LED street lamp lightning protection device fault detection method and system

Abstract

The invention relates to the technical field of electrical variable measurement, in particular to an LED street lamp lightning protection device fault detection method and system, and the method comprises the steps: obtaining a voltage curve and a temperature curve of an internal circuit of a street lamp; dividing according to the period of the voltage curve to obtain a plurality of voltage time periods; acquiring a voltage jump degree according to the voltage fluctuation degree of each voltage time period; according to the temperature rising and falling degree and time of each voltage time period, the temperature abnormal degree is obtained; obtaining the lightning stroke intensity evaluation of each voltage time period by combining the voltage jump degree and the temperature anomaly degree of each voltage time period and the relevance between the voltage fluctuation and the temperature rise; screening to obtain all lightning stroke time periods; and obtaining the device fault probability of the lightning protection device according to the lightning stroke intensity evaluation of all the lightning stroke time periods, and achieving the fault detection of the lightning protection device. According to the method, the voltage abrupt change degree and the temperature abnormal degree are combined, the more accurate device fault probability of the lightning protection device is obtained, the fault detection efficiency is improved, and misjudgment is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical variable measurement, and in particular to a fault detection method and system for a lightning protection device of an LED street lamp. Background Art

[0002] The lightning protection device of LED street lights usually includes an external lightning protection system and an internal lightning protection system. The external lightning protection system is composed of a lightning rod, a grounding wire, and a grounding grid. The lightning rod guides the lightning strike through the grounding wire and into the grounding grid buried underground, so that the lightning is safely dispersed and the damage to the street light circuit is reduced. The internal lightning protection system uses a metal oxide varistor as an internal voltage protection element. The metal oxide varistor exhibits high impedance and is non-conductive when the circuit voltage is normal. When a lightning strike causes a surge voltage in the street light circuit, the resistance of the metal oxide varistor drops sharply and quickly conducts, leading the surge voltage in the LED street light circuit to the ground, protecting other components in the LED circuit from lightning strikes.

[0003] When an LED street light is struck by lightning, voltage fluctuations will occur. When lightning strikes affect the power grid near the street light, it will also cause large voltage fluctuations in the street light circuit. Judging whether an LED street light has been struck by lightning and has failed only by the voltage fluctuations in the street light's internal circuit may cause misjudgment, resulting in inaccurate fault detection results. Summary of the invention

[0004] The present invention provides a method and system for detecting faults of a lightning protection device of an LED street lamp, so as to solve the problem that the existing method of detecting faults of a lightning protection device only through voltage fluctuations of an internal circuit of a street lamp may lead to misjudgment and inaccurate results.

[0005] A fault detection method and system for a LED street lamp lightning protection device of the present invention adopts the following technical solutions:

[0006] An embodiment of the present invention provides a method for detecting a fault in a lightning protection device of an LED street lamp, the method comprising the following steps:

[0007] Acquire voltage data and temperature data at all times, wherein the voltage data at all times constitute a voltage curve, and the temperature data at all times constitute a temperature curve;

[0008] The voltage curve is divided into periods to obtain several voltage time periods; each identical moment in all voltage time periods is recorded as each site, and the steady-state voltage of each site is obtained according to the clustered distribution of the voltage at each site; the voltage offset amplitude at each moment in each voltage time period and the maximum offset moment of each voltage time period are obtained according to the difference between the voltage at each moment in each voltage time period and the steady-state voltage of the corresponding site; the voltage mutation degree of each voltage time period is obtained according to the position of the maximum offset moment of each voltage time period in the voltage curve and the voltage offset amplitude at all moments in the same voltage time period;

[0009] According to all extreme values ​​of the temperature curve, the temperature rise point and the highest temperature point corresponding to each voltage period are obtained; according to the amplitude changes of the temperature rise point and the highest temperature point corresponding to each voltage period, the temperature anomaly degree of each voltage period is obtained; in combination with the voltage mutation degree and temperature anomaly degree of each voltage period, as well as the correlation between voltage fluctuation and temperature rise, the lightning strike intensity evaluation of each voltage period is obtained; according to the lightning strike intensity evaluation, all lightning strike periods are obtained;

[0010] According to the evaluation of lightning strike intensity in all lightning strike periods, the device failure probability of the lightning protection device is obtained; according to the device failure probability of the lightning protection device, the LED street lamp lightning protection device failure detection is realized.

