Low-power-consumption awakening method and system for partial discharge detection equipment of power distribution cabinet

Abstract

A power distribution cabinet partial discharge detection device low power consumption wake-up method and system relates to the discharge detection field, and the method comprises the following steps: when a power distribution cabinet is standby, a preprocessing and core detection unit is dormant, and a passive induction unit continuously monitors partial discharge signals; when the signal amplitude reaches a preset trigger threshold value, the passive induction unit triggers the preprocessing unit through the level conversion circuit, and the preprocessing unit amplifies and filters the signal, extracts amplitude, frequency and time domain features and verifies whether the amplitude, frequency and time domain features meet preset conditions. And after the conditions are met, the preprocessing unit awakens the core detection unit and synchronously transmits the cached power distribution cabinet and detection parameters. After the core detection unit is started, parameters are called to complete signal detection and pulse identification, and a partial discharge detection result is output. By implementing the method, the overall power consumption of the detection equipment can be reduced.

Description

Technical Field

[0001] This application relates to the field of discharge detection, and in particular to a low-power wake-up method and system for a partial discharge detection device for a power distribution cabinet. Background Technology

[0002] As a core piece of equipment in the power transmission and distribution system, the operational reliability of the distribution cabinet directly affects the safety and stability of the power supply. During long-term operation, the core components inside the distribution cabinet are prone to partial discharge due to factors such as insulation aging, poor contact, and changes in environmental humidity. Partial discharge is characterized by its short duration (1-100μs), low amplitude (mV level), and wide frequency range (10kHz-100MHz). If it is not detected and warned in time, it will gradually develop into insulation breakdown, leading to serious accidents such as short circuits and fires.

[0003] Existing partial discharge detection equipment for distribution cabinets typically employs a continuous power supply and operation mode for the core detection unit. This core detection unit directly monitors and analyzes the signals acquired by the partial discharge sensors in real time. The core detection unit integrates a high-performance processor, memory, communication module, and other complex circuit systems. It captures and identifies partial discharge signals through continuous sampling, signal processing, data storage, and network transmission. Its internal analog-to-digital converter, digital signal processor, memory, and communication module are all continuously running.

[0004] However, partial discharge events in power distribution cabinets are sporadic in actual operation, and a real partial discharge signal may only appear once every few hours or even days under normal operating conditions. The continuous operation mode of the core detection unit in existing technologies means that the equipment is in an idle standby state most of the time, but the complex circuit systems such as high-performance processors, memory, and communication modules still continuously consume power, resulting in significant energy waste in long-term operation scenarios for power distribution cabinets. Summary of the Invention

[0005] This application provides a low-power wake-up method and system for a partial discharge detection device in a power distribution cabinet, which reduces the overall power consumption of the detection device.

[0006] In a first aspect, this application provides a low-power wake-up method for a partial discharge detection device for a power distribution cabinet, applied to such a device. The device includes a passive sensing unit, a preprocessing unit, and a core detection unit. The passive sensing unit is connected to the general-purpose input / output interface of the preprocessing unit via a level conversion circuit. The preprocessing unit is connected to the core detection unit via a hardware interrupt pin. The method includes: when the power distribution cabinet is in standby mode, the preprocessing unit and the core detection unit are in sleep mode, and the passive sensing unit continuously monitors the partial discharge signal within the power distribution cabinet; when the passive sensing unit detects that the amplitude of the partial discharge signal reaches a preset trigger threshold, it outputs a signal through the level conversion circuit. A trigger signal is sent to the preprocessing unit; the preprocessing unit amplifies and filters the partial discharge signal to obtain amplitude characteristics, frequency characteristics, and time-domain characteristics, and determines whether the amplitude characteristics reach a preset amplitude threshold, whether the frequency characteristics are within a preset frequency range, and whether the time-domain characteristics meet preset time-domain conditions; when the amplitude characteristics, frequency characteristics, and time-domain characteristics simultaneously meet the preset conditions, the preprocessing unit sends a wake-up pulse to the core detection unit and transmits the power distribution cabinet parameters and detection parameters pre-stored in the parameter buffer pool to the core detection unit; after receiving the wake-up pulse, the core detection unit starts power supply, calls the received power distribution cabinet parameters and detection parameters, performs detection and pulse identification on the partial discharge signal, obtains the partial discharge detection result, and transmits it.

[0007] In the above embodiments, by adopting a three-level wake-up architecture, the passive sensing unit continuously monitors partial discharge signals in a zero-power state. The preprocessing unit is only woken up when the detected signal amplitude reaches a preset trigger threshold. The preprocessing unit further comprehensively judges the signal amplitude, frequency, and time-domain characteristics. The core detection unit is only woken up when all three characteristics simultaneously meet preset conditions, achieving a stepped power consumption distribution. Simultaneously, the preprocessing unit pre-stores power distribution cabinet parameters and detection parameters in a parameter cache pool. Upon wake-up, it directly triggers rapid transmission via a hardware interrupt, eliminating the need for initialization and calibration processes for the core detection unit. This enables wake-up-to-detection, reducing the wake-up response delay from over 3 seconds in traditional devices to less than 100 microseconds, ensuring that brief discharge signals are not missed.

[0008] In conjunction with some embodiments of the first aspect, in some embodiments, the preprocessing unit amplifies and filters the partial discharge signal to obtain amplitude features, frequency features, and time-domain features, and determines whether the amplitude features reach a preset amplitude threshold, whether the frequency features are within a preset frequency range, and whether the time-domain features meet preset time-domain conditions. Specifically, the preprocessing unit amplifies the partial discharge signal through an amplification circuit, filters it through a bandpass filter, and extracts amplitude features, frequency features, and time-domain features through a peak hold and a zero-crossing detector. The preprocessing unit simultaneously determines whether the amplitude features reach a preset amplitude threshold, whether the main frequency of the frequency features is within a preset frequency range and whether the proportion of harmonic components is lower than a preset harmonic threshold, whether the rise time and pulse width of the time-domain features are within a preset time-domain range and whether the waveform is a non-periodic pulse. When the amplitude features, frequency features, and time-domain features simultaneously meet the determination conditions, the partial discharge signal is determined to be a valid trigger signal, and the wake-up process begins.

[0009] In the above embodiments, a signal preprocessing link consisting of an amplifier circuit, a bandpass filter, a peak hold circuit, and a zero-crossing detector is used to extract multi-dimensional features from the partial discharge signal. Simultaneously, it determines whether the amplitude reaches a preset amplitude threshold, whether the main frequency is within a preset frequency range and whether the harmonic component ratio is lower than a preset harmonic threshold, whether the rise time and pulse width are within a preset time domain range, and whether the waveform is a non-periodic pulse. This constructs a three-dimensional fusion criterion of amplitude, frequency, and time domain. Compared to traditional devices that rely solely on a single amplitude criterion, this scheme can effectively distinguish partial discharge signals from electromagnetic interference such as switching operations and motor start-stop, reducing the false wake-up rate from over 20% to below 2%.

[0010] In conjunction with some embodiments of the first aspect, in some embodiments, the step of the preprocessing unit sending a wake-up pulse to the core detection unit and transmitting the power distribution cabinet parameters and detection parameters pre-stored in the parameter cache pool to the core detection unit specifically includes: the preprocessing unit sending a wake-up pulse to the core detection unit via a hardware interrupt pin; after sending the wake-up pulse, the preprocessing unit reading the power distribution cabinet parameters and detection parameters from the parameter cache pool, the power distribution cabinet parameters including the power distribution cabinet model, rated voltage, and detection point coordinates, and the detection parameters including the detector chip gain, microcontroller processing frequency, and communication mode; the preprocessing unit transmitting the power distribution cabinet parameters and detection parameters to the SRAM of the core detection unit via the SPI bus; and the core detection unit starting power supply and completing module initialization after receiving the wake-up pulse.

[0011] In the above embodiment, the wake-up pulse is transmitted by using a hardware interrupt pin, and the power distribution cabinet parameters (including power distribution cabinet model, rated voltage and detection point coordinates) and detection parameters (including detector chip gain, microcontroller processing frequency and communication mode) pre-stored in the parameter cache pool are quickly transmitted to the SRAM of the core detection unit via the SPI bus. This allows the core detection unit to immediately call the cached parameters for detection after receiving the wake-up pulse, without the need for reloading and calibration. The parameter transmission time is shortened from 1-2 seconds in traditional equipment to less than 1 millisecond, realizing deep software and hardware collaboration.

