Fault monitoring device for cooling fan of optical fiber cabinet of transformer substation and monitoring method thereof

Abstract

The invention provides a transformer substation optical fiber cabinet cooling fan fault monitoring device and method, and the device comprises a pickup sensor module which is used for collecting an audio signal of a fan; the temperature sensor module is used for acquiring temperature signals inside and outside the optical fiber cabinet of the transformer substation; the microprocessor module is connected with the pickup sensor module and the temperature sensor module and used for analyzing and processing the audio signals and the temperature signals and judging whether the fan breaks down or not according to the analysis result. The sound pick-up module is used for obtaining the vibration or friction frequency spectrum of fan work, auxiliary judgment is carried out by combining the temperature difference between the interior and the exterior of the transformer substation optical fiber cabinet, and whether the fan breaks down or not is accurately monitored. According to the method, no monitoring device needs to be implanted into original equipment, manual inspection is completely replaced, the real-time performance is good, faults can be found in time, accident expansion is avoided, and the method has great significance in guaranteeing the operation safety of the equipment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fault detection, in particular to a substation optical fiber cabinet cooling fan fault monitoring device and a monitoring method thereof. BACKGROUND

[0002] In order to ensure the continuous and stable operation of the internal equipment of the substation optical fiber cabinet, a fan is usually used for heat dissipation. In particular, in the hot summer, the fan needs to work uninterruptedly throughout the day to reduce the temperature in the cabinet. Once the fan fails during the high-temperature period, the temperature in the cabinet will rise rapidly, which will easily cause the communication equipment to malfunction and seriously affect the normal operation of the substation. SUMMARY

[0003] In order to overcome the above shortcomings, the present application provides a substation optical fiber cabinet cooling fan fault monitoring device and a monitoring method thereof, which uses a pickup module to obtain the vibration or friction frequency spectrum of the fan, and combines the temperature difference inside and outside the substation optical fiber cabinet to assist in judging whether the fan has failed.

[0004] The technical scheme provided by the present application is as follows: On the one hand, the present application provides a substation optical fiber cabinet cooling fan fault monitoring device, wherein the substation optical fiber cabinet is internally configured with a fan for heat dissipation, and the fault monitoring device comprises: a pickup sensor module installed near the fan inside the substation optical fiber cabinet, for collecting audio signals of the fan; a temperature sensor module configured inside and outside the substation optical fiber cabinet respectively, for collecting temperature signals inside and outside the substation optical fiber cabinet; a microprocessor module connected with the pickup sensor module and the temperature sensor module respectively, for analyzing and processing the audio signals and the temperature signals, and judging whether the fan has failed according to the analysis results.

[0005] On the other hand, the present application provides a substation optical fiber cabinet cooling fan fault monitoring method, wherein the substation optical fiber cabinet is internally configured with a fan for heat dissipation, and the fault monitoring method comprises: collecting audio signals of the fan by a pickup sensor module; the pickup sensor module is installed near the fan inside the substation optical fiber cabinet; collecting temperature signals inside and outside the substation optical fiber cabinet by a temperature sensor module; the temperature sensor module is configured inside and outside the substation optical fiber cabinet respectively; analyzing and processing the audio signals and the temperature signals by a microprocessor module, and judging whether the fan has failed according to the analysis results.

[0006] The substation optical fiber cabinet heat dissipation fan fault monitoring device and the monitoring method thereof provided by the application can accurately identify fan faults and ensure equipment safety. By comprehensively analyzing abnormal features of fan voiceprint spectrum and fluctuation data of temperature difference between inside and outside the cabinet, the temperature-voice mixed method can effectively avoid the limitations of single monitoring method, greatly improves the accuracy of fan fault judgment compared with the conventional method of identifying by human ear, and provides more reliable protection for stable operation of the substation optical fiber cabinet. Moreover, the method does not need to implant any monitoring device in the original equipment, completely replaces manual inspection, has good real-time performance, can timely find faults, avoids accident expansion, and has important significance for ensuring equipment operation safety. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 It is an embodiment structure schematic view of the substation optical fiber cabinet heat dissipation fan fault monitoring device in the application. Figure 2 It is a multi-resonance circuit diagram in an example of the application. Figure 3 It is an example of the application. Figure 2 It is a relationship curve diagram between the multi-resonance circuit output frequency and temperature in the example of the application. Figure 4 It is an embodiment flow schematic view of the substation optical fiber cabinet heat dissipation fan fault monitoring method in the application.