[0011] Further, the obtaining of a plurality of voltage time periods includes:

[0012] The voltage curve is subjected to fast Fourier transform to obtain a spectrum diagram of the voltage curve. The inverse of the frequency with the largest amplitude in the spectrum diagram is recorded as the period of the voltage curve. The voltage curve is divided into several voltage time periods based on the period of the voltage curve, taking the first zero crossing point in the voltage curve as the starting point.

[0013] Further, obtaining the steady-state voltage of each site includes:

[0014] The clustering conditions are preset, and the voltages of the a-th site in all voltage periods are clustered by DBSCAN density to obtain several clusters of the a-th site. The average of all voltages in the largest cluster among all clusters of the a-th site is taken and recorded as the steady-state voltage of the a-th site.

[0015] Further, the obtaining of the voltage offset amplitude at each moment in each voltage period and the maximum offset moment of each voltage period includes:

[0016] The absolute value of the difference between the steady-state voltage at each moment in each voltage period and the corresponding point is recorded as the voltage offset amplitude at each moment, the voltage offset amplitude at each moment in each voltage period is obtained, and the moment when the voltage offset amplitude takes the maximum value in each voltage period is recorded as the maximum offset moment of each voltage period.

[0017] Further, obtaining the voltage mutation degree of each voltage period includes:

[0018] The voltage mutation degree F in the i-th voltage period i The calculation method is:

[0019]

[0020] Where: t i represents the maximum offset time of the i-th voltage period, t0 represents the zero-crossing time closest to the maximum offset time of the i-th voltage period, T represents the period of the voltage curve, d i represents the voltage at the moment of maximum deviation in the i-th voltage period, represents the average value of the voltage at all times in the post-fluctuation period of the i-th voltage period; || represents the absolute value function.

[0021] Furthermore, the step of obtaining the temperature rise point and the highest temperature point corresponding to each voltage period includes:

[0022] The minimum point of the temperature curve closest to the maximum offset moment after the maximum offset moment of each voltage period in the temperature curve is recorded as the heating point corresponding to each voltage period, and the maximum point of the temperature curve closest to the maximum offset moment after the maximum offset moment of each voltage period is recorded as the highest temperature point corresponding to each voltage period.

[0023] Further, obtaining the temperature abnormality degree of each voltage period includes:

[0024] The temperature abnormality degree D in the i-th voltage period i The calculation method is:

[0025]

[0026] Where: r i represents the temperature of the highest point corresponding to the i-th voltage period, r' i represents the temperature of the heating point corresponding to the i-th voltage period, m i Indicates the time of the highest temperature point corresponding to the i-th voltage period, m' i represents the time of the temperature rise point corresponding to the i-th voltage period, m' i+1 Indicates the time of the temperature rise point corresponding to the i+1th voltage period.

[0027] Further, obtaining the lightning strike intensity evaluation for each voltage period includes:

[0028] Lightning intensity evaluation h in the ith voltage period i The calculation method is:

[0029] h i =Sigmoid{exp[-(m′ i -t i )]×F i ×D i}

[0030] Where: m' i represents the time of the temperature rise point corresponding to the i-th voltage period, t i represents the maximum deviation time of the ith voltage period, F i Indicates the voltage mutation degree in the ith voltage period, D i represents the degree of temperature anomaly in the ith voltage period; Sigmoid{} represents the Sigmoid function; exp[] represents an exponential function with a natural constant as the base.

