A Fault Detection Method and System for a Lightning Protection Device of an LED Street Lamp

Abstract

The present invention relates to the technical field of electrical variable measurement, and specifically relates to a method and system for detecting faults in a lightning protection device for LED street lights, including: obtaining the voltage curve and temperature curve of the internal circuit of the street light; obtaining a number of voltage time periods according to the period division of the voltage curve; obtaining the degree of voltage mutation according to the degree of voltage fluctuation in each voltage time period; obtaining the degree of temperature anomaly according to the degree of temperature rise and fall and time in each voltage time period; combining the degree of voltage mutation and temperature anomaly in each voltage time period, as well as the correlation between voltage fluctuation and temperature rise, to obtain the lightning strike intensity evaluation for each voltage time period; screening to obtain all lightning strike time periods; obtaining the device failure probability of the lightning protection device according to the lightning strike intensity evaluation of all lightning strike time periods, so as to realize the detection of faults in the lightning protection device. The present invention combines the degree of voltage mutation and the degree of temperature anomaly to obtain a more accurate device failure probability of the lightning protection device, improves the fault detection efficiency, and avoids misjudgment.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical variable measurement, and particularly relates to a method and system for detecting faults of a lightning protection device for LED street lamps. Background Art

[0002] The lightning protection device of an LED street lamp 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 ground grid. The lightning rod guides the lightning strike to be introduced into the ground grid buried underground through the grounding wire, so that the lightning is safely dispersed and the damage to the street lamp circuit caused by lightning is reduced. The internal lightning protection system uses a metal oxide varistor as an element for internal voltage protection. The metal oxide varistor shows high impedance and does not conduct when the circuit voltage is normal. When a lightning strike causes a surge voltage in the street lamp circuit, the resistance of the metal oxide varistor drops sharply and conducts quickly, leading the surge voltage in the LED street lamp circuit to the ground and protecting other components in the LED circuit from lightning strikes;

[0003] When an LED street lamp is struck by lightning, voltage fluctuations will occur. When lightning affects the power grid near the street lamp, it will also cause large voltage fluctuations in the street lamp circuit. Judging whether the LED street lamp has a fault due to being struck by lightning only based on the voltage fluctuation situation of the internal circuit of the street lamp may cause misjudgment and result 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 for LED street lamps to solve the problem of misjudgment and inaccurate results in the existing fault detection of the lightning protection device only through the voltage fluctuation of the internal circuit of the street lamp.

[0005] The method and system for detecting faults of a lightning protection device for LED street lamps of the present invention adopt the following technical solutions:

[0006] An embodiment of the present invention provides a method for detecting faults of a lightning protection device for LED street lamps, and the method includes the following steps:

[0007] Obtain voltage data and temperature data at all times. The voltage data at all times constitutes a voltage curve, and the temperature data at all times constitutes a temperature curve;

[0008] Perform a periodic division on the voltage curve to obtain several voltage time periods; mark each same moment in all voltage time periods as each site, and obtain the steady-state voltage of each site according to the clustering distribution of the voltages at each site; according to the difference between the voltage at each moment in each voltage time period and the steady-state voltage of the corresponding site, obtain the voltage offset amplitude at each moment in each voltage time period and the maximum offset moment of each voltage time period; according to the position of the maximum offset moment of each voltage time period in the voltage curve and the voltage offset amplitudes of all moments in the same voltage time period, obtain the voltage mutation degree of each voltage time period.

[0009] According to all the extreme values of the temperature curve, obtain the heating point and the highest temperature corresponding to each voltage time period; according to the amplitude change of the heating point and the highest temperature corresponding to each voltage time period, obtain the temperature anomaly degree of each voltage time period; combine the voltage mutation degree and the temperature anomaly degree of each voltage time period, and the correlation between voltage fluctuation and heating, to obtain the lightning strike intensity evaluation of each voltage time period; according to the lightning strike intensity evaluation, obtain all lightning strike time periods.

[0010] According to the lightning strike intensity evaluations of all lightning strike time periods, obtain the device failure probability of the lightning protection device; according to the device failure probability of the lightning protection device, implement the fault detection of the LED street lamp lightning protection device.

