaly index.

[0030] It should be noted that the basis for setting the influencing weight factors corresponding to the current anomaly index, voltage anomaly index and temperature anomaly index is that different types of faults have different probabilities of occurring during cable operation. For example, an overload fault may more easily lead to current anomalies, while an insulation aging fault may more often manifest as voltage anomalies or temperature anomalies. By analyzing historical fault data, the frequency of occurrence of current, voltage and temperature anomalies in different types of faults can be statistically calculated, thereby determining the probability of fault occurrence corresponding to each indicator. The weight factor can be adjusted according to the probability of fault occurrence. If the probability of a certain type of fault is high, and the fault is mainly manifested as an abnormality in a certain indicator, then the weight factor of this indicator can be set higher accordingly.

[0031] For example, .

[0032] It needs to be further explained that the specific analysis steps for the preliminary positioning of the cable operation fault are as follows: the cable operation abnormality index of each monitoring section is averaged to obtain the average operation abnormality index of the target cable, the cable operation abnormality index of each monitoring section is differenced with the average cable operation abnormality index to obtain the cable operation abnormality index deviation of each monitoring section, and then the cable operation abnormality index of each monitoring section is ratioed to the average cable operation abnormality index to obtain the abnormality degree of the cable operation abnormality index of each monitoring section.

[0033] The cable operation abnormality index and the cable operation abnormality index abnormality of each monitoring section are summed up according to the weights to obtain the cable operation abnormality of each monitoring section, and the cable operation abnormality of each monitoring section is compared with the preset cable operation abnormality threshold. If the cable operation abnormality of a monitoring section is greater than the cable operation abnormality threshold, it is judged that the cable operation of the monitoring section is faulty; otherwise, it is judged that the cable operation of the monitoring section is normal, and the monitoring section is recorded as a cable operation fault monitoring section.

[0034] It should be noted that the cable operation abnormality threshold is set based on: the cable's rated current, voltage, temperature and other design parameters are important references for setting the abnormality threshold. Generally speaking, the cable should not exceed its rated value under normal operation. For example, for a cable with a certain rated current, the current abnormality threshold can be determined based on its allowable overload capacity and safety factor. If the current exceeds a certain percentage of the rated value, the cable is considered to be in an abnormal state.

[0035] Exemplarily, the cable operation abnormality threshold is .

[0036] The time domain reflection positioning module is used to perform time domain reflection method fault positioning detection on the target cable of the target photovoltaic power station, and to identify the cable running fault position to obtain the running fault position of each cable.

[0037] For further explanation, see Figure 2 As shown, the specific analysis steps of the time domain reflectometry fault location detection are as follows: A1. Connect the probe of the TDR device to one end of the cable, and record the position of the cable end as the initial position.

[0038] A2. Setting pulse parameters on the TDR device, wherein the pulse parameters include setting pulse wave speed, setting pulse width, setting pulse amplitude and setting pulse rise time.

[0039] A3. Start the TDR equipment, send a pulse signal to the cable, and record the time when the pulse signal is sent.

[0040] A4. Use TDR equipment to receive and display the waveform of each reflected signal and obtain the arrival time of each reflected signal.

[0041] It should be further explained that the specific analysis of the cable operation fault location identification is as follows: Using the formula The distance between the fault location and the initial location of each cable is obtained by analysis. ,in Indicates the reflection signal number, , Indicates the number of reflected signals, Indicates The arrival time of the reflected signal, Indicates the pulse signal sending time, Indicates the preset pulse wave speed.

[0042] It should be noted that the pulse velocity is set based on the following: different types of cables have different structures and material compositions, which will affect the propagation speed of the pulse in the cable. For example, coaxial cables, twisted pair cables, and power cables have different internal structures and insulation materials, resulting in differences in pulse velocity. Generally speaking, cable manufacturers usually provide typical velocity values ​​for specific types of cables. When setting the pulse velocity, you can refer to the cable's technical specifications or consult the manufacturer to obtain accurate velocity information.

[0043] The distance between each cable running fault position and the initial position is extracted to obtain each cable running fault position.

[0044] The pulse signal propagation correction module is used to obtain the pulse signal propagation correction data corresponding to each cable operation fault position, analyze the pulse signal propagation correction index corresponding to each cable operation fault position, and then determine whether it is necessary to correct each cable operation fault position, record the cable operation fault position that is determined to need to be corrected as the position to be corrected, and then perform cable operation fault position correction on each position to be corrected to obtain each corrected cable operation fault position. If not necessary, the cable operation fault position is recorded as the corrected cable operation fault position.