[0031] Furthermore, the obtaining of the device failure probability of the lightning protection device includes:

[0032] The calculation method of the device failure probability of the lightning protection device is:

[0033]

[0034] Formula explanation: represents the mean value of the lightning intensity evaluation of all lightning strike periods, n represents the number of all lightning strike periods, h k represents the evaluation of lightning strike intensity during the kth lightning strike period; Sigmoid[] represents the Sigmoid function.

[0035] A LED street lamp lightning protection device fault detection system comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, steps of a LED street lamp lightning protection device fault detection method are implemented.

[0036] The beneficial effects of the technical solution of the present invention are as follows: since the voltage of a street lamp has a certain periodicity under normal working conditions, the periodicity of the street lamp voltage is obtained to segment the voltage curve, and the voltage at the same time in different time periods is used as a reference for the normal value, so that the calculation of voltage fluctuations is more in line with the actual working conditions of the street lamp. Since the impact degree of surge voltage occurring at different times on the circuit is different, the degree of voltage mutation in each time period is calculated according to the degree of voltage mutation occurring at each moment and the distance between the moment of voltage mutation and the zero-crossing point, so as to more accurately reflect the degree of loss of the lightning protection device caused by each voltage fluctuation; the temperature rise caused by the normal working of the street lamp and the temperature rise caused by lightning strike are distinguished by the speed of temperature rise, and the degree of lightning energy impact suffered by the street lamp when struck by lightning is reflected by the amplitude of temperature rise and the time consumed for temperature drop; the intensity of lightning strike on the street lamp is accurately reflected in combination with the voltage mutation and the abnormal temperature, and the threshold screening excludes fluctuations in the voltage or temperature of the street lamp caused by non-lightning strikes. The failure probability is calculated based on historical lightning strikes and the average intensity of lightning strikes to prevent the lightning protection device from being directly damaged by the lightning energy the next time a lightning strike occurs, causing the components in the street lamp to be burned out by lightning. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 The present invention is a flowchart of the steps of a method for detecting a fault of a lightning protection device of an LED street lamp. DETAILED DESCRIPTION

[0039] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a method and system for detecting a fault of a lightning protection device for an LED street lamp proposed by the present invention, its specific implementation, structure, features and effects, in combination with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0040] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0041] The specific scheme of a fault detection method and system for a LED street lamp lightning protection device provided by the present invention is described in detail below with reference to the accompanying drawings.

[0042] First, see Figure 1 , which shows a flowchart of a method for detecting a fault of a lightning protection device of an LED street lamp provided by an embodiment of the present invention, the method comprising the following steps:

[0043] Step S001: Obtain voltage data and temperature data at all times.

[0044] The purpose of this embodiment is to analyze the damage of the LED street lamp lightning protection device in combination with voltage and temperature, and realize the fault detection of the LED street lamp lightning protection device. Therefore, the voltage data and temperature data of the internal circuit of the street lamp are first collected; the voltage monitoring frequency and the temperature monitoring frequency are preset, and the voltage data of all moments after the current lightning protection device is installed are collected at the temperature monitoring frequency, and all temperature data after the current lightning protection device is installed are collected at the voltage monitoring frequency. After the collection, the temperature data is linearly interpolated and filled to make it correspond to the voltage data one by one at the time; the voltage data at all moments constitute the voltage curve, and the temperature data at all moments constitute the temperature curve;

[0045] In this embodiment, the preset voltage monitoring frequency is 1000 Hz and the temperature monitoring frequency is 10 Hz. Other embodiments may be set to other values, which are not specifically limited in this embodiment. It should be noted that due to the large frequency of voltage changes and the rapid voltage changes caused by lightning strikes, while the temperature data changes relatively more slowly, the voltage data is collected at a high frequency and the temperature data is collected at a low frequency.