[0012] In conjunction with some embodiments of the first aspect, in some embodiments, the core detection unit, upon receiving a wake-up pulse, starts power supply, calls the received power distribution cabinet parameters and detection parameters, performs detection and pulse identification on the partial discharge signal, obtains the partial discharge detection result, and transmits it. Specifically, this includes: the core detection unit, upon receiving a wake-up pulse, starts power supply and completes the initialization of the microcontroller, detection module, and wireless communication module; the core detection unit calls the detection parameters from SRAM and configures the detection module and data processing module according to the detection parameters; the detection module performs detection processing on the partial discharge signal according to the detection parameters, converting the partial discharge signal into a DC voltage signal; the data processing module calculates the discharge quantity based on the DC voltage signal, and when the discharge quantity reaches a preset discharge quantity threshold, generates the partial discharge detection result; the wireless communication module performs graded transmission based on the discharge quantity.

[0013] In the above embodiment, by adopting the core detection unit to immediately start power supply after receiving the wake-up pulse and complete the rapid initialization of the microcontroller, detection module and wireless communication module, the detection parameters are called from SRAM to configure the detection module and data processing module. The detection module converts the partial discharge signal into a DC voltage signal. The data processing module calculates the discharge quantity and generates the detection result based on the DC voltage signal. The wireless communication module transmits the data in stages according to the discharge quantity. This achieves low-power optimization of the entire process from signal detection to data transmission, ensuring detection accuracy while controlling the operating power consumption to within 0.5W.

[0014] In conjunction with some embodiments of the first aspect, in some embodiments, the step of the wireless communication module performing graded transmission based on the discharge amount specifically includes: when the discharge amount is not lower than an emergency threshold, transmitting partial discharge detection results within a first preset time period; when the discharge amount is lower than the emergency threshold, transmitting partial discharge detection results in batches within a second preset time period, wherein the second preset time period is longer than the first preset time period.

[0015] In the above embodiments, by adopting a hierarchical transmission mechanism, the detection results are transmitted immediately within a first preset time period when the discharge level is not lower than the emergency threshold, and the detection results are transmitted in batches within a second preset time period when the discharge level is lower than the emergency threshold. This not only ensures the real-time reporting of emergency fault information, but also reduces the communication frequency of regular data through batch transmission, effectively reducing the power consumption of the wireless communication module and extending the device's battery life.

[0016] In conjunction with some embodiments of the first aspect, in some embodiments, after the steps of detecting and identifying the partial discharge signal to obtain the partial discharge detection result and transmitting it, the method further includes: a preprocessing unit storing the amplitude characteristics, frequency characteristics, time domain characteristics, and judgment result of each triggering event into a historical record cache; the preprocessing unit statistically analyzing the false triggering rate in the historical record cache according to a preset period; when the false triggering rate is higher than a preset false triggering threshold, increasing the preset amplitude threshold and narrowing the preset frequency range or tightening the preset time domain conditions; when the effective triggering rate is lower than a preset effective triggering threshold, decreasing the preset amplitude threshold and expanding the preset frequency range or relaxing the preset time domain conditions.

[0017] In the above embodiments, by employing a preprocessing unit to store the characteristics and judgment results of each triggering event in a historical record cache, and statistically analyzing the false trigger rate according to a preset period, when the false trigger rate is higher than a preset false trigger threshold, the preset amplitude threshold is automatically increased and the preset frequency range is narrowed or the preset time domain conditions are tightened. When the effective trigger rate is lower than a preset effective trigger threshold, the preset amplitude threshold is automatically decreased and the preset frequency range is expanded or the preset time domain conditions are relaxed. This achieves adaptive adjustment of the judgment threshold, enabling the device to dynamically adapt to the interference environment of different power distribution cabinets and continuously optimize wake-up accuracy.

[0018] In conjunction with some embodiments of the first aspect, in some embodiments, after the steps of detecting and identifying the partial discharge signal, obtaining the partial discharge detection result and transmitting it, the method further includes: when any of the amplitude feature, frequency feature and time domain feature does not meet the preset conditions, the preprocessing unit returns to the standby state.

[0019] In the above embodiments, by adopting a mechanism in which the preprocessing unit immediately returns to standby state when any of the amplitude characteristics, frequency characteristics and time domain characteristics does not meet the preset conditions, the power consumption waste caused by invalid wake-up is avoided, and the core detection unit is ensured to start only when a valid partial discharge signal is confirmed, thereby further reducing the average power consumption of the device.

[0020] In a second aspect, embodiments of this application provide a partial discharge detection device for a power distribution cabinet, the device comprising: one or more processors and a memory; the memory is coupled to the one or more processors, the memory being used to store computer program code, the computer program code including computer instructions, the one or more processors calling the computer instructions to cause the partial discharge detection device to perform the method described in the first aspect and any possible implementation thereof.

[0021] Thirdly, embodiments of this application provide a computer program product containing instructions that, when the computer program product is run on a partial discharge detection device for a power distribution cabinet, cause the partial discharge detection device for the power distribution cabinet to execute the method described in the first aspect and any possible implementation thereof.

[0022] Fourthly, embodiments of this application provide a computer-readable storage medium including instructions that, when executed on a partial discharge detection device for a distribution cabinet, cause the distribution cabinet partial discharge detection device to perform the method described in the first aspect and any possible implementation thereof.

[0023] Understandably, the partial discharge detection device for the distribution cabinet provided in the second aspect, the computer program product provided in the third aspect, and the computer storage medium provided in the fourth aspect are all used to execute the method provided in the embodiments of this application. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods, and will not be repeated here.

[0024] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages: 1. This application employs a three-tiered wake-up architecture consisting of a passive sensing unit, a preprocessing unit, and a core detection unit. The passive sensing unit continuously monitors partial discharge signals using a dual-mode array of electromagnetic induction coils and piezoelectric sensors. The preprocessing unit amplifies, bandpass filters, and extracts three-dimensional features from the trigger signal. The core detection unit is only woken up via a hardware interrupt pin when the amplitude, frequency, and time domain features simultaneously meet preset conditions. This achieves a tiered startup process from zero-power monitoring to low-power prediction and precise wake-up. This design reduces the standby power consumption of the passive sensing unit to below 0.1W, the operating power consumption of the preprocessing unit to below 50mA, and the core detection unit only starts supplying power when a valid discharge signal is confirmed. This reduces the overall standby power consumption of the device from over 5W in traditional devices to below 0.1W, and shortens the wake-up response delay from over 3 seconds to less than 100 microseconds. This effectively solves the inherent contradiction between power consumption and response speed in existing technologies, thereby enabling long-term real-time monitoring of partial discharge in distribution cabinets in scenarios without external power supply.

[0025] 2. This application employs an amplification circuit in the preprocessing unit to amplify the partial discharge signal with an adjustable gain of 100-500 times. A bandpass filter removes power frequency interference and high-frequency noise. A peak hold circuit and a zero-crossing detector extract amplitude, frequency, and time-domain features. Simultaneously, it determines whether the amplitude reaches a preset amplitude threshold, whether the main frequency is within the range of 100kHz-50MHz and whether the harmonic component ratio is less than 30%, whether the rise time is less than 1 microsecond and the pulse width is within the range of 5-20 microseconds, and whether the waveform is a non-periodic pulse. This constructs a three-dimensional fusion wake-up criterion based on signal amplitude, frequency, and time-domain waveform. This multi-dimensional feature comprehensive judgment mechanism can effectively distinguish partial discharge signals from electromagnetic interference pulses such as switch operations and motor start-stop in the distribution cabinet. Compared with traditional equipment that relies solely on a single amplitude exceeding a preset threshold criterion, it reduces the false wake-up rate from over 20% to below 2%, effectively solving the problem of insufficient accuracy caused by a single wake-up criterion in existing technologies, thereby achieving high-precision and low-power partial discharge signal identification.

