An early warning system for switch and socket circuit malfunctions

Abstract

This invention relates to the fields of signaling devices, command transmission devices, and status alarm technology. It discloses an early warning system for switch and socket circuit anomalies, comprising: a multi-dimensional physical quantity sensing module for the circuit, a physical feature extraction and decoupling module, a multi-dimensional feature dynamic fusion and status arbitration module, and a graded early warning and command transmission module. The system collects high-frequency transient signals, power frequency instantaneous current, terminal temperature, and ambient reference temperature; extracts the high-frequency energy mean, zero-crossing distortion rate, and terminal temperature rise gradient; calculates a weighted comprehensive anomaly early warning index; performs continuous periodic sliding smoothing verification; and outputs graded audible and visual alarm signals, remote maintenance early warning messages, and linkage tripping command transmissions. This invention eliminates nonlinear load inrush current interference through orthogonal decoupling of multiple physical quantities, achieving high-confidence graded early warning transmission and proactive alarm indication of electrical anomalies in the early stages of contact degradation.

Description

Technical Field

[0001] This invention relates to an early warning system for abnormal switch and socket circuits, belonging to the technical field of signal devices, command transmission devices, and status alarms. Background Technology

[0002] In low-voltage terminal power distribution systems in buildings, switches and sockets are an important component of terminal power circuits. Their operational reliability is directly related to electrical safety. Existing devices for fault monitoring and alarming of switch and socket circuits typically rely on overcurrent protection and residual current protection of circuit breakers, as well as a single thermal element installed inside the casing for detection. When a circuit experiences severe overload, grounding leakage, or a significant increase in casing temperature, an alarm signal is sent to the terminal to achieve basic safety protection.

[0003] Under frequent plugging and unplugging and repeated heating under load, the internal terminals of switches and sockets are prone to contact degradation, leading to increased contact resistance and potentially intermittent series micro-arcs. These early anomalies are often difficult to detect. Firstly, the operating current does not exceed the overload threshold, and there is no leakage path to ground, making conventional overcurrent and residual current protection difficult to detect. Secondly, by the time Joule heat reaches the thermistor, the terminals often show insulation carbonization. Simultaneously, nonlinear devices connected to the terminal circuit generate transient electromagnetic inrush currents during start-up and shutdown. If only the alarm threshold is lowered to detect weak discharges, normal load disturbances may be misjudged as discharge faults. Furthermore, simply increasing the number of thermistors, without an ambient temperature reference, will not effectively detect the surrounding heat dissipation conditions. Changes can still cause a shift in the transmission reference, leading to an increase in the false alarm rate and the risk of missed detection. To compensate for the limitations of hardware sensing, existing technologies attempt to extract arc features from the signal analysis algorithm level. For example, Chinese invention patent CN101696986B discloses a fault arc detection method and protection device. It separates high-frequency components by performing wavelet packet decomposition on the sampled current and determines the fault arc based on high-frequency energy mutations and the cumulative number of arcs, thereby driving the trip. However, this type of method only extracts high-frequency transient features in the frequency domain of the electrical signal. When a nonlinear load such as a large capacitor filter is connected to the switch socket, the transient electromagnetic inrush current during closing can also cause significant high-frequency energy mutations, which can easily lead to false triggering of the single frequency domain criterion.

[0004] Therefore, the technical problem to be solved by this invention is how to reduce false alarms caused by transient inrush currents of nonlinear loads in environments with background electromagnetic noise and dynamic load changes, and how to achieve reliable status judgment, graded audible and visual alarms and remote command transmission in the early stages of contact degradation of switches and sockets. Summary of the Invention

[0005] To address the problems in the background art, the technical solution of the present invention is as follows: A pre-warning system for abnormal switch socket circuits, comprising:

[0006] The loop multidimensional physical quantity sensing module includes a high-frequency current mutual inductance sensing unit, a power frequency current sampling unit, a terminal contact temperature measurement unit, and an environmental reference temperature measurement unit, which are used to collect high-frequency current transient signals, power frequency current instantaneous values, terminal temperatures, and environmental reference temperatures inside the housing.

[0007] The physical feature extraction and decoupling module is connected to the loop multidimensional physical quantity sensing module. It is used to calculate the average value of high-frequency transient energy within half a cycle of power frequency, extract the zero-crossing distortion rate of the power frequency current zero-crossing stagnation time as a half-cycle duration, and calculate the difference between the terminal temperature and the reference temperature of the environment inside the housing as the relative temperature rise gradient of the terminal.

[0008] The multi-dimensional feature dynamic fusion and state arbitration module is connected to the physical feature extraction and decoupling module. It is used to perform upper limit saturation calculations based on preset benchmarks on the average high-frequency transient energy and the relative temperature rise gradient of the terminals to generate high-frequency transient normalized anomaly and temperature rise gradient normalized anomaly. The high-frequency transient normalized anomaly, temperature rise gradient normalized anomaly, and zero-crossing distortion rate are weighted and fused to generate a comprehensive anomaly warning index closed in the range of 0 to 1. The index is then slid-smoothly verified over multiple consecutive half-cycles and the loop status is determined by combining preset alarm thresholds and hysteresis.

[0009] The graded early warning and command transmission module, connected to the multi-dimensional feature dynamic fusion and status arbitration module, includes a local sound and light indication unit, a remote command encoding and transmission unit, and a cascaded trip trigger unit. It is used to output sound and light alarms, remote early warning messages, or trip instructions based on the judgment results, and return to normal state when the comprehensive abnormal early warning index falls below the difference between the first-level alarm threshold and the hysteresis lag.

[0010] Preferably, the sampling frequency of the high-frequency current transformer sensing unit and the power frequency current sampling unit is set to 200kHz; the physical feature extraction and decoupling module acquires 2000 discrete sampling points within 10.0ms of each power frequency half-cycle and extracts the high-frequency instantaneous current value of each sampling point; when the physical feature extraction and decoupling module calculates the average value of high-frequency transient energy, it squares the difference between the high-frequency instantaneous current value of each sampling point in a single power frequency half-cycle and the preset steady-state background high-frequency noise floor setting value of 0.001A, and accumulates and averages the 2000 squared results in a single power frequency half-cycle.

[0011] Preferably, the power frequency current sampling unit establishes a symmetrical time detection window based on the zero point of current polarity reversal within each power frequency half-cycle; when the physical feature extraction and decoupling module extracts the zero-crossing distortion rate, the absolute value of the cumulative instantaneous value of the power frequency current within the symmetrical time detection window is continuously lower than the preset micro-arc extinguishing threshold of 0.050A for a certain duration, and the stagnation duration is divided by the power frequency half-cycle duration of 10.0ms to obtain the dimensionless zero-crossing distortion rate.

[0012] Preferably, the terminal contact temperature measuring unit adopts a miniature thin-film thermistor and is set on the outside of the conductive metal sheet of the phase wire terminal of the switch socket; the ambient reference temperature measuring unit is set in the air convection baffle cavity next to the inlet hole on the back of the switch socket box, and the physical distance between the ambient reference temperature measuring unit and the terminal contact temperature measuring unit is set to 25mm; the physical feature extraction and decoupling module subtracts the ambient reference temperature inside the housing collected by the ambient reference temperature measuring unit from the terminal temperature collected by the terminal contact temperature measuring unit to generate a relative temperature rise gradient of the terminal that characterizes the power consumption of the contact resistance.

[0013] Preferably, when the multi-dimensional feature dynamic fusion and state arbitration module calculates the comprehensive anomaly early warning index, the following weighted fusion relationship is adopted: ,in This is a comprehensive anomaly early warning index; This represents the average of high-frequency transient energy. The preset high-frequency transient reference energy, For high-frequency transient normalized anomalies; The distortion rate is zero-crossing. The relative temperature rise gradient of the terminals; The preset terminal limit temperature rise reference, The anomaly is normalized to the temperature rise gradient. For high-frequency transient energy weights; Zero-crossing distortion weight; The weights are the gradient weights for the temperature rise. , and All are dimensionless constants and satisfy .

[0014] Preferred, high-frequency transient energy weight The value range is from 0.35 to 0.45, with zero-crossing distortion weights. The value range is from 0.30 to 0.40, and the temperature rise gradient weight is... The value range is 0.20 to 0.30; the preset high-frequency transient reference energy The value range is 0.040. Up to 0.060 Preset terminal limit temperature rise benchmark The value range is from 12.0℃ to 18.0℃.

[0015] Preferably, the multi-dimensional feature dynamic fusion and state arbitration module is configured with a sliding time window filtering logic for 3 to 5 consecutive power frequency half-cycles. When a large capacitor filter nonlinear load is connected to the switch socket, causing a sudden increase in high-frequency transient energy during closing and the comprehensive anomaly warning index in the first power frequency half-cycle exceeds the first-level alarm threshold, the multi-dimensional feature dynamic fusion and state arbitration module continuously performs sliding smoothing verification on the comprehensive anomaly warning index in subsequent power frequency half-cycles. When the high-frequency transient energy decays as the capacitor is fully charged and the comprehensive anomaly warning index in subsequent power frequency half-cycles falls back below the first-level alarm threshold, it is determined to be a non-fault transient disturbance and remains silent. When the comprehensive anomaly warning index in 3 to 5 consecutive power frequency half-cycles reaches the corresponding threshold, the state determination result is locked and signal transmission is initiated.

[0016] Preferably, the multi-dimensional feature dynamic fusion and state arbitration module is equipped with a hierarchical state determination logic that incorporates hysteresis: when the comprehensive anomaly warning index is less than the first-level alarm threshold, the determination loop is in normal operation; when the comprehensive anomaly warning index is greater than or equal to the first-level alarm threshold and less than the second-level alarm threshold, and continuously meets the sliding time window smoothing verification determination, the determination loop has a contact degradation risk and outputs a first-level warning signaling command; when the comprehensive anomaly warning index is greater than or equal to the second-level alarm threshold, and continuously meets the sliding time window smoothing verification determination, the determination loop experiences a continuous series fault arc and overheating anomaly and outputs a second-level emergency alarm signaling command; wherein the value range of the first-level alarm threshold is 0.25 to 0.35, the value range of the second-level alarm threshold is 0.50 to 0.60, and the value range of the hysteresis is 0.02 to 0.05.