[0008] Reference signs: 100-fault monitoring device, 110-pickup sensor module, 120-temperature sensor module, 130-microprocessor module. DETAILED DESCRIPTION

[0009] In order to more clearly illustrate the technical solutions in the application examples or prior art, the specific embodiments of the application will be described below with reference to the drawings. Obviously, the drawings described below are only some embodiments of the application, and for those skilled in the art, other drawings can be obtained from these drawings without creative labor, and other embodiments can also be obtained.

[0010] In one embodiment of the application, a substation optical fiber cabinet heat dissipation fan fault monitoring device, as shown in the figure, the fault monitoring device 100 comprises: Figure 1 A pickup sensor module 110 is installed near the fan inside the substation optical fiber cabinet, and is used to collect audio signals of the fan. A temperature sensor module 120 is respectively arranged inside and outside the substation optical fiber cabinet, and is used to collect temperature signals inside and outside the substation optical fiber cabinet. ​The microprocessor module 130 is connected with the pickup sensor module 110 and the temperature sensor module 120 respectively, and is used for analyzing and processing the audio signal and the temperature signal, and judging whether the fan is faulty according to the analysis result.

[0011] The substation optical fiber cabinet is internally configured with a fan for heat dissipation, in order to improve the accuracy of fan fault monitoring, the embodiment is based on the thermoacoustic hybrid method for comprehensive judgment.

[0012] The pickup sensor module 110 is used for collecting the audio signal in the working process of the fan, so it is installed in the internal position of the communication cabinet close to the fan, and can be realized by using an electret microphone (MIC) and the like, and the selection can be made according to the requirements in the application. The number of the pickup sensor module 110 can also be configured in multiple numbers according to the application requirements.

[0013] In order to further improve the accuracy, an audio amplification circuit with an input end connected with the output end of the pickup sensor module 110 and an output end connected with the input I / O port of the microprocessor module 130 is also configured, which is used for amplifying the audio signal collected by the pickup sensor module 110. The selection of the audio amplification circuit can be made according to the actual situation. In an example, the audio amplification circuit uses an LM386 low-voltage audio power amplifier, the working voltage of which is 4V-12V, and the output power is 0.25W-1W.

[0014] The temperature sensor module 120 is configured in the internal and external positions of the substation optical fiber cabinet, that is, the temperature sensor module 120 is configured in the cabinet and outside the cabinet, and the temperature in the cabinet and outside the cabinet at the same time is detected, which is convenient for the microprocessor module 130 to assist in judging the fan fault according to the temperature difference between the cabinet and outside the cabinet.

[0015] For the selection of temperature sensor module 120, theoretically, any sensor that can achieve temperature detection can be used, but due to the harsh electromagnetic environment inside and outside the cabinet, in order to improve the accuracy of temperature measurement and improve the interference ability, the embodiment proposes to use a thermistor, cooperate with a multi-vibrator circuit, convert temperature changes into frequency changes, and use an optocoupler for isolation to achieve the detection purpose, thereby greatly improving the anti-interference ability of the temperature measurement circuit. Specifically, the temperature sensor module 120 includes: a thermistor, a multi-vibrator circuit, a switching circuit, and an optocoupler circuit, wherein the thermistor is connected to the input end of the multi-vibrator circuit, the input end of the switching circuit is connected to the output end of the multi-vibrator circuit, the output end of the optocoupler circuit is connected to the output end of the switching circuit, and the output end of the optocoupler circuit is connected to the input end of the microprocessor module 130. The oscillation frequency of the multi-vibrator circuit changes with the resistance value of the thermistor; when the multi-vibrator circuit outputs a high level, the switching circuit is turned on, and then the optocoupler circuit is turned on; the microprocessor module 130 obtains the oscillation frequency of the multi-vibrator circuit by interrupt technology to obtain the temperature measurement value.

[0016] In an example, an NE555N chip is used in the multi-vibrator circuit, an NTC10k constant 3950 thermistor is selected as the temperature measuring element, and a P521-1 optocoupler chip is selected for the optocoupler circuit. As shown in Figure 2 R1 of the thermistor, one end of R1 is connected to the trigger control end TRIG and the threshold control end THR of the NE555N chip, and the other end is connected to the discharge end DISC of the NE555N chip. The multi-vibrator circuit further includes: a resistor R2 with a resistance of 10Ω, one end of R2 is connected to the discharge end DISC of the NE555N chip, and the other end is connected to the reset end RST and the power supply end VCC of the NE555N chip; a capacitor C1, one end of C1 is connected to the trigger control end TRIG and the threshold control end THR of the NE555N chip, and the other end is connected to the control end CVOLT and the ground end GND of the NE555N chip. The switching circuit is a NPN triode Q 1, the base is connected to the output end OUT of the NE555N chip through the resistor R3, the collector is connected to the input end of the optocoupler chip P521-1, and the emitter is grounded. The output end of the optocoupler chip P521-1 is connected to the input end I / O port of the microprocessor module through the resistor R6.