[0046] Step S002, obtaining the steady-state voltage at each moment in all voltage time periods; obtaining the voltage offset amplitude at each moment in each voltage time period and the maximum offset moment in each voltage time period; and obtaining the voltage mutation degree in each voltage time period.

[0047] It should be noted that usually the LED street lamp circuit maintains a normal working state, and the voltage data of the internal circuit of the street lamp is periodic. Therefore, the voltage data at the same time of each cycle under normal working conditions should be concentrated on one value. First, the frequency spectrum of the voltage curve is obtained through fast Fourier transform. The frequency with the largest amplitude in the frequency spectrum reflects the period of the voltage curve, and the period of the voltage curve is obtained; according to the period of the voltage curve, all time points are divided into several time periods, and the clustered distribution of the voltage at each time point that is the same in all time periods is used to reflect the normal working voltage at each time point that is the same in each time period when the street lamp circuit is working normally; according to the voltage at each time point in each time period, and the deviation from the clustered distribution of the voltage at each time point that is the same in all time periods, the voltage offset amplitude at each time point is obtained, and the voltage offset amplitude is used to reflect the gap between the voltage data at each time point and the steady-state voltage. The larger the gap, the more abnormal the working voltage is.

[0048] Specifically, a fast Fourier transform is performed on the voltage curve to obtain a spectrum diagram of the voltage curve, and the result of taking the inverse of the frequency with the largest amplitude in the spectrum diagram is recorded as the period of the voltage curve. The first zero crossing point in the voltage curve is taken as the starting point, and the voltage curve is divided according to the period of the voltage curve to obtain a number of voltage time periods, and all moments before the first zero crossing point and all moments after the last zero crossing point whose length is less than one cycle are discarded; the zero crossing point represents the moment when the voltage in the voltage curve is 0, and the moments on the left and right sides of the moment correspond to one positive voltage and the other negative voltage, and the zero crossing point is a well-known technology, and this embodiment does not specifically limit it;

[0049] A clustering condition is preset, and each identical moment in all voltage time periods is recorded as each site. The voltage of the a-th site in all voltage time periods is clustered by DBSCAN density based on the clustering condition to obtain several clusters of the a-th site. The average of all voltages in the largest cluster among all clusters of the a-th site is taken and recorded as the steady-state voltage of the a-th site. Similarly, the steady-state voltage of all sites is obtained. The clustering radius of the clustering condition preset in this embodiment is 10, and the number of sample points is 5. Other embodiments may be set to other values, which are not specifically limited in this embodiment.

[0050] The absolute value of the difference between the steady-state voltage at each moment in each voltage period and the corresponding point is recorded as the voltage offset amplitude at each moment, the voltage offset amplitude at each moment in each voltage period is obtained, and the moment when the voltage offset amplitude takes the maximum value in each voltage period is recorded as the maximum offset moment of each voltage period.

[0051] It should be further explained that when the internal circuit of the street lamp is directly struck by lightning or the power grid near the street lamp is struck by lightning, the voltage in the internal circuit of the street lamp will suddenly increase, and after the sudden voltage increase, the subsequent voltage fluctuation will continue for a period of time; the position of the maximum offset moment in the voltage curve and the voltage fluctuation in each voltage period of the internal circuit of the street lamp from the maximum offset moment to the voltage recovery to steady state are analyzed, and the voltage offset amplitude at all times in each voltage period is combined to obtain the degree of voltage mutation in each voltage period.

[0052] Specifically, a neighborhood length and a steady-state recovery threshold are preset, and each moment is taken as the center, and the neighborhood length moments are taken forward and backward, which are recorded as the neighborhood interval of each moment. In particular, when the number of available moments is less than the neighborhood length, the maximum number that can be obtained is taken; the average value of the voltage offset amplitudes of all moments in the neighborhood interval of each moment is normalized using the Sigmoid function, and recorded as the neighborhood fluctuation evaluation of each moment; for any voltage period, the maximum offset moment is taken as the starting point, and the moment after the maximum offset moment when the first neighborhood fluctuation evaluation is less than the steady-state recovery threshold is taken as the end point, and all moments between the starting point and the end point are recorded as the post-fluctuation period of the voltage period; in this embodiment, the neighborhood length is preset to 10, and the steady-state recovery threshold is 0.1. Other embodiments can be set to other values, which are not specifically limited in this embodiment.

