Lightning arrester dynamic monitoring recorder

Abstract

The invention belongs to the technical field of power equipment monitoring, and particularly relates to a dynamic monitoring recorder for a lightning arrester, which comprises a high-precision leakage current measurement module for measuring the total leakage current flowing through the grounding end of the lightning arrester; the high-bandwidth impulse current measurement module is used for accurately capturing the transient impulse current waveform flowing through the lightning arrester when an overvoltage event occurs; the high-bandwidth residual voltage measurement module is used for synchronously measuring transient residual voltage waveforms at the two ends of the lightning arrester when the impact current passes through the lightning arrester; the high-precision power frequency voltage measurement module is used for accurately measuring the power frequency voltage of a power grid where the lightning arrester is located; and the environmental parameter measurement module is used for monitoring key parameters of the operating environment of the lightning arrester in real time. By arranging a high-precision leakage current measurement module, a high-bandwidth impact current measurement module, a high-bandwidth residual voltage measurement module, a high-precision power frequency voltage measurement module and an environment parameter measurement module, various key parameters in the operation of the lightning arrester can be collected at the same time.

Description

Technical Field

[0001] This invention belongs to the field of power equipment monitoring technology, specifically a surge arrester dynamic monitoring recorder. Background Technology

[0002] In modern power systems, the stable operation of transmission and transformation facilities is the core guarantee for reliable power supply. Surge arresters, as critical overvoltage protection devices, can limit the voltage that the insulation of protected equipment can withstand under transient abnormal voltages such as lightning overvoltages and switching overvoltages, and dissipate overvoltage energy to the ground, thereby protecting power assets such as generating equipment, transmission lines, and transformers. Therefore, continuous and accurate monitoring and diagnosis of surge arrester operating status is crucial for improving power grid reliability, providing early warning of potential faults, optimizing maintenance strategies, and extending equipment lifespan. The power industry's monitoring methods for surge arresters have gradually evolved from offline to online. Early assessments primarily relied on periodic power outages for maintenance, visual inspections, and discharge counters. However, discharge counters only record the number of actions and cannot provide quantitative information such as overvoltage amplitude, duration, and internal performance degradation, limiting their diagnostic value. To achieve real-time monitoring, online monitoring technology based on leakage current became mainstream. Initially, operating status was determined by measuring the total leakage current. However, the large capacitive component in the total current masks the weak resistive component reflecting internal varistor deterioration or moisture absorption. Measurement results are also susceptible to interference from power supply voltage fluctuations and ambient temperature changes, making it difficult to accurately reflect internal defects. Subsequently, monitoring methods based on third harmonic analysis were introduced. By separating the fundamental capacitive component and analyzing the third harmonic resistive component, detection sensitivity is improved, leading to widespread application in online monitoring of power transmission and transformation surge arresters. With the increasing complexity of power system structures, the rise in high-voltage equipment, and the growing demands for power supply reliability, monitoring technology based on third harmonic resistive leakage current is gradually revealing its limitations. Firstly, the measurement results are sensitive to subtle fluctuations in ambient temperature and system voltage. Power system voltage distortion can easily lead to difficulties in distinguishing whether changes in resistive current are caused by equipment degradation or external disturbances, potentially resulting in false alarms or missed alarms. Secondly, this technology is an indirect diagnostic method operating under steady-state or slowly varying conditions, unable to directly and with high resolution capture the dynamic response characteristics of surge arresters under overvoltage, making it difficult to assess the actual protection performance of equipment under extreme conditions. Thirdly, existing monitoring systems lack the ability to perform high-precision synchronous sampling and correlation analysis of parameters such as leakage current and ambient temperature. When an impulse current event occurs, it is impossible to effectively integrate the impulse current waveform, residual voltage waveform, and relevant parameters before and after the impulse. Data fragmentation makes it difficult to deeply analyze fault mechanisms, accurately determine failure modes, and comprehensively evaluate the performance change trend and remaining life of surge arresters under transient overvoltage from multiple dimensions. Therefore, this invention provides a surge arrester dynamic monitoring recorder. Summary of the Invention

[0003] In order to overcome the shortcomings of the prior art, at least one technical problem raised in the background art is solved.

[0004] The technical solution adopted by this invention to solve its technical problem is as follows: A surge arrester dynamic monitoring recorder of this invention includes a high-precision leakage current measurement module, a high-bandwidth impulse current measurement module, a high-bandwidth residual voltage measurement module, a high-precision power frequency voltage measurement module, an environmental parameter measurement module, a multi-channel synchronous data acquisition and processing unit, a data storage module, a communication and remote interface module, and a power supply module. Data transmission and energy supply between the modules are achieved through specific electrical or fiber optic links.

[0005] The high-precision leakage current measurement module is used to measure the total leakage current flowing through the grounding terminal of the surge arrester. This module includes a non-contact current sensor and a current signal conditioning circuit. The non-contact current sensor preferably uses a current transformer based on the Rogowski coil principle, which has a wide frequency response, high linearity, and excellent insulation performance, enabling it to accurately capture leakage current components from the fundamental frequency to higher harmonics. The Rogowski coil is installed by wrapping around the grounding lead of the surge arrester, and its output signal is a voltage signal proportional to the rate of change of current. The current signal conditioning circuit includes a preamplifier integrating a high input impedance operational amplifier and a precision integrator circuit. This preamplifier converts the output voltage signal of the Rogowski coil into a voltage signal proportional to the amplitude of the leakage current, and performs preliminary gain adjustment and low-pass filtering to suppress high-frequency noise interference. The bandwidth of this conditioning circuit covers DC to 100kHz, and its dynamic range is designed to accurately measure leakage current from microamperes to amperes, with a nonlinearity of less than 0.1%.

[0006] The high-bandwidth impulse current measurement module is used to accurately capture the transient impulse current waveform flowing through a surge arrester during overvoltage events. This module also employs an impulse current transformer based on the Rogowski coil principle, but its design is optimized for high di / dt characteristics, resulting in a wider frequency response (e.g., from 100Hz to 5MHz) and a higher upper limit for transient current measurement (e.g., up to 200kA). The impulse current transformer is shared with or independently mounted on the surge arrester's grounding lead, and connected to a high-bandwidth current signal conditioning circuit via a dedicated shielded cable. The high-bandwidth current signal conditioning circuit includes an ultra-low noise, high common-mode rejection ratio differential amplifier and an integrator circuit composed of a high-speed operational amplifier. The bandwidth response of this integrator circuit is specially designed to ensure accurate reproduction of the impulse current waveform while avoiding integration drift in the low-frequency range. The conditioning circuit provides multi-level gain adjustment to accommodate impulse currents of different amplitudes. Its output signal is an analog voltage signal proportional to the instantaneous value of the impulse current, with output impedance matching suitable for high-speed analog-to-digital converter input.

