Energy recovery intelligent charging pile

Abstract

The present invention provides an energy recovery type intelligent charging pile, comprising a charging pile body, a charging module, a control module, an insulation monitoring module, a fault warning module, an energy recovery module and an active repair module. The insulation resistance value of the charging cable is monitored in real time by the insulation monitoring module; the multi-stage processing mechanism including early warning, power reduction charging and circuit breaking is triggered by the fault warning module according to the comparison data; the residual electric energy in the charging circuit is stored by the energy recovery module when the fault triggering data includes triggering power reduction or circuit breaking; the electric energy stored in the energy recovery module is used by the active repair module to generate a high-voltage pulse with a preset peak frequency, and the insulation damaged part of the charging cable is physically repaired. Through the real-time perception of the insulation monitoring module, the intelligent decision-making of the fault warning module, the closed-loop management of the energy recovery module and the physical intervention of the active repair module, the insulation fault of the charging cable is warned in advance and repaired actively, thereby improving the availability of the charging pile.

Description

Technical Field

[0001] The present invention relates to the technical field of charging piles, and in particular to an energy recovery type intelligent charging pile. Background Art

[0002] With the rapid development of the global new energy vehicle industry, electric vehicles, owing to their environmentally friendly and efficient advantages, have gradually become a mainstream means of transportation, and the construction of supporting charging infrastructure has also entered a period of rapid development. As key equipment connecting the power grid and electric vehicles, the safety, reliability, and intelligence level of charging piles directly affect the stability of the charging process and the user experience. In existing technologies, the functions of charging piles are mainly focused on power conversion and transmission control. Although some high-end products have introduced energy recovery technology to improve energy utilization efficiency, significant technical bottlenecks still exist in the field of charging cable safety monitoring.

[0003] During the charging process, the insulation layer of the charging cable may degrade or even fail due to factors such as aging caused by long-term use, external mechanical damage, and changes in ambient humidity. This can lead to safety hazards such as leakage and short circuits. Currently, traditional charging piles generally use a passive safety protection strategy, triggering power-off protection only when the leakage current exceeds a threshold. This post-processing approach has obvious flaws: on the one hand, it is impossible to monitor the deterioration trend of insulation performance in real time and provide early warning before the insulation failure occurs, making it difficult to avoid accidents. On the other hand, when an insulation failure occurs, the charging pile lacks the ability to actively repair it and can only be handled by manually replacing the cable. This leads to high maintenance costs and long downtime, seriously affecting the availability of the charging pile. Summary of the Invention

[0004] In view of this, the present invention proposes an energy recovery type intelligent charging pile to solve the technical problem that the existing charging piles cannot provide early warning and active repair of charging cable insulation faults, resulting in low availability of the charging piles.

[0005] The technical solution of the present invention is achieved as follows:

[0006] An energy recovery smart charging pile comprises: a charging pile body and a charging module, a control module, an insulation monitoring module, a fault warning module, an energy recovery module, and an active repair module arranged on the charging pile body; the charging module is connected to a device to be charged via a charging cable;

[0007] The insulation monitoring module is used to monitor the insulation resistance value of the charging cable in real time and compare it with a preset multi-level threshold value to generate comparison data;

[0008] The fault warning module is used to trigger a multi-level processing mechanism including warning, power reduction charging and circuit breaking according to the comparison data;

[0009] The energy recovery module is configured to store the remaining electric energy in the charging circuit when the fault triggering data includes triggering power reduction or circuit breaking;

[0010] The active repair module is used to use the electric energy stored in the energy recovery module to generate high-voltage pulses with a preset peak frequency, and to physically repair the damaged insulation of the charging cable.

[0011] Optionally, the insulation monitoring module includes a distributed insulation detection unit, a dynamic threshold adjustment unit and a comparison unit;

[0012] The distributed insulation detection unit includes a plurality of insulation detection sensors, which are arranged at intervals on the outer insulation layer of the charging cable in a spirally wound manner and are used to synchronously detect the temperature, humidity, and insulation resistance values ​​at various axial positions of the charging cable, and generate temperature data, humidity data, and insulation resistance values;

[0013] The dynamic threshold adjustment unit is configured to dynamically modify the threshold using the temperature data, the humidity data, and the historical insulation degradation curve through an adaptive algorithm to generate a target multi-level threshold;

[0014] The comparison unit is used to compare the insulation resistance value with the target multi-level threshold value to generate comparison data.

[0015] Optionally, the distributed insulation detection unit further includes:

[0016] a sensor self-calibration module, configured to substitute the temperature data, the humidity data, and the insulation resistance value into a preset resistance compensation formula, calculate an insulation resistance correction value, and send the calculated insulation resistance correction value to a comparison unit;

[0017] A high-frequency pulse injection module is used to inject a non-destructive high-voltage pulse signal into the charging cable, calculate the amount of partial discharge inside the cable by detecting the pulse attenuation characteristics, and send the partial discharge amount as an auxiliary parameter to the dynamic threshold adjustment unit.