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

[0012] Perform a fast Fourier transform on the voltage curve to obtain the frequency spectrum diagram of the voltage curve, record the result of taking the reciprocal of the frequency with the largest amplitude in the frequency spectrum diagram as the period of the voltage curve, and starting from the first zero-crossing point in the voltage curve, divide the voltage curve by the period of the voltage curve to obtain several voltage time periods.

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

[0014] Preset the clustering condition, perform DBSCAN density clustering on the voltages of the a-th site in all voltage time periods according to the clustering condition, obtain several clusters of the a-th site, and take the average value of all voltages in the largest cluster among all clusters of the a-th site, which is 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 time period and the maximum offset moment of each voltage time period includes:

[0016] Record the absolute value of the difference between each moment in each voltage time period and the steady-state voltage of the corresponding site as the voltage offset amplitude at each moment, obtain the voltage offset amplitude at each moment in each voltage time period, and record the moment when the voltage offset amplitude takes the maximum value in each voltage time period as the maximum offset moment of each voltage time period.

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

[0018] The voltage mutation degree F of the i-th voltage period i is calculated as follows:

[0019]

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

[0021] Further, obtaining the heating point and the highest temperature corresponding to each voltage period includes:

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

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

[0024] The temperature anomaly degree D of the i-th voltage period i is calculated as follows:

[0025]

[0026] In the formula: r i represents the temperature of the highest temperature 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 represents the moment of the highest temperature point corresponding to the i-th voltage period, m' i represents the moment of the heating point corresponding to the i-th voltage period, m' i+1 represents the moment of the heating point corresponding to the (i + 1)-th voltage period.

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

[0028] The lightning strike intensity evaluation h of the i-th voltage period i is calculated as follows:

[0029] h i = Sigmoid{exp[-(m' i -t i )]×F i ×D i}

[0030] In the formula: m' i represents the moment of the temperature rise point corresponding to the i-th voltage period, t i represents the maximum offset moment of the i-th voltage period, F i represents the degree of voltage mutation of the i-th voltage period, D i represents the degree of temperature abnormality of the i-th voltage period; Sigmoid{} represents the Sigmoid function; exp[] represents the exponential function with the natural constant as the base.

[0031] Furthermore, obtaining 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 strike intensity evaluations of all lightning strike periods, n represents the number of all lightning strike periods, h k represents the lightning strike intensity evaluation of the k-th lightning strike period; Sigmoid[] represents the Sigmoid function.

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

[0036] The beneficial effects of the technical solution of the present invention are as follows: Since the street lamp voltage has a certain periodicity under normal working conditions, obtaining the periodicity of the street lamp voltage to segment the voltage curve and using the voltage at the same moment in different time periods as a reference for the normal value makes the calculation of voltage fluctuations more in line with the actual working conditions of the street lamps. Since the surge voltages occurring at different times have different impacts on the circuit, calculate the degree of voltage mutation in each time period according to the degree of voltage mutation at each moment and the distance between the moment of voltage mutation and the zero-crossing point, which can more accurately reflect the loss degree of each voltage fluctuation on the lightning protection device; distinguish the temperature rise caused by the normal operation of the street lamp from the temperature rise caused by lightning strikes by the speed of temperature rise, and reflect the degree of lightning energy impact on the street lamp when it is struck by lightning through the amplitude of temperature rise and the time consumed for cooling; combine the voltage mutation situation and the abnormal temperature situation to accurately reflect the intensity of the street lamp being struck by lightning, and use threshold screening to exclude the fluctuations of the street lamp voltage or temperature caused by non-lightning strikes. According to the historical lightning strike situation and the average intensity of lightning strikes, calculate the failure probability to avoid the direct damage of the lightning protection device due to its inability to withstand the lightning energy during the next lightning strike, resulting in the components inside the street lamp being burned out by lightning. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0038] Figure 1 It is a flowchart of the steps of a method for detecting faults in a lightning protection device for an LED street lamp according to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following will, in conjunction with the accompanying drawings and preferred embodiments, detail the specific implementation manners, structures, features, and effects of a method and system for detecting faults in a lightning protection device for an LED street lamp according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

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

[0041] The following will specifically describe the specific solutions of a method and system for detecting faults in a lightning protection device for an LED street lamp provided by the present invention in conjunction with the accompanying drawings.