[0053] Furthermore, the voltage mutation degree F of the i-th voltage period i The calculation method is:

[0054]

[0055] Where: t i represents the maximum offset time of the i-th voltage period, t0 represents the zero-crossing time closest to the maximum offset time of the i-th voltage period, T represents the period of the voltage curve, d i represents the voltage at the moment of maximum deviation in the i-th voltage period, represents the average value of the voltage at all times in the post-fluctuation period of the i-th voltage period; || represents the absolute value function;

[0056] It should be noted that when a sudden voltage change occurs in the internal circuit of a street lamp, The larger the value, the farther the maximum offset moment of the ith voltage period is from the zero crossing point, the larger the peak value of the voltage rise, the greater the impact on the circuit, and the greater the voltage mutation degree of the ith voltage period; d i The larger the value of , the greater the difference between the voltage at the maximum offset moment of the i-th voltage period and the steady-state voltage in the normal working state, and the greater the voltage mutation degree of the i-th voltage period; The larger the value of is, the greater the voltage fluctuation degree in the post-fluctuation period of the i-th voltage period is, and the greater the voltage mutation degree in the i-th voltage period is;

[0057] Similarly, the voltage mutation degree of all voltage time periods is obtained.

[0058] Step S003, obtaining the temperature anomaly degree of each voltage period; obtaining the lightning strike intensity evaluation of each voltage period; and obtaining all lightning strike periods.

[0059] It should be noted that when the street lamp is in normal working condition, the street lamp starts to work at night and the internal circuit of the street lamp heats up slowly. In the morning, the street lamp is turned off and the internal circuit of the street lamp cools down slowly. When lightning strikes the street lamp, the lightning protection device protects the street lamp circuit by reducing resistance to lead the lightning energy to the ground. When the lightning protection device is subjected to lightning energy, it instantly absorbs a large amount of electrical energy, and part of the electrical energy will be converted into heat energy, causing the temperature of the lightning protection device to rise rapidly in a short period of time. The greater the lightning energy, the more the lightning protection device heats up. The degree of temperature anomaly in each voltage period is obtained by the degree of temperature rise, the temperature rise time and the temperature drop time of the internal circuit of the street lamp. The lightning intensity evaluation of each voltage period is obtained by combining the degree of temperature anomaly and the degree of voltage mutation in the internal circuit of the street lamp and the correlation between the two phenomena of voltage fluctuation and temperature rise. The lightning strike period when the internal circuit of the street lamp is subjected to lightning strike is further screened out according to the lightning strike intensity evaluation.

[0060] Specifically, all the maximum and minimum points of the temperature curve are obtained; the minimum point of the temperature curve closest to the maximum offset moment after the maximum offset moment of each voltage period in the temperature curve is recorded as the temperature rise point corresponding to each voltage period, and the maximum point of the temperature curve closest to the maximum offset moment after the maximum offset moment of each voltage period is recorded as the highest temperature point corresponding to each voltage period; the temperature anomaly degree D of the i-th voltage period i The calculation method is:

[0061]

[0062] Where: r i represents the temperature of the highest point corresponding to the i-th voltage period, r' i represents the temperature of the heating point corresponding to the i-th voltage period, m i Indicates the time of the highest temperature point corresponding to the i-th voltage period, m' i represents the time of the temperature rise point corresponding to the i-th voltage period, m' i+1 represents the time of the temperature rise point corresponding to the i+1th voltage period;