[0017] When the temperature of the thermistor R1 changes, the resistance value changes, and the frequency f of the output end OUT of the NE555N chip also changes, and the change rule is: When the output end OUT of the NE555N chip is at a high level, the triode The light coupling chip P521-1 is turned on when the transistor is turned on, and the light coupling chip P521-1 is turned off when the output end OUT of the NE555N chip is at a low level. Thus, the light coupling chip P521-1 is turned on once for each oscillation of the NE555N chip, and the subsequent microprocessor obtains the oscillation frequency by interrupt technology to obtain the temperature measurement value.

[0018] The microprocessor module has high-efficiency operation and precise control capabilities, can realize complex logical judgment and data processing through programming, and can respond to external events in real time by means of built-in timers, interrupt controllers and other components to meet the real-time needs of industrial control, intelligent devices and other scenes. It integrates the microprocessor core, memory, various interfaces and control units into one, forming a complete micro-computing unit. It not only contains a processor core (such as ARM Cortex, RISC-V architecture) responsible for instruction execution and data operation, but also integrates Flash, RAM and other storage modules, as well as GPIO, UART, I2C, SPI and other peripheral interfaces, which can directly interact with external devices. In this embodiment, the specific model of the microprocessor module can be selected according to actual conditions, such as STM32 microprocessor chip, as long as it can achieve the purpose of the invention. Under this model, the ADC resolution is 12-bit (default for STM32), and the quantization accuracy affects the dynamic range.

[0019] To obtain the temperature measurement value, the microprocessor module 130 includes: an oscillation frequency acquisition unit for obtaining the number of light coupling switchings through interrupt technology, and then obtaining the oscillation frequency of the multi-tuned oscillation circuit; a frequency interval determination unit connected with the oscillation frequency acquisition unit, for determining the frequency interval of the obtained oscillation frequency, the frequency interval being obtained from the oscillation frequency / temperature relationship curve fitted based on the temperature / resistance value table of the thermistor and the frequency calculation formula of the multi-tuned oscillation circuit, and the oscillation frequency and the temperature being in a linear relationship in each divided frequency interval; and a temperature calculation unit connected with the frequency interval determination unit, for calculating the corresponding temperature measurement value according to the frequency interval determined by the frequency interval determination unit.

[0020] Before monitoring, the corresponding frequency at different resistances is calculated according to the known thermistor temperature / resistance value table and the oscillation circuit frequency calculation formula, so that the corresponding frequency at different temperatures can be obtained. The relationship between the output frequency and the temperature is plotted by using the polynomial fitting method of Matlab, as shown in the formula Figure 3 The abscissa is the frequency, with Hz (hertz) as the unit; and the ordinate is the temperature, with ℃ (Celsius) as the unit.

[0021] As can be seen from the figure, the oscillation frequency and temperature show nonlinear characteristics, although the curve fitting method, neural network and other methods can effectively improve the accuracy of temperature calculation results, but due to the limited floating point calculation accuracy of the microprocessor module 130, it is difficult to process high-order fitting equations and neural network calculations, therefore, in this embodiment, the frequency-temperature curve is divided into several frequency intervals according to the curve derivative, and a linear equation of frequency-temperature is established in each frequency interval, so as to obtain a segmented function of frequency-temperature. In this way, after the microprocessor module 130 obtains the oscillation frequency of the multi-vibration circuit through the interruption technology of the optical coupling switch times, the corresponding frequency interval is found, and the corresponding temperature measurement value can be calculated according to the linear relationship in the corresponding frequency interval. In the example shown in FIG. 10, the NTC 10k thermistor temperature and resistance value table is shown in Table 1. Figure 2

[0022] Table 1: Corresponding relationship between resistance value and temperature

[0023] In order to obtain the frequency spectrum information of the fan, the microprocessor module 130 further includes: an ADC sampling unit for further sampling the fan audio signal collected by the pickup sensor module 110 to obtain a digital audio signal; a frequency domain signal conversion unit connected with the ADC sampling unit, for performing discrete Fourier transform on the digital audio signal generated by the ADC sampling unit to obtain a frequency domain audio signal; an amplitude extraction unit connected with the frequency domain signal conversion unit, for extracting the amplitude of each frequency component in the frequency domain audio signal generated by the frequency domain signal conversion unit; and a frequency characteristic analysis unit connected with the amplitude extraction unit, for analyzing the frequency characteristics of the vibration or friction of the fan according to the amplitude information extracted by the amplitude extraction unit.