[0017] Preferably, when the graded early warning and command transmission module responds to the first-level early warning transmission command, it drives the yellow LED in the local audible and visual indicator unit to flash, and sends a preventive maintenance message carrying the socket physical address code, comprehensive abnormality early warning index, and terminal temperature reading to the power distribution monitoring terminal through the remote command encoding transmission unit; when the graded early warning and command transmission module responds to the second-level emergency alarm transmission command, it drives the red LED in the local audible and visual indicator unit to flash at a frequency of 4.0Hz, drives the buzzer in the local audible and visual indicator unit to emit an intermittent alarm sound with a sound pressure level greater than 80dB, broadcasts a telemetry alarm message through the remote command encoding transmission unit, and outputs a level pulse to the cascade trip trigger unit to disconnect the socket circuit incoming contact within 20.0ms.

[0018] Preferably, the terminal contact temperature measuring unit is disposed on an alumina ceramic thermally conductive insulating substrate and is bonded and fixed to the outer surface of the root of the conductive metal sheet of the terminal block by high-temperature thermally conductive adhesive; the environmental reference temperature measuring unit is suspended and fixed at the louvered convection hole inside the air convection cavity, and the physical partition inside the switch socket housing blocks the heat radiation from the conductive metal sheet of the terminal block, isolating the Joule heat of the terminal block from the heat conduction and diffusion to the temperature measuring area where the environmental reference temperature measuring unit is located.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. In the early warning of switch and socket circuit anomalies, the circuit status is judged by simultaneously using the average high-frequency transient energy, zero-crossing distortion rate, and relative temperature rise gradient of the terminals. This makes it easier to distinguish between transient electromagnetic inrush currents generated by normal load start-up and shutdown and continuous anomalies caused by contact degradation and intermittent series discharge. For load disturbances that only occur for a short period of time, it is less likely to cause false alarms due to a sudden increase in a single signal. When actual contact degradation occurs at the wiring terminals, multiple abnormal characteristics can jointly reflect the fault changes, allowing the comprehensive anomaly early warning index to reflect the degree of anomaly in a timely manner, thereby reducing false alarms caused by normal load disturbances and improving the ability to detect early contact hazards. At the same time, this invention introduces an upper limit saturation operation to normalize the average high-frequency transient energy and the relative temperature rise gradient of the terminals, making them uniformly calibrated with the zero-crossing distortion rate in the 0 to 1 interval. From the algorithm structure and mathematical theory, this ensures that the comprehensive anomaly early warning index is closed within the benchmark interval of 0 to 1, eliminating the numerical flooding effect of extreme single-dimensional disturbances on multi-dimensional weights and ensuring the theoretical reliability of graded state arbitration.

[0021] 2. This invention separates the terminal contact temperature measurement unit from the environmental reference temperature measurement unit, so that the actual heating of the terminal can be referenced to the ambient temperature inside the housing, reducing the influence of ambient temperature changes and housing thermal inertia on the temperature measurement results. The resulting relative temperature rise gradient of the terminal can more directly reflect the heating caused by the increase in contact resistance, reducing the temperature reference drift caused by seasonal changes and changes in surrounding heat dissipation conditions. At the same time, the temperature rise information can also be corroborated with the zero-crossing characteristics of high-frequency current and power frequency current, providing a more stable and reliable temperature basis for circuit anomaly judgment.

[0022] 3. This invention uses sliding smoothing verification over multiple consecutive power frequency half-cycles and employs hysteresis during state return to prevent short-term spike disturbances from easily triggering alarms. For transient changes such as the closing of large-capacity filter capacitors, the system can maintain its original state since the abnormal state cannot continuously meet the judgment conditions, reducing false alarms caused by transient impacts. For continuous anomalies caused by real micro-discharges, hysteresis can prevent the comprehensive anomaly warning index from repeatedly switching states when fluctuating near the alarm threshold, thereby improving the stability of the alarm state and reducing the risk of false alarms and malfunctions of cascade tripping trigger units. Attached Figure Description

[0023] Figure 1 This is a flowchart of the multidimensional physical feature extraction and hierarchical state determination process of the present invention;

[0024] Figure 2 This is a diagram showing the physical closed-loop topology and system module architecture of the present invention.

[0025] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0027] An early warning system for switch and socket circuit anomalies includes:

[0028] The loop multidimensional physical quantity sensing module includes a high-frequency current mutual inductance sensing unit, a power frequency current sampling unit, a terminal contact temperature measurement unit, and an environmental reference temperature measurement unit, which are used to collect high-frequency current transient signals, power frequency current instantaneous values, terminal temperatures, and environmental reference temperatures inside the housing.

[0029] The physical feature extraction and decoupling module is connected to the loop multidimensional physical quantity sensing module. It is used to calculate the average value of high-frequency transient energy within half a cycle of power frequency, extract the zero-crossing distortion rate of the power frequency current zero-crossing stagnation time as a half-cycle duration, and calculate the difference between the terminal temperature and the reference temperature of the environment inside the housing as the relative temperature rise gradient of the terminal.

[0030] The multi-dimensional feature dynamic fusion and state arbitration module is connected to the physical feature extraction and decoupling module. It is used to perform upper limit saturation calculations based on preset benchmarks on the average high-frequency transient energy and the relative temperature rise gradient of the terminals to generate high-frequency transient normalized anomaly and temperature rise gradient normalized anomaly. The high-frequency transient normalized anomaly, temperature rise gradient normalized anomaly, and zero-crossing distortion rate are weighted and fused to generate a comprehensive anomaly warning index closed in the range of 0 to 1. The index is then slid-smoothly verified over multiple consecutive half-cycles and the loop status is determined by combining preset alarm thresholds and hysteresis.

[0031] The graded early warning and command transmission module, connected to the multi-dimensional feature dynamic fusion and status arbitration module, includes a local sound and light indication unit, a remote command encoding and transmission unit, and a cascaded trip trigger unit. It is used to output sound and light alarms, remote early warning messages, or trip instructions based on the judgment results, and return to normal state when the comprehensive abnormal early warning index falls below the difference between the first-level alarm threshold and the hysteresis lag.

[0032] Preferably, the sampling frequency of the high-frequency current transformer sensing unit and the power frequency current sampling unit is set to 200kHz; the physical feature extraction and decoupling module acquires 2000 discrete sampling points within 10.0ms of each power frequency half-cycle and extracts the high-frequency instantaneous current value of each sampling point; when the physical feature extraction and decoupling module calculates the average value of high-frequency transient energy, it squares the difference between the high-frequency instantaneous current value of each sampling point in a single power frequency half-cycle and the preset steady-state background high-frequency noise floor setting value of 0.001A, and accumulates and averages the 2000 squared results in a single power frequency half-cycle.

[0033] Preferably, the power frequency current sampling unit establishes a symmetrical time detection window based on the zero point of current polarity reversal within each power frequency half-cycle; when the physical feature extraction and decoupling module extracts the zero-crossing distortion rate, the absolute value of the cumulative instantaneous value of the power frequency current within the symmetrical time detection window is continuously lower than the preset micro-arc extinguishing threshold of 0.050A for a certain duration, and the stagnation duration is divided by the power frequency half-cycle duration of 10.0ms to obtain the dimensionless zero-crossing distortion rate.

[0034] Preferably, the terminal contact temperature measuring unit adopts a miniature thin-film thermistor and is set on the outside of the conductive metal sheet of the phase wire terminal of the switch socket; the ambient reference temperature measuring unit is set in the air convection baffle cavity next to the inlet hole on the back of the switch socket box, and the physical distance between the ambient reference temperature measuring unit and the terminal contact temperature measuring unit is set to 25mm; the physical feature extraction and decoupling module subtracts the ambient reference temperature inside the housing collected by the ambient reference temperature measuring unit from the terminal temperature collected by the terminal contact temperature measuring unit to generate a relative temperature rise gradient of the terminal that characterizes the power consumption of the contact resistance.

[0035] Preferably, when the multi-dimensional feature dynamic fusion and state arbitration module calculates the comprehensive anomaly early warning index, the following weighted fusion relationship is adopted: ,in This is a comprehensive anomaly early warning index; This represents the average of high-frequency transient energy. The preset high-frequency transient reference energy, For high-frequency transient normalized anomalies; The distortion rate is zero-crossing. The relative temperature rise gradient of the terminals; The preset terminal limit temperature rise reference, The anomaly is normalized to the temperature rise gradient. For high-frequency transient energy weights; Zero-crossing distortion weight; The weights are the gradient weights for the temperature rise. , and All are dimensionless constants and satisfy .

[0036] Preferred, high-frequency transient energy weight The value range is from 0.35 to 0.45, with zero-crossing distortion weights. The value range is from 0.30 to 0.40, and the temperature rise gradient weight is... The value range is 0.20 to 0.30; the preset high-frequency transient reference energy The value range is 0.040. Up to 0.060 Preset terminal limit temperature rise benchmark The value range is from 12.0℃ to 18.0℃.

[0037] Preferably, the multi-dimensional feature dynamic fusion and state arbitration module is configured with a sliding time window filtering logic for 3 to 5 consecutive power frequency half-cycles. When a large capacitor filter nonlinear load is connected to the switch socket, causing a sudden increase in high-frequency transient energy during closing and the comprehensive anomaly warning index in the first power frequency half-cycle exceeds the first-level alarm threshold, the multi-dimensional feature dynamic fusion and state arbitration module continuously performs sliding smoothing verification on the comprehensive anomaly warning index in subsequent power frequency half-cycles. When the high-frequency transient energy decays as the capacitor is fully charged and the comprehensive anomaly warning index in subsequent power frequency half-cycles falls back below the first-level alarm threshold, it is determined to be a non-fault transient disturbance and remains silent. When the comprehensive anomaly warning index in 3 to 5 consecutive power frequency half-cycles reaches the corresponding threshold, the state determination result is locked and signal transmission is initiated.