[0026] 3. This application utilizes a parameter buffer pool in the preprocessing unit to pre-store power distribution cabinet parameters (including power distribution cabinet model, rated voltage, and detection point coordinates) and detection parameters (including detector chip gain, microcontroller processing frequency, and communication mode). When a valid trigger signal is detected, the preprocessing unit sends a wake-up pulse to the core detection unit via a hardware interrupt pin and transmits the parameters from the parameter buffer pool to the SRAM of the core detection unit via the SPI bus at a rate of 10 Mbps. Upon receiving the wake-up pulse, the core detection unit immediately starts power supply and completes initialization within 50 microseconds. It then calls the preset parameters from the SRAM to configure the detection module and data processing module, eliminating the need for the traditional process of sequentially completing module initialization, parameter loading, and accuracy calibration after wake-up. This hardware-software co-caching synchronization mechanism reduces the parameter loading time after wake-up from 1-2 seconds to less than 1 millisecond, achieving wake-up-and-detection. This effectively solves the problem of poor hardware-software coordination affecting real-time performance in existing technologies, thereby achieving seamless real-time detection of partial discharge signals. Attached Figure Description

[0027] Figure 1 This is a flowchart illustrating a low-power wake-up method for a partial discharge detection device in a power distribution cabinet, as described in this application. Figure 2 This is another flowchart illustrating the low-power wake-up method for the partial discharge detection device in the power distribution cabinet in this application embodiment; Figure 3 This is a schematic diagram of the physical device structure of a partial discharge detection device for a distribution cabinet in the embodiments of this application. Detailed Implementation

[0028] The terminology used in the following embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. As used in the specification of this application, the singular expressions “a,” “an,” “the,” “the,” and “this” are intended to include the plural expressions as well, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this application refers to any or all possible combinations including one or more of the listed items.

[0029] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature, and in the description of the embodiments of this application, unless otherwise stated, "multiple" means two or more.

[0030] To facilitate understanding, the application scenarios of the embodiments of this application are described below.

[0031] In practical applications of partial discharge detection in distribution cabinets, partial discharge signals refer to the weak discharge phenomena generated by the concentration of electric field stress in the insulating materials or metal contact points inside the distribution cabinet. The amplitude of these electromagnetic radiation signals is typically in the millivolt range, lasting only 1-100 microseconds, with frequencies distributed across a wide frequency band from 10kHz to 100MHz. This brief and weak signal characteristic makes it difficult for traditional detection equipment to accurately capture the signal in low-power standby mode. The passive sensing unit employs a dual-mode array composed of an electromagnetic induction coil and a piezoelectric sensor. It can simultaneously monitor partial discharge signals through both electromagnetic induction and mechanical vibration sensing without external power supply. When the induced voltage reaches 20 millivolts or higher, it automatically outputs a trigger signal, achieving continuous monitoring with zero power consumption.

[0032] The preprocessing unit serves as an intermediate processing layer connecting the passive sensing unit and the core detection unit. Its core function is to condition and extract features from the trigger signal. It amplifies the weak sensing signal to a processable range using a low-noise operational amplifier, filters out 50Hz power frequency interference and high-frequency white noise using a Chebyshev bandpass filter, captures the signal peak value as an amplitude feature using a peak-hold circuit, statistically analyzes the zero-crossing frequency of the signal as a frequency feature using a zero-crossing detector, and measures the signal rise time and pulse width as time-domain features using a high-speed comparator. This multi-dimensional feature extraction mechanism enables rapid signal prediction at the hardware level. Compared to traditional devices that directly send the raw signal to the core processor for software analysis, the preprocessing unit can complete feature extraction and preliminary judgment with a power consumption of only 50 mA, significantly reducing the startup frequency of the core detection unit.

[0033] The core detection unit employs a signal detection and data processing module composed of a logarithmic detector chip and a low-power microcontroller. The logarithmic detector chip converts the pre-processed AC partial discharge signal into a DC voltage signal proportional to the signal amplitude. The microcontroller then uses this DC voltage signal to run a pulse recognition algorithm to calculate key parameters such as discharge quantity and discharge count. The parameter buffer pool is a dedicated storage area reserved in the Flash memory of the pre-processing unit. During device initialization, it receives the inherent parameters of the power distribution cabinet and the detection configuration parameters sent from the backend via the wireless communication module and stores them in this area for quick retrieval upon wake-up, avoiding the time loss of reloading parameters every time the device is woken up.

[0034] The hardware interrupt pin is a dedicated wake-up interface for the microcontroller, supporting both rising edge triggering and pulse triggering modes. When the preprocessing unit outputs a 10-microsecond high-level pulse through this pin, the core detection unit can respond and start power supply within 100 microseconds. Compared to traditional devices that detect wake-up signals through software polling, the response latency of the hardware interrupt mechanism is reduced by two orders of magnitude. The SPI bus is a high-speed data transmission interface between the preprocessing unit and the core detection unit, supporting a transmission rate of 10Mbps. It can complete the transmission of 128 bytes of parameter data within 1 millisecond, ensuring that the core detection unit immediately obtains all the configuration information required for detection after wake-up. The hierarchical transmission mechanism divides the detection data into two categories based on the discharge level: emergency data and regular data. Emergency data is uploaded immediately via the 4G module, while regular data is uploaded in batches via the LoRa module. This differentiated transmission strategy ensures the real-time nature of fault information and reduces the power consumption of the wireless module by reducing the communication frequency.

[0035] To facilitate understanding, the method provided in this implementation will be described in detail below, using the above scenario as an example. Please refer to [link / reference]. Figure 1 This is a flowchart illustrating a low-power wake-up method for a partial discharge detection device in a power distribution cabinet, as described in this application.

[0036] S101. When the power distribution cabinet is in standby mode, the preprocessing unit and the core detection unit are in hibernation mode, and the passive sensing unit continuously monitors the partial discharge signal in the power distribution cabinet.

[0037] In this context, "standby mode" indicates that the power distribution cabinet is not experiencing any partial discharge abnormalities and the equipment is operating in a low-power monitoring mode. "Sleep mode" refers to the STM32L151C8T6A microcontroller in the preprocessing unit and the STM32F103 microcontroller in the core detection unit entering a power-off or minimum power mode. In this mode, the microcontroller's internal clock stops, peripherals are powered off, and only necessary register states are maintained. The passive sensing unit represents a dual-mode sensor array composed of an electromagnetic induction coil and a piezoelectric sensor. This array can continuously capture electromagnetic radiation and mechanical vibration signals inside the power distribution cabinet without external power supply.

[0038] Specifically, when the distribution cabinet is in standby mode and insulation degradation has not occurred, the TPS63070 chip of the intelligent power management unit only provides a 3.3-volt voltage and a supply current of no more than 10 mA to the passive sensing unit. At this time, the power supply channels of the preprocessing unit and the core detection unit remain closed. The iron-based nanocrystalline alloy coil in the passive sensing unit continuously senses the changes in electromagnetic fields generated by key parts such as the busbar joints and circuit breaker contacts of the distribution cabinet, while the piezoelectric sensor synchronously monitors the weak mechanical vibration at the root of the insulator. The analog signals output by the two types of sensors are transmitted to the input of the level conversion circuit in real time.

[0039] S102. When the passive sensing unit detects that the amplitude of the partial discharge signal reaches the preset trigger threshold, it outputs a trigger signal to the preprocessing unit through the level conversion circuit.

[0040] The signal amplitude represents the peak value of the analog voltage signal output by the passive sensing unit, and this amplitude is directly proportional to the intensity of partial discharge within the distribution cabinet. The preset trigger threshold is a signal amplitude judgment benchmark pre-set according to the rated voltage level of the distribution cabinet; different voltage levels correspond to different thresholds. The level conversion circuit is a circuit module used to convert the analog signal output by the passive sensing unit into a digital signal conforming to the electrical specifications of the preprocessing unit's GPIO interface. The trigger signal is the digital pulse signal sent by the level conversion circuit to the preprocessing unit.