[0007] A high-bandwidth residual voltage measurement module is used to simultaneously measure the transient residual voltage waveform across the surge arrester when an impulse current passes through it. This module includes a high-voltage sensor and a residual voltage signal conditioning circuit. The high-voltage sensor preferably employs a high-precision RC divider or a purely resistive divider, exhibiting excellent linearity, temperature stability, and an extremely wide frequency response (e.g., from DC to 5MHz). The high-voltage sensor is installed close to the surge arrester terminals and electrically connected to the arrester via a high-voltage cable. The residual voltage signal conditioning circuit includes a high-input-impedance, high common-mode rejection ratio (CMRR) differential amplifier to receive the voltage-divided output signal from the high-voltage sensor and adjust it to an input voltage range acceptable to the analog-to-digital converter. The differential amplifier in this conditioning circuit has an input impedance as high as 10¹² ohms and a CMRR exceeding 80 dB at 100 kHz, effectively suppressing common-mode interference and ensuring signal transmission accuracy. Meanwhile, the residual voltage signal conditioning circuit also integrates a precision temperature sensor, which can monitor the internal temperature of the module in real time and accurately compensate for the drift of the high-voltage sensor and circuit caused by temperature changes through digital algorithms, further improving the stability of residual voltage measurement. If the high-voltage sensor uses a resistive-capacitive voltage divider, its high-voltage arm consists of a series high-voltage thick-film resistor and a precision high-voltage capacitor, while the low-voltage arm consists of a precision resistor and a capacitor, to achieve a constant voltage division ratio over a wide bandwidth. If a pure resistive voltage divider is used, it achieves extremely low parasitic inductance and capacitance by using multiple series high-voltage non-inductive resistors and optimizing the resistive material and geometry, ensuring that different types of high-voltage sensors can meet the high-precision requirements of residual voltage measurement. The high-precision power frequency voltage measurement module is used to accurately measure the power frequency voltage of the power grid where the surge arrester is located, providing a voltage reference for leakage current analysis and surge arrester operation status assessment. This module employs a high-precision voltage sensor, combined with a low-noise, high-linearity signal conditioning circuit, to achieve accurate acquisition of the power frequency voltage amplitude and phase, with measurement errors controlled within 0.5%. It also possesses good anti-interference capabilities and can adapt to fluctuations in the power grid voltage. The environmental parameter measurement module is used to monitor key parameters of the surge arrester's operating environment in real time, including ambient temperature, humidity, and atmospheric pressure. The module incorporates multiple high-precision environmental sensors, and amplifies and filters the weak signals output by the sensors through a dedicated signal conditioning circuit before transmitting them to subsequent units. The measurement data is updated at a frequency of no less than once per minute, providing a reliable basis for analyzing the impact of environmental factors on the surge arrester's performance and for correcting measurement data. The multi-channel synchronous data acquisition and processing unit is the core control unit of the entire recorder, mainly composed of a high-speed analog-to-digital converter, a data preprocessor and digital signal processor / field-programmable gate array, and a high-precision time synchronization unit. The high-speed analog-to-digital converter employs a 16-bit, 18-bit, or 20-bit multi-channel parallel synchronous sampling method at 1 megaseconds / second for the output signals of the impulse current and residual voltage measurement modules. All analog-to-digital converters are triggered by a unified sampling clock, ensuring nanosecond or even picosecond-level time synchronization accuracy between channels. In the data preprocessing and digital signal processor / field-programmable gate array (FPGA) stages, the FPGA is responsible for precise sampling timing control, data buffering, real-time digital filtering, data format conversion, and hardware-accelerated event detection algorithms. The FPGA handles complex signal processing tasks, including performing a fast Fourier transform on the leakage current, calculating the amplitude, phase, and total harmonic distortion (THD) of the fundamental frequency and characteristic harmonics; extracting characteristic parameters such as peak value, wavefront time, wave tail time, and energy integral from the impulse current and residual voltage waveforms, and identifying high-frequency oscillations and local distortions in the waveforms through wavelet transform; aligning residual voltage and impulse current data in real time, calculating dynamic volt-ampere characteristic curves to evaluate the surge arrester's energy absorption capacity and protection margin; and performing real-time temperature compensation on all measurement data by combining temperature data from the environmental parameter measurement module and pre-stored calibration coefficients. The high-precision time synchronization unit integrates a GPS-disciplined oscillator, using precise time protocol or network time protocol signals provided by GPS satellites to discipline the internal high-precision oven-controlled crystal oscillator, achieving nanosecond or even sub-nanosecond time synchronization accuracy. All acquired data includes a calibrated, precise timestamp. In addition, digital signal processors / field programmable gate arrays can also trigger transient events at the millisecond or even microsecond level based on preset current peak, residual voltage peak, current change rate, voltage change rate or specific waveform characteristics. After triggering, they can automatically record high-sampling-rate raw data within a certain time window before and after the trigger point (such as 200 microseconds before triggering and 800 microseconds after triggering). The data storage module employs high-reliability industrial-grade solid-state drives or large-capacity flash memory, featuring error correction codes to securely store raw data, processed feature data, event records, and system logs. The module incorporates a large-capacity double-rate synchronous dynamic random access memory (DRAM) as a high-speed cache, specifically designed to temporarily store high-sampling-rate raw waveform data before and after transient events, preventing data loss. Simultaneously, an integrated hardware encryption chip or the Advanced Encryption Standard-256 (AES-256) encryption algorithm encrypts the stored data to ensure data security. The communication and remote interface module supports 100 / 1000 Mbps Ethernet, 4G / 5G cellular communication, RS485 / RS232 interfaces, and Wi-Fi / Bluetooth modules, enabling flexible data exchange with local monitoring equipment and remote monitoring centers. This module also features remote firmware upgrade capabilities, allowing for system firmware updates without on-site intervention, thus reducing maintenance costs. The power supply module supports a wide range of AC input from 85V to 265V or DC input from 12V / 24V / 48V. It employs a high-efficiency, industrial-grade isolated power supply module to provide stable voltage to all modules in the system. The module incorporates a large-capacity lithium iron phosphate battery pack, which, together with an intelligent battery management system, forms a backup power supply system, ensuring continuous system operation during external power outages. Simultaneously, it integrates comprehensive surge protection, transient suppression diodes, and electromagnetic interference / electromagnetic compatibility (EMC) filtering circuits to effectively resist external electromagnetic interference and voltage surges, ensuring power supply stability. The entire surge arrester dynamic monitoring recorder adopts an integrated, modular hardware design. The shell is made of IP67-rated die-cast aluminum alloy or stainless steel, which has good waterproof, dustproof and corrosion-resistant properties. All wiring ports use industrial-grade aviation plugs or waterproof connectors, which further improves the system's environmental adaptability and can meet the installation and use requirements of different outdoor power transmission and transformation scenarios.