[0024] The digital audio signal sampled by the ADC sampling unit is as follows:

[0025] Wherein, Ts represents the sampling interval, which is determined by the clock of the ADC sampling unit, such as Ts = 1 / fs; fs is the sampling frequency, which needs to satisfy the Nyquist sampling theorem fs≥2fmax, since the frequency of the fan sound is usually <10kHz, therefore, fs≥20kHz is preferred. The sampling point number N determines the FFT frequency resolution, such as N = 1024.

[0026] The time domain signal x [n] is converted into a frequency domain signal X[k] by the frequency domain signal conversion unit, and the discrete Fourier transform (DFT) formula is as follows:

[0027] ​In order to realize the judgment of whether the fan is malfunctioning based on the temperature measurement value and the audio signal, the microprocessor module 130 further comprises: a fan spectrum judgment unit for judging whether the frequency of fan vibration or friction exceeds a preset frequency threshold; a temperature difference judgment unit for judging whether the temperature difference between the inside and outside of the substation optical fiber cabinet is greater than a preset temperature threshold; and a malfunction judgment unit respectively connected with the fan spectrum judgment unit and the temperature difference judgment unit, for further judging whether the fan is malfunctioning according to the results of the fan spectrum judgment unit and the malfunction judgment unit; when the frequency of fan vibration or friction exceeds the preset frequency threshold, and the temperature difference between the inside and outside of the substation optical fiber cabinet is greater than the preset temperature threshold, it is judged that the fan is malfunctioning.

[0028] The preset frequency threshold is determined according to the fan used in the actual scene, which can be limited to 1kHz-2kHz, etc.; and the preset temperature difference threshold can also be set in combination with factors such as weather, such as 2℃-8℃, etc.

[0029] The judgment process specifically includes: When it is monitored that the fan sound vibration spectrum exceeds the preset frequency threshold, the temperature difference between the inside and outside of the cabinet is checked at the same time, and if the temperature difference is not greater than the preset temperature threshold, it is judged that the fan is not malfunctioning; When it is monitored that the fan sound vibration spectrum exceeds the preset frequency threshold, the temperature difference between the inside and outside of the cabinet is checked at the same time, and if the temperature difference is greater than the preset temperature threshold, it is judged that the fan may be malfunctioning; When it is monitored that the fan sound vibration spectrum does not exceed the preset frequency threshold, the temperature difference between the inside and outside of the cabinet is checked at the same time, and if the temperature difference is not greater than the preset temperature threshold, it is judged that the fan is not malfunctioning.

[0030] When it is monitored that the fan sound vibration spectrum does not exceed the preset frequency threshold, the temperature difference between the inside and outside of the cabinet is checked at the same time, and if the temperature difference is greater than the preset temperature threshold, it is judged that the fan is not malfunctioning, which may be caused by the high ambient temperature.

[0031] In order to synchronize the clock, a clock module connected with the I / O port of the microprocessor is further configured in the embodiment, such as a DS1302 type clock chip in an example, which has a normal working voltage range of 2.5-5.5V, the main power supply VCC2 is powered by a 3.3V system power supply, a 3.3V button cell battery is used as a backup power supply VCC1, and the module can still work normally when the main power supply of the circuit board is powered off. DS1302 and the microprocessor module 130 adopt I2C communication, and a 32.768kHz external crystal oscillator is used.

[0032] In another embodiment, the fault monitoring device 100 is also configured with a display module connected to the output I / O port of the microprocessor module 130 to display the monitoring data in real time. The display module can be a TFT liquid crystal display screen or the like, as long as it can achieve the display purpose, which is not specifically limited here. In an example, the display module is a domestic 4.3-inch enhanced HMI programmable touch screen TJC4827K043_011X to realize human-computer interaction. The touch screen can be used on the PC side to design the display screen interface directly using the host computer development software, and can add buttons, check boxes, curve waveform diagrams, character libraries, background pictures, and simple animation making functions. This model of touch screen generally needs voltage power supply, and is also compatible with voltage. The touch screen communicates with the processor through the UART serial port, and the communication protocol only includes string instructions and end symbols, which can effectively reduce the development time.