[0041] Specifically, after the electromagnetic induction coil and piezoelectric sensor in the passive sensing unit detect signals inside the power distribution cabinet, they output analog voltage signals and transmit them to the level conversion circuit. The comparator inside the level conversion circuit compares the amplitude of the analog signal with a preset trigger threshold. When the signal amplitude reaches or exceeds the preset trigger threshold, the comparator output flips to a 3.3V high level. This high-level signal is transmitted to the GPIO interface of the preprocessing unit, simultaneously triggering the intelligent power management unit to start the power supply channel of the preprocessing unit.

[0042] In some embodiments, the trigger signal can be generated in multiple ways. Optionally, the level conversion circuit uses a Schmitt trigger, setting an upper trigger threshold and a lower reset threshold to avoid false triggering caused by signal jitter; the trigger signal is transmitted to the preprocessing unit through an optocoupler isolator to achieve electrical isolation; while outputting the trigger signal, the level conversion circuit simultaneously converts the signal peak value into a digital quantity for synchronous transmission via an analog-to-digital converter. Optionally, the passive sensing unit sets a dual-threshold trigger mechanism, with the first threshold used for early warning to put the preprocessing unit into a ready state, and the second threshold used for formal triggering to start power supply; the trigger signal uses a differential signal transmission method, extracting the effective signal and suppressing common-mode interference through a differential receiver.

[0043] S103. The preprocessing unit amplifies and filters the partial discharge signal to obtain amplitude characteristics, frequency characteristics and time domain characteristics, and determines whether the amplitude characteristics reach the preset amplitude threshold, whether the frequency characteristics are within the preset frequency range and whether the time domain characteristics meet the preset time domain conditions.

[0044] The amplification process involves the preprocessing unit linearly amplifying the amplitude of the partial discharge signal by using a low-noise operational amplifier with a preset gain. The filtering process involves using a bandpass filter to select the frequency of the amplified signal, removing power frequency interference and high-frequency noise. The amplitude characteristic represents the peak voltage of the filtered signal, captured by a peak-hold circuit. The frequency characteristic refers to the signal's dominant frequency component and harmonic distribution, calculated by counting the number of zero-crossings using a zero-crossing detector. The time-domain characteristic represents the rise time and pulse width of the signal waveform.

[0045] Specifically, after receiving the trigger signal, the preprocessing unit initiates amplification based on the gain parameters in the parameter buffer. The amplified signal is then input to a bandpass filter to retain the main frequency components of the partial discharge signal. The filtered output signal is split into two paths: the first path is transmitted to a peak hold circuit to capture the peak voltage, and the second path is transmitted to a zero-crossing comparator to output a square wave signal for frequency calculation. The microcontroller samples the peak voltage using an analog-to-digital converter, calculates the main frequency by counting the number of square wave pulses using a timer, and synchronously executes a three-dimensional fusion criterion algorithm to determine whether each feature meets the preset conditions.

[0046] In some embodiments, signal preprocessing can be implemented in various ways. Optionally, the amplification circuit uses a programmable gain amplifier, and the microcontroller automatically adjusts the gain level according to the signal amplitude; the filter uses a switched capacitor filter, and the center frequency and bandwidth are dynamically adjusted by controlling the clock frequency; the feature extraction module adds waveform correlation analysis, performing correlation operations between the signal waveform and typical templates. Optionally, the preprocessing unit uses dual-channel parallel processing, with the first channel performing fast amplitude determination and the second channel performing detailed frequency and time domain analysis; frequency feature extraction uses the Goertzel algorithm to calculate only key frequency points; time domain feature extraction uses a hardware comparator to achieve high-precision time measurement.

[0047] In some embodiments, the preprocessing unit amplifies and filters the partial discharge signal to extract the amplitude features, the frequency features, and the time-domain features. The preprocessing unit matches the amplitude feature, frequency feature, and time domain feature with typical interference signal features pre-stored in the parameter cache pool. When the matching similarity exceeds a preset similarity threshold, the partial discharge signal is determined to be an interference signal, the partial discharge signal is discarded, and a power-off command is sent to the power management unit. When the matching similarity is lower than the preset similarity threshold, the preprocessing unit sequentially determines whether the amplitude feature reaches the preset amplitude threshold, whether the frequency feature is within the preset frequency range, and whether the time domain feature meets the preset time domain conditions. When any feature determination does not meet the corresponding condition, the partial discharge signal is discarded and a power-off command is sent to the power management unit; When the amplitude feature, the frequency feature, and the time domain feature sequentially satisfy the determination conditions, the partial discharge signal is determined to be a valid trigger signal.

[0048] S104. When the amplitude characteristics, frequency characteristics and time domain characteristics simultaneously meet the preset conditions, the preprocessing unit sends a wake-up pulse to the core detection unit and transmits the power distribution cabinet parameters and detection parameters pre-stored in the parameter cache pool to the core detection unit.

[0049] Among them, the preset conditions indicate that the amplitude characteristics, frequency characteristics, and time-domain characteristics simultaneously meet their respective judgment criteria. The wake-up pulse refers to the pulse signal sent by the preprocessing unit to the core detection unit via a hardware interrupt pin. The parameter buffer pool represents the pre-allocated storage area in the flash memory of the preprocessing unit. Distribution cabinet parameters refer to fixed data describing the hardware characteristics of the distribution cabinet, including the distribution cabinet model, rated voltage, and detection point coordinates. Detection parameters refer to adjustable parameters controlling the working state of the core detection unit, including the detector chip gain, microcontroller processing frequency, and communication mode.

[0050] Specifically, after all 3D feature determinations pass, the microcontroller in the preprocessing unit outputs a pulse signal via its hardware interrupt pin to trigger an external interrupt in the core detection unit. Simultaneously, the microcontroller initiates an SPI bus to read the power distribution cabinet parameters and detection parameters from the parameter buffer in the Flash memory, and transmits the parameter data to the SRAM of the core detection unit via the SPI bus. After the parameter transmission is complete, the preprocessing unit sends a start command to the intelligent power management unit, triggering the core detection unit's power supply channel to output voltage.

[0051] In some embodiments, wake-up and parameter transmission can be implemented in multiple ways. Optionally, the wake-up pulse uses a dual-pulse encoding method to distinguish between normal wake-up and emergency wake-up; parameter transmission uses DMA direct memory access to reduce CPU power consumption; and the parameter cache pool uses a circular buffer structure to store historical parameter sets. Optionally, the preprocessing unit reads the ready status signal of the core detection unit before sending the wake-up pulse; parameter transmission uses CRC cyclic redundancy check to ensure data correctness; and the power distribution cabinet parameters and detection parameters are transmitted separately to ensure the correct loading order.

[0052] In some embodiments, the preprocessing unit sends a wake-up pulse to the core detection unit via a hardware interrupt pin; While sending the wake-up pulse, the preprocessing unit reads the power distribution cabinet parameters and detection parameters from the parameter cache pool. The power distribution cabinet parameters and detection parameters are divided into a static parameter layer, a quasi-static parameter layer, and a dynamic parameter layer in the parameter cache pool. The preprocessing unit transmits the detection parameters and the version number of the quasi-static parameter layer as the first packet parameter to the core detection unit via the SPI bus; The core detection unit compares the version number with the version number stored locally. When the version number matches, it skips the transmission of the quasi-static parameter layer. When the version number does not match, it receives the quasi-static parameter layer transmitted by the preprocessing unit. The core detection unit immediately starts the detection function after receiving the first packet parameters; After the first packet parameter transmission is completed, the preprocessing unit will continue to transmit the dynamic parameter layer as the second packet parameter to the core detection unit via the SPI bus.

[0053] S105. After receiving the wake-up pulse, the core detection unit starts power supply, calls the received power distribution cabinet parameters and detection parameters, performs detection and pulse identification on the partial discharge signal, obtains the partial discharge detection result and transmits it.

[0054] The partial discharge signal detection refers to the process by which the core detection unit converts high-frequency partial discharge signals into intermediate-frequency signals using a superheterodyne detector circuit, and extracts signal features through peak envelope detection. The degree of partial discharge refers to the severity level of the discharge, determined by a comprehensive evaluation of parameters such as the amplitude, frequency, and energy of the detected discharge signal. The discharge type represents the discharge mode identified based on signal waveform characteristics and spectral distribution, including types such as corona discharge, surface discharge, and internal discharge.