[0038] Preferably, the multi-dimensional feature dynamic fusion and state arbitration module is equipped with a hierarchical state determination logic that incorporates hysteresis: when the comprehensive anomaly warning index is less than the first-level alarm threshold, the determination loop is in normal operation; when the comprehensive anomaly warning index is greater than or equal to the first-level alarm threshold and less than the second-level alarm threshold, and continuously meets the sliding time window smoothing verification determination, the determination loop has a contact degradation risk and outputs a first-level warning signaling command; when the comprehensive anomaly warning index is greater than or equal to the second-level alarm threshold, and continuously meets the sliding time window smoothing verification determination, the determination loop experiences a continuous series fault arc and overheating anomaly and outputs a second-level emergency alarm signaling command; wherein the value range of the first-level alarm threshold is 0.25 to 0.35, the value range of the second-level alarm threshold is 0.50 to 0.60, and the value range of the hysteresis is 0.02 to 0.05.

[0039] Preferably, when the graded early warning and command transmission module responds to the first-level early warning transmission command, it drives the yellow LED in the local audible and visual indicator unit to flash, and sends a preventive maintenance message carrying the socket physical address code, comprehensive abnormality early warning index, and terminal temperature reading to the power distribution monitoring terminal through the remote command encoding transmission unit; when the graded early warning and command transmission module responds to the second-level emergency alarm transmission command, it drives the red LED in the local audible and visual indicator unit to flash at a frequency of 4.0Hz, drives the buzzer in the local audible and visual indicator unit to emit an intermittent alarm sound with a sound pressure level greater than 80dB, broadcasts a telemetry alarm message through the remote command encoding transmission unit, and outputs a level pulse to the cascade trip trigger unit to disconnect the socket circuit incoming contact within 20.0ms.

[0040] Preferably, the terminal contact temperature measuring unit is disposed on an alumina ceramic thermally conductive insulating substrate and is bonded and fixed to the outer surface of the root of the conductive metal sheet of the terminal block by high-temperature thermally conductive adhesive; the environmental reference temperature measuring unit is suspended and fixed at the louvered convection hole inside the air convection cavity, and the physical partition inside the switch socket housing blocks the heat radiation from the conductive metal sheet of the terminal block, isolating the Joule heat of the terminal block from the heat conduction and diffusion to the temperature measuring area where the environmental reference temperature measuring unit is located.

[0041] Example 1: In a building's low-voltage terminal power distribution system, a switch and socket circuit is deployed on a power supply network with a rated voltage of 220V and a rated power frequency of 50Hz. This is used to achieve online monitoring and tiered early warning of abnormal circuit conditions under alternating connection of nonlinear switching power supplies and resistive-inductive loads. The switch and socket housing integrates a multi-dimensional physical quantity sensing module for the circuit. The sampling frequency of the high-frequency current transformer sensing unit and the power frequency current sampling unit is set to 200kHz, used to synchronously acquire high-frequency transient current signals within each 10ms power frequency half-cycle. Instantaneous value of power frequency current The terminal contact temperature sensing unit uses a miniature thin-film thermistor, mounted on an alumina ceramic thermally conductive insulating substrate and bonded to the outer surface of the conductive metal sheet at the base of the phase wire terminal with high-temperature thermally conductive adhesive. This unit captures the temperature rise at the contact point caused by localized contact area degradation. The 25mm physical spacing is determined based on the thermal conduction attenuation characteristics inside the standard 86-type switch and socket box. Thermal simulation and experimental measurements show that when the terminal reaches its maximum temperature rise of 15℃, the temperature rise attenuation rate at 25mm is over 96% due to the physical barrier of the flame-retardant plastic internal partition and the airflow in the air convection cavity. This ensures that the temperature collected by the environmental reference temperature sensing unit accurately reflects the background air temperature inside the box without being directly interfered with by localized terminal heating. The environmental reference temperature sensing unit is suspended and fixed at the louvered convection hole inside the air convection cavity next to the inlet hole on the back of the switch and socket box, maintaining a 25mm physical spacing with the terminal contact temperature sensing unit. The internal partition blocks heat radiation from the conductive metal sheet of the terminal, allowing the unit to collect the environmental reference temperature inside the box. Eliminate the effect of ambient temperature fluctuations and housing thermal inertia on terminal temperature. To mitigate the baseline drift effect, specifically in the hardware topology, the high-frequency current transformer sensing unit uses a miniature Rogowski coil wrapped around the phase line input conductor. Its output is connected to the microcontroller's first analog-to-digital converter (ADC) channel via a second-order bandpass filter circuit and an instrumentation amplifier. The power frequency current sampling unit uses a 5mΩ manganese-copper shunt resistor connected in series in the phase line loop. The differential voltage drop signal across the shunt resistor is connected to the microcontroller's second ADC channel via a RC low-pass filter network. The terminal contact temperature measurement unit and the ambient reference temperature measurement unit are connected to the microcontroller's third and fourth ADC channels via constant current source excitation bridges, respectively. The physical feature extraction and decoupling module, as a parallel firmware routine in the microcontroller's digital signal processing core, independently reads the high-frequency instantaneous current discrete sampling values ​​from the first ADC channel. The system uses the zero-crossing sampling value of the power frequency current from the second analog-to-digital conversion channel, the terminal contact temperature reading from the third analog-to-digital conversion channel, and the ambient reference temperature reading from the fourth analog-to-digital conversion channel to calculate three independent discrete physical characteristics—the average high-frequency transient energy, the zero-crossing distortion rate, and the relative temperature rise gradient of the terminals—in parallel within the same sampling period. The physical feature extraction and decoupling module, as well as the multi-dimensional feature dynamic fusion and state arbitration module, all run within the internal digital signal processing core of the microcontroller. The general-purpose input / output pins of the microcontroller are electrically connected to the base of the driving transistor of the local acoustic-optical indicator unit and the opto-isolated thyristor gate of the cascaded trip trigger unit, respectively. The serial communication interface of the microcontroller is bidirectionally connected to the transceiver chip pins of the remote command encoding and sending unit to form a signal connection path for sensing acquisition, feature decoupling, state arbitration, and drive transmission.

[0042] The physical feature extraction and decoupling module communicates with the loop multidimensional physical quantity sensing module to acquire 2000 discrete sampling points within a single power frequency half-cycle and extract the high-frequency instantaneous current value of each sampling point. Subtracting the preset steady-state background high-frequency noise floor value Then, the squares are calculated and the sums are accumulated to obtain the mean. Take 0.001A to generate the average high-frequency transient energy. ,in, This represents the number of discrete sampling points within a single power frequency half-cycle, with a value of 2000. For the first The high-frequency instantaneous current value at each sampling point The set value for the steady-state background high-frequency noise floor. The dimension is A²; the power frequency current sampling unit establishes a symmetrical time detection window based on the zero point of power frequency current polarity reversal, and the absolute value of the cumulative instantaneous value of the power frequency current within the symmetrical time detection window by the physical feature extraction and decoupling module remains below the preset micro-arc extinguishing threshold. stagnation duration ,in Take 0.05A and set the duration of stagnation. Divide by the half-cycle length of the power frequency Generate dimensionless zero-crossing distortion , Take 10ms, where, The absolute value of the loop current near the zero-crossing point remains below the preset micro-arc extinction threshold. The duration of stagnation The measurement is a dimensionless scalar with a value range of 0 to 1; the physical feature extraction and decoupling module extracts the terminal temperature collected by the terminal contact temperature measurement unit. Subtract the ambient reference temperature inside the housing collected by the ambient reference temperature measurement unit The relative temperature rise gradient of the terminals, which characterizes the net Joule heat increment of the contact resistance, is calculated. ,in, and The units are all in °C. The unit is ℃; at the instant the load of a high-power switching power supply is closed, the charging of the filter capacitor is accompanied by a transient high-frequency inrush current, causing the average measured high-frequency transient energy within a single power frequency half-cycle to suddenly increase to 0.038 A². However, since this physical process does not have the stagnation and blocking characteristic of arc extinction and dielectric re-ignition, the stagnation duration is only 0.18 ms, corresponding to the zero-crossing distortion rate. The value was 0.018, and no local Joule heat accumulation occurred during the transient process; the measured terminal temperature was [value missing]. The reference temperature for the internal environment of the casing is 26.8℃. The temperature is 26℃, and the corresponding terminal relative temperature rise gradient is only 0.8℃, thereby achieving orthogonal decoupling between high-frequency disturbance and discharge physical characteristics at the source of the feature.