[0045] It needs to be further explained that the pulse signal propagation correction data includes pulse signal data, cable data and environmental data, wherein the pulse signal data includes pulse width, pulse amplitude and pulse rise time, the cable data includes cable length and cable impedance, and the environmental data includes temperature, humidity and magnetic field strength.

[0046] It should be noted that the reasons for selecting pulse width, pulse amplitude and pulse rise time as the pulse signal propagation correction data corresponding to the pulse signal data are: 1. Pulse width determines the duration of the pulse signal in time. It has an important impact on the propagation of the pulse in the cable, because pulses of different widths will produce different reflection characteristics when encountering cable faults or impedance mismatches. 2. Pulse amplitude indicates the intensity of the pulse signal. It directly reflects the amount of energy carried by the pulse signal. In cable fault location, changes in pulse amplitude can provide information about changes in impedance at the fault point. 3. Pulse rise time refers to the time required for the pulse to rise from a low level to a high level. It reflects the speed and steepness of the change of the pulse signal. In cable fault location, pulse rise time has an important impact on resolution and accuracy.

[0047] It should be explained that the reasons for selecting cable length and cable impedance as the corresponding cable data for pulse signal propagation correction data are: 1. As the cable length increases, the pulse signal will gradually attenuate during transmission. The attenuation of long cables is more obvious than that of short cables, which will affect the intensity and shape of the reflected pulse. When performing fault location analysis, it is necessary to consider the effect of cable length on signal attenuation in order to more accurately determine the nature and location of the fault point. 2. Cable impedance affects the transmission characteristics of pulse signals in cables, including the amplitude, phase, and frequency response of the signal. Cables with different impedances have different transmission effects on pulse signals, which will affect the accuracy of fault detection and positioning. When performing pulse signal propagation correction, the influence of cable impedance must be considered to ensure accurate signal transmission and correct fault positioning.

[0048] It should be noted that the reasons for selecting temperature, humidity and magnetic field strength as the environmental data corresponding to the pulse signal propagation correction data are: 1. Temperature changes will change the dielectric properties inside the cable, thereby affecting the propagation speed of the pulse signal. At different temperatures, the propagation time of the pulse signal will be different, so the correction of the propagation speed by temperature needs to be considered when locating the fault. 2. Changes in humidity will affect the dielectric constant of the cable, thereby changing the capacitance of the cable. This will affect the propagation of the pulse signal and needs to be corrected when locating the fault. 3. Changes in magnetic field strength may affect the inductance and capacitance of the cable, thereby changing the propagation characteristics of the pulse signal. For example, a strong magnetic field may cause the cable inductance to increase, affecting the transmission speed and attenuation of the signal.

[0049] It should be further explained that the specific steps of analyzing the pulse signal propagation correction index corresponding to each cable operation fault position are as follows: extract the pulse width, pulse amplitude and pulse rise time corresponding to each cable operation fault position, and record them as , , ,in Indicates the number of the cable operation fault location, , Indicates the number of cable operation fault locations, and analyzes the pulse signal influence coefficient corresponding to each cable operation fault location .

[0050] It should be added that the specific steps of the analysis to obtain the pulse signal influence coefficient corresponding to each cable operation fault position are as follows: extract the pulse width, pulse amplitude and pulse rise time corresponding to each cable operation fault position, and use the formula The pulse signal influence coefficient corresponding to each cable operation fault position is obtained by analysis. ,in Indicates the set pulse width in time domain reflectometry fault location detection. Indicates the set pulse amplitude in time domain reflectometry fault location detection. Indicates the set pulse rise time in time domain reflectometry fault location detection.

[0051] The cable length and cable impedance corresponding to each cable fault position are extracted and recorded as , , the cable influence coefficient corresponding to each cable operation fault position is obtained by analysis .

[0052] It should be added that the specific steps of the analysis to obtain the cable influence coefficient corresponding to each cable operation fault position are as follows: extract the cable length and cable impedance corresponding to each cable operation fault position, and use the formula The cable influence coefficient corresponding to each cable operation fault position is obtained by analysis ,in Indicates the preset reference cable length, Indicates the preset reference cable impedance.

[0053] The temperature, humidity and magnetic field strength corresponding to each cable fault position are extracted and recorded as , , , the environmental impact coefficient corresponding to each cable operation fault position is obtained by analysis .