[0063] It should be noted that r i -r' i Indicates the temperature rise degree corresponding to the voltage fluctuation in the i-th voltage period. The larger the value, the more the temperature rises in the internal circuit of the street lamp, and the greater the temperature anomaly degree in the i-th voltage period; m i -m' i Indicates the time it takes for the temperature to rise to the maximum temperature corresponding to the voltage fluctuation in the i-th voltage period. The smaller the value, the faster the temperature rises. It is more likely that the lightning protection device is heated by lightning, and the greater the temperature anomaly in the i-th voltage period. i+1 -m iIt indicates the time consumed by the temperature rise corresponding to the voltage fluctuation in the i-th voltage period to cool down from the highest temperature. The larger the value, the slower the cooling. The longer the internal circuit of the street lamp is in a high temperature state, the greater the temperature abnormality in the i-th voltage period.

[0064] Similarly, the temperature anomaly degree of each voltage period is obtained.

[0065] It should be further explained that when lightning strikes affect the power grid near street lamps, they will also cause large voltage fluctuations in the street lamp circuit, but there will be no obvious temperature increase; when other components in the street lamp circuit are working abnormally, the circuit temperature may also increase, but there will not necessarily be large voltage fluctuations; the lightning strike intensity evaluation of each voltage period is obtained by combining temperature and voltage, and fluctuations in street lamp voltage or temperature that are not caused by lightning strikes are eliminated through threshold screening; the closer the maximum offset moment of each voltage period is to the moment of the corresponding temperature rise point, and the greater the voltage mutation degree and the temperature abnormality, the more likely the current lightning protection device has been struck by lightning and the greater the lightning strike intensity evaluation.

[0066] Specifically, the lightning intensity evaluation h of the i-th voltage period i The calculation method is:

[0067] h i =Sigmoid{exp{exp[-(m′ i -t i )]×F i ×D i}

[0068] Where: m' i represents the time of the temperature rise point corresponding to the i-th voltage period, t i represents the maximum deviation time of the ith voltage period, F i Indicates the voltage mutation degree in the ith voltage period, D i represents the temperature anomaly degree of the i-th voltage period; Sigmoid{} represents the Sigmoid function; exp[] represents the exponential function with the natural constant as the base;

[0069] It should be noted that (m' i -t i ) represents the difference between the maximum offset time of the ith voltage period and the time of the corresponding temperature rise point. The smaller the value, the more the voltage fluctuation and temperature rise occur together. The more likely it is that the voltage fluctuation and temperature rise are caused by lightning strike, the greater the lightning strike intensity evaluation of the ith voltage period. i The larger the value, the more sudden the circuit voltage is. i The larger the value of is, the more abnormal the circuit temperature is, and the greater the lightning strike intensity evaluation of the i-th voltage period is;

[0070] Similarly, the lightning strike intensity evaluation of all voltage periods is obtained; a lightning strike threshold is preset, and when the lightning strike intensity of the i-th voltage period is greater than the lightning strike threshold, the i-th voltage period is recorded as the lightning strike period, and all lightning strike periods are obtained in the same way; the lightning strike threshold is preset to 0.5 in this embodiment, and other embodiments may be set to other values, which are not specifically limited in this embodiment;

[0071] Step S004, obtaining the device failure probability of the lightning protection device; and implementing LED street lamp lightning protection device failure detection according to the device failure probability of the lightning protection device.

[0072] It should be noted that the more times a lightning protection device is struck by lightning, the more likely it is to be damaged. In addition to replacing the lightning protection device after it has burned out, the failure probability of the lightning protection device can be obtained based on historical lightning strikes and the average lightning strike intensity evaluation to avoid the lightning protection device being unable to withstand the lightning energy and being directly damaged the next time it is struck by lightning, resulting in economic losses caused by burning out components in the street lamp.