[0043] The multidimensional feature dynamic fusion and state arbitration module receives three orthogonal feature quantities generated by the physical feature extraction and decoupling module, and calls the weighted fusion relation. Calculate the comprehensive anomaly early warning index ,in, The high-frequency transient energy weight is set to 0.4. The distortion weight is set to zero and is set to 0.35. The temperature rise gradient weights are set to 0.25, and the sum of the three is always equal to 1. The preset high-frequency transient reference energy is set to 0.05 A². The preset terminal temperature rise limit is set to 15°C. It is a dimensionless scalar; in this embodiment, the ratio of the average high-frequency transient energy to the high-frequency transient reference energy is... The high-frequency transient normalized anomaly is obtained by upper limit saturation calculation. The ratio of the terminal relative temperature rise gradient to the terminal limit temperature rise reference is calculated. The upper limit saturation operation yields the normalized anomaly degree of the temperature rise gradient, ensuring that the high-frequency components and the temperature rise component are aligned with the zero-crossing distortion rate within the 0-1 interval. Each feature component is strictly normalized and mapped to a closed interval of 0-1 within both normal operation and various abnormal fault ranges. Combined with the weighted fusion weights, this satisfies... The constraints ensure that the calculated comprehensive anomaly warning index remains constant within the reference range of 0 to 1 in both mathematical theory and engineering implementation, eliminating the flooding effect of single characteristic component amplitude divergence on the weighting weights. The first-level alarm threshold is set to 0.25 to 0.35 based on the response boundary of the comprehensive anomaly warning index when the circuit exhibits mild contact degradation, zero-crossing stagnation, and weak temperature rise anomalies. Under this critical condition of mild contact degradation, the measured average high-frequency transient energy is 0.024 A², the zero-crossing distortion rate is 0.075, and the relative temperature rise gradient of the terminals is 5.8℃. Substituting these values ​​into the weighted fusion formula, the high-frequency component contribution term is calculated to be 0.4 multiplied by 0.02. 4A² divided by 0.050A² equals 0.1920. The zero-crossing distortion contribution is 0.35 multiplied by 0.075, which equals 0.0263. The temperature rise gradient contribution is 0.25 multiplied by 5.8℃ divided by 15.0℃, which equals 0.0967. Adding these three terms together yields a comprehensive anomaly warning index of 0.3150, which falls precisely within the first-level alarm threshold range of 0.25 to 0.35. The second-level alarm threshold is set to 0.50 to 0.60 based on the critical boundary of the comprehensive anomaly warning index when a continuous series fault arc and severe overheating co-deteriorate. Under this condition of severe arcing and overheating co-deterioration, the measured average high-frequency transient energy is 0.0. With an A² value of 42A, a zero-crossing distortion rate of 0.165, and a relative temperature rise gradient at the terminals of 12.6℃, substituting these values ​​into the weighted fusion formula, the high-frequency component contribution is calculated as follows: 0.4 multiplied by 0.042A² divided by 0.050A² equals 0.3360; the zero-crossing distortion contribution is calculated as 0.35 multiplied by 0.165 equals 0.0578; and the temperature rise gradient contribution is calculated as 0.25 multiplied by 12.6℃ divided by 15.0℃ equals 0.2100. Adding these three values ​​together yields a comprehensive anomaly warning index of 0.6038, which is stably outside the second-level alarm threshold range of 0.50 to 0.60. When a single-dimensional high-frequency disturbance such as the closing of a switching power supply occurs, due to the excessive... With zero distortion rate and terminal relative temperature rise gradient both at near-zero steady-state levels, even if the average high-frequency transient energy during closing surges dramatically and reaches or exceeds the high-frequency transient reference energy, after upper limit saturation calculation, its maximum saturation of high-frequency transient normalized anomaly is 1.0. The limiting contribution of the high-frequency transient energy component is clamped to 0.4, always below the second-level alarm threshold of 0.55. Theoretically, this completely blocks the possibility of a single high-frequency disturbance exceeding the second-level alarm threshold, thus ensuring stable arbitration judgment based on numerical values ​​and weights. Under the aforementioned switching power supply inrush current condition, the high-frequency component contribution obtained by substituting each parameter component within the first half-cycle of the power frequency is... The zero-crossing distortion contribution term is The contribution term of the temperature rise gradient is Summing these values ​​yields the comprehensive anomaly warning index for the first half-cycle as follows: The multi-dimensional feature dynamic fusion and state arbitration module starts continuously. The sliding time window filter verification is performed for one half-cycle of the power frequency, where... Given a continuous power frequency half-cycle number of 3, as the filter capacitor completes charging, the average high-frequency transient energy rapidly decays to 0.004A² in the subsequent second and third power frequency half-cycles. The calculated comprehensive anomaly warning index drops to 0.0712 and 0.065 respectively, both below the first-level alarm threshold. ,in The threshold value is set to 0.3. Because the threshold judgment window of three consecutive half-cycles of power frequency is not continuously met, the system determines that the operating condition is a non-fault transient disturbance and remains in a quiet state, thus blocking the false alarm signaling caused by the single-dimensional high-frequency signal criterion.

[0044] Under the fault evolution condition where a loose screw on the phase wire terminal of the socket causes local contact area deterioration and the contact resistance worsens from the normal 0.02Ω to 1.85Ω, micro-gap ionization discharge generates broadband electromagnetic white noise. The measured average high-frequency transient energy is stable at 0.042A². At the zero-crossing point of the current, due to the delay in the recovery of the gap dielectric deionization and the re-ignition of the arc, a flat-topped waveform is produced, which is discontinuous. The measured stagnation duration reaches 1.65ms, corresponding to a zero-crossing distortion rate. Simultaneously, the contact resistance generates heat, causing the terminal contact temperature measurement unit to measure the actual temperature of the wiring terminals. The temperature rose to 38.6°C, which is close to the reference temperature of the internal environment of the casing. To create a terminal relative temperature rise gradient of 12.6°C at 26°C, i.e. The multi-dimensional feature dynamic fusion and state arbitration module, by substituting weights and benchmark parameters, calculates the contribution term of high-frequency components. The zero-crossing distortion contribution term is The contribution term of the temperature rise gradient is The summation yields the comprehensive anomaly warning index as follows: In continuous Within one half-cycle of the power frequency, the comprehensive abnormal early warning index It remained stable at 0.6038, consistently exceeding the second-level alarm threshold. ,in The multi-dimensional feature dynamic fusion and state arbitration module locks the level-two emergency fault state and drives the hierarchical early warning and command transmission module to respond. This drives the red LED in the local audible and visual indicator unit to flash at a frequency of 4Hz and drives the buzzer to emit an intermittent alarm sound with a sound pressure level greater than 80dB. The remote command encoding and transmission unit broadcasts a telemetry alarm message to the power distribution monitoring gateway, carrying the socket's physical address code, a comprehensive anomaly warning index of 0.6038, and a terminal temperature of 38.6℃. It also outputs a level pulse to the cascaded trip trigger unit to drive the trip coil to disconnect the socket circuit's incoming contact within 20ms. When the circuit anomaly is eliminated and the comprehensive anomaly warning index falls back to the first-level alarm threshold... Subtract hysteresis When the obtained first-level regression threshold is below 0.27, the system returns to a normal state. Take 0.3, Take 0.03, hysteresis As a quantifiable dimensionless value, its range of 0.02 to 0.05 is determined based on the fluctuation amplitude calculated by the comprehensive anomaly warning index caused by steady-state background noise under normal operating conditions. The specific quantification derivation is as follows: When the circuit is operating in steady state and there is no discharge, the instantaneous current of the line background electromagnetic noise fluctuates between 0.0003A and 0.0008A. The resulting high-frequency transient energy mean value generates a discrete fluctuation with a maximum of ±0.0018A² near the zero point. This discrete fluctuation is dimensionless after being processed by the preset high-frequency transient reference energy of 0.050A² and linearly transmitted by multiplying it by the high-frequency transient energy weight of 0.4. That is, 0.4 multiplied by ±0.0018A² divided by 0.050A² equals ±0.0144, which is thus represented by a dimensionless numerical jitter of ±0.0144 in the comprehensive anomaly warning index, and the hysteresis is also considered. The value is set to be greater than the jitter amplitude, which is between 0.02 and 0.05, and in this embodiment, it is set to 0.0300. By creating a judgment dead zone greater than the fluctuation amplitude between the first-level alarm threshold and the first-level reset threshold, the high-frequency oscillation of the alarm state caused by the dynamic fluctuation of the contact resistance is suppressed. Specifically, the cascaded trip trigger unit includes an optocoupler isolation drive circuit, a miniature electromagnetic trip coil, and a miniature spring energy storage mechanical linkage mechanism. The high-level trigger pulse output by the microprocessor is isolated by the optocoupler and triggers the unidirectional thyristor to conduct. The instantaneous discharge current is released to the miniature electromagnetic trip coil by the power supply bus capacitor of the socket circuit. The electromagnetic attraction generated by the coil pulls the trip pin to strike the energy storage trip latch, so that the normally closed micro-motion spring of the phase line and the neutral line is instantly opened under the spring reaction force. The mechanical disconnection and electrical isolation of the physical input contact of the socket main circuit are achieved within 20ms.

[0045] Example 2: In this example, the low-voltage terminal power distribution test circuit uses a power supply bus with a rated phase voltage of 220V and a rated power frequency of 50Hz. The end of the bus is connected to a test bench containing the switch and socket body. The load end is equipped with a flyback switching power supply, a variable frequency speed control motor, and a contact degradation simulator with a micro-displacement adjustment mechanism to form load start-up and shutdown and contact interface degradation conditions of different degrees. The high-frequency current transformer sensing unit is equipped with a 10MHz analog bandwidth, and the power frequency current sampling unit is equipped with a 16-bit analog-to-digital conversion channel. Both are synchronously acquiring high-frequency current transient signals at a sampling frequency of 200kHz. Instantaneous value of power frequency current The sampling frequency takes into account both the acquisition of the 100kHz micro-arc high-frequency electromagnetic oscillation component and the computational load of 2000 sampling points per half-cycle of power frequency. A fourth-order Butterworth low-pass anti-aliasing filter circuit with a cutoff frequency of 80kHz is cascaded at the back end of the high-frequency current transformer sensing unit, which provides a stopband attenuation of more than 40dB for out-of-band high-frequency components above 100kHz, limiting the input signal bandwidth to within 80kHz, so as to reduce the aliasing effect of 10MHz wideband spurious signals on discrete sampling results and high-frequency transient energy mean calculation.

[0046] The terminal contact temperature sensing unit is attached to the base of the conductive metal strip of the phase wire terminal of the socket, with a temperature resolution of 0.05℃. The environmental reference temperature sensing unit is suspended in the air convection baffle cavity next to the cable inlet on the back of the box, maintaining a physical distance of 25mm from the terminal contact temperature sensing unit, and collects the temperature of the terminals respectively. relative to the ambient temperature inside the housing The experimental signal source was superimposed with a Gaussian white noise substrate with a signal-to-noise ratio of 20 dB. The steady-state background high-frequency noise substrate setting value in the physical feature extraction and decoupling module was... Set the current to 0.001A and preset the micro-arc extinction threshold. Take 0.05A as the high-frequency transient reference energy. Take 0.05A² as the terminal limit temperature rise reference. Set the temperature to 15℃; High-frequency transient energy weighting Take 0.4, zero-crossing distortion weight Set to 0.35, for the temperature rise gradient weight. Set the value to 0.25, which is the first-level alarm threshold. Set the threshold to 0.3, which is the second-level alarm threshold. Take 0.55, hysteresis Take 0.03.