[0054] It should be added that the specific steps of analyzing and obtaining the environmental impact coefficient corresponding to each cable operation fault position are as follows: extract the temperature, humidity and magnetic field strength corresponding to each cable operation fault position, and use the formula The environmental impact coefficient corresponding to each cable operation fault position is obtained by analysis ,in Indicates the preset reference monitoring temperature. Indicates the preset reference monitoring humidity. Indicates the preset reference monitoring magnetic field strength.

[0055] Using the formula The pulse signal propagation correction index corresponding to each cable operation fault position is obtained by analysis. ,in They respectively represent the weight factors of the pulse signal influence coefficient, cable influence coefficient and environmental influence coefficient corresponding to each cable operation fault position.

[0056] It should be noted that the weight factors of the pulse signal influence coefficient, cable influence coefficient and environmental influence coefficient are set based on: by building a cable model in the laboratory, simulating different pulse signals, cable conditions and environmental factors, and measuring the changes in pulse propagation. Based on the experimental results, the degree of influence of different factors on pulse propagation can be determined, and then the weight factors can be set.

[0057] For example, .

[0058] It should be noted that when the present invention analyzes the cable operation fault position, the pulse signal propagation correction index corresponding to each cable operation fault position is analyzed to correct the cable operation fault position. This analysis method can more accurately consider the impact of these actual factors on signal propagation, thereby making a more accurate correction to the fault position. Accurate fault position correction can help maintenance personnel find the fault point faster and reduce the time and workload of troubleshooting. Maintenance personnel can perform detection and maintenance more targetedly, improving the efficiency of troubleshooting and repair.

[0059] It needs to be further explained that the specific analysis method for determining whether it is necessary to correct the fault position of each cable operation is as follows: extract the pulse signal propagation correction index corresponding to each cable operation fault position, and then compare the pulse signal propagation correction index corresponding to each cable operation fault position with the pre-set pulse signal propagation correction index threshold. If the pulse signal propagation correction index corresponding to a cable operation fault position is greater than the pulse signal propagation correction index threshold, it is determined that the cable operation fault position needs to be corrected; otherwise, it is determined that the cable operation fault position does not need to be corrected.

[0060] It should be noted that the reasons for judging whether it is necessary to correct the fault position of each cable are as follows: 1. If correction is made without judgment, over-correction may occur. Over-correction may introduce new problems or cause unnecessary interference to the cable system. By judging whether correction is needed, the appropriateness of the correction work can be ensured and the accuracy and reliability of fault handling can be improved. 2. If correction is made blindly without judgment, a lot of time may be wasted on unnecessary correction work. Accurately judging the fault location can determine which situations really need to be corrected, so that limited time can be concentrated on key fault points and work efficiency can be improved.

[0061] It should be noted that the threshold value of the pulse signal propagation correction index is set based on: Based on the analysis of electromagnetic theory and cable transmission characteristics, a mathematical model of pulse signal propagation in the cable can be established. Through theoretical calculations, the propagation characteristics and possible range of changes of pulse signals under different cable parameters and environmental conditions can be predicted. According to the theoretical model, the expected range of the pulse signal propagation correction index under normal circumstances is determined. This range can be used as a reference basis for setting the threshold value. A correction index outside this range may indicate a fault or abnormality in the cable.

[0062] Exemplarily, the pulse signal propagation correction index threshold is .

[0063] It needs to be further explained that the specific analysis method for correcting the cable operation fault position is as follows: extract the distance from the initial position corresponding to each position to be corrected and the corresponding pulse signal propagation correction index, multiply the distance from the initial position of each position to be corrected by the corresponding pulse signal propagation correction index to obtain the corrected distance of each position to be corrected, and then perform a difference calculation on the distance from the initial position of each position to be corrected and the corresponding correction distance to obtain the corrected distance from the initial position of each position to be corrected, and then obtain the corrected cable operation fault position corresponding to the position to be corrected.

[0064] The fault point identification module is used to identify the target fault monitoring section and the risk fault monitoring section based on each cable operation fault monitoring section and each corrected cable operation fault position.

[0065] It needs to be further explained that the specific analysis steps for identifying the target fault monitoring section and the risk fault monitoring section are as follows: extract each cable operation fault monitoring section and each corrected cable operation fault position, and then compare each cable operation fault monitoring section and each corrected cable operation fault position, and then identify the abnormal monitoring section.