[0033] In another embodiment, to realize communication between the microprocessor module 130 and external devices, the fault monitoring device 100 is also configured with a communication module connected to the output end of the microprocessor module 130. In an example, the communication module is an RS485 communication module, which is widely used in industrial control, instruments, meters, and mechatronic products, and is usually transmitted in twisted pair lines. The standard node number is 32, the maximum communication distance is 1200m, the receiver differential input range is -7V+12V, and the receiver input sensitivity is ±200Mv. RS485 uses differential transmission mode using A and B two-wire data transmission mode, and judges the high and low of the output logic level by calculating the level difference between A and B two lines. The voltages of the differential input ends are VA and VB respectively. When the difference between VA and VB is greater than or equal to 0.2V, it represents the output logic level 1; when the difference between VA and VB is less than 0.2V, it represents the output logic level 0. RS485 uses twisted pair transmission, and the maximum transmission rate is 10Mbps. Its impedance characteristic is 120Ω, so a matching resistance of 120Ω is added to the output end to improve the transmission stability of the system and eliminate reflected signals. The high-voltage circuit breaker mechanical characteristic online fault monitoring device 100 usually works in a complex environment with strong electromagnetic field, and generally uses transient suppression diodes to protect the circuit.

[0034] In another embodiment, to realize data storage, a storage module is also configured and connected to the output I / O port of the microprocessor module 130. For example, the storage module selects W25Q128 as the Flash memory, which has an internal capacity of 16M, is divided into 256 blocks, each block is divided into 16 sectors, a total of 4096 sectors, each sector is divided into 4K bytes, the erase cycle is as high as 10W times, and the data retention period is 20 years, which meets the actual use requirements. W25Q128 is connected to the microprocessor module through an SPI interface.

[0035] In order to realize the power supply of each module, a power module is also configured in the embodiment. In the selection examples of each electronic device mentioned above, the power module adopts a 9V rechargeable lithium battery as the power supply of the circuit, which is small in size and can be charged repeatedly, saving resources. According to the selected scheme, a +5V power supply is required for the filter and voltage follower, a 5V power supply is required for the storage module, and the working voltage of the remaining modules is 3.3V. Therefore, in the design process, the size of the power supply voltage, the power supply ripple, and the output current of the power supply chip, the conversion efficiency, the heat dissipation effect and other factors need to be considered. The low-voltage linear power stabilizing chip LM2940-5, LM1117-3.3 can be selected, the 9V power supply is reduced to 5V by the LM2940-5 chip, and then stabilized to 3.3V by the LM1117-3.3 chip. The 5V negative power supply adopts a voltage inverting chip MX660, which directly outputs-5V with an input of 5V, has a simple peripheral circuit and small output error.

[0036] In the above embodiment, the vibration frequency spectrum of the fan working is obtained by using the pickup sensor module, and whether the fan works normally is monitored according to the vibration frequency spectrum generated by the fan rotation, which completely replaces the human ear identification method. In order to more accurately judge whether the fan has a fault, the temperature difference method is introduced to assist in judging whether the fan has a fault, and the judgment accuracy is further improved.

[0037] Another embodiment of the application is a substation optical fiber cabinet cooling fan fault monitoring method, as shown in Figure 4 The fault monitoring method comprises the following steps: S10 collects the audio signal of the fan through the pickup sensor module; the pickup sensor module is installed near the fan inside the substation optical fiber cabinet; S20 collects the temperature signals inside and outside the substation optical fiber cabinet through the temperature sensor module; the temperature sensor module is respectively arranged inside and outside the substation optical fiber cabinet; S30 analyzes and processes the audio signal and the temperature signal through the microprocessor module, and judges whether the fan has a fault according to the analysis result.

[0038] The substation optical fiber cabinet is configured with a fan for heat dissipation, in order to improve the accuracy of the fan fault monitoring, the embodiment is based on the temperature-sound hybrid method for comprehensive judgment.

[0039] The function of the pickup sensor module is to collect the audio signal in the working process of the fan, so it is installed near the fan inside the communication cabinet, which can be realized by using an electret microphone (MIC) and the like, and the selection can be performed according to the requirements in the application. The number of pickup sensor modules can also be configured in multiple numbers according to the application requirements.

[0040] To further improve the accuracy, an audio amplification circuit is further configured, with an input end connected with the output end of the pickup sensor module and an output end connected with the input I / O port of the microprocessor module, for amplifying the audio signal collected by the pickup sensor module. The selection of the audio amplification circuit can be made according to the actual situation. In an example, the audio amplification circuit uses an LM386 low-voltage audio power amplifier, with a working voltage of 4V-12V and an output power of 0.25W-1W.

[0041] The temperature sensor module is arranged in the interior and exterior of the optical fiber cabinet of the transformer substation, i.e. the temperature sensor module is arranged in the interior and exterior of the cabinet, to detect the temperature in the interior and exterior of the cabinet at the same time, so that the microprocessor module can assist in judging the fan failure according to the temperature difference between the interior and exterior of the cabinet.