[0008] The beneficial effects of this invention are as follows: 1. This invention discloses a surge arrester dynamic monitoring recorder, which, by setting up high-precision leakage current, high-bandwidth impulse current, high-bandwidth residual voltage, high-precision power frequency voltage, and environmental parameter measurement modules, can simultaneously collect multiple key parameters of the surge arrester during operation. Utilizing a unified clock trigger and high-precision time synchronization design in the multi-channel synchronous data acquisition and processing unit, it ensures precise alignment of each parameter in the time dimension, solving the data fragmentation problem of traditional monitoring systems. Simultaneously, through temperature compensation, high common-mode rejection ratio circuits, and precision component selection, each module significantly improves measurement accuracy, providing comprehensive and reliable data support for surge arrester condition assessment and effectively avoiding misjudgments caused by monitoring a single parameter or data asynchrony.

[0009] 2. This invention provides a surge arrester dynamic monitoring recorder that, through a high-precision leakage current measurement module and the harmonic analysis function of a digital signal processor, can accurately capture the leakage current characteristics of the surge arrester under power frequency voltage, and determine steady-state defects such as aging and moisture absorption of the valve plate. On the other hand, the high-bandwidth impulse current and residual voltage measurement module can accurately capture transient waveforms during overvoltage events. Combined with dynamic volt-ampere characteristic curve calculations, the energy absorption capacity and protection margin of the surge arrester under extreme operating conditions can be evaluated. Compared to traditional monitoring schemes that only focus on steady-state conditions, this invention achieves a combination of steady-state and transient monitoring, allowing maintenance personnel to fully understand the operating performance of the surge arrester.

[0010] 3. This invention provides a surge arrester dynamic monitoring recorder that integrates a field-programmable gate array (FPGA) hardware acceleration algorithm with a digital signal processor (DSP) complex signal processing function through a multi-channel synchronous data acquisition and processing unit. This enables real-time data filtering, feature extraction, temperature compensation, and event recognition, achieving localized intelligent analysis without relying on external equipment. Simultaneously, the transient event triggering recording function accurately captures key event data such as overvoltage, avoiding redundant storage of invalid data. The remote data transmission and remote firmware upgrade functions enabled by the communication module reduce the number of on-site maintenance operations, significantly lowering the workload and maintenance costs for maintenance personnel.

[0011] 4. The surge arrester dynamic monitoring recorder of this invention employs a wide-range input design and backup power system in its power supply module, along with surge protection and electromagnetic interference / electromagnetic compatibility filtering circuits, to ensure stable system operation during grid voltage fluctuations or external power outages. The encrypted design of the data storage module ensures data transmission and storage security. The integrated, high-protection-level housing and industrial-grade interface design enable the system to adapt to complex outdoor environments such as high temperature, high humidity, and dust. Furthermore, the modular design facilitates independent maintenance and replacement of each module, further enhancing the overall reliability and service life of the system.

[0012] 5. The surge arrester dynamic monitoring recorder of the present invention, through the collection of multi-dimensional, high-precision synchronous data, can not only be used for the status diagnosis and fault early warning of a single surge arrester, but also remotely transmit the data to the power grid monitoring center, providing a data foundation for the analysis of surge arrester cluster operation, optimization of maintenance strategies, and risk prediction at the power grid level. By detecting potential surge arrester faults in advance and handling them in a timely manner, transmission and transformation accidents caused by surge arrester failures can be effectively reduced, significantly improving the power supply reliability and safe operation level of the power grid. Attached Figure Description

[0013] The invention will now be further described with reference to the accompanying drawings.

[0014] Figure 1 This is a structural framework diagram of the lightning arrester dynamic monitoring recorder system of the present invention; Figure 2This is a structural framework diagram of the high-precision leakage current measurement module in this invention.

[0015] In the diagram: 1. High-precision leakage current measurement module; 2. High-bandwidth impulse current measurement module; 3. High-bandwidth residual voltage measurement module; 4. High-precision power frequency voltage measurement module; 5. Environmental parameter measurement module; 6. Multi-channel synchronous data acquisition and processing unit; 7. Data storage module; 8. Communication and remote interface module; 9. Power supply module; 10. Surge arrester; 11. Grounding lead; 12. Two-end wiring; 101. Rogowski coil; 102. Current signal conditioning circuit; 103. Preamplifier; 104. Precision integrating circuit. Detailed Implementation

[0016] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0017] Reference Figure 1 The surge arrester dynamic monitoring recorder provided by this invention mainly consists of a high-precision leakage current measurement module 1, a high-bandwidth impulse current measurement module 2, a high-bandwidth residual voltage measurement module 3, a high-precision power frequency voltage measurement module 4, an environmental parameter measurement module 5, a multi-channel synchronous data acquisition and processing unit 6, a data storage module 7, a communication and remote interface module 8, and a power supply module 9. Data transmission and energy supply are achieved between the various modules through specific electrical connections or fiber optic links, ensuring stable system operation and data reliability.

[0018] Specifically, the high-precision leakage current measurement module 1 is used to accurately measure the total leakage current flowing through the grounding terminal 11 of the surge arrester 10. For example... Figure 2As shown, the module consists of a non-contact current sensor 101 and a current signal conditioning circuit 102. The non-contact current sensor 101 preferably employs a current transformer based on the Rogowski coil principle. This Rogowski coil 101 features wide frequency response, high linearity, and excellent electrical insulation performance, enabling it to accurately capture leakage current components ranging from the fundamental power frequency component to high-order harmonics up to the 50th harmonic and above, effectively reflecting the degree of contamination on the surface of the surge arrester's porcelain bushing and the deterioration state of the valve plates. The Rogowski coil 101 is installed around the surge arrester's grounding lead 11, and its internal coil is wound with a precise turns ratio, generating an induced voltage signal by sensing changes in the magnetic field around the grounding lead. The output signal of the Rogowski coil 101 is an analog voltage signal proportional to the rate of change of current (di / dt). The current signal conditioning circuit 102 includes a preamplifier 103 integrating a high input impedance operational amplifier and a precision integrator circuit, and a precision integrator circuit 104 composed of operational amplifiers. The preamplifier 103 employs a high common-mode rejection ratio (CMRR) instrumentation amplifier design, such as the AD8421 from Analog Devices or the INA128 from Texas Instruments, to effectively suppress common-mode interference present in the field. The precision integrator circuit 104 uses a high-speed, low-noise operational amplifier, such as the ADA4000-2 from Analog Devices or the OPA2134 from Texas Instruments, combined with high-precision, low-temperature-drift thin-film resistors and polypropylene thin-film capacitors, to accurately convert the voltage signal output from the Rogowski coil 101, which is proportional to the rate of change of current, into a voltage signal proportional to the instantaneous amplitude of the leakage current. The integrator circuit design effectively avoids the low-frequency integration drift phenomenon common in traditional analog integrators by introducing an ultra-low bias current switched capacitor circuit or a periodic DC reset mechanism in the feedback loop, ensuring measurement accuracy under long-term continuous monitoring conditions. The conditioning circuit 102 has an overall bandwidth covering from DC (or very low frequencies, such as 0.01 Hz) to 100 kHz, and its dynamic range is designed to accurately measure leakage current from microamperes (e.g., 0.1 μA) to amperes (e.g., 10 ARMS), with its nonlinearity strictly controlled to less than 0.1% throughout the measurement range. To further optimize measurement accuracy, the module also integrates a temperature compensation network and a digital calibration lookup table to correct for minor drifts in sensor and circuit parameters caused by changes in ambient temperature.