[0042] In a first aspect, please refer to Figure 1 , which shows a flowchart of steps of a method for detecting a fault of a lightning protection device for an LED street lamp provided by an embodiment of the present invention. The method includes 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 condition of the lightning protection device for the LED street lamp by combining voltage and temperature, and to realize the fault detection of the lightning protection device for the LED street lamp. Therefore, first collect the voltage data and temperature data of the internal circuit of the street lamp; preset the voltage monitoring frequency and the temperature monitoring frequency, collect the voltage data at all times after the current lightning protection device is installed at the temperature monitoring frequency, and collect all temperature data after the current lightning protection device is installed at the voltage monitoring frequency. After collection, perform linear interpolation filling on the temperature data to make it correspond one-to-one with the voltage data in terms of time; the voltage data at all times constitutes a voltage curve, and the temperature data at all times constitutes a temperature curve;

[0045] In this embodiment, the preset voltage monitoring frequency is 1000 Hz, and the temperature monitoring frequency is 10 Hz. Other embodiments can be set to other values, and this embodiment does not make specific limitations; it should be noted that since the voltage changes frequently and the voltage change caused by lightning strike occurs quickly, while the temperature data changes relatively more slowly, high-frequency collection is performed on the voltage data and low-frequency collection is performed on the temperature data.

[0046] Step S002: Obtain the steady-state voltage at each same moment in all voltage periods; obtain the voltage offset amplitude at each moment in each voltage period and the maximum offset moment of each voltage period; obtain the voltage mutation degree of each voltage period.

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

[0048] Specifically, perform a fast Fourier transform on the voltage curve to obtain the spectrogram of the voltage curve. Denote the result of taking the reciprocal of the frequency with the largest amplitude in the spectrogram as the period of the voltage curve. Starting from the first zero-crossing point in the voltage curve, divide the voltage curve by the period of the voltage curve to obtain several voltage time periods, and discard all the moments before the first zero-crossing point and all the moments with a length less than one period after the last zero-crossing point; the zero-crossing point refers to the moment when the voltage in the voltage curve is 0, and the moments on both sides of this moment correspond to voltages with one being positive and the other being negative. The zero-crossing point is a well-known technology, and no specific limitation is made in this embodiment.

[0049] Preset the clustering condition. Denote each identical moment in all voltage time periods as each site. Perform DBSCAN density clustering on the voltages of the a-th site in all voltage time periods according to the clustering condition to obtain several clusters of the a-th site. Take the average value of all the voltages in the largest cluster among all the clusters of the a-th site, and denote it as the steady-state voltage of the a-th site; similarly, obtain the steady-state voltages of all sites. In this embodiment, the clustering radius of the preset clustering condition is 10, and the number of sample points is 5. Other embodiments can be set to other values, and no specific limitation is made in this embodiment.

[0050] Denote the absolute value of the difference between the voltage at each moment in each voltage time period and the steady-state voltage of the corresponding site as the voltage offset amplitude of each moment. Obtain the voltage offset amplitude of each moment in each voltage time period, and denote the moment with the maximum voltage offset amplitude in each voltage time period as the maximum offset moment of each voltage time period.

[0051] Furthermore, it should be noted that when the internal circuit of the street lamp directly withstands lightning strikes or the power grid near the street lamp withstands lightning strikes, it will cause the voltage inside the street lamp to suddenly increase, and it will also cause subsequent voltage fluctuations to continue for a period of time after the voltage suddenly increases; analyze the position of the maximum offset moment in the voltage curve, and the voltage fluctuations of each voltage time period of the internal circuit of the street lamp from the maximum offset moment to the voltage recovery steady state, and combine the voltage offset amplitudes of all moments in each voltage time period to obtain the voltage mutation degree of each voltage time period.