[0042] As to the selection of the temperature sensor module, theoretically, any sensor that can realize temperature detection can be used. However, as the electromagnetic environment in the interior and exterior of the cabinet is harsh, in order to improve the accuracy of temperature measurement and the anti-interference ability, in the present embodiment, a thermistor is used, cooperating with a multi-resonance circuit, to convert the temperature change into frequency change, and an optical coupler is used for isolation, to greatly improve the anti-interference ability of the temperature measurement circuit. Specifically, the temperature sensor module includes a thermistor, a multi-resonance circuit, a switching circuit and an optical coupler circuit, wherein the thermistor is connected with the input end of the multi-resonance circuit, the input end of the switching circuit is connected with the output end of the multi-resonance circuit, the optical coupler circuit is connected with the output end of the switching circuit, and the output end of the optical coupler circuit is connected with the input end of the microprocessor module. The oscillation frequency of the multi-resonance circuit changes with the resistance value of the thermistor; when the multi-resonance circuit outputs a high level, the switching circuit is turned on, and then the optical coupler circuit is turned on; the microprocessor module obtains the oscillation frequency of the multi-resonance circuit by the interruption technique to obtain the temperature measurement value.

[0043] To obtain the temperature measurement value, the microprocessor module obtains the oscillation frequency of the multi-resonance circuit by the interruption technique to obtain the temperature measurement value, including: obtaining the oscillation frequency of the multi-resonance circuit by the interruption technique; determining the frequency interval where the oscillation frequency is located according to the obtained oscillation frequency, the frequency interval being divided according to the oscillation frequency / temperature relationship curve fitted according to the temperature / resistance value table of the thermistor and the frequency calculation formula of the multi-resonance circuit, and the oscillation frequency and the temperature in each frequency interval are in a linear relationship; and calculating the corresponding temperature measurement value according to the determined frequency interval.

[0044] Before monitoring, according to the known thermistor temperature and resistance value table and the oscillation circuit frequency calculation formula, the corresponding frequency under different resistance values is calculated, that is, the corresponding frequency under different temperatures is obtained. The relationship curve between the output frequency and the temperature is drawn by using the polynomial fitting method of Matlab, as shown in the figure. Figure 3 The abscissa is the frequency, unit Hz (Hertz); the ordinate is the temperature, unit ℃ (Celsius).

[0045] As can be seen from the figure, the oscillation frequency and the temperature present a nonlinear characteristic, although the curve fitting method, neural network and other methods can effectively improve the temperature calculation result accuracy, but due to the limited floating point calculation accuracy of the microprocessor module, it is difficult to process high-order fitting equation and neural network calculation, therefore, in the embodiment, the frequency-temperature curve is divided into several frequency intervals according to the curve derivative, and a linear equation of frequency-temperature is established in each frequency interval, so as to obtain the frequency-temperature segmented function. In this way, after the microprocessor module obtains the oscillation frequency of the multi-tuned oscillation circuit through the interrupt technology of the photocoupler switch times, the corresponding frequency interval is found, and the corresponding temperature measurement value can be calculated according to the linear relationship in the corresponding frequency interval.

[0046] In order to obtain the frequency spectrum information of the fan, the audio signal and the temperature signal are analyzed and processed by the microprocessor module, and whether the fan is faulty is judged according to the analysis result, and the method further comprises: S31 The fan audio signal collected by the pickup sensor module is further sampled to obtain a digital audio signal.

[0047] The sampled digital audio signal is as follows:

[0048] Wherein, Ts represents the sampling interval, which is determined by the clock of the ADC, such as Ts=1 / fs; fs is the sampling frequency, which needs to satisfy the Nyquist sampling theorem fs≥2fmax, since the frequency of the fan sound is usually <10kHz, therefore, fs≥20kHz is preferred. The sampling point number N determines the FFT frequency resolution, such as N=1024.

[0049] S32 Discrete Fourier transform is performed on the digital audio signal to obtain a frequency domain audio signal.

[0050] The time domain signal x [n] is converted into a frequency domain signal X[k], and the discrete Fourier transform (DFT) formula is as follows:

[0051] S33 The amplitude of each frequency component in the frequency domain audio signal is extracted; S34 analyze the frequency characteristics of the vibration or friction of the fan according to the extracted amplitude information.