[0073] Specifically, the calculation method of the failure probability of the lightning protection device is:

[0074]

[0075] Formula explanation: represents the mean value of the lightning intensity evaluation of all lightning strike periods, n represents the number of all lightning strike periods, h k represents the lightning intensity evaluation of the kth lightning strike period; Sigmoid[] represents the Sigmoid function;

[0076] It should be noted that It represents the average of the lightning strike intensity evaluations during all lightning strike periods. This value represents the lightning strike intensity evaluation of the next lightning strike. The larger the value, the more likely the lightning protection device will not be able to withstand the lightning strike energy when it is struck by lightning next time, and the greater the probability of device failure of the lightning protection device. It represents the weighted mean of the lightning strike intensity evaluation of all lightning strike periods experienced by the lightning protection device, with n as the weight. The more times the lightning protection device is struck by lightning, the greater the loss to the lightning protection device caused by the next lightning strike. The lightning protection device is more likely to be unable to withstand the lightning strike energy the next time it is struck by lightning, and the greater the probability of device failure of the lightning protection device.

[0077] A fault threshold is preset. When the failure probability of the lightning protection device is greater than the fault threshold, the LED street light lightning protection device can no longer withstand the next lightning strike, so that relevant maintenance personnel can inspect or replace the lightning protection device to achieve fault detection of the LED street light lightning protection device. The preset fault threshold in this embodiment is 0.8, and other embodiments can be set to other values, which are not specifically limited in this embodiment.

[0078] It should be noted that the exp(-x) model used in this embodiment only indicates that the result of the negative correlation and constraint model output is in the interval (0, 1], where x is the input of this model. It can be replaced by other models with the same purpose during specific implementation. This embodiment only takes the exp(-x) model as an example for description without specific limitation.

[0079] In a second aspect, an embodiment of the present invention provides a fault detection system for a LED street lamp lightning protection device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above steps S001 to S004 when executing the computer program.

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting faults in a lightning protection device for an LED street lamp, characterized in that: The method comprises the following steps: Acquire voltage data and temperature data at all times, wherein the voltage data at all times constitute a voltage curve, and the temperature data at all times constitute a temperature curve; The voltage curve is divided into periods to obtain several voltage time periods; each identical moment in all voltage time periods is recorded as each site, and the steady-state voltage of each site is obtained according to the clustered distribution of the voltage at each site; the voltage offset amplitude at each moment in each voltage time period and the maximum offset moment of each voltage time period are obtained according to the difference between the voltage at each moment in each voltage time period and the steady-state voltage of the corresponding site; the voltage mutation degree of each voltage time period is obtained according to the position of the maximum offset moment of each voltage time period in the voltage curve and the voltage offset amplitude at all moments in the same voltage time period; According to all extreme values ​​of the temperature curve, the temperature rise point and the highest temperature point corresponding to each voltage period are obtained; according to the amplitude changes of the temperature rise point and the highest temperature point corresponding to each voltage period, the temperature anomaly degree of each voltage period is obtained; in combination with the voltage mutation degree and temperature anomaly degree of each voltage period, as well as the correlation between voltage fluctuation and temperature rise, the lightning strike intensity evaluation of each voltage period is obtained; according to the lightning strike intensity evaluation, all lightning strike periods are obtained; According to the evaluation of lightning strike intensity in all lightning strike periods, the device failure probability of the lightning protection device is obtained; according to the device failure probability of the lightning protection device, the LED street lamp lightning protection device failure detection is realized.

2. According to claim 1, a method for detecting faults in a LED street lamp lightning protection device is characterized in that: The obtaining of a plurality of voltage time periods comprises: The voltage curve is subjected to fast Fourier transform to obtain a spectrum diagram of the voltage curve. The inverse of the frequency with the largest amplitude in the spectrum diagram is recorded as the period of the voltage curve. The voltage curve is divided into several voltage time periods based on the period of the voltage curve, taking the first zero crossing point in the voltage curve as the starting point.