[0052] Specifically, a preset neighborhood length and a steady-state recovery threshold are set. Taking the neighborhood length of moments before and after each moment as the center, the neighborhood interval of each moment is recorded. Specifically, when the number of available moments is less than the neighborhood length, the maximum number that can be obtained is taken. The result of normalizing the average value of the voltage offset amplitudes of all moments within the neighborhood interval of each moment using the Sigmoid function is recorded as the neighborhood fluctuation evaluation of each moment. For any voltage period, taking the moment with the maximum offset as the starting point and the first moment after the moment with the maximum offset whose neighborhood fluctuation evaluation is less than the steady-state recovery threshold as the ending point, all moments between the starting point and the ending point are recorded as the post-fluctuation period of the voltage period. In this embodiment, the preset neighborhood length is 10 and the steady-state recovery threshold is 0.1. Other embodiments can be set to other values, and this embodiment does not make specific limitations.

[0053] Further, the voltage mutation degree F of the i-th voltage period i is calculated as follows:

[0054]

[0055] In the formula: t i represents the moment with the maximum offset of the i-th voltage period, t0 represents the zero-crossing moment closest to the moment with the maximum offset of the i-th voltage period, T represents the period of the voltage curve, and d i represents the voltage at the moment with the maximum offset of the i-th voltage period. represents the average value of the voltages of all moments in the post-fluctuation period of the i-th voltage period; || represents the absolute value function.

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

[0057] Similarly, the voltage mutation degrees of all voltage periods are obtained.

[0058] Step S003: Obtain the temperature anomaly degree of each voltage period; obtain the lightning strike intensity evaluation of each voltage period; obtain all lightning strike periods.

[0059] It should be noted that under the normal working condition of the street lamp, the street lamp starts to work at night, and the internal circuit of the street lamp slowly heats up. In the morning, the street lamp is turned off, and the internal circuit of the street lamp slowly cools down. When lightning strikes the street lamp, the lightning protection device protects the street lamp circuit by reducing the resistance to conduct the lightning energy to the ground. When the lightning protection device bears the lightning energy, it instantaneously absorbs a large amount of electrical energy, and part of the electrical energy will be converted into heat energy, resulting in a rapid increase in the temperature of the lightning protection device in a short period of time. The greater the lightning energy, the more the temperature of the lightning protection device rises. The temperature anomaly degree of each voltage period is obtained through the heating degree, heating time and cooling time of the internal circuit of the street lamp. Combining the temperature anomaly degree, voltage mutation degree of the internal circuit of the street lamp and the correlation between voltage fluctuation and heating phenomenon, the lightning strike intensity evaluation of each voltage period is obtained. Further, the lightning strike period when the internal circuit of the street lamp bears lightning strikes is screened 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 deviation moment after the maximum deviation 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 deviation moment after the maximum deviation moment of each voltage period is recorded as the highest temperature point corresponding to each voltage period. The temperature anomaly degree D i of the i-th voltage period is calculated as follows:

[0061]

[0062] In the formula: r i represents the temperature of the highest temperature 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 represents the moment of the highest temperature point corresponding to the i-th voltage period, m' i represents the moment of the heating point corresponding to the i-th voltage period, m' i+1 represents the moment of the heating point corresponding to the (i + 1)-th voltage period;

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

[0064] Similarly, obtain the temperature abnormality degree of each voltage period.

[0065] It should be further noted that when lightning strikes affect the power grid near the street lamp, it will also cause a large voltage fluctuation in the street lamp circuit, but there will be no obvious temperature rise; when the working state of other components in the street lamp circuit is abnormal, it may also cause the circuit temperature to rise, but there may not be a large voltage fluctuation; obtain the lightning strike intensity evaluation of each voltage period by combining temperature and voltage, and exclude the voltage or temperature fluctuations of the street lamp caused by non-lightning strikes 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 degree are, the more likely the current lightning protection device has withstood a lightning strike and the greater the lightning strike intensity evaluation.