[0018] Optionally, the dynamic threshold adjustment unit performs the following steps:

[0019] Filtering and denoising the temperature data and the humidity data to generate target temperature data and target humidity data;

[0020] Calculate the comprehensive impact factor of environmental parameters using the target temperature data, the target humidity data, and preset temperature and humidity upper limits;

[0021] Use historical insulation degradation curves to predict the baseline threshold at the current moment;

[0022] The comprehensive influencing factors of the environmental parameters are used to correct the baseline threshold to generate a target multi-level threshold.

[0023] Optionally, the target multi-level threshold includes a normal threshold, a warning threshold, and a fault threshold; and the execution steps of the fault warning module are:

[0024] When the insulation resistance value of the comparison data is lower than the normal threshold value and higher than the warning threshold value, the warning mechanism is triggered and a warning signal is issued through the sound and light alarm device;

[0025] When the comparison data shows that the insulation resistance value is lower than the warning threshold and higher than the fault threshold, the power reduction charging mechanism is triggered, and the charging power is linearly reduced to a preset range of the rated power according to the deviation ratio between the insulation resistance value and the warning threshold;

[0026] When the comparison data shows that the insulation resistance value is lower than the fault threshold, the circuit breaker mechanism is triggered to cut off the charging circuit, and the fault information is sent to the management terminal through the wireless communication module.

[0027] Optionally, the energy recovery module includes a bidirectional DC converter, a supercapacitor bank and a charge and discharge control unit;

[0028] The bidirectional DC converter is connected to the charging circuit and the supercapacitor bank, and is used to switch to the energy recovery mode when the power is reduced or the circuit is disconnected;

[0029] The supercapacitor bank is used to store the remaining electrical energy in the charging circuit;

[0030] The charge and discharge control unit is used to trigger overload protection and stop recycling when the remaining electric energy is greater than or equal to a preset rated capacity.

[0031] Optionally, the active repair module executes the following steps:

[0032] The damage location algorithm based on the traveling wave ranging principle calculates the insulation damage position through the pulse reflection time difference;

[0033] using the electrical energy stored in the energy recovery module to generate high-voltage pulses of a preset peak frequency, and physically repairing the damaged insulation portion of the charging cable;

[0034] During the repair process, the pulse decay rate is monitored in real time, and the repair is determined to be complete when the pulse decay rate drops by more than or equal to a preset drop threshold.

[0035] Optionally, the active repair module includes a high-voltage pulse generator, a repair effect evaluation unit, and a pulse applying electrode, wherein the pulse applying electrode is annularly wrapped around the insulation damaged portion of the charging cable;

[0036] The high-voltage pulse generator is used to output square pulses and transmit them to the pulse applying electrode;

[0037] The repair effect evaluation unit is used to re-detect the insulation resistance value after the pulse is applied, and trigger a secondary repair if the new insulation resistance value is less than a preset recovery threshold.

[0038] Optionally, the execution steps of the repair effect evaluation unit are:

[0039] Re-test the insulation resistance value after the pulse is applied and calculate the corresponding resistance recovery rate;

[0040] When the resistance recovery rate is less than a preset recovery rate threshold, the pulse voltage is increased by a preset multiple corresponding to the current voltage value to perform secondary repair;

[0041] When the resistance recovery rate corresponding to the secondary repair is less than the preset recovery rate threshold, the insulation damaged portion of the charging cable is marked as unrepairable and the management terminal is notified.

[0042] Optionally, the control module adopts a dual redundant control system, including a main control unit and a backup control unit. When the main control unit fails, the backup control unit automatically takes over control within a preset time to ensure the normal operation of the charging pile.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] The present invention provides an energy recovery smart charging pile, comprising a charging pile body and a charging module, a control module, an insulation monitoring module, a fault warning module, an energy recovery module, and an active repair module arranged on the charging pile body. The insulation monitoring module can timely detect potential insulation degradation problems by monitoring the insulation resistance value of the charging cable in real time, thereby avoiding sudden failures caused by degradation of insulation performance. By setting a multi-level threshold comparison mode, hierarchical management can be achieved, judgment accuracy can be improved, and false alarms or missed alarms can be reduced. The fault warning module is used to adopt different levels of processing mechanisms according to different states of the insulation resistance value, thereby effectively reducing safety hazards. The energy recovery module is used to recover the residual electrical energy in the charging circuit to the supercapacitor group when a power reduction or circuit breaker event occurs, thereby avoiding energy waste caused by direct discharge. The active repair module is used to determine the location of insulation damage, and then use the electrical energy stored in the energy recovery module to generate high-voltage pulses to perform physical repairs such as local discharge or thermal effect treatment on the insulation defect site, thereby promoting the recovery of the insulation material and achieving autonomous repair. The intelligence level, safety, and availability of the charging pile are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 This is a schematic structural diagram of an energy recovery smart charging pile according to the present invention;