[0047] The experiment also examined the value range of the above-mentioned weights and benchmark parameters. The high-frequency transient energy weight was set between 0.35 and 0.45, the zero-crossing distortion weight was set between 0.30 and 0.40, and the temperature rise gradient weight was set between 0.20 and 0.30. When the high-frequency transient energy weight was higher than 0.45, the variable frequency load was more likely to enter the warning range. When the temperature rise gradient weight was lower than 0.20, the state transition of the severe overheating fault was delayed. The high-frequency transient benchmark reference energy was set between 0.040 and 0.060 A². When it was lower than 0.040 A², the contribution of normal closing inrush current to the comprehensive abnormal warning index increased. When it was higher than 0.060 A², the high-frequency transient energy change corresponding to the micro-arc was compressed. The terminal limit temperature rise benchmark was set between 12.0 and 18.0℃, where the lower limit corresponds to the critical temperature rise starting point of long-term thermal aging of the socket plastic shell, and the upper limit corresponds to the critical safety upper limit of accelerated softening of the insulation material due to thermal deformation.

[0048] The average high-frequency transient energy measured in sample group 1 of this invention during normal stable operation under resistive-inductive load. The zero-crossing dwell time is 0.003A². The value is 0.12ms, corresponding to a zero-crossing distortion rate. The relative temperature rise gradient of the terminals is 0.012. The temperature was 2.1℃; after weighting the three characteristic quantities according to predetermined weights, the comprehensive anomaly warning index was calculated. The value is 0.0632, which is lower than the first-level alarm threshold. The status arbitration result is that the system is in normal operation. The graded early warning and instruction sending module remains silent and does not send any messages.

[0049] When a high-power switching power supply is switched on, the average high-frequency transient energy measured in sample group 2 of this invention is... The zero-crossing dwell time is 0.038A². The zero-crossing distortion rate is 0.18ms. The relative temperature rise gradient of the terminals is 0.018. The comprehensive anomaly warning index for the first half-cycle of the power frequency is 0.8℃. After weighting the above characteristic quantities, the index is 0.8℃. The value was 0.3236; the multi-dimensional feature dynamic fusion and state arbitration module continued to perform sliding smoothing verification for 3 half-cycles of power frequency. As the closing transient decayed, the comprehensive abnormal warning index dropped to 0.065. The system judged this state as a non-fault transient disturbance and kept it quiet, without outputting a false alarm signal.

[0050] During the operation of the variable frequency motor at variable speed, the average high-frequency transient energy of sample group 3 of this invention was measured. The zero-crossing dwell time is 0.032A². The zero-crossing distortion rate is 0.15ms. The relative temperature rise gradient of the terminals is 0.015. The temperature was 1.4℃; the weighted comprehensive anomaly warning index was 1.4℃. The value is 0.2846, which is still below the first-level alarm threshold. The status arbitration result remains in normal operation, and the graded early warning and instruction sending module has no action.

[0051] The contact degradation test uses a contact degradation simulator to gradually increase the contact resistance of the terminals, covering a range from 0.45Ω to 2.40Ω. When the wiring is slightly loose and a weak arc occurs, the average high-frequency transient energy of sample group 4 of this invention is measured. The zero-crossing dwell time is 0.024A². The zero-crossing distortion rate is 0.75ms. The relative temperature rise gradient of the terminals is 0.075. The temperature was 5.8℃; after weighting the above characteristic quantities, the comprehensive anomaly warning index was calculated. When the value is 0.315, the system enters the first-level alarm range and outputs a first-level warning. The yellow LED in the local audible and visual indicator unit flashes, and at the same time, a preventive maintenance message is sent through the remote command encoding and sending unit, which completes the transmission within 30ms.

[0052] When the terminal further deteriorates to a moderate degree and micro-arcs continue to appear, the average high-frequency transient energy measured in sample group 5 of this invention is... The zero-crossing dwell time is 0.035A². The zero-crossing distortion rate is 1.20ms. The relative temperature rise gradient of the terminals is 0.120. The temperature was 9.6℃; the weighted comprehensive anomaly warning index was obtained. The value is 0.482, which is still within the first-level alarm range. The system continues to output a first-level warning, indicated by a flashing yellow LED and the sending of a preventive maintenance message, with a transmission time of 30ms.

[0053] When the contact resistance reaches 1.85Ω, the terminals are severely loose, and arcing and overheating occur, the average high-frequency transient energy of sample group 6 of this invention is measured. The zero-crossing dwell time is 0.042A². The zero-crossing distortion rate is 1.65ms. The relative temperature rise gradient of the terminals is 0.165. The temperature was 12.6℃; after weighting the three characteristic quantities, the comprehensive anomaly warning index was... The value is 0.6038, exceeding the second-level alarm threshold. The status arbitration result enters the second-level emergency alarm state. The graded early warning and command transmission module drives the audible and visual alarm, sends the telemetry alarm message through the remote command encoding and sending unit, and outputs a level pulse to the cascade trip trigger unit. The trip is completed and the circuit is cut off in 18.5ms.

[0054] When the contact surface continues to deteriorate to the limit of ablation and generates violent discharge, the average high-frequency transient energy of sample group 7 of this invention is measured. The zero-crossing dwell time is 0.048A². The zero-crossing distortion rate is 1.92ms. The relative temperature rise gradient of the terminals is 0.192. The temperature rise is 16.5℃. After weighted fusion processing, the relative temperature rise gradient of the terminals is 16.5℃, which exceeds the limit temperature rise benchmark of 15℃. After upper limit saturation calculation, the normalized anomaly degree of the corresponding temperature rise gradient is saturated to 1.0, and the comprehensive anomaly warning index is calculated. Increased to 0.7012, the status arbitration result remains at level two emergency alarm, the system outputs audible and visual alarm, telemetry alarm message and trip command, and completes the trip disconnection circuit in 17.2ms.

[0055] The feature-deficient control experiment used the same input conditions as the corresponding operating conditions described above. The partially deficient control group A removed the high-frequency transient energy mean feature, and did not perform the acquisition and calculation of this feature. Only the zero-crossing dwell time of 0.75 ms, the zero-crossing distortion rate of 0.075, and the terminal relative temperature rise gradient of 5.8℃ were retained for state calculation. The resulting comprehensive anomaly warning index... The value is 0.1229; the status arbitration result is normal operation, no alarm signal is output, and early weak arc is missed.

[0056] Partially missing control group B, zero-crossing distortion features removed, mean high-frequency transient energy. The value is 0.038 A², and the zero-crossing dwell time and zero-crossing distortion rate are not collected and calculated. The relative temperature rise gradient of the terminals is... The value is 0.8℃; in the absence of zero-crossing distortion rate as a weighting factor, the comprehensive anomaly warning index is... The value is 0.3173. The status arbitration result enters the first-level early warning and outputs a yellow indication signal, causing a false alarm during the switching power supply closing transient.

[0057] The relative temperature rise gradient and mean high-frequency transient energy of the partially missing control group C-terminal knockout terminal The zero-crossing dwell time is 0.042A². The zero-crossing distortion rate is 1.65ms. The value is 0.165, and the relative temperature rise gradient of the terminals is not collected and calculated; the comprehensive anomaly warning index is obtained from the remaining characteristic quantities. The value is 0.3938, the status remains at the first-level warning level, and the trip signal has not been triggered. Under the condition of severe overheating fault, there is a missed alarm at a higher level.

[0058] The partially missing control group D retains the high-frequency transient energy mean of 0.038 A², zero-crossing dwell time of 0.18 ms, zero-crossing distortion rate of 0.018, and terminal relative temperature rise gradient of 0.8℃, but removes the sliding time window filtering logic and hysteresis. After the comprehensive abnormal warning index calculated by the first power frequency half cycle is 0.3236, it is directly judged as a first-level warning and outputs a signal. The closing transient inrush current thus triggers a false signal.

[0059] The parameter out-of-range test further modified individual parameters. The out-of-range control group E had its high-frequency transient energy weight set to 0.60. Under the variable frequency motor speed regulation condition, the average high-frequency transient energy... The zero-crossing dwell time is 0.032A². The zero-crossing distortion rate is 0.15ms. The relative temperature rise gradient of the terminals is 0.015. The temperature was 1.4℃, resulting in a comprehensive anomaly warning index. The value is 0.4057, which exceeds the first-level alarm threshold, causing frequent false alarms under normal speed regulation conditions.

[0060] The out-of-range control group F sets the terminal limit temperature rise benchmark at 25°C. Under the condition of severe terminal loosening and arc overheating, the average high-frequency transient energy is... The zero-crossing dwell time is 0.042A². The zero-crossing distortion rate is 1.65ms. The relative temperature rise gradient of the terminals is 0.165. The temperature was 12.6℃; the weighted comprehensive anomaly warning index was obtained. The value was 0.5198, which is lower than the second-level alarm threshold. No tripping command was generated, and the tripping action was delayed.

[0061] In the above tests, normal resistive load, switching power supply closing and frequency conversion speed regulation conditions were all kept in normal state or returned to rest after sliding smoothing verification; when the connection terminal developed from slight loosening to continuous micro-arc, severe arc overheating and extreme ablation, the average value of high frequency transient energy, zero-crossing distortion rate and terminal relative temperature rise gradient increased together with the degree of contact degradation. The comprehensive abnormal warning index changed from the first-level alarm range to the second-level alarm range. After the serious fault entered the second-level alarm state, the cascade trip trigger unit completed the circuit disconnection within 20ms.

[0062] The remote command encoding and sending unit uses a power line carrier communication modem chip. The microprocessor combines and encapsulates the 16-bit socket hardware physical address code, the 8-bit abnormality level status code, the 16-bit comprehensive abnormality early warning index fixed-point quantization value, and the 16-bit terminal temperature data into a data link layer message frame. A 16-bit cyclic redundancy check code is added to the end of the frame. Then, the carrier chip couples and injects the signal into the power supply bus using orthogonal frequency division multiplexing modulation, and broadcasts it to the building power distribution monitoring terminal.

[0063] Example 3: The current low-voltage building terminal power distribution switch socket uses a power supply circuit with a rated voltage of 220V and a rated power frequency of 50Hz. In this example, the spatial isolation, feature extraction and parameter calibration of the circuit multi-dimensional physical quantity sensing module are further tested. The terminal contact temperature measuring unit uses a miniature thin film thermistor with a nominal resistance of 10kΩ and a temperature measuring resolution of 0.05℃. It is attached and fixed to the outer surface of the conductive metal sheet root of the phase wire terminal of the switch socket through an alumina ceramic thermally conductive insulating substrate. The environmental reference temperature measuring unit is suspended and mounted in the air convection baffle cavity next to the inlet hole on the back of the socket housing bottom box, maintaining a physical distance of 25mm from the terminal contact temperature measuring unit. The heat radiation from the conductive metal sheet of the terminal is blocked by the internal partition of the socket housing, and it is used to collect the environmental reference temperature inside the housing.