[0055] Specifically, upon receiving a wake-up pulse, the core detection unit switches from low-power sleep mode to operating mode, and the intelligent power management unit activates the core detection unit's power supply channel. The microcontroller loads the power distribution cabinet parameters and detection parameters from SRAM, and configures the local oscillator frequency and gain level of the superheterodyne detector chip according to the detection parameters. The partial discharge signal continuously output by the passive sensing unit is down-converted into an intermediate frequency signal by the detector chip, and the signal envelope waveform is extracted by the envelope detector. The microcontroller samples the envelope waveform using a high-speed ADC, executes a peak statistical algorithm to calculate the signal amplitude, pulse repetition frequency, and discharge energy. The microcontroller performs pattern matching between the sampled data and the waveform feature library, determines the discharge type based on the matching result, and determines the discharge severity level by querying the discharge severity assessment table based on the amplitude and frequency.

[0056] In some embodiments, partial discharge signal detection can be achieved in multiple ways. Optionally, the superheterodyne detector chip adopts a dual-local oscillator mixing architecture, with the first local oscillator performing coarse frequency selection and the second local oscillator performing precise frequency tracking; the envelope detector uses synchronous detection to improve the sensitivity of weak signal detection; and the microcontroller uses a sliding window algorithm to statistically analyze the discharge pulse density in real time. Optionally, the core detection unit sets up a multi-channel parallel detection mechanism, with different channels corresponding to discharge signals in different frequency bands; the waveform feature library uses a neural network classifier to achieve adaptive pattern recognition; and the discharge degree assessment incorporates time series analysis to predict the discharge development trend.

[0057] Optionally, the detector chip performs automatic gain control before down-conversion to avoid signal saturation; the microcontroller synchronously records sampling timestamps to establish a time-series database during sampling; and a multi-feature fusion decision tree algorithm is used to improve the accuracy of discharge type identification. Optionally, the core detection unit continuously monitors signal quality indicators during detection and automatically adjusts detection parameters when the signal-to-noise ratio is below a threshold; fuzzy logic reasoning is used to handle boundary conditions for discharge degree assessment; and the detection results include a confidence parameter to characterize the reliability of the judgment.

[0058] In some embodiments, the core detection unit starts power supply after receiving the wake-up pulse, reads the detection parameters from the memory and directly writes them into the register configuration, skipping the initialization and calibration process; The core detection unit performs detection and pulse identification on the partial discharge signal based on the detection parameters, and calculates the discharge quantity. When the discharge amount reaches a preset discharge amount threshold, the core detection unit generates the partial discharge detection result and determines the transmission priority according to the relationship between the discharge amount and the emergency threshold: when the discharge amount reaches the emergency threshold, the partial discharge detection result is transmitted immediately; when the discharge amount is lower than the emergency threshold, the partial discharge detection result is stored and transmitted in batches. The core detection unit is set with a preset monitoring window. When no valid partial discharge signal is detected within the monitoring window, a hibernation command is triggered and the system returns to standby mode.

[0059] The following provides a more detailed description of the process of the method provided in this implementation. Please refer to [link / reference]. Figure 2 This is another flowchart illustrating the low-power wake-up method for the partial discharge detection device of the power distribution cabinet in this application embodiment.

[0060] S201. When the power distribution cabinet is in standby mode, the preprocessing unit and the core detection unit are in hibernation mode, and the passive sensing unit continuously monitors the partial discharge signal in the power distribution cabinet.

[0061] Among them, standby state indicates that the power distribution cabinet is operating normally but the detection device is not performing partial discharge detection tasks. Sleep state refers to the microcontrollers of the preprocessing unit and the core detection unit being in a low-power mode with the clock stopped, peripherals turned off, and power consumption kept to a minimum. Continuous monitoring indicates that the electromagnetic induction coil and piezoelectric sensor in the passive sensing unit are kept powered on, sensing electromagnetic and acoustic signals inside the power distribution cabinet in real time.

[0062] Specifically, when the distribution cabinet is in standby mode, the intelligent power management unit only supplies power to the passive sensing unit, while the power supply channels to the preprocessing unit and the core detection unit are turned off. The electromagnetic induction coil in the passive sensing unit senses changes in the high-frequency electromagnetic field inside the distribution cabinet through its magnetic core, while the piezoelectric sensor senses the ultrasonic vibration of the cabinet body through the piezoelectric effect. The electromagnetic induction coil outputs an induced voltage signal, and the piezoelectric sensor outputs a piezoelectric voltage signal; both signals are transmitted to the input of the level conversion circuit. The comparator inside the level conversion circuit continuously compares the input signal amplitude with a preset trigger threshold. When the signal amplitude is lower than the preset trigger threshold, the comparator output remains low, and no trigger signal is sent to the preprocessing unit.

[0063] S202. When the passive sensing unit detects that the amplitude of the partial discharge signal reaches the preset trigger threshold, it outputs a trigger signal to the preprocessing unit through the level conversion circuit.

[0064] The signal amplitude represents the peak voltage value of the analog voltage signal output by the passive sensing unit. The preset trigger threshold refers to a voltage judgment benchmark pre-set based on the rated voltage level of the distribution cabinet and the ambient noise level; for example, a 10 kV distribution cabinet might have a trigger threshold of 50 mV. The level conversion circuit represents the signal conditioning circuit, which includes a comparator, Schmitt trigger, and optocoupler. The trigger signal is a 3.3V high-level digital pulse output by the level conversion circuit to the GPIO interface of the preprocessing unit.

[0065] Specifically, when the passive sensing unit detects partial discharge within the distribution cabinet, the electromagnetic induction coil senses a high-frequency pulsed electromagnetic field and outputs a pulse voltage signal. A peak detector in the level conversion circuit captures the peak voltage value of the pulse, and a comparator compares this peak voltage value with a preset trigger threshold. When the peak voltage value reaches or exceeds the preset trigger threshold, the comparator output flips from low to high. The high-level signal is shaped into a standard digital pulse by a Schmitt trigger, and then electrically isolated by an optocoupler before being transmitted to the GPIO interrupt pin of the preprocessing unit. Upon detecting the rising edge interrupt signal on the GPIO pin, the microcontroller of the preprocessing unit triggers the interrupt service routine and simultaneously sends a start request to the intelligent power management unit to activate the preprocessing unit's power supply channel.

[0066] S203 The preprocessing unit amplifies the partial discharge signal through an amplification circuit, filters it through a bandpass filter, and extracts amplitude, frequency, and time domain features through a peak hold and a zero-crossing detector.

[0067] The amplifier circuit represents a non-inverting amplifier circuit built using a low-noise operational amplifier, with the gain set by the feedback resistor ratio. The bandpass filter is a frequency selection circuit composed of a cascaded high-pass and low-pass filter, with the passband set to the main frequency band of the partial discharge signal. The peak hold circuit represents a peak sample-and-hold circuit composed of diodes, capacitors, and an operational amplifier. The zero-crossing detector is a zero-crossing comparator circuit that converts an analog signal into a square wave signal. The amplitude characteristic represents the peak voltage of the signal captured by the peak hold circuit. The frequency characteristic refers to the dominant frequency and harmonic components calculated from the square wave signal output by the zero-crossing detector. The time-domain characteristic represents the rise time and pulse width parameters of the signal waveform.

[0068] Specifically, after the preprocessing unit starts, it reads the amplification gain parameters from the parameter buffer pool to configure the amplification circuit. The partial discharge signal is amplified by the amplification circuit according to the set gain and then input to the bandpass filter. The bandpass filter filters out 50 Hz power frequency interference and high-frequency noise, retaining the partial discharge signal in the 20 kHz to 200 kHz frequency band. The filtered output signal is processed in three paths. The first path is transmitted to the peak hold circuit, where the capacitor is quickly charged to the signal peak value through the charging diode and held. The operational amplifier buffers the output peak voltage and sends it to the ADC sampling channel. The second path is transmitted to the zero-crossing detector, where the comparator outputs a square wave signal at the zero-crossing point of the signal. The microcontroller's timer counts the square wave period to calculate the main frequency. The third path is transmitted to the differentiating circuit, where the comparator detects the rising edge time and the timer measures the pulse width. The microcontroller synchronously acquires the peak voltage, square wave period, rise time, and pulse width data to complete feature extraction.