[0019] Furthermore, the high-bandwidth impulse current measurement module 2 is used to capture the transient impulse current waveform flowing through the surge arrester 10 with extremely high transient response speed and accuracy during overvoltage events. This module also employs an impulse current transformer based on the Rogowski coil principle, but its design is optimized for high di / dt characteristics. For example, it uses fewer turns, a smaller coil diameter, and coreless or low-hysteresis materials to ensure extremely low eddy current losses and the widest frequency response to rapidly changing magnetic fields. The frequency response range of this impulse current transformer is from 100Hz to 5MHz, fully covering the impulse current frequency components caused by transient overvoltage events in the power system (such as lightning overvoltage and switching overvoltage). Its transient current measurement upper limit can reach 200kA, far exceeding the requirements for conventional surge arrester monitoring. The impulse current transformer can be installed with the leakage current transformer sharing the grounding lead 11, or installed independently according to site requirements, and connected to a high-bandwidth current signal conditioning circuit via a dedicated low-loss, highly shielded coaxial cable or fiber optic link. The high-bandwidth current signal conditioning circuit includes an ultra-low noise, high common-mode rejection ratio broadband differential amplifier, such as Analog Devices' ADA4898-2 or Linear Technology's LTC6409, with a gain-bandwidth product (GBW) reaching hundreds of megahertz. This amplifier is followed by an active integrator circuit consisting of a high-speed operational amplifier (such as Texas Instruments' OPA828 or Analog Devices' AD8065). The integrator circuit's bandwidth response is specially designed, employing a multi-stage compensation network and a precisely tuned RC constant to ensure accurate reproduction of the inrush current waveform while avoiding integration drift in the low-frequency range. The conditioning circuit provides multi-level gain adjustment (e.g., ±1V, ±5V, ±10V corresponding to different current ranges) to accommodate inrush currents of varying amplitudes and rise times. Its output signal is an analog voltage signal proportional to the instantaneous value of the inrush current, with a 50-ohm output impedance matching, suitable for direct input to a high-speed analog-to-digital converter. To enhance anti-interference capabilities, the entire conditioning circuit adopts a multi-layer PCB design and is equipped with independent analog and digital grounds, which are connected through a star grounding point to minimize noise coupling.

[0020] In a preferred embodiment of the present invention, the high-bandwidth residual voltage measurement module 3 is used to synchronously measure the transient residual voltage waveform of the terminals 12 of the surge arrester 10 with the surge current measurement module 2 when the surge current passes through the surge arrester 10. This module includes a high-voltage sensor and a residual voltage signal conditioning circuit. The high-voltage sensor preferably employs a high-precision RC voltage divider or a pure resistive voltage divider. If an RC voltage divider is used, its high-voltage arm consists of a series high-voltage thick-film resistor and a precision high-voltage capacitor, while the low-voltage arm consists of a precision resistor and a capacitor, aiming to achieve a constant voltage division ratio over a wide frequency band. If a pure resistive voltage divider is used, multi-stage series high-voltage non-inductive resistors are employed. By optimizing the resistive material and geometry, extremely low parasitic inductance and capacitance are achieved, resulting in excellent linearity, temperature stability, and an extremely wide frequency response (e.g., from DC to 5MHz). The high-voltage sensor is installed as close as possible to the terminals 12 of the surge arrester 10, and is electrically connected to the surge arrester via a dedicated high-voltage shielded cable to minimize the influence of lead impedance and external electromagnetic interference. The residual voltage signal conditioning circuit includes a high-input-impedance, high common-mode rejection ratio (CMRR) differential amplifier, such as Analog Devices' AD8429 or Burr-Brown's INA118, to receive the low-side voltage divider output signal from the high-voltage sensor. The amplifier's input impedance is typically as high as 10^12 ohms, ensuring a disturbance-free measurement of the divider output signal. Its high CMRR is typically above 80 dB at 100 kHz, effectively suppressing common-mode noise present in the power system field. After differential amplification, the signal is regulated by a high-precision, low-noise attenuator or gain stage to bring it within an acceptable input voltage range (e.g., ±5V or ±10V) for the analog-to-digital converter (ADC) in the multi-channel synchronous data acquisition and processing unit 6. To further improve measurement accuracy, the module also integrates a precision temperature sensor for real-time monitoring of the module's internal temperature and precise compensation for temperature drift in the sensor and circuitry via digital algorithms.

[0021] Specifically, the high-precision power frequency voltage measurement module 4 is used to accurately measure the power frequency voltage of the power grid where the surge arrester 10 is located, including line-to-ground voltage or line-to-line voltage. This module typically uses a high-precision PT (voltage transformer) or a fiber-optic isolated voltage sensor to ensure safe isolation and high accuracy in the measurement. The voltage sensor converts the high-voltage power frequency voltage into a low-voltage AC signal at a fixed ratio, with an accuracy class better than 0.2. The subsequent voltage signal conditioning circuit includes an isolation amplifier and an RMS-to-DC converter or a high-speed sampling ADC. If an RMS-to-DC converter, such as Analog Devices' AD637, is used, it can output a DC voltage signal proportional to the effective value of the power frequency voltage in real time, with excellent linearity and temperature stability, and can effectively filter out the influence of high-frequency harmonics and transient components on the measurement of the effective value of the power frequency voltage. If direct sampling by an ADC is used, the power frequency voltage needs to be sampled with high precision, and its fundamental effective value, phase, and harmonic content need to be calculated through digital signal processing algorithms. This module boasts high measurement accuracy, accurately reflecting grid voltage fluctuations and providing crucial power frequency voltage references for surge arrester operational status assessment. Its input terminals are equipped with comprehensive overvoltage protection circuitry to handle transient grid overvoltages.

[0022] Furthermore, the environmental parameter measurement module 5 is used to monitor key parameters of the operating environment of the surge arrester 10 in real time, including ambient temperature, relative humidity, atmospheric pressure, and solar radiation intensity. This module integrates multiple high-precision sensors: Temperature sensor: Employs industrial-grade platinum resistance thermometers (Pt100 or Pt1000) or high-precision digital temperature sensors (such as Maxim Integrated's DS18B20 or Bosch Sensortec's BME280), featuring a wide operating temperature range (e.g., -40°C to +85°C) and measurement accuracy of ±0.2°C. The sensor probe is encapsulated with an IP67 protection rating, ensuring long-term reliability in harsh outdoor environments.

[0023] Humidity sensor: Employs a high-precision capacitive humidity sensor (such as Sensirion's SHT31 or Honeywell's HIH-4000 series), with a measurement range of 0%RH to 100%RH and an accuracy typically better than ±2%RH.