[0064] After the system is powered on, under steady-state pure resistive-inductive load operation, the physical feature extraction and decoupling module discretely collects 2000 high-frequency instantaneous current sampling points at a sampling frequency of 200kHz within each 10ms power frequency half-cycle. After continuously statistically analyzing the background electromagnetic radiation background under arc-free discharge conditions, the steady-state background high-frequency noise floor setting value is set. The calibration is set to 0.001A. The physical feature extraction and decoupling module subtracts the steady-state background high-frequency noise baseline setting value of 0.001A from the high-frequency instantaneous current readings of each discrete sampling point, performs self-square calculation on each effective difference, and accumulates all 2000 square calculation results within a 10.0ms half-cycle time domain window and divides them by the total number of sampling points of 2000. This calculates the mean square statistic characterizing the intensity of high-frequency fluctuations as the mean of high-frequency transient energy. Its actual physical dimension is the discrete statistical mean of the current square and the unit is A². At the same time, the high-frequency transient benchmark reference energy used for comparison is calibrated to 0.050A². The upper limit of the discrete variance statistics when the rated current of a purely resistive load is used as the benchmark denominator for the upper limit saturation normalization operation to calculate the high-frequency transient normalized anomaly degree with a value range closed between 0 and 1.

[0065] The power frequency current sampling unit collects the instantaneous value of the power frequency current within each power frequency half-cycle and locks the current polarity reversal zero point. The physical feature extraction and decoupling module constructs a symmetrical time detection window with a width of 2ms centered on this zero point, that is, taking 1ms before and after the zero point; within this detection window, the absolute value of the instantaneous value of the power frequency current is continuously lower than the preset micro-arc extinguishing threshold. The complete duration is accumulated by discrete sampling points to obtain the stagnation duration. ,in Take 0.05A, then... Compared with the 10ms power frequency half-cycle duration, the zero-crossing distortion rate was obtained. The stagnation duration measured during normal smooth zero crossing is 0.12 ms; during weak intermittent series discharge, the arc extinguishes near the zero crossing of the AC current and reignites after the terminal voltage reaches the breakdown condition again, and the power frequency current forms a flat-topped discontinuous waveform near the zero crossing, and the stagnation duration increases accordingly.

[0066] To address the issue of small amplitude and gentle zero-crossing slope of the sinusoidal current under low-power pure resistive-inductive loads, current rate of change verification is performed simultaneously within the aforementioned 2ms symmetrical time detection window. When a normal sinusoidal small current crosses zero, the current rate of change maintains a non-zero slope, and the absolute value of the current remains below the preset micro-arc extinguishing threshold for no more than 0.20ms. When a micro-gap arc discharge occurs, the current rate of change near the zero crossing approaches zero, and the duration below this threshold exceeds 0.20ms. This 0.20ms criterion is used to help distinguish between normal zero crossing and discharge stagnation, without changing the duration of stagnation. The cumulative caliber; The total duration during which the absolute value of the current within the symmetrical time detection window remains below the preset micro-arc extinction threshold is accumulated, without deducting 0.20ms.

[0067] Terminal limit temperature rise reference Based on the fact that the critical temperature rise for long-term contact thermal degradation of the socket's insulating flame-retardant housing under rated current load is calibrated to be 15℃, the physical feature extraction and decoupling module extracts the terminal temperature collected by the terminal contact temperature measurement unit. Subtract the ambient reference temperature inside the housing collected by the ambient reference temperature measurement unit The relative temperature rise gradient of the terminals was obtained. The temperature difference changes with the local heating of the terminals, and the overall rise and fall of the ambient temperature cancels out the effect of the measurement baseline on the temperature difference between the two paths.

[0068] The multi-dimensional feature dynamic fusion and state arbitration module processes the high-frequency transient energy mean according to a predetermined weighted fusion relationship. Zero-crossing distortion rate temperature gradient relative to terminals Among them, high-frequency transient energy weight Take 0.4, zero-crossing distortion weight Set to 0.35, for the temperature rise gradient weight. With a weight of 0.25 and a sum of 1 for the three weights, the average high-frequency transient energy and zero-crossing distortion rate reflect the rapid changes in electrical quantities within a sliding time window of 30ms to 50ms. The relative temperature rise gradient of the terminal is affected by the heat capacity of the metal conductor and the heat transfer process, and changes slowly within the same millisecond time window. When a non-heating transient electromagnetic inrush current occurs, the relative temperature rise gradient of the terminal remains at a low level. As the electrical transient decays, the comprehensive anomaly warning index drops synchronously. When the wiring terminal continues to heat up, the relative temperature rise gradient of the terminal continues to increase with contact degradation, and participates in the state determination together with the subsequent high-frequency transient and zero-crossing distortion.

[0069] Length of the first-in-first-out queue buffer register inside the multi-dimensional feature dynamic fusion and state arbitration module The comprehensive anomaly warning index is calculated based on three consecutive power frequency half-cycles. When the sliding time window filtering logic is executed, the comprehensive anomaly warning index reaches 0.3236 for a single power frequency half-cycle when the nonlinear capacitive load is closed. It then decays to 0.0712 and 0.065 for the next two power frequency half-cycles, respectively. Since the comprehensive anomaly warning index has not consistently reached the first-level alarm threshold for three consecutive power frequency half-cycles... The module determined the disturbance to be a non-faulty transient disturbance, and the graded early warning and command transmission module remained silent.

[0070] After persistent poor contact and micro-arc discharge occur at the wiring terminals, if the comprehensive abnormality warning index remains at the first-level alarm threshold for three consecutive half-cycles of power frequency, the alarm will be triggered. Compared with the second-level alarm threshold During this period, the multi-dimensional feature dynamic fusion and state arbitration module locks the first-level warning state, drives the hierarchical warning and command transmission module to control the yellow indicator light in the local sound and light indicator unit to flash, and sends a preventive maintenance message carrying the socket physical address code, comprehensive abnormal warning index and terminal temperature reading to the power distribution monitoring terminal through the remote command encoding and transmission unit; after the loose wiring worsens and violent discharge and severe overheating of the terminals occur, when the comprehensive abnormal warning index reaches or exceeds the second-level alarm threshold for three consecutive power frequency half-cycles. When the alarm is locked at level two, the red indicator light in the local audible and visual indicator unit flashes at a frequency of 4Hz, the buzzer outputs an intermittent alarm sound greater than 80dB, and at the same time outputs a level pulse to the cascade trip trigger unit to disconnect the incoming contact of the socket circuit within 20ms.

[0071] Hysteresis is used during state recovery. Only when the circuit anomaly is eliminated and the comprehensive anomaly warning index falls back to the first-level alarm threshold. Hysteresis When the difference is below a certain threshold, it returns to normal, preventing repeated switching of the alarm state when the contact resistance fluctuates briefly under mechanical vibration conditions.

[0072] In the dynamic environmental test of the building terminal socket, the rated voltage of the power supply circuit is 220V and the rated power frequency is 50Hz. The test environment temperature cycles between -10℃ and 45℃ at a rate of 5℃ per hour. The system collects the terminal temperature and the reference temperature of the environment inside the housing in real time. The environmental reference temperature measurement unit changes with the temperature of the environmental chamber, and the difference between the two temperatures is maintained within 0.3℃. When a micro-gap is formed between the phase wire terminals and a micro-arc discharge is continuously generated, the terminal temperature reaches 42.5℃, the reference temperature of the environment inside the housing is 28℃, and the corresponding relative temperature rise gradient of the terminals is 14.5℃. The physical feature extraction and decoupling module simultaneously obtains a high-frequency transient energy average of 0.039A² and a zero-crossing distortion rate of 0.145. The comprehensive abnormal warning index calculated by the multi-dimensional feature dynamic fusion and state arbitration module is 0.6044. After the second-level alarm condition is reached for three consecutive power frequency half-cycles, the system triggers a second-level emergency alarm, and the cascaded trip trigger unit executes the trip signal action.

[0073] Example 4: This example combines Figures 1 to 2 This paper describes an early warning system for a switch and socket circuit malfunction, such as... Figure 1As shown, the power frequency current sampling unit collects the power frequency current of the circuit and transmits it to the zero-crossing distortion rate extraction process. This process calculates the zero-crossing distortion rate, which characterizes the zero-crossing stagnation characteristic, and outputs it to the comprehensive anomaly warning index calculation process. The high-frequency current transformer sensing unit collects the high-frequency transient signal of the circuit and transmits it to the high-frequency transient energy mean extraction process. This process calculates the high-frequency transient energy mean and outputs it to the comprehensive anomaly warning index calculation process. The terminal contact temperature measurement unit collects the terminal temperature, and the environmental reference temperature measurement unit collects the ambient reference temperature inside the housing. The temperatures collected by the terminal contact temperature measurement unit and the environmental reference temperature measurement unit are input together to the terminal relative temperature rise gradient calculation process to eliminate ambient background temperature interference and obtain the terminal relative temperature rise gradient. The calculated terminal relative temperature rise gradient is synchronously output to the comprehensive anomaly warning index calculation process. The data processing process dynamically weights and fuses multiple physical quantities, including the average high-frequency transient energy, zero-crossing distortion rate, and relative temperature rise gradient of the terminals, to generate a comprehensive anomaly warning index. This comprehensive anomaly warning index is then transmitted to the sliding smoothing verification and state determination process. The sliding smoothing verification and state determination process, combined with hysteresis judgment, performs time-domain smoothing filtering verification and graded state determination on the comprehensive anomaly warning index within a continuous period to block transient disturbances and lock in the true anomaly state. When the determination circuit is at different anomaly levels, the sliding smoothing verification and state determination process collaboratively sends corresponding control and trigger signals to the local audible and visual indicator unit, the remote command encoding and sending unit, and the cascade trip trigger unit. This drives the local audible and visual indicator unit to issue graded audible and visual alarm indications, drives the remote command encoding and sending unit to send remote early warning messages, and drives the cascade trip trigger unit to operate in emergency fault conditions to disconnect the circuit power supply contacts.