[0069] S204. The preprocessing unit synchronously judges whether the amplitude characteristic reaches the preset amplitude threshold, whether the main frequency of the frequency characteristic is within the preset frequency range and whether the proportion of harmonic components is lower than the preset harmonic threshold, and whether the rise time and pulse width of the time domain characteristic are within the preset time domain range and whether the waveform is a non-periodic pulse.

[0070] The preset amplitude threshold represents the minimum peak voltage of the effective discharge signal set according to the insulation level of the distribution cabinet; for example, 100 millivolts for a 10 kV distribution cabinet. The preset frequency range refers to the upper and lower limits of the typical frequency band of the partial discharge signal, typically set to 30 kHz to 150 kHz. The harmonic component ratio represents the ratio of non-dominant frequency harmonic energy to the total energy in the signal spectrum. The preset harmonic threshold is the criterion for distinguishing the harmonic ratio of the partial discharge signal from periodic interference, typically set to 30%. The preset time domain range represents the reasonable range of rise time and pulse width for the effective partial discharge signal. An aperiodic pulse refers to a random pulse sequence with variable intervals between adjacent pulses.

[0071] Specifically, the preprocessing unit microcontroller reads the peak voltage output from the peak-hold circuit via the ADC and compares it with a preset amplitude threshold to determine if the amplitude characteristics meet the requirements. The microcontroller uses a timer to count the period of the square wave signal from the zero-crossing detector, calculates the dominant frequency value, and determines if the dominant frequency value is within a preset frequency range. The microcontroller performs a Fast Fourier Transform on the sampled waveform to calculate the spectral distribution, counts the energy of the dominant frequency component and all harmonic components, calculates the harmonic percentage, and compares it with a preset harmonic threshold. The microcontroller reads the timer values ​​from the rising edge detection circuit and the pulse width measurement circuit to determine if the rising edge time and pulse width are within a preset time domain range. The microcontroller counts the interval time of 10 consecutive pulses, calculates the standard deviation of the interval time, and determines a non-periodic pulse when the standard deviation is greater than 20% of the mean. The microcontroller performs a logical AND operation on the amplitude, frequency, and time domain results to obtain a comprehensive judgment result.

[0072] S205. When the amplitude characteristics, frequency characteristics and time domain characteristics simultaneously meet the judgment conditions, the partial discharge signal is determined to be a valid trigger signal, and the wake-up process is initiated.

[0073] The judgment criteria consist of a three-dimensional combination of factors: the amplitude characteristic reaches a preset amplitude threshold, the frequency characteristic's dominant frequency is within a preset frequency range and the harmonic proportion is below a preset harmonic threshold, and the rise time and pulse width of the time domain characteristic are within a preset time domain range and the waveform is a non-periodic pulse. A valid trigger signal refers to a voltage pulse that is verified as a genuine partial discharge signal through the three-dimensional criteria. The wake-up process represents the complete sequence of operations from the preprocessing unit to the core detection unit, including sending a wake-up pulse, transmitting parameters, and initiating power supply.

[0074] Specifically, the preprocessing unit microcontroller stores the amplitude characteristic determination result, frequency characteristic determination result, and time domain characteristic determination result in three Boolean variables. The microcontroller performs a logical AND operation on the three Boolean variables, and determines that the partial discharge signal meets all the determination conditions when all three variables are true. The microcontroller sets the valid trigger flag to true and starts the wake-up process state machine. The state machine first enters the parameter preparation state to read the power distribution cabinet parameters and detection parameters from the Flash memory, then enters the wake-up signal sending state to output pulses through the hardware interrupt pin, and finally enters the parameter transmission state to transmit parameter data through the SPI bus. During the execution of the state machine, the microcontroller monitors the timeout timer of each state. When the execution time of a certain state exceeds the preset timeout time, the state machine returns to the initial state and records the error code.

[0075] S206. When the amplitude characteristics, frequency characteristics and time domain characteristics simultaneously meet the preset conditions, the preprocessing unit sends a wake-up pulse to the core detection unit through the hardware interrupt pin.

[0076] S207. After sending the wake-up pulse, the preprocessing unit reads the power distribution cabinet parameters and detection parameters from the parameter buffer pool. The power distribution cabinet parameters include the power distribution cabinet model, rated voltage, and detection point coordinates. The detection parameters include the detector chip gain, microcontroller processing frequency, and communication mode.

[0077] S208 The preprocessing unit transmits the power distribution cabinet parameters and detection parameters to the SRAM of the core detection unit via the SPI bus.

[0078] The SPI bus represents the serial peripheral interface bus where the preprocessing unit acts as the master device and the core detection unit acts as the slave device. It includes four signal lines: clock (SCK), master-slave input (MOSI), master-slave output (MISO), and chip select (CS). Transmission refers to the process by which the preprocessing unit sends parameter data byte-by-byte to the core detection unit via the SPI bus according to the protocol timing. SRAM represents the static random access memory inside the core detection unit's microcontroller, with a 512-byte area allocated starting at address 0x20000000 for receiving parameter data.

[0079] Specifically, the preprocessing unit microcontroller is configured with the SPI controller in master mode, setting the clock frequency to 1 MHz, clock polarity to low-level idle, and clock phase to first-edge sampling. The microcontroller pulls the CS chip select signal low to select the core detection unit and writes the first byte of power distribution cabinet model data into the SPI data register to initiate transmission. The SPI controller outputs 8 clock pulses on the SCK clock line, and the MOSI line outputs data bits on each rising edge of the clock. The core detection unit SPI controller samples the MOSI line data bits on the falling edge of the clock to receive byte data and stores the received byte in SRAM address 0x20000000. The preprocessing unit microcontroller cyclically writes subsequent parameter bytes, automatically incrementing the SRAM storage address after each byte is transmitted. After all parameter data transmissions are complete, the preprocessing unit pulls the CS chip select signal high to end transmission, and the core detection unit performs a CRC16 check on the received data to confirm data integrity.

[0080] S209. After receiving the wake-up pulse, the core detection unit starts power supply and completes the initialization of the microcontroller, detection module and wireless communication module.

[0081] The "Power-on startup" function indicates that after receiving the startup request from the core detection unit, the intelligent power management unit activates the LDO regulator to output 3.3 volts to the core detection unit's power supply pin. "Initialization" refers to the sequence of configuration operations executed after the microcontroller, detection module, and wireless communication module are powered on. Microcontroller initialization includes clock configuration, GPIO configuration, timer configuration, and ADC configuration. Detector module initialization includes setting the local oscillator frequency, gain, and filter of the superheterodyne detector chip. Wireless communication module initialization includes setting the frequency point, spreading factor, and transmit power of the LoRa chip.

[0082] Specifically, after the power supply pin voltage of the core detection unit rises to 3.3 volts, the microcontroller's reset pin is released, and the microcontroller exits the reset state and begins executing the startup code. The microcontroller first configures the system clock to multiply the internal RC oscillator to 72 MHz. Then, it configures the GPIO pins to set the detector module control pin to push-pull output, the ADC sampling pin to analog input, and the wireless communication module SPI pin to multiplexed function. The microcontroller configures Timer 1 to free-running mode for timestamp generation, and configures the ADC to 12-bit resolution and a sampling time of 1.5 microseconds. The microcontroller writes an initialization register to the superheterodyne detector chip via the SPI bus, setting the local oscillator frequency to 100 MHz, gain to 0 dB, and intermediate frequency bandwidth to 200 kHz. The microcontroller also writes a configuration register to the LoRa chip via the SPI bus, setting the frequency to 470 MHz, spreading factor to 7, and transmit power to 20 dBmW.

[0083] S210: The core detection unit retrieves detection parameters from the SRAM and configures the detection module and data processing module according to the detection parameters.

[0084] The "call" option indicates that the core detection unit microcontroller reads detection parameter data from SRAM address 0x20000000 via address access. "Configuring the detection module" refers to writing the detection chip gain control register via the SPI bus according to the gain level of the detection chip in the detection parameters. "Configuring the data processing module" refers to adjusting the microcontroller system clock frequency according to the microcontroller processing frequency in the detection parameters and selecting whether to enable the LoRa or NB-IoT module according to the communication mode parameters.