3. According to claim 1, a method for detecting faults in a lightning protection device for an LED street lamp is characterized in that: The step of obtaining the steady-state voltage at each site includes: The clustering conditions are preset, and the voltages of the a-th site in all voltage periods are clustered by DBSCAN density to obtain several clusters of the a-th site. The average of all voltages in the largest cluster among all clusters of the a-th site is taken and recorded as the steady-state voltage of the a-th site.

4. According to claim 1, a method for detecting faults in a lightning protection device for an LED street lamp is characterized in that: The obtaining of the voltage offset amplitude at each moment in each voltage period and the maximum offset moment of each voltage period comprises: The absolute value of the difference between the steady-state voltage at each moment in each voltage period and the corresponding point is recorded as the voltage offset amplitude at each moment, the voltage offset amplitude at each moment in each voltage period is obtained, and the moment when the voltage offset amplitude takes the maximum value in each voltage period is recorded as the maximum offset moment of each voltage period.

5. A method for detecting faults in a lightning protection device for an LED street lamp according to claim 1, characterized in that: The obtaining of the voltage mutation degree in each voltage period includes: The voltage mutation degree F in the i-th voltage period i The calculation method is: Where: t i represents the maximum offset time of the i-th voltage period, t0 represents the zero-crossing time closest to the maximum offset time of the i-th voltage period, T represents the period of the voltage curve, d i represents the voltage at the moment of maximum deviation in the i-th voltage period, represents the average value of the voltage at all times in the post-fluctuation period of the i-th voltage period; || represents the absolute value function.

6. A method for detecting faults in a lightning protection device for an LED street lamp according to claim 1, characterized in that: The step of obtaining the temperature rise point and the highest temperature point corresponding to each voltage period includes: The minimum point of the temperature curve closest to the maximum offset moment after the maximum offset moment of each voltage period in the temperature curve is recorded as the heating point corresponding to each voltage period, and the maximum point of the temperature curve closest to the maximum offset moment after the maximum offset moment of each voltage period is recorded as the highest temperature point corresponding to each voltage period.

7. A method for detecting faults in a lightning protection device for an LED street lamp according to claim 1, characterized in that: The obtaining of the temperature abnormality degree of each voltage period includes: The temperature abnormality degree D in the i-th voltage period i The calculation method is: Where: r i represents the temperature of the highest point corresponding to the i-th voltage period, r' i represents the temperature of the heating point corresponding to the i-th voltage period, m i Indicates the time of the highest temperature point corresponding to the i-th voltage period, m' i represents the time of the temperature rise point corresponding to the i-th voltage period, m' i+1 Indicates the time of the temperature rise point corresponding to the i+1th voltage period.

8. A method for detecting faults in a lightning protection device for an LED street lamp according to claim 1, characterized in that: The step of obtaining the lightning strike intensity evaluation for each voltage period includes: Lightning intensity evaluation h in the ith voltage period i The calculation method is: h i =Sigmoid{exp[-(m’ i -t i )×F i ×D i } Where: m' i represents the time of the temperature rise point corresponding to the i-th voltage period, t i represents the maximum deviation time of the ith voltage period, F i Indicates the voltage mutation degree in the ith voltage period, D i represents the degree of temperature anomaly in the ith voltage period; Sigmoid{} represents the Sigmoid function; exp[ ] represents the exponential function with a natural constant as the base.

9. A method for detecting faults in a lightning protection device for an LED street lamp according to claim 1, characterized in that: The obtaining of the device failure probability of the lightning protection device includes: The calculation method of the device failure probability of the lightning protection device is: Formula explanation: represents the mean value of the lightning intensity evaluation of all lightning strike periods, n represents the number of all lightning strike periods, h k represents the lightning strike intensity evaluation of the kth lightning strike period; Sigmoid[ ] represents the Sigmoid function.

10. A fault detection system for a LED street lamp lightning protection device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 9 are implemented.

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