[0074] like Figure 2As shown, a topology architecture centered on a physical closed-loop path is constructed. The loop multi-dimensional physical quantity sensing module, physical feature extraction and decoupling module, multi-dimensional feature dynamic fusion and state arbitration module, and hierarchical early warning and command transmission module are connected to the centrally located physical closed-loop path to form a closed-loop collaborative system for sensing acquisition, feature decoupling, state arbitration, and drive transmission. The loop multi-dimensional physical quantity sensing module integrates a high-frequency current mutual inductance sensing unit, a power frequency current sampling unit, a terminal contact temperature measurement unit, and an environmental reference temperature measurement unit. It collects high-frequency current transient signals, power frequency current instantaneous values, terminal temperatures, and the environmental reference temperature inside the housing, respectively. The collected multi-dimensional physical quantities are input to the physical feature extraction and decoupling module. This module receives the acquired signals from the loop multi-dimensional physical quantity sensing module and decouples and extracts the average high-frequency transient energy, zero-crossing distortion rate, and terminal temperature. The relative temperature rise gradient is used to transmit the decoupled physical quantities to the multi-dimensional feature dynamic fusion and state arbitration module. The multi-dimensional feature dynamic fusion and state arbitration module receives the average high-frequency transient energy, zero-crossing distortion rate and terminal relative temperature rise gradient, and then calculates a comprehensive anomaly warning index by weighting. Based on the configured sliding time window filtering logic and the hierarchical state judgment logic combined with hysteresis, it performs time-domain smoothing verification and loop state arbitration. The hierarchical warning and command transmission module is connected to the multi-dimensional feature dynamic fusion and state arbitration module. According to the state arbitration result, it links and controls the internally integrated local sound and light indication unit, remote command encoding and transmission unit and cascade trip trigger unit to perform local sound and light alarm indication, remote early warning message transmission and loop contact disconnection and trip control, respectively. At the same time, the disconnection control signal is applied to the loop monitored by the loop multi-dimensional physical quantity sensing module to complete the closed-loop state monitoring and control linkage.

[0075] Example 5: After the switch and socket are powered on at the site, the microprocessor initialization program first performs zero-point drift self-test and thermal balance calibration on the multi-dimensional physical quantity sensing module of the circuit. The high-frequency current transformer sensing unit and the power frequency current sampling unit continuously collect the background electromagnetic signal for 10 power frequency cycles under the no-load and no-load state at the initial stage of the power supply bus closing. The background bias of each sampling point is extracted and written into the internal static memory as the initial zero-point correction reference, so that the steady-state background high-frequency noise floor setting value is set. The signal converges stably to 0.001A to reduce the impact of parasitic capacitance of power distribution lines in different buildings and differences in spatial electromagnetic radiation on the average high-frequency transient energy. The initial effects of the solution.

[0076] The steady-state background high-frequency noise floor setting value of 0.001A was determined by the no-load background test of a typical building low-voltage power distribution line. The test line connection length was 10m to 50m, and the spatial electromagnetic radiation field strength was less than 3V / m. A total of 50 sets of no-load background tests were conducted. The statistical fluctuation range of the high-frequency transient noise current amplitude generated by the inherent distributed capacitance of the line and the spatial stray switch radiation was 0.0003A to 0.0008A. The setting value of 0.001A covers the upper limit of Gaussian noise of 3 times the standard deviation. When the setting value is lower than 0.0008A, the inherent background noise of the line will be included in the transient discharge energy. When the setting value is higher than 0.003A, the high-frequency current component corresponding to the weak discharge will be excessively subtracted. Therefore, in this embodiment, 0.001A is used as the steady-state background high-frequency noise floor setting value.

[0077] The terminal contact temperature sensing unit is attached to the base of the conductive metal sheet of the phase wire terminal, while the ambient reference temperature sensing unit is suspended and mounted in the air convection baffle cavity next to the inlet hole on the back of the socket housing. The two units maintain a physical distance of 25mm. Under the initial thermal equilibrium state without load, the microprocessor synchronously reads the initial values ​​of the terminal temperature and the ambient reference temperature inside the housing, and calculates the initial temperature difference between the two readings. When the absolute value of the initial temperature difference is within 0.2℃, it is determined that the two temperature sensing points meet the thermal equilibrium calibration conditions, the initial relative temperature rise deviation is cleared to zero, and the terminal limit temperature rise reference is set. The temperature was set to 15°C to correct for the relative temperature rise gradient at the terminals caused by the manufacturing tolerances of the two temperature sensors and the inherent thermal conductivity differences of the housing. The impact of measurement results.

[0078] The physical feature extraction and decoupling module converts the collected physical quantities into high-frequency transient energy averages. Zero-crossing distortion rate temperature gradient relative to terminals Subsequently, the multi-dimensional feature dynamic fusion and state arbitration module performs state arbitration according to the judgment rules preset in the memory, wherein the high-frequency transient energy weight Set to 0.4, zero-crossing distortion weight Set to 0.35, temperature rise gradient weight The value is set to 0.25, and the comprehensive anomaly early warning index is calculated in real time according to the established weighted fusion relationship. ; Length of the first-in-first-out queue buffer register Initialized to three power frequency half-cycles, when a single-cycle non-fault spike disturbance occurs during load switching, each storage unit shifts sequentially, and a sliding time window filtering logic is implemented on the comprehensive anomaly warning index for three consecutive power frequency half-cycles.

[0079] When the circuit contact interface continues to degrade, and the comprehensive abnormality warning index is at the first-level alarm threshold for three consecutive power frequency half-cycles. Up to the second-level alarm threshold Between, the first-level alarm threshold The exponential response boundary, calculated by summing the measured high-frequency component contribution (0.1920), zero-crossing distortion contribution (0.0263), and temperature rise gradient contribution (0.0967) under mild contact degradation, is calibrated to 0.3000, and this is the second-level alarm threshold. Based on the summation of the three characteristic components (0.3360, 0.0578, and 0.2100) when the arc overheating severely deteriorates, the exponential response boundary of 0.6038 is calibrated to 0.5500. The multi-dimensional feature dynamic fusion and state arbitration module locks the first-level warning state, driving the hierarchical warning and command transmission module to generate a preventive maintenance message carrying the socket physical address code, comprehensive abnormal warning index, and terminal temperature. When the loose wiring worsens and induces continuous discharge, and the comprehensive abnormal warning index reaches or exceeds the second-level alarm threshold for three consecutive power frequency half-cycles. When the alarm is locked at level two, the red indicator light in the local audible and visual indicator unit flashes at a frequency of 4Hz, and the buzzer outputs an intermittent alarm sound greater than 80dB. At the same time, a level pulse is output to the cascade trip trigger unit to disconnect the incoming contact of the socket circuit within 20ms.

[0080] In the state regression determination, the multi-dimensional feature dynamic fusion and state arbitration module adopts hysteresis hysteresis. The hysteresis is quantized to 0.0300 based on the calculated noise floor fluctuation of ±0.0144 caused by the measured background Gaussian white noise of the line. Specifically, the quantization derivation is as follows: When the circuit is in steady-state operation and there is no discharge, the instantaneous current of the background electromagnetic noise of the line fluctuates between 0.0003A and 0.0008A. This causes a discrete fluctuation of up to ±0.0018A² near the zero point in the calculated average value of the high-frequency transient energy. This discrete fluctuation is dimensionless after being processed by a preset high-frequency transient reference energy of 0.050A² and linearly transferred by multiplying it by a high-frequency transient energy weight of 0.4. That is, 0.4 multiplied by ±0.0018A² divided by 0.050A² equals ±0.0144, thus manifesting as a dimensionless numerical jitter of ±0.0144 in the comprehensive anomaly warning index. This ensures that the dead zone width completely covers the fluctuation range of the environmental electromagnetic noise, thus setting the first-level alarm threshold. Hysteresis The difference corresponds to a first-level reset threshold of 0.27; when the comprehensive abnormal warning index falls below 0.27, the system returns to normal, so that when the contact resistance undergoes dynamic jumps under mechanical vibration conditions, it does not repeatedly trigger alarm state switching and tripping actions.

[0081] Example 6: The current loop multidimensional physical quantity sensing module is connected to the offline calibration test bench. Before the system leaves the factory or is deployed in the field, parameter initialization and offline calibration of the sensor response matrix are performed. The high-frequency current transformer sensing unit is connected to a standard high-frequency current generator on the calibration workbench. High-frequency current transient signals with amplitudes increasing from 0.010A to 0.100A and a frequency of 100kHz are input sequentially, and the corresponding output voltage response amplitude is recorded. Based on the high-frequency current transient signal with known amplitude and the measured voltage response, the microprocessor uses the least squares method to linearly fit and determine the linear proportional conversion gain between the high-frequency instantaneous current and the induced output voltage, and writes the gain into the non-volatile memory.

[0082] In actual operation, the microprocessor converts the induced output voltage of each discrete sampling point into a high-frequency instantaneous current value based on the linear proportional conversion gain. After subtracting the steady-state background high-frequency noise floor setpoint, the differences are squared and summed, then divided by the total number of sampling points. The mean high-frequency transient energy is then calculated according to the square mean relationship. This allows the sensor's linear calibration parameters to be substituted into the square of the mean high-frequency transient energy.

[0083] The power frequency current sampling unit collects data for different dwell times under a standard power frequency of 50Hz steady-state current. The corresponding analog-to-digital converter raw count value, and the stagnation duration is established. With zero-crossing distortion rate A mapping lookup table is used, with an offset of 0.05ms. The ratio of the dwell time in the range of 0ms to 10ms to the 10ms power frequency half-cycle duration is pre-calculated and stored in a read-only memory array. When the system is running in real time, the microprocessor directly reads the quantized zero-crossing distortion rate by indexing the address corresponding to the original count value. This is used for the subsequent calculation of the comprehensive anomaly early warning index.