[0085] Specifically, the core detection unit microcontroller reads 1 byte of gain level data from SRAM address 0x20000014, with a value ranging from 0 to 7 corresponding to a gain of 0 to 42 dB. The microcontroller writes the gain level value to the gain control register of the superheterodyne detector chip via the SPI bus, and the programmable gain amplifier inside the detector chip adjusts the amplification factor according to the register value. The microcontroller reads 4 bytes of microcontroller processing frequency data from SRAM address 0x20000015, and adjusts the system clock to the target frequency by configuring the PLL frequency multiplication factor according to the frequency value. The microcontroller reads 1 byte of communication mode enumeration value from SRAM address 0x20000019. When the enumeration value is 0, the LoRa chip is initialized and the NB-IoT module power supply is turned off; when the enumeration value is 1, the NB-IoT module is initialized and the LoRa chip power supply is turned off.

[0086] S211 The detection module performs detection processing on the partial discharge signal according to the detection parameters and converts the partial discharge signal into a DC voltage signal.

[0087] In this context, "detection processing" refers to the process by which the superheterodyne detector chip converts a high-frequency partial discharge signal to an intermediate frequency signal via frequency mixing and downconversion, and then extracts the signal amplitude envelope through envelope detection. The partial discharge signal refers to a high-frequency pulse signal with a frequency range of 20 kHz to 200 kHz output from the passive sensing unit. The DC voltage signal refers to a low-frequency DC voltage output from the envelope detector, proportional to the amplitude envelope of the partial discharge signal, with a voltage range of 0 to 3.3 volts. "Conversion" refers to the signal form transformation process of the DC voltage signal output after the high-frequency pulse signal undergoes detection processing.

[0088] Specifically, the partial discharge signal output by the passive sensing unit is transmitted to the mixer of the superheterodyne detector chip via the RF input pin. The mixer multiplies the partial discharge signal with the local oscillator signal to generate sum and difference frequency components. The intermediate frequency (IF) filter removes the sum frequency component and retains the difference frequency component to obtain the IF signal. The IF signal is amplified by the IF amplifier according to the configured gain and then transmitted to the envelope detector. The envelope detector uses a diode peak detection circuit. The charging diode charges the load capacitor to its peak voltage during the positive half-cycle of the IF signal, while the discharge resistor slowly discharges the capacitor during the negative half-cycle. The voltage across the load capacitor follows the envelope change of the IF signal to form a low-frequency envelope signal. A low-pass filter removes residual IF ripple and outputs a smooth DC voltage signal. The DC voltage signal is transmitted to the ADC input pin of the core detection unit microcontroller via a buffer amplifier.

[0089] S212 The data processing module calculates the discharge quantity based on the DC voltage signal. When the discharge quantity reaches the preset discharge quantity threshold, it generates a partial discharge detection result.

[0090] The data processing module refers to the software function module within the core detection unit's microcontroller that performs data acquisition, calculation, and analysis. Calculating the discharge quantity refers to obtaining the apparent discharge quantity of partial discharge from the DC voltage signal amplitude using a calibration formula, measured in picocoulombs. The formula for calculating the apparent discharge quantity is Q = K × V × C, where Q is the apparent discharge quantity, K is the calibration coefficient, V is the DC voltage signal amplitude, and C is the equivalent capacitance. The preset discharge quantity threshold represents the lower limit of the apparent discharge quantity required for recording partial discharge, typically set to 100 picocoulombs. The partial discharge detection result refers to a data structure containing a timestamp, discharge quantity, discharge type, and detection point coordinates.

[0091] Specifically, the data processing module initiates ADC conversion to sample the DC voltage signal, with the ADC continuously acquiring 1024 sampling points at 1 microsecond sampling intervals. The microcontroller executes a peak search algorithm on the sampled data to find the maximum sampled value as the DC voltage signal amplitude V. The microcontroller reads the equivalent capacitance C value from the distribution cabinet parameters from SRAM and the factory calibration coefficient K value from Flash, calculating the apparent discharge quantity Q = K × V × C. The microcontroller compares the calculated apparent discharge quantity Q with a preset discharge quantity threshold; when Q reaches or exceeds the threshold, the detection result generation process is triggered. The microcontroller reads the current timestamp from the timer, reads the detection point coordinates from SRAM, and calls the discharge type identification algorithm to determine the discharge type based on waveform characteristics. The microcontroller packages the timestamp, discharge quantity, discharge type, and detection point coordinates into a detection result data structure and stores it in the result buffer.

[0092] S213. When the discharge amount is not lower than the emergency threshold, the partial discharge detection results are transmitted within a first preset time period. When the discharge amount is lower than the emergency threshold, the partial discharge detection results are transmitted in batches within a second preset time period. The second preset time period is longer than the first preset time period.

[0093] The emergency threshold represents the critical discharge quantity required for immediate reporting of partial discharge, typically set to 1000 picocoulombs. The first preset time period is the interval between detecting an emergency discharge and immediately initiating wireless transmission, set to 1 second. Batch transmission refers to the method of packaging multiple detection results into a single data frame for transmission. The second preset time period is the transmission cycle for non-emergency discharges using batch transmission mode, set to 300 seconds. Transmission refers to the process of sending the detection result data to the cloud platform via a LoRa or NB-IoT wireless communication module.

[0094] Specifically, the data processing module compares the calculated discharge quantity Q with an emergency threshold to determine the severity of the discharge. When the discharge quantity Q is greater than or equal to the emergency threshold, the microcontroller sets the emergency transmission flag to true and starts a timer with a delay time of 1 second (the first preset time period). After the timer expires, the microcontroller reads the current detection result from the result buffer and calls the wireless transmission module to immediately send the single detection result. When the discharge quantity Q is lower than the emergency threshold, the microcontroller appends the detection result to the batch transmission buffer, and the batch transmission timer continues to count down. The batch transmission timer triggers a transmission every 300 seconds (the second preset time period). The microcontroller reads all detection results from the batch transmission buffer, packages them into a single data frame, calls the wireless transmission module to send it, and then clears the buffer. The wireless transmission module selects either the LoRa or NB-IoT interface according to the communication mode parameters, encapsulates the data frame according to the communication protocol format, and sends it to the cloud platform receiver via radio frequency.

[0095] In some embodiments, the system preprocessing unit stores the amplitude characteristics, frequency characteristics, time domain characteristics, and determination results of each triggered event into a historical record cache. The preprocessing unit calculates the false trigger rate in the historical record cache according to a preset period. When the false trigger rate is higher than a preset false trigger threshold, the preset amplitude threshold is increased and the preset frequency range is narrowed or the preset time domain conditions are tightened. When the effective trigger rate is lower than a preset effective trigger threshold, the preset amplitude threshold is decreased and the preset frequency range is expanded or the preset time domain conditions are relaxed.

[0096] In some embodiments, the preprocessing unit returns to standby mode when any of the amplitude characteristics, frequency characteristics, and time domain characteristics does not meet a preset condition.

[0097] The partial discharge detection device for the power distribution cabinet in the embodiments of this invention is described below from the perspective of hardware processing. Please refer to [link / reference needed]. Figure 3This is a schematic diagram of the physical device structure of a partial discharge detection device for a distribution cabinet in this application embodiment.

[0098] It should be noted that, Figure 3 The structure of the partial discharge detection device for the distribution cabinet shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0099] like Figure 3 As shown, the partial discharge detection device for the distribution cabinet includes a Central Processing Unit (CPU) 301, which can perform various appropriate actions and processes according to a program stored in a Read-Only Memory (ROM) 302 or a program loaded from a storage section 308 into a Random Access Memory (RAM) 303, such as performing the methods described in the above embodiments. The RAM 303 also stores various programs and data required for system operation. The CPU 301, ROM 302, and RAM 303 are interconnected via a bus 304. An Input / Output (I / O) interface 305 is also connected to the bus 304.