[0052] To determine whether the fan is malfunctioning based on the temperature measurement and the audio signal, the audio signal and the temperature signal are analyzed by the microprocessor module, and whether the fan is malfunctioning is determined according to the analysis result, and further comprising: S35 determine whether the frequency of the fan vibration or friction exceeds a preset frequency threshold; S36 determine whether the temperature difference between the inside and outside of the substation optical fiber cabinet is greater than a preset temperature threshold; S37 further determine whether the fan is malfunctioning according to the frequency determination result and the temperature difference determination result; S38 when the frequency of the fan vibration or friction exceeds the preset frequency threshold, and the temperature difference between the inside and outside of the substation optical fiber cabinet is greater than the preset temperature threshold, determine that the fan is malfunctioning.

[0053] The preset frequency threshold is determined according to the fan used in the actual scene, which can be limited to 1kHz-2kHz, etc.; the preset temperature difference threshold can also be set in combination with weather and other factors, such as 2℃-8℃, etc.

[0054] The determination process specifically includes: When the fan sound vibration frequency spectrum is monitored to exceed the preset frequency threshold, the temperature difference between the inside and outside of the cabinet is checked at the same time, and if the temperature difference is not greater than the preset temperature threshold, it is determined that the fan is not malfunctioning; When the fan sound vibration frequency spectrum is monitored to exceed the preset frequency threshold, the temperature difference between the inside and outside of the cabinet is checked at the same time, and if the temperature difference is greater than the preset temperature threshold, it is determined that the fan may malfunction; When the fan sound vibration frequency spectrum is monitored to not exceed the preset frequency threshold, the temperature difference between the inside and outside of the cabinet is checked at the same time, and if the temperature difference is not greater than the preset temperature threshold, it is determined that the fan is not malfunctioning.

[0055] When the fan sound vibration frequency spectrum is monitored to not exceed the preset frequency threshold, the temperature difference between the inside and outside of the cabinet is checked at the same time, and if the temperature difference is greater than the preset temperature threshold, it is determined that the fan is not malfunctioning, which may be caused by high ambient temperature.

[0056] It should be noted that the above embodiments can be freely combined as needed. The above is only a preferred embodiment of the present application, and it should be noted that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, which improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A substation optical fiber cabinet cooling fan failure monitoring device, characterized in that, The substation optical fiber cabinet is internally provided with a fan for heat dissipation, and the fault monitoring device comprises: A pickup sensor module is installed at a position close to the fan inside the substation optical fiber cabinet, and is used to collect audio signals of the fan; A temperature sensor module is respectively arranged inside and outside the substation optical fiber cabinet, and is used to collect temperature signals inside and outside the substation optical fiber cabinet; A microprocessor module is connected with the pickup sensor module and the temperature sensor module respectively, and is used to analyze and process the audio signals and the temperature signals, and to determine whether the fan is faulty according to the analysis results.

2. The fault monitoring apparatus of claim 1, wherein The temperature sensor module comprises: A thermistor, a multi-resonance circuit, a switching circuit and an optocoupler circuit, wherein the thermistor is connected with the input end of the multi-resonance circuit, the input end of the switching circuit is connected with the output end of the multi-resonance circuit, the optocoupler circuit is connected with the output end of the switching circuit, and the output end of the optocoupler circuit is connected with the input end of the microprocessor module; The oscillation frequency of the multi-resonance circuit changes with the resistance value of the thermistor; when the multi-resonance circuit outputs a high level, the switching circuit is turned on, and then the optocoupler circuit is turned on; the microprocessor module obtains the oscillation frequency of the multi-resonance circuit through the number of times of switching of the optocoupler, so as to obtain the temperature measurement value.

3. The fault monitoring apparatus of claim 2, wherein The microprocessor module comprises: An oscillation frequency obtaining unit, which is used to obtain the number of times of switching of the optocoupler through the interrupt technology, and then obtain the oscillation frequency of the multi-resonance circuit; A frequency interval determining unit connected with the oscillation frequency obtaining unit, which is used to determine the frequency interval where the obtained oscillation frequency is located, and the frequency interval is divided according to the oscillation frequency / temperature relationship curve fitted based on a temperature / resistance value table of the thermistor and a frequency calculation formula of the multi-resonance circuit, and in each divided frequency interval, the oscillation frequency and the temperature are in a linear relationship; A temperature calculating unit connected with the frequency interval determining unit, which is used to calculate the corresponding temperature measurement value according to the frequency interval determined by the frequency interval determining unit.

4. The fault monitoring device according to any one of claims 1 to 3, characterized in that The microprocessor module further comprises: An ADC sampling unit, which is used to further sample the audio signals of the fan collected by the pickup sensor module to obtain digital audio signals; A frequency domain signal converting unit connected with the ADC sampling unit, which is used to perform discrete Fourier transform on the digital audio signals generated by the ADC sampling unit to obtain frequency domain audio signals; An amplitude extracting unit connected with the frequency domain signal converting unit, which is used to extract the amplitude of each frequency component in the frequency domain audio signals generated by the frequency domain signal converting unit; A frequency feature analyzing unit connected with the amplitude extracting unit, which is used to analyze the frequency features of vibration or friction of the fan according to the amplitude information extracted by the amplitude extracting unit.