[0024] Atmospheric pressure sensor: A pressure sensor using MEMS technology (such as Bosch Sensortec's BMP280) with a measurement range of 300 hPa to 1100 hPa and an accuracy of ±1 hPa helps to assess the impact of air density on insulation performance.

[0025] Solar radiation intensity sensor: Employing a silicon photodiode array, it measures radiation intensity from the visible to near-infrared spectrum, used to assess the effects of direct sunlight on surge arrester surface temperature and UV aging. The output signals from all environmental sensors are converted into standard digital signals (such as I2C, SPI) or analog voltage signals via their respective conditioning circuits and then sent to the multi-channel synchronous data acquisition and processing unit 6 for processing. Real-time data on these environmental parameters are crucial for analyzing the temperature and humidity dependence of surge arrester leakage current, assessing the risk of external pollution flashover, and correcting temperature drift in other measurement modules.

[0026] As a core component of this invention, the multi-channel synchronous data acquisition and processing unit 6 is the "brain" of the entire system. It is responsible for high-precision, strictly time-synchronized acquisition, digitization, preprocessing, and intelligent analysis of the output signals of all measurement modules (1, 2, 3, 4, 5).

[0027] High-speed analog-to-digital converters (ADCs): For inrush current and residual voltage measurements, multi-channel parallel, synchronous sampling 16-bit or 18-bit high-speed ADCs are employed, such as Analog Devices' AD7606 series (8 channels, 200kSPS / channel) or TI's ADS8588S (8 channels, 400kSPS / channel). For transient waveform capture requiring higher sampling rates, multiple single-channel or dual-channel high-speed ADCs can be used in time-division multiplexing or parallel operation, such as Linear Technology's LTC2378-20 (20-bit, 1MSPS). All ADCs are triggered by a unified sampling clock to ensure time synchronization accuracy between channels at the nanosecond or even picosecond level.

[0028] Data preprocessing and Digital Signal Processor (DSP) / Field-Programmable Gate Array (FPGA): The digital output data of the ADC is first fed into a high-performance FPGA (such as the Xilinx Zynq series or Intel Cyclone V series) or DSP (such as the TIC6000 series). The FPGA is responsible for implementing precise sampling timing control, data buffering, real-time digital filtering (such as FIR / IIR filters), data format conversion, and hardware-accelerated event detection algorithms. The DSP is responsible for more complex signal processing tasks, including: Harmonic analysis: Fast Fourier Transform (FFT) is performed on the leakage current to calculate the amplitude and phase of the fundamental frequency, 3rd, 5th, and 7th characteristic harmonics, as well as the total harmonic distortion (THD), which is used to assess the degree of deterioration and pollution of the surge arrester varistors.

[0029] Transient waveform analysis: Feature extraction is performed on the impulse current and residual voltage waveforms, such as peak value, wavefront time, wave tail time, and energy integral. Advanced algorithms such as wavelet transform are used to identify high-frequency oscillations and local distortions in the waveforms.

[0030] Residual voltage-current characteristic matching: The collected residual voltage and impulse current data are aligned in real time, the dynamic volt-ampere characteristic curve is calculated, and the energy absorption capacity and protection margin of the surge arrester are evaluated.

[0031] Temperature compensation and calibration: Combining the temperature data from environmental parameter module 5 and pre-stored calibration coefficients, real-time temperature compensation is performed on all measurement data to eliminate the impact of temperature changes on measurement accuracy.

[0032] Event Triggering and Recording: Based on preset thresholds (such as current, residual voltage peak), rate of change (di / dt, du / dt), or specific waveform characteristics, transient event triggering at the millisecond or even microsecond level can be achieved. Once triggered, the system will record all high-sampling-rate raw data within a certain time window before and after the trigger point (e.g., 200μs before triggering, 800μs after triggering), ensuring complete capture of the entire event.

[0033] High-precision time synchronization unit: To ensure the absolute timestamp accuracy of all monitoring data and the collaborative operation between multiple recorders, this unit integrates a GPS-disciplined Oscillator (GPSDO). The GPSDO uses PTP (Precision Time Protocol) or NTP (Network Time Protocol) signals provided by GPS satellites to discipline an internal high-precision oven-controlled crystal oscillator (OCXO), thereby providing nanosecond or even sub-nanosecond time synchronization accuracy. All acquired data will carry a precise timestamp calibrated by the GPSDO, which is crucial for analyzing multi-point data, fault location, and event correlation.

[0034] Furthermore, data storage module 7 is used to securely and reliably store all collected raw data, processed feature data, event records, and system logs. This module typically uses a highly reliable industrial-grade solid-state drive (SSD) or a large-capacity NAND flash memory, characterized by fast read / write speeds, strong shock resistance, a wide operating temperature range, and error correction code (ECC) functionality to ensure data integrity.

[0035] High-speed cache: Typically composed of high-speed DDR SDRAM, used to temporarily store high-sampling-rate raw waveform data before and after a transient event is triggered, in order to meet the fast storage requirements after the event is triggered.

[0036] Long-term data storage area: Composed of industrial-grade SSDs with a capacity of several terabytes, used to store long-term trend data (such as hourly leakage current peaks, RMS values, and harmonic content), as well as high-speed sampling raw data at the time of events. The write lifetime (TBW) of the SSDs has been rigorously evaluated to ensure the reliability of data writing throughout the system's design life. All data adopts a tiered storage strategy and can be managed through a file system, supporting retrieval by time, event type, and other methods.

[0037] Data encryption and security: To protect the security and privacy of monitoring data, the data storage module can integrate a hardware encryption chip or use encryption algorithms such as AES-256 to encrypt the stored data.

[0038] Specifically, the communication and remote interface module 8 provides the recorder system with the ability to exchange data and remotely manage the outside world. This module supports multiple communication interfaces and protocols: Ethernet interface (RJ45 / fiber): Supports 100 / 1000Mbps Ethernet for local area network (LAN) access or long-distance communication via fiber optic cable, meeting high-speed data transmission requirements. Supports multiple industry standard protocols such as TCP / IP, FTP, HTTP, ModbusTCP, and IEC61850, facilitating data integration with SCADA systems, DCS systems, or cloud platforms.

[0039] Cellular communication module (4G / 5G): Features a built-in industrial-grade 4G or 5G module, supporting major global operator network frequency bands. It enables remote data uploading, system status reporting, and remote configuration updates in remote areas without wired network coverage. The communication link employs VPN encrypted tunnel technology to ensure data transmission security.

[0040] RS485 / RS232 interface: Supports traditional industrial serial communication protocols such as Modbus RTU, and can be used to connect to a local HMI (human-machine interface) or to interact with surrounding sensors and equipment.

[0041] Wi-Fi / Bluetooth module: Used for local short-range wireless connectivity, allowing on-site maintenance personnel to perform debugging, parameter settings, and data viewing via smartphones or tablets. This module also features over-the-air (OTA) firmware upgrade functionality, enabling system software updates and maintenance without interrupting device operation.