[0084] The terminal contact temperature measurement unit and the environmental reference temperature measurement unit are placed in a high-precision constant temperature oil bath. Within a temperature range of 20℃ to 80℃, the resistance sampling values ​​of the two temperature sensors are simultaneously acquired in 10℃ increments, and the terminal temperature is monitored. relative to the ambient temperature inside the housing The zero-point relative deviation is calculated and corrected to complete the relative temperature rise gradient of the terminals. The physical compensation matrix is ​​initialized.

[0085] After completing offline calibration and initialization configuration, the multi-dimensional feature dynamic fusion and state arbitration module averages the high-frequency transient energy. Zero-crossing distortion rate and the relative temperature rise gradient of the terminals Online arbitration is implemented, and the microprocessor calculates the comprehensive anomaly early warning index in real time according to the predetermined weighted fusion relationship. The calculation results are then compared with the first-level alarm threshold. Second-level alarm threshold Compare.

[0086] When the comprehensive abnormal warning index of three consecutive power frequency half cycles All meet the first-level alarm threshold. Up to the second-level alarm threshold When the first-level warning condition is met, the multi-dimensional feature dynamic fusion and state arbitration module locks the first-level warning state, the hierarchical warning and command transmission module drives the local yellow indicator light to flash, and sends a preventive maintenance message to the remote power distribution monitoring terminal; when the comprehensive abnormal warning index of three consecutive power frequency half cycles reaches the first-level warning condition, the warning status is locked. All reached or exceeded the second-level alarm threshold. When the alarm is locked at level two, the tiered warning and command transmission module drives the buzzer and red indicator light to output an audible and visual alarm. At the same time, it outputs a level pulse to the cascade trip trigger unit to disconnect the socket circuit incoming contact within 20ms.

[0087] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An early warning system for abnormal switch and socket circuits, characterized in that, include: The loop multidimensional physical quantity sensing module includes a high-frequency current mutual inductance sensing unit, a power frequency current sampling unit, a terminal contact temperature measurement unit, and an environmental reference temperature measurement unit, which are used to collect high-frequency current transient signals, power frequency current instantaneous values, terminal temperatures, and environmental reference temperatures inside the housing. The physical feature extraction and decoupling module is connected to the loop multidimensional physical quantity sensing module. It is used to calculate the average value of high-frequency transient energy within half a cycle of power frequency, extract the zero-crossing distortion rate of the power frequency current zero-crossing stagnation time as a half-cycle duration, and calculate the difference between the terminal temperature and the reference temperature of the environment inside the housing as the relative temperature rise gradient of the terminal. The multi-dimensional feature dynamic fusion and state arbitration module is connected to the physical feature extraction and decoupling module. It is used to perform upper limit saturation calculations based on preset benchmarks on the average high-frequency transient energy and the relative temperature rise gradient of the terminals to generate high-frequency transient normalized anomaly and temperature rise gradient normalized anomaly. The high-frequency transient normalized anomaly, temperature rise gradient normalized anomaly, and zero-crossing distortion rate are weighted and fused to generate a comprehensive anomaly warning index closed in the range of 0 to 1. The index is then slid-smoothly verified over multiple consecutive half-cycles and the loop status is determined by combining preset alarm thresholds and hysteresis. The graded early warning and command transmission module, connected to the multi-dimensional feature dynamic fusion and status arbitration module, includes a local sound and light indication unit, a remote command encoding and transmission unit, and a cascaded trip trigger unit. It is used to output sound and light alarms, remote early warning messages, or trip instructions based on the judgment results, and return to normal state when the comprehensive abnormal early warning index falls below the difference between the first-level alarm threshold and the hysteresis lag.

2. The early warning system for switch and socket circuit abnormalities according to claim 1, characterized in that, The sampling frequency of the high-frequency current transformer sensing unit and the power frequency current sampling unit is set to 200kHz. The physical feature extraction and decoupling module acquires 2000 discrete sampling points within 10.0ms of each power frequency half-cycle and extracts the high-frequency instantaneous current value of each sampling point. When calculating the average value of high-frequency transient energy, the physical feature extraction and decoupling module squares the difference between the high-frequency instantaneous current value of each sampling point in a single power frequency half-cycle and the preset steady-state background high-frequency noise floor setting value of 0.001A, and sums up the 2000 squared results in a single power frequency half-cycle to calculate the average value.

3. The early warning system for switch and socket circuit abnormalities according to claim 1, characterized in that, The power frequency current sampling unit establishes a symmetrical time detection window based on the zero point of current polarity reversal within each power frequency half-cycle. When the physical feature extraction and decoupling module extracts the zero-crossing distortion rate, the absolute value of the cumulative instantaneous value of the power frequency current within the symmetrical time detection window is continuously lower than the preset micro-arc extinguishing threshold of 0.050A for a certain duration. The stagnation duration is then divided by the power frequency half-cycle duration of 10.0ms to obtain the dimensionless zero-crossing distortion rate.

4. The early warning system for switch and socket circuit abnormalities according to claim 1, characterized in that, The terminal contact temperature measurement unit uses a miniature thin-film thermistor and is located on the outside of the conductive metal sheet of the phase wire terminal of the switch socket; the ambient reference temperature measurement unit is located in the air convection cavity next to the inlet hole on the back of the switch socket box, and the physical distance between the ambient reference temperature measurement unit and the terminal contact temperature measurement unit is set to 25mm; the physical feature extraction and decoupling module subtracts the ambient reference temperature inside the housing collected by the ambient reference temperature measurement unit from the terminal temperature collected by the terminal contact temperature measurement unit to generate a relative temperature rise gradient of the terminal that characterizes the power consumption of the contact resistance.

5. The early warning system for switch and socket circuit abnormalities according to claim 1, characterized in that, When calculating the comprehensive anomaly early warning index, the multi-dimensional feature dynamic fusion and state arbitration module adopts the following weighted fusion formula: ,in This is a comprehensive anomaly early warning index; This represents the average of high-frequency transient energy. The preset high-frequency transient reference energy, For high-frequency transient normalized anomalies; The distortion rate is zero-crossing. The relative temperature rise gradient of the terminals; The preset terminal limit temperature rise reference, The anomaly is normalized to the temperature rise gradient. For high-frequency transient energy weights; Zero-crossing distortion weights; The weights are the gradient weights for the temperature rise. , and All are dimensionless constants and satisfy .

6. The early warning system for switch and socket circuit abnormalities according to claim 5, characterized in that, High-frequency transient energy weight The value range is from 0.35 to 0.45, with zero-crossing distortion weights. The value range is from 0.30 to 0.40, and the temperature rise gradient weight is... The value range is 0.20 to 0.30; the preset high-frequency transient reference energy The value range is from 0.040A² to 0.060A²; the preset terminal limit temperature rise benchmark. The value range is from 12.0℃ to 18.0℃.

7. The early warning system for switch and socket circuit abnormalities according to claim 1, characterized in that, The multi-dimensional feature dynamic fusion and state arbitration module is equipped with a sliding time window filtering logic for 3 to 5 consecutive power frequency half-cycles. When a large capacitor filter nonlinear load is connected to the switch socket, causing a sudden increase in high-frequency transient energy during closing and the comprehensive anomaly warning index in the first power frequency half-cycle exceeds the first-level alarm threshold, the multi-dimensional feature dynamic fusion and state arbitration module continuously performs sliding smoothing verification on the comprehensive anomaly warning index in subsequent power frequency half-cycles. When the high-frequency transient energy decays as the capacitor is fully charged and the comprehensive anomaly warning index in subsequent power frequency half-cycles falls back below the first-level alarm threshold, it is determined to be a non-fault transient disturbance and remains silent. When the comprehensive anomaly warning index in 3 to 5 consecutive power frequency half-cycles reaches the corresponding threshold, the state determination result is locked and signal transmission is initiated.

8. The early warning system for switch and socket circuit abnormalities according to claim 1, characterized in that, The multi-dimensional feature dynamic fusion and state arbitration module is equipped with a hierarchical state determination logic that incorporates hysteresis: when the comprehensive anomaly warning index is less than the first-level alarm threshold, the determination loop is in normal operation; when the comprehensive anomaly warning index is greater than or equal to the first-level alarm threshold and less than the second-level alarm threshold, and continuously meets the sliding time window smoothing verification judgment, the determination loop has a potential contact degradation risk and outputs a first-level warning signal command; when the comprehensive anomaly warning index is greater than or equal to the second-level alarm threshold, and continuously meets the sliding time window smoothing verification judgment, the determination loop experiences a continuous series fault arc and overheating anomaly and outputs a second-level emergency alarm signal command; the value range of the first-level alarm threshold is 0.25 to 0.35, the value range of the second-level alarm threshold is 0.50 to 0.60, and the value range of the hysteresis is 0.02 to 0.

05.

9. The early warning system for switch and socket circuit abnormalities according to claim 8, characterized in that, When the graded early warning and command transmission module responds to a level 1 early warning command, it drives the yellow LED in the local audible and visual indicator unit to flash, and sends a preventive maintenance message carrying the socket physical address code, comprehensive abnormality early warning index, and terminal temperature reading to the power distribution monitoring terminal through the remote command encoding and transmission unit. When the graded early warning and command transmission module responds to a level 2 emergency alarm command, it drives the red LED in the local audible and visual indicator unit to flash at a frequency of 4.0Hz, drives the buzzer in the local audible and visual indicator unit to emit an intermittent alarm sound with a sound pressure level greater than 80dB, broadcasts a telemetry alarm message through the remote command encoding and transmission unit, and outputs a level pulse to the cascade trip trigger unit to disconnect the socket circuit incoming contact within 20.0ms.

10. The early warning system for switch and socket circuit abnormalities according to claim 1, characterized in that, The terminal contact temperature measuring unit is set on an alumina ceramic thermally conductive insulating substrate and is bonded and fixed to the outer surface of the conductive metal sheet root of the terminal block with high-temperature thermally conductive adhesive; the environmental reference temperature measuring unit is suspended and fixed at the louvered convection hole inside the air convection cavity. The physical partition inside the switch socket housing blocks the heat radiation from the conductive metal sheet of the terminal block and isolates the Joule heat of the terminal block from the heat conduction and diffusion to the temperature measuring area where the environmental reference temperature measuring unit is located.

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