5. The fault monitoring device according to any one of claims 1 to 3, wherein The microprocessor module further comprises: A fan frequency spectrum determining unit, which is used to determine whether the frequency of vibration or friction of the fan exceeds a preset frequency threshold; A temperature difference determining unit, which is used to determine whether the temperature difference between the inside and outside of the substation optical fiber cabinet is greater than a preset temperature threshold; The fault determination unit is respectively connected with the fan spectrum judgment unit and the temperature difference judgment unit, and is used for further judging whether the fan is faulty according to the results of the fan spectrum judgment unit and the fault determination unit; when the frequency of the vibration or friction of the fan exceeds the preset frequency threshold value, and the temperature difference between the inside and outside of the substation optical fiber cabinet is greater than the preset temperature threshold value, it is judged that the fan is faulty.

6. A substation optical fiber cabinet cooling fan failure monitoring method, characterized by, The substation optical fiber cabinet is internally provided with a fan for heat dissipation, and the fault monitoring method comprises the following steps: An audio signal of the fan is collected by a pickup sensor module; the pickup sensor module is installed at a position close to the fan inside the substation optical fiber cabinet; Temperature signals inside and outside the substation optical fiber cabinet are respectively collected by a temperature sensor module; the temperature sensor module is respectively arranged inside and outside the substation optical fiber cabinet; The audio signal and the temperature signal are analyzed and processed by a microprocessor module, and whether the fan is faulty is judged according to the analysis result.

7. The failure monitoring method according to claim 6, wherein The temperature sensor module comprises: A thermistor, a multi-resonance circuit, a switching circuit and an optocoupler circuit, wherein the thermistor is connected with the input end of the multi-resonance circuit, the input end of the switching circuit is connected with the output end of the multi-resonance circuit, the optocoupler circuit is connected with the output end of the switching circuit, and the output end of the optocoupler circuit is connected with the input end of the microprocessor module; The multi-resonance circuit outputs a high level, the switching circuit is turned on, and then the optocoupler circuit is turned on; when the resistance value of the thermistor changes, the oscillation frequency of the multi-resonance circuit changes accordingly; The audio signal and the temperature signal are analyzed and processed by the microprocessor module, and whether the fan is faulty is judged according to the analysis result. The microprocessor module obtains the oscillation frequency of the multi-resonance circuit by interrupt technology to obtain the temperature measurement value.

8. The failure monitoring method according to claim 7, wherein The microprocessor module obtains the oscillation frequency of the multi-resonance circuit by interrupt technology to obtain the temperature measurement value. The number of times of switching of the optocoupler is obtained by interrupt technology, and then the oscillation frequency of the multi-resonance circuit is obtained; The frequency interval in which the oscillation frequency is located is determined according to the obtained oscillation frequency, the frequency interval is divided according to the oscillation frequency / temperature relationship curve fitted according to the temperature / resistance value table of the thermistor and the frequency calculation formula of the multi-resonance circuit, and in each frequency interval, the oscillation frequency and the temperature have a linear relationship; The corresponding temperature measurement value is calculated according to the determined frequency interval.

9. The fault monitoring method according to any one of claims 6 to 8, characterized by, The audio signal and the temperature signal are analyzed and processed by the microprocessor module, and whether the fan is faulty is judged according to the analysis result. The fan audio signal collected by the pickup sensor module is further sampled to obtain a digital audio signal; The digital audio signal is subjected to discrete Fourier transform to obtain a frequency domain audio signal; The amplitude of each frequency component in the frequency domain audio signal is extracted; The amplitude information is extracted to analyze the frequency characteristics of the vibration or friction of the fan.

10. The fault monitoring method according to any one of claims 6 to 8, characterized by, The audio signal and the temperature signal are analyzed and processed by the microprocessor module, and whether the fan is faulty is judged according to the analysis result. determining whether the frequency of the fan vibration or friction exceeds a preset frequency threshold value; determining whether the temperature difference between the inside and outside of the substation optical fiber cabinet is greater than a preset temperature threshold value; further determining whether the fan is faulty according to the frequency determination result and the temperature difference determination result; determining that the fan is faulty when the frequency of the fan vibration or friction exceeds the preset frequency threshold value, and the temperature difference between the inside and outside of the substation optical fiber cabinet is greater than the preset temperature threshold value.

Images