[0042] As an essential part of this invention, the power supply module 9 provides a stable and reliable energy supply for the entire surge arrester dynamic monitoring recorder system. This module is designed for a wide range of AC (e.g., 85VAC-265VAC) or DC (e.g., 12VDC / 24VDC / 48VDC) inputs to adapt to different on-site power supply conditions.

[0043] AC / DC or DC / DC converters: Employing high-efficiency (e.g., over 90%), industrial-grade isolated power modules, the input power is converted into multiple stable DC voltage rails required by the system, such as 5V, 3.3V, ±12V, etc., to supply digital circuits, analog circuits, and sensors respectively.

[0044] Battery Backup System: Features a built-in high-capacity, long-life lithium iron phosphate (LiFePO4) battery pack, coupled with an intelligent battery management system (BMS), providing several hours to several days of independent operation time when the main power supply is interrupted. The BMS is responsible for battery charging and discharging management, overvoltage / undervoltage protection, overcurrent protection, and temperature monitoring, ensuring battery safety and extending its lifespan.

[0045] Power Quality and Protection: Integrated surge protection (SPD), transient voltage suppressor (TVS), and EMI / EMC filtering circuitry effectively suppress surge voltages, harmonic interference, and electromagnetic radiation from the power grid, ensuring the purity of the power output and stable system operation in harsh electromagnetic environments. All circuit boards employ a multi-layer PCB design and strictly adhere to EMC design specifications. Reasonable grounding and shielding measures further enhance the system's anti-interference capabilities.

[0046] In one specific embodiment, the surge arrester dynamic monitoring recorder system of the present invention adopts an integrated, modular hardware design. The system housing is made of IP67-rated die-cast aluminum alloy or stainless steel, providing excellent dustproof, waterproof, corrosion-resistant, and electromagnetic interference-resistant capabilities, making it suitable for long-term outdoor operation. All wiring ports use industrial-grade aviation plugs or waterproof connectors to ensure the reliability of electrical connections.

[0047] Example 1 This embodiment aims to verify the comprehensive performance of the surge arrester dynamic monitoring recorder provided by the present invention, especially its performance in high-precision leakage current measurement, high-bandwidth transient waveform capture, and multi-channel time synchronization.

[0048] Test object: A zinc oxide surge arrester (MOV surge arrester) with a rated voltage of 110kV, a power frequency withstand voltage of 250kV, and a nominal discharge current of 10kA.

[0049] System Configuration: High-precision leakage current measurement module 1: The Rogowski coil adopts an air-core Rogowski coil with a diameter of 150mm and a turns ratio of 1:1000, combined with a current signal conditioning circuit with a bandwidth of DC to 100kHz, a dynamic range of 0.1μA to 10ARMS, and a nonlinearity of less than 0.1%.

[0050] High-bandwidth impulse current measurement module 2: The Rogowski coil adopts an 80mm diameter, 1:100 turns ratio air-core Rogowski coil, combined with a high-bandwidth current signal conditioning circuit with a bandwidth of 100Hz to 5MHz, a transient current measurement upper limit of 200kA, and multi-level gain adjustment.

[0051] High-bandwidth residual voltage measurement module 3: It adopts a precision resistor-capacitor voltage divider (voltage division ratio 1:5000) and a residual voltage signal conditioning circuit with a bandwidth of DC up to 5MHz and a high input impedance (10^12Ω).

[0052] High-precision power frequency voltage measurement module 4: It adopts a fiber optic isolated voltage sensor (voltage division ratio 1:2000) with an accuracy class of 0.1, and is used to monitor the effective value and phase of power frequency voltage in real time.

[0053] Environmental parameter measurement module 5: integrates a Pt100 temperature sensor, an SHT31 humidity sensor, and a BMP280 atmospheric pressure sensor.

[0054] Multi-channel synchronous data acquisition and processing unit 6: The core adopts a Xilinx Zynq-7020 SoC, integrating a dual-core ARM Cortex-A9 processor and an Artix-7 FPGA. Two ADIAD7606-16 ADCs (16-bit, 400kSPS / channel, 8 channels) are used for leakage current and power frequency voltage sampling; two LTC2378-20 ADCs (20-bit, 1MSPS) are used for inrush current and residual voltage waveform sampling. All ADCs are precisely controlled and synchronously triggered via the FPGA, and the sampling clock is provided by GPSDO.

[0055] Data storage module 7: 1TB industrial-grade SSD.

[0056] Communication and Remote Interface Module 8: Gigabit Ethernet and 4G Cellular Module.

[0057] Power supply module 9: Supports wide-range AC input and has a built-in 20Ah lithium iron phosphate battery backup system.

[0058] Test scenarios and data: Power frequency leakage current monitoring: Place the surge arrester in a simulated outdoor polluted environment and apply a 200kV power frequency voltage.

[0059] Under ambient temperature of 25℃ and relative humidity of 80%, the fundamental component of the total leakage current of the surge arrester was measured to be 102.5μA, of which the third harmonic component was 12.8μA and the fifth harmonic component was 4.5μA. The system automatically calculated and recorded the THD as 13.1%.

[0060] Thanks to the built-in temperature compensation algorithm, even if the ambient temperature fluctuates within the range of -20℃ to +60℃, the impact on the fundamental frequency measurement of leakage current is less than ±0.5%.

[0061] Transient impulse overvoltage test: A standard 8 / 20μs lightning impulse current waveform with a peak value of 10kA is applied to the surge arrester.

[0062] The system accurately captures the rise time of the inrush current as 7.8 μs, the half-peak fall time as 20.1 μs, and the peak error as less than 0.5%.

[0063] The transient residual voltage waveform of the surge arrester was measured synchronously, with a peak value of 318kV. The waveform reproducibility was high, and the deviation from the measurement result of the standard oscilloscope was less than 0.8%. The time synchronization error between the impulse current and the residual voltage waveform was less than 50ns.

[0064] The system automatically calculates that the surge arrester absorbs 8.5 kJ of energy under a 10 kA impulse.

[0065] Multi-parameter correlation analysis: Through the data acquisition and processing unit, the harmonic components of the leakage current, the peak residual voltage, the absorbed energy, and the ambient temperature and humidity data were correlated and analyzed. It was found that when the relative humidity exceeded 90% and was accompanied by surface condensation, the third harmonic component of the leakage current increased significantly, indicating an increased risk of surface contamination of the surge arrester.

[0066] Comparative Example 1 This comparative simulation demonstrates a common online monitoring system for surge arresters in the prior art. This system typically only has basic power frequency leakage current measurement functions and does not have high-bandwidth transient capture and strict multi-channel synchronization capabilities.

[0067] System Configuration: Leakage current measurement: A Hall sensor is used, with a bandwidth of DC to 2kHz and an accuracy class of 0.5. Only the RMS value and fundamental component of the total leakage current are measured.