[0100] The following components are connected to I / O interface 305: input section 306 including audio input devices, push-button switches, etc.; output section 307 including a liquid crystal display (LCD) and audio output devices, indicator lights, etc.; storage section 308 including a hard disk, etc.; and communication section 309 including a network interface card such as a LAN (Local Area Network) card, modem, etc. Communication section 309 performs communication processing via a network such as the Internet. Drive 310 is also connected to I / O interface 305 as needed. Removable media 311, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 310 as needed so that computer programs read from them can be installed into storage section 308 as needed.

[0101] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing computer programs for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 309, and / or installed from removable medium 311. When the computer program is executed by central processing unit (CPU) 301, it performs the various functions defined in the present invention.

[0102] It should be noted that specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0103] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. Each block in a flowchart or block diagram may represent a module, program segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those shown in the drawings.

[0104] Specifically, the partial discharge detection device for the distribution cabinet in this embodiment includes a processor and a memory. The memory stores a computer program. When the computer program is executed by the processor, it implements the low-power wake-up method for the partial discharge detection device for the distribution cabinet provided in the above embodiment.

[0105] In another aspect, the present invention also provides a computer-readable storage medium, which may be included in the partial discharge detection device for the distribution cabinet described in the above embodiments; or it may exist independently and not assembled into the partial discharge detection device for the distribution cabinet. The storage medium carries one or more computer programs, which, when executed by a processor of the partial discharge detection device for the distribution cabinet, cause the partial discharge detection device for the distribution cabinet to implement the low-power wake-up method for the partial discharge detection device for the distribution cabinet provided in the above embodiments.

[0106] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0107] As used in the above embodiments, depending on the context, the term "when..." can be interpreted as meaning "if...", "after...", "in response to determining...", or "in response to detecting...". Similarly, depending on the context, the phrase "when determining..." or "if (the stated condition or event) is interpreted as meaning "if determining...", "in response to determining...", "when (the stated condition or event) is detected", or "in response to detecting (the stated condition or event)".

[0108] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM or random access memory (RAM), magnetic disks, or optical disks.

Claims

1. A low-power wake-up method for a power distribution cabinet partial discharge detection device, characterized in that, The application is applied to power distribution cabinet partial discharge detection equipment, the power distribution cabinet partial discharge detection equipment includes passive induction unit, preprocessing unit and core detection unit, the passive induction unit is connected with the general input and output interface of the preprocessing unit through the level conversion circuit, the preprocessing unit is connected with the core detection unit through the hardware interrupt pin, and the method comprises: When the power distribution cabinet is in standby state, the preprocessing unit and the core detection unit are in dormant state, and the passive induction unit continuously monitors the partial discharge signal in the power distribution cabinet; When the passive induction unit detects that the signal amplitude of the partial discharge signal reaches the preset trigger threshold, the trigger signal is output to the preprocessing unit through the level conversion circuit; The preprocessing unit amplifies and filters the partial discharge signal to obtain amplitude characteristics, frequency characteristics and time domain characteristics, and judges whether the amplitude characteristics reach the preset amplitude threshold, whether the frequency characteristics are within the preset frequency range and whether the time domain characteristics meet the preset time domain condition; When the amplitude characteristics, the frequency characteristics and the time domain characteristics meet the preset conditions at the same time, the preprocessing unit sends a wake-up pulse to the core detection unit, and transmits the power distribution cabinet parameters and detection parameters pre-stored in the parameter cache pool to the core detection unit; The core detection unit starts power supply after receiving the wake-up pulse, calls the received power distribution cabinet parameters and detection parameters, detects the partial discharge signal, obtains the partial discharge detection result and transmits it.

2. The method of claim 1, wherein, The step that the preprocessing unit amplifies and filters the partial discharge signal to obtain amplitude characteristics, frequency characteristics and time domain characteristics, and judges whether the amplitude characteristics reach the preset amplitude threshold, whether the frequency characteristics are within the preset frequency range and whether the time domain characteristics meet the preset time domain condition, specifically comprises: The preprocessing unit amplifies the partial discharge signal through the amplification circuit, filters it through the band-pass filter, and extracts the amplitude characteristics, the frequency characteristics and the time domain characteristics through the peak value holder and the zero-crossing detector; The preprocessing unit synchronously judges whether the amplitude characteristics reach the preset amplitude threshold, whether the main frequency of the frequency characteristics is within the preset frequency range and whether the harmonic component ratio is lower than the preset harmonic threshold, whether the rising edge time and the pulse width of the time domain characteristics are within the preset time domain range and whether the waveform is a non-periodic pulse; When the amplitude characteristics, the frequency characteristics and the time domain characteristics meet the judgment conditions at the same time, it is judged that the partial discharge signal is an effective trigger signal, and the wake-up process is entered.

3. The method of claim 1, wherein, The step that the preprocessing unit sends a wake-up pulse to the core detection unit and transmits the power distribution cabinet parameters and detection parameters pre-stored in the parameter cache pool to the core detection unit, specifically comprises: The preprocessing unit sends a wake-up pulse to the core detection unit through the hardware interrupt pin; The preprocessing unit reads the power distribution cabinet parameters and detection parameters from the parameter cache pool after sending the wake-up pulse, the power distribution cabinet parameters including power distribution cabinet model, rated voltage and detection point coordinates, and the detection parameters including wave detection chip gain, single-chip processor processing frequency and communication mode; The preprocessing unit transmits the power distribution cabinet parameters and detection parameters to the SRAM of the core detection unit through the SPI bus.

4. The method of claim 3, wherein, After receiving the wake-up pulse, the core detection unit starts power supply, calls the received power distribution cabinet parameters and detection parameters, detects and identifies the partial discharge signal, obtains the partial discharge detection result and transmits it, which specifically includes: After receiving the wake-up pulse, the core detection unit starts power supply, completes the initialization of the single-chip processor, wave detection module and wireless communication module; The core detection unit calls the detection parameters from the SRAM, and configures the wave detection module and data processing module according to the detection parameters; The wave detection module detects the partial discharge signal according to the detection parameters, and converts the partial discharge signal into a direct current voltage signal; The data processing module calculates the discharge amount according to the direct current voltage signal, and generates the partial discharge detection result when the discharge amount reaches the preset discharge amount threshold; The wireless communication module performs hierarchical transmission according to the discharge amount.

5. The method of claim 4, wherein, The step of the wireless communication module performing hierarchical transmission according to the discharge amount specifically includes: When the discharge amount is not less than the emergency threshold, the wireless communication module transmits the partial discharge detection result within a first preset time period; When the discharge amount is less than the emergency threshold, the wireless communication module transmits the partial discharge detection result in batches within a second preset time period, and the second preset time period is greater than the first preset time period.

6. The method of claim 1, wherein, After the step of detecting and identifying the partial discharge signal to obtain the partial discharge detection result and transmission, the method further includes: The preprocessing unit stores the amplitude feature, frequency feature, time domain feature and judgment result of each triggering event to the historical record cache; The preprocessing unit calculates the false triggering rate in the historical record cache according to a preset period, increases the preset amplitude threshold and narrows the preset frequency range or tightens the preset time domain condition when the false triggering rate is higher than a preset false triggering threshold; When the effective triggering rate is lower than a preset effective triggering threshold, the preset amplitude threshold is reduced and the preset frequency range is expanded or the preset time domain condition is relaxed.

7. The method of claim 1, wherein, After the step of detecting and identifying the partial discharge signal to obtain the partial discharge detection result and transmission, the method further includes: When any of the amplitude feature, frequency feature and time domain feature does not meet the preset condition, the preprocessing unit returns to standby state.

8. A power distribution cabinet partial discharge detection apparatus, characterized by, The power distribution cabinet partial discharge detection device comprises one or more processors and a memory; the memory is coupled with the one or more processors, the memory is configured to store computer program codes, the computer program codes comprise computer instructions, and the one or more processors invoke the computer instructions to enable the power distribution cabinet partial discharge detection device to perform the method in any one of claims 1-7.

9. A computer-readable storage medium comprising instructions, characterized in that, When the instructions run on the power distribution cabinet partial discharge detection device, the power distribution cabinet partial discharge detection device is enabled to perform the method in any one of claims 1-7.

10. A computer program product, characterised in that, When the computer program product runs on the power distribution cabinet partial discharge detection device, the power distribution cabinet partial discharge detection device is enabled to perform the method in any one of claims 1-7.

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