[0066] If a monitoring area is a cable operation fault monitoring section or there is a corrected cable operation fault position in the monitoring section, then the monitoring section is judged to be an abnormal monitoring section; if a monitoring section is not a cable operation fault monitoring section and there is no corrected cable operation fault position in the monitoring section, then the monitoring section is judged not to be an abnormal monitoring section, and further identification of target fault monitoring sections and risk fault monitoring sections is performed.

[0067] It should be noted that, when locating cable faults in photovoltaic power stations, the present invention analyzes the cable operation fault monitoring section and the cable operation fault position, and then comprehensively determines the abnormal monitoring section where each cable fault may exist. This analysis method can more comprehensively understand the fault situation and reduce the misjudgment that may be caused by a single factor, thereby improving the accuracy of fault location and more quickly determining the scope and severity of the fault.

[0068] If an abnormal monitoring section is a cable operation fault monitoring section and there is a corrected cable operation fault location, the abnormal monitoring section is recorded as a target fault monitoring section; otherwise, the abnormal monitoring section is recorded as a risk fault monitoring section.

[0069] It is necessary to explain the reason for identifying risky fault monitoring sections: identifying risky fault monitoring sections can send out early warning signals before a fault occurs. In this way, maintenance personnel can take preventive measures in advance to avoid the occurrence of faults, thereby reducing the losses and impacts caused by the faults. By identifying risky fault monitoring sections, areas with potential fault risks can be discovered in a timely manner. Focusing on monitoring and maintaining these areas can reduce the possibility of faults and improve the reliability and stability of the cable system.

[0070] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the present invention, they shall all fall within the protection scope of the present invention.

Claims

1. A photovoltaic power station cable fault location system, characterized in that: include: A monitoring section division module is used to divide the target cable of the target photovoltaic power station into monitoring sections to obtain each monitoring section, and record the center point of each monitoring section as a monitoring point; The preliminary fault location module is used to monitor the cable operation data of each monitoring section, obtain the cable operation data of each monitoring section, analyze the abnormal cable operation of each monitoring section, and perform preliminary cable operation fault location to obtain each cable operation fault monitoring section; The time domain reflection positioning module is used to perform time domain reflection method fault positioning detection on the target cable of the target photovoltaic power station, and identify the cable operation fault position to obtain the operation fault position of each cable; A pulse signal propagation correction module is used to obtain pulse signal propagation correction data corresponding to each cable operation fault position, analyze the pulse signal propagation correction index corresponding to each cable operation fault position, and then determine whether it is necessary to correct each cable operation fault position, record the cable operation fault position that needs to be corrected as the position to be corrected, and then perform cable operation fault position correction on each position to be corrected to obtain each corrected cable operation fault position. If it is not necessary, the cable operation fault position is recorded as the corrected cable operation fault position; A fault point identification module is used to identify a target fault monitoring section and a risk fault monitoring section based on each cable operation fault monitoring section and each corrected cable operation fault position; The cable operation data includes a current anomaly index, a voltage anomaly index and a temperature anomaly index; The pulse signal propagation correction data includes pulse signal data, cable data and environmental data, wherein the pulse signal data includes pulse width, pulse amplitude and pulse rise time, the cable data includes cable length and cable impedance, and the environmental data includes temperature, humidity and magnetic field strength; The specific analysis method for analyzing the abnormal operation of cables in each monitoring section requires constructing the abnormal operation index of cables in each monitoring section as follows: The current anomaly index, voltage anomaly index and temperature anomaly index of each monitoring section are extracted and recorded as , , ,in Indicates the number of the monitoring section. , Indicates the number of the monitoring section; Using the formula Analyze and obtain the cable operation abnormality index of each monitoring section ,in Indicates the preset current abnormality index threshold. Indicates the preset voltage anomaly index threshold. Indicates the preset temperature anomaly index threshold. Respectively represent the influence weight factors corresponding to the preset current anomaly index, voltage anomaly index and temperature anomaly index; The specific steps of analyzing the pulse signal propagation correction index corresponding to each cable operation fault position are as follows: The pulse width, pulse amplitude and pulse rise time corresponding to each cable operation fault position are extracted and recorded as , , ,in Indicates the number of the cable operation fault location, , Indicates the number of cable operation fault locations, and analyzes the pulse signal influence coefficient corresponding to each cable operation fault location ; The cable length and cable impedance corresponding to each cable fault position are extracted and recorded as , , the cable influence coefficient corresponding to each cable operation fault position is obtained by analysis ; The temperature, humidity and magnetic field strength corresponding to each cable fault position are extracted and recorded as , , , the environmental impact coefficient corresponding to each cable operation fault position is obtained by analysis ; Using the formula The pulse signal propagation correction index corresponding to each cable operation fault position is obtained by analysis. ,in Respectively represent the weight factors of the pulse signal influence coefficient, cable influence coefficient and environmental influence coefficient corresponding to each cable operation fault position; The specific analysis method for determining whether it is necessary to correct the fault position of each cable operation is as follows: Extract the pulse signal propagation correction index corresponding to each cable operation fault position, and then compare the pulse signal propagation correction index corresponding to each cable operation fault position with a preset pulse signal propagation correction index threshold. If the pulse signal propagation correction index corresponding to a certain cable operation fault position is greater than the pulse signal propagation correction index threshold, it is determined that the cable operation fault position needs to be corrected; otherwise, it is determined that the cable operation fault position does not need to be corrected; The specific analysis method for correcting the cable operation fault position is as follows: Extract the distance from the initial position and the corresponding pulse signal propagation correction index corresponding to each position to be corrected, multiply the distance from the initial position to each position to be corrected by the corresponding pulse signal propagation correction index to obtain the corrected distance of each position to be corrected, and then perform difference calculation on the distance from the initial position to each position to be corrected and the corresponding correction distance to obtain the corrected distance from the initial position to each position to be corrected, and then obtain the corrected cable operation fault position corresponding to the position to be corrected; The specific analysis steps for identifying the target fault monitoring section and the risk fault monitoring section are as follows: Extract each cable operation fault monitoring section and each corrected cable operation fault position, and then compare each cable operation fault monitoring section with each corrected cable operation fault position, and then identify the abnormal monitoring section; If a monitoring area is a cable operation fault monitoring section or there is a corrected cable operation fault position in the monitoring section, then the monitoring section is judged to be an abnormal monitoring section; if a monitoring section is not a cable operation fault monitoring section and there is no corrected cable operation fault position in the monitoring section, then the monitoring section is judged not to be an abnormal monitoring section, and further identification of target fault monitoring sections and risk fault monitoring sections is performed; If an abnormal monitoring section is a cable operation fault monitoring section and there is a corrected cable operation fault location, the abnormal monitoring section is recorded as a target fault monitoring section; otherwise, the abnormal monitoring section is recorded as a risk fault monitoring section.