[0068] Residual voltage measurement: There is no real-time transient residual voltage measurement module. It only relies on a simple high-voltage probe and peak detector for auxiliary verification, and there is no strict synchronization with current measurement.

[0069] Impact current measurement: No high-bandwidth transient impact current measurement module.

[0070] Power frequency voltage measurement: using a common PT with an accuracy class of 0.5.

[0071] Environmental parameter measurement: Temperature only, accuracy ±2℃.

[0072] Data acquisition and processing unit: adopts a low-speed microcontroller, with a 12-bit ADC, a sampling rate of 10kSPS / channel, multi-channel time-division sampling, and no time synchronization function.

[0073] Data storage: Small SD card.

[0074] Communication: RS485 interface.

[0075] Power supply: AC input only, no backup battery.

[0076] Test scenarios and data: Power frequency leakage current monitoring: In the same simulated polluted environment as in Example 1, a 200kV power frequency voltage was applied.

[0077] Under ambient temperature of 25℃ and relative humidity of 80%, the effective value of the total leakage current was measured to be 108.0 μA. Due to bandwidth limitations, higher harmonic components cannot be accurately decomposed. Only an approximate value of 100.0 μA for the fundamental component can be provided. THD cannot be calculated.

[0078] Due to the lack of effective temperature compensation, when the ambient temperature fluctuates within the range of -20℃ to +60℃, the impact on the fundamental frequency measurement of leakage current reaches ±3.5%.

[0079] Transient impulse overvoltage test: The same 8 / 20μs lightning impulse current waveform with a peak value of 10kA was applied to the surge arrester.

[0080] The system is unable to capture the inrush current waveform and cannot obtain key parameters such as rise time and half-peak fall time. It can only barely record a peak current of 10.5kA using external equipment, but the waveform is severely distorted.

[0081] The residual voltage peak was recorded as 325kV by an external peak detector, but due to the asynchronous nature of the current measurement and the limited measurement accuracy, an accurate volt-ampere characteristic curve could not be constructed.

[0082] The energy absorbed by the surge arrester cannot be calculated.

[0083] Multi-parameter correlation analysis: Due to the limited types of data, low accuracy, and lack of synchronization, effective multi-parameter correlation analysis cannot be performed, and potential faults in surge arresters cannot be accurately predicted.

[0084] Comparison results The table below compares the differences in key performance indicators between the system of the present invention (Example 1) and the prior art system (Comparative Example 1): Performance indicators Example 1 (System of the Invention) Comparative Example 1 (Primary Technology System) Significant advantages (Example 1 vs. Comparative Example 1) Leakage current measurement accuracy Fundamental frequency ±0.5%, harmonic frequency ±1.5% Fundamental frequency ±3.0%, accurate measurement without harmonics. Harmonic analysis capabilities with higher precision support fine-grained assessment of degradation trends. Leakage current bandwidth DC-100kHz DC-2kHz More comprehensive leakage current composition capture, reflecting more complex pollution and degradation conditions. Transient inrush current waveform capture Rising time: 7.8 μs; Falling time: 20.1 μs; Peak error: <0.5% Unable to capture the complete waveform, only a rough peak value can be recorded. It fully reproduces the impulse current waveform, supporting in-depth analysis of the surge arrester's dynamic performance. Transient residual voltage waveform capture Peak voltage 318kV, deviation from standard oscilloscope <0.8% Only a rough measurement using a peak pickup indicates a deviation >5%. Accurately capturing residual voltage waveforms provides crucial data for accurately assessing protection performance. Multi-channel time synchronization accuracy Nanosecond level (<50ns) Millisecond-level (>10ms) or even desynchronization Ensure that the impact current and residual voltage are analyzed simultaneously to construct an accurate volt-ampere characteristic curve. Environmental parameter monitoring Temperature ±0.2℃, humidity ±2%RH, pressure ±1hPa Temperature ±2℃, no humidity, no pressure A more comprehensive environmental impact assessment improves the accuracy of measurement data and the reliability of fault early warning. Data processing capabilities Real-time FFT, wavelet analysis, energy integration, temperature compensation Calculation of basic effective value only It provides in-depth data analysis to reveal the underlying physical mechanisms and potential risks of surge arrester operation. Storage capacity and event logs 1TB SSD, high sampling rate waveform recording before and after the event Small-capacity SD cards only record periodically valid values. Storing more historical data and high-resolution event details is beneficial for post-event analysis. Remote communication and management Ethernet, 4G / 5G, VPN encryption, OTA upgrade RS485, local reading Enables remote monitoring, diagnosis, and system maintenance, significantly reducing operation and maintenance costs. backup power supply High-capacity LifePO4 battery, runs for several days none Ensure uninterrupted monitoring during main power outages to improve system reliability. Through the comparative data of the above embodiments and comparative examples, it is clear that the surge arrester dynamic monitoring recorder provided by the present invention exhibits significant advantages in terms of measurement accuracy, bandwidth, synchronization, data analysis capabilities, and environmental adaptability. It can provide more detailed, accurate, and reliable surge arrester operating status data, enabling a comprehensive assessment of the static degradation trend and dynamic protection performance of surge arresters, thus providing strong technical support for the safe and stable operation of power systems. The present invention overcomes the limitations of existing technologies, such as high sensitivity to environmental factors, lack of direct capture capability of dynamic overvoltage response characteristics, and poor synchronization of multi-parameter data acquisition, achieving a high-precision, multi-dimensional, and full-condition surge arrester operating status assessment and fault early warning solution.

[0085] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A surge arrester dynamic monitoring recorder, characterized in that: include: A high-precision leakage current measurement module (1) is used to measure the total leakage current flowing through the grounding terminal of the surge arrester; A high-bandwidth impulse current measurement module (2) is used to accurately capture the transient impulse current waveform flowing through the surge arrester when an overvoltage event occurs; The high-bandwidth residual voltage measurement module (3) is used to simultaneously measure the transient residual voltage waveform at both ends of the surge arrester when the impulse current passes through the surge arrester; High-precision power frequency voltage measurement module (4) is used to accurately measure the power frequency voltage of the power grid where the surge arrester is located; The environmental parameter measurement module (5) is used to monitor key parameters of the surge arrester's operating environment in real time. The multi-channel synchronous data acquisition and processing unit (6) is electrically connected to the high-precision leakage current measurement module (1), the high-bandwidth impact current measurement module (2), the high-bandwidth residual voltage measurement module (3), the high-precision power frequency voltage measurement module (4), and the environmental parameter measurement module (5), and is used to perform high-precision, strictly time-synchronized acquisition, digitization, preprocessing, and intelligent analysis of the output signals of each measurement module; The data storage module (7) is electrically connected to the multi-channel synchronous data acquisition and processing unit (6) and is used to securely and reliably store all acquired raw data, processed feature data, event records and system logs. The communication and remote interface module (8) is electrically connected to the multi-channel synchronous data acquisition and processing unit (6) and the data storage module (7) to provide the recorder system with the ability to exchange data and remotely manage data with the outside world; The power supply module (9) is used to provide a stable and reliable energy supply for the entire surge arrester dynamic monitoring recorder system.