[0066] Specifically, the lightning strike intensity evaluation h i of the i-th voltage period is calculated as follows:

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

[0068] In the formula: m' i represents the moment of the temperature rise point corresponding to the i-th voltage period, t i represents the maximum offset moment of the i-th voltage period, F i represents the voltage mutation degree of the i-th voltage period, D i represents the temperature abnormality 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 moment and the moment of the corresponding temperature rise point of the i-th voltage period. The smaller this value is, the more the voltage fluctuation and the temperature rise accompany each other, and the more likely it is that the voltage fluctuation and the temperature rise are caused by lightning strikes, and the greater the lightning strike intensity evaluation of the i-th voltage period; the larger the value of F i , the more the circuit voltage mutates, and the larger the value of D i , the more abnormal the circuit temperature is, and the greater the lightning strike intensity evaluation of the i-th voltage period;

[0070] Similarly, obtain the lightning strike intensity evaluations for all voltage periods; preset a lightning strike threshold. When the lightning strike intensity in the \(i\)-th voltage period is greater than the lightning strike threshold, record the \(i\)-th voltage period as a lightning strike period. Similarly, obtain all lightning strike periods; in this embodiment, the preset lightning strike threshold is 0.5, and other embodiments can set it to other values, which are not specifically limited in this embodiment;

[0071] Step S004, obtain the device failure probability of the lightning protection device; based on the device failure probability of the lightning protection device, implement the fault detection of the LED street lamp lightning protection device.

[0072] It should be noted that the more lightning strikes the lightning protection device withstands, the more easily it is damaged. In addition to replacing the lightning protection device after it has burned out, according to the historical lightning strike situation and the average lightning strike intensity evaluation of the lightning strikes, obtain the failure probability of the lightning protection device to prevent the lightning protection device from being directly damaged by the lightning energy it cannot withstand during the next lightning strike, resulting in economic losses due to the components in the street lamp being burned out by the lightning strike.

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

[0074]

[0075] Formula explanation: represents the mean value of the lightning strike intensity evaluations for all lightning strike periods, \(n\) represents the number of all lightning strike periods, \(h\) k represents the lightning strike intensity evaluation of the \(k\)-th lightning strike period; Sigmoid[] represents the Sigmoid function;

[0076] Among them, it should be noted that represents the mean value of the lightning strike intensity evaluations for all lightning strike periods, and this value is used to represent the lightning strike intensity evaluation of the next lightning strike. The larger this value is, the more likely the lightning protection device will not be able to withstand the lightning energy during the next lightning strike, and the greater the device failure probability of the lightning protection device; represents the weighted mean value of the lightning strike intensity evaluations for all lightning strike periods experienced by the lightning protection device, with \(n\) as the weight. The more lightning strikes the lightning protection device withstands, the greater the loss of the lightning protection device when it withstands another lightning strike, and the more likely the lightning protection device will not be able to withstand the lightning energy during the next lightning strike, and the greater the device failure probability of the lightning protection device;

[0077] Preset a failure threshold. When the device failure probability of the lightning protection device is greater than the failure threshold, the LED street lamp lightning protection device can no longer withstand the next lightning strike, enabling relevant maintenance personnel to repair or replace the lightning protection device to implement the fault detection of the LED street lamp lightning protection device; in this embodiment, the preset failure threshold is 0.8, and other embodiments can set it 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 represents a negative correlation relationship and restricts the output result of the model to be within the interval (0, 1]. Here, x is the input of this model, and in specific implementation, it can be replaced with other models with the same purpose. This embodiment only takes the exp(-x) model as an example for description and is not specifically limited.

[0079] In a second aspect, an LED street lamp lightning protection device fault detection system according to an embodiment of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above steps S001 to S004 are implemented.

[0080] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the principles of the present invention shall 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 lightning intensity evaluation of 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; The obtaining of the voltage mutation degree of 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.

2. 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 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 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.

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 abnormality degree of each voltage period includes: The temperature abnormality degree D of 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 represents 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.

7. 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 an exponential function with a natural constant as the base.

8. 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 evaluation of lightning strike intensity during the kth lightning strike period; Sigmoid[] represents the Sigmoid function.

9. 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 8 are implemented.

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