2. A photovoltaic power station cable fault location system as claimed in claim 1, characterized in that: The specific analysis steps for preliminary positioning of cable operation faults are as follows: The cable operation abnormality index of each monitoring section is averaged to obtain the average operation abnormality index of the target cable, and the cable operation abnormality index of each monitoring section is differentially calculated with the average cable operation abnormality index to obtain the cable operation abnormality index deviation of each monitoring section, and then the cable operation abnormality index of each monitoring section is ratio-calculated with the average cable operation abnormality index to obtain the abnormality degree of the cable operation abnormality index of each monitoring section; The cable operation abnormality index and the cable operation abnormality index abnormality of each monitoring section are summed up according to the weights to obtain the cable operation abnormality of each monitoring section, and the cable operation abnormality of each monitoring section is compared with the preset cable operation abnormality threshold. If the cable operation abnormality of a monitoring section is greater than the cable operation abnormality threshold, it is judged that the cable operation of the monitoring section is faulty; otherwise, it is judged that the cable operation of the monitoring section is normal, and the monitoring section is recorded as a cable operation fault monitoring section.

3. A photovoltaic power station cable fault location system as claimed in claim 1, characterized in that: The specific analysis steps of the time domain reflectometry fault location detection are as follows: A1. Connect the probe of the TDR device to one end of the cable and record the position of the cable end as the initial position; A2. Setting pulse parameters on the TDR device, wherein the pulse parameters include setting pulse wave speed, setting pulse width, setting pulse amplitude and setting pulse rise time; A3. Start the TDR device, send a pulse signal to the cable, and record the time when the pulse signal is sent; A4. Use TDR equipment to receive and display the waveform of each reflected signal and obtain the arrival time of each reflected signal.

4. A photovoltaic power station cable fault location system as claimed in claim 3, characterized in that: The specific analysis of the cable operation fault location identification is as follows: Using the formula The distance between the fault location and the initial location of each cable is obtained by analysis. ,in Indicates the reflection signal number, , Indicates the number of reflected signals, Indicates The arrival time of the reflected signal, Indicates the pulse signal sending time, Indicates the preset pulse wave speed; The distance between the running fault position of each cable and the initial position is extracted to obtain the running fault position of each cable.

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