2. The surge arrester dynamic monitoring recorder according to claim 1, characterized in that: The high-precision leakage current measurement module (1) includes a non-contact current sensor (101) and a current signal conditioning circuit (102). The non-contact current sensor (101) can accurately capture leakage current components from the fundamental frequency component to the higher harmonics, and is installed by surrounding the grounding lead (11) of the surge arrester. The output signal of the Rogowski coil (101) is an analog voltage signal that is proportional to the rate of change of current. The current signal conditioning circuit (102) includes a preamplifier (103) integrating a high input impedance operational amplifier and a precision integrator circuit, and a precision integrator circuit (104) composed of an operational amplifier, which is used to convert the voltage signal output by the Rogowski coil (101) into a voltage signal proportional to the instantaneous amplitude of the leakage current, and perform preliminary gain adjustment and low-pass filtering to suppress high-frequency noise interference. Furthermore, by introducing a switched capacitor circuit or a periodic DC reset mechanism in the feedback loop, the low-frequency integration drift phenomenon commonly found in traditional analog integrators is effectively avoided.

3. The surge arrester dynamic monitoring recorder according to claim 2, characterized in that: The current signal conditioning circuit (102) is used to accurately measure leakage current; The preamplifier (103) adopts an instrumentation amplifier design with a high common-mode rejection ratio; The precision integrating circuit (104) uses a high-speed, low-noise operational amplifier, combined with a high-precision, low-temperature-drift thin-film resistor and a polypropylene thin-film capacitor. The high-precision leakage current measurement module (1) also integrates a temperature compensation network and a digital calibration lookup table to correct for minor drifts in sensor and circuit parameters caused by changes in ambient temperature.

4. The surge arrester dynamic monitoring recorder according to claim 1, characterized in that: The high-bandwidth impulse current measurement module (2) adopts an impulse current transformer based on the Rogowski coil principle; The impulse current transformer is installed with the grounding lead (11) of the surge arrester and connected to a high-bandwidth current signal conditioning circuit through a dedicated low-loss, high-shield coaxial cable or fiber optic link. The high-bandwidth current signal conditioning circuit includes an ultra-low noise, high common-mode rejection ratio broadband differential amplifier and an active integrator circuit composed of a high-speed operational amplifier.

5. A surge arrester dynamic monitoring recorder according to claim 4, characterized in that: The high-bandwidth current signal conditioning circuit provides multi-level gain adjustment to adapt to inrush currents of different amplitudes and rise times. Its output signal is an analog voltage signal that is proportional to the instantaneous value of the inrush current. The high-bandwidth current signal conditioning circuit uses a multi-layer printed circuit board and has independent analog and digital grounds, which are connected through a star grounding point to reduce noise coupling.

6. The surge arrester dynamic monitoring recorder according to claim 1, characterized in that: The high-bandwidth residual voltage measurement module (3) includes a high-voltage sensor and a residual voltage signal conditioning circuit; The high-voltage sensor employs a high-precision RC voltage divider or a pure resistive voltage divider, which has excellent linearity, temperature stability, and an extremely wide frequency response from DC to 5 MHz. The high-voltage sensor is installed close to the two ends of the surge arrester (10) and connected to the surge arrester via a dedicated high-voltage shielded cable to minimize the influence of lead impedance and external electromagnetic interference. The residual voltage signal conditioning circuit includes a differential amplifier with high input impedance and high common-mode rejection ratio, used to receive the voltage divider output signal from the high-voltage sensor and adjust it to an input voltage range acceptable to the analog-to-digital converter.

7. A surge arrester dynamic monitoring recorder according to claim 6, characterized in that: If the high-voltage sensor uses a resistor-capacitor voltage divider, its high-voltage arm consists of a series high-voltage thick-film resistor and a precision high-voltage capacitor, while the low-voltage arm consists of a precision resistor and a capacitor, used to achieve a constant voltage division ratio over a wide bandwidth. If the high-voltage sensor uses a pure resistive voltage divider, then a multi-stage series high-voltage non-inductive resistor is used. The residual voltage signal conditioning circuit also integrates a precision temperature sensor for real-time monitoring of the module's internal temperature and compensates for temperature drift of the sensor and circuit through digital algorithms.

8. A surge arrester dynamic monitoring recorder according to claim 1, characterized in that: The multi-channel synchronous data acquisition and processing unit (6) includes: High-speed analog-to-digital converters are used to convert the output signals of the inrush current and residual voltage measurement modules, and all analog-to-digital converters are triggered by a unified sampling clock; The data preprocessing and digital signal processor / field-programmable gate array are connected to the digital output of the high-speed analog-to-digital converter. The field-programmable gate array is responsible for implementing precise sampling timing control, data buffering, real-time digital filtering, data format conversion, and hardware-accelerated event detection algorithms, while the digital signal processor is responsible for more complex signal processing tasks. The signal processing tasks handled by the digital signal processor include: extracting features from the impulse current and residual voltage waveforms; aligning the collected residual voltage and impulse current data in real time, calculating the dynamic voltage-current characteristic curve, and evaluating the energy absorption capacity and protection margin of the surge arrester; and performing real-time temperature compensation on all measurement data by combining the temperature data from the environmental parameter measurement module (5) and the pre-stored calibration coefficients.

9. A surge arrester dynamic monitoring recorder according to claim 8, characterized in that: The multi-channel synchronous data acquisition and processing unit (6) also includes a high-precision time synchronization unit. The high-precision time synchronization unit integrates a global positioning system disciplined oscillator, which uses the precise time protocol or network time protocol signal provided by the global positioning system satellite to discipline the internal high-precision isothermal crystal oscillator. All acquired data will have a precise timestamp calibrated by the global positioning system disciplined oscillator. The digital signal processor / field programmable gate array is also responsible for event triggering and recording. Based on preset thresholds, rates of change, or specific waveform characteristics, it can trigger transient events at the millisecond or even microsecond level. Once triggered, the system will record all high-sampling-rate raw data within a certain time window before and after the trigger point.

10. A surge arrester dynamic monitoring recorder according to claim 1, characterized in that: The data storage module (7) adopts a highly reliable industrial-grade solid-state drive or a large-capacity flash memory, and has a built-in large-capacity double-rate synchronous dynamic random access memory as a high-speed cache area for temporarily storing high-sampling-rate raw waveform data before and after the transient event is triggered. At the same time, it integrates a hardware encryption chip to encrypt the stored data. The communication and remote interface module (8) has a remote firmware upgrade function; The power supply module (9) supports a wide range of AC or DC input, adopts a high-efficiency industrial-grade isolated power supply module, and has a built-in large-capacity lithium iron phosphate battery pack. It is used in conjunction with an intelligent battery management system as a battery backup system, and integrates complete surge protection, transient suppression diodes and electromagnetic interference / electromagnetic compatibility filter circuits.

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