[0047] Figure 2 This is a schematic structural diagram of an insulation monitoring module in an energy recovery smart charging pile of the present invention;

[0048] Figure 3 A schematic structural diagram of an energy recovery module in an energy recovery smart charging pile of the present invention;

[0049] Figure 4 A schematic structural diagram of an active repair module in an energy recovery smart charging pile of the present invention;

[0050] Figure 5 A schematic structural diagram of a control module in an energy recovery smart charging pile of the present invention. DETAILED DESCRIPTION

[0051] See also Figure 1 An energy recovery smart charging pile includes: a charging pile body and a charging module, a control module, an insulation monitoring module, a fault warning module, an energy recovery module, and an active repair module arranged on the charging pile body; the charging module is connected to the device to be charged via a charging cable;

[0052] The insulation monitoring module is used to monitor the insulation resistance of the charging cable in real time and compare it with the preset multi-level thresholds to generate comparison data;

[0053] Fault warning module, used to trigger a multi-level processing mechanism including warning, power reduction and disconnection based on the comparison data;

[0054] An energy recovery module, configured to store the remaining electrical energy in the charging circuit when the fault triggering data includes triggering a power reduction or a circuit breaker;

[0055] The active repair module is used to use the electrical energy stored in the energy recovery module to generate high-voltage pulses with a preset peak frequency and physically repair the damaged insulation of the charging cable.

[0056] In this embodiment of the present invention, the charging pile body adopts an IP55 protection grade metal shell with dimensions of 800mm×600mm×1800mm, and integrates the following modules:

[0057] Charging module (located at the bottom): Contains AC / DC or DC / DC power conversion unit, supporting a maximum charging power of 120kW (DC fast charging) and 7kW (AC slow charging);

[0058] Control module (central industrial computer): uses Advantech UNO-3082G industrial computer, equipped with Intel Atom E3845 processor (1.91GHz), and integrated dual redundant control units (master unit: STM32H750; backup unit: NXP i.MX 8M);

[0059] Insulation monitoring module, fault warning module (top control cabinet): installed through standardized DIN rail;

[0060] Energy recovery module (left cabinet): includes supercapacitor bank and bidirectional DC-DC converter;

[0061] Active repair module (right cabinet): includes a high-voltage pulse generator and pulse application electrodes.

[0062] Specifically, the hardware configuration of the charging module includes: (1) DC fast charging: using a three-phase PFC + full-bridge LLC resonant converter, input voltage AC = 380V ± 15%, output voltage DC = 200V-1000V, efficiency ≥ 96%; AC slow charging: using an on-board charger (OBC), input AC = 220V / 32A, output DC = 400V / 16A; (2) Charging interface: compatible with GB / T20234-2023 DC / AC charging interface, built-in CC / CP signal detection circuit; safety protection: integrated 500A high-voltage DC relay (Hongfa HF3000), response time ≤ 10ms. The charging module communicates with the control module via the CAN bus (ISO 11898-2 standard), reporting the charging voltage and current in real time; receiving power adjustment instructions (0-10V analog signal) from the control module, and supporting 0-100% power linear adjustment.

[0063] The insulation monitoring module uses distributed sensors to monitor the insulation resistance, temperature, and humidity of the charging cable in real time, generating comparison data. The dynamic threshold adjustment unit combines temperature and humidity data with historical degradation curves to adjust the threshold to adapt to environmental changes. The fault warning module triggers a three-level response based on this comparison data: warning (audio-visual alarm), reduced charging power (linearly reducing power in proportion to deviation), and circuit breaker (disconnecting the circuit and notifying the management terminal). During power reduction or circuit breaker, the energy recovery module stores excess energy in a supercapacitor bank via a bidirectional DC-DC converter. The charge-discharge control unit triggers overload protection when energy storage exceeds the limit. The active repair module uses recovered energy to generate high-voltage pulses at a preset peak frequency (e.g., 1-5kV, 1-10kHz) using ring electrodes to physically repair damaged insulation. The repair effectiveness evaluation unit determines repair completion based on the pulse decay rate and insulation resistance recovery rate. The control module uses dual redundant control systems (active and standby control units) to ensure automatic failover and maintain operation in the event of a fault.

[0064] Further, see Figure 2 ,The insulation monitoring module includes a distributed insulation detection unit, a dynamic threshold adjustment unit, and a comparison unit;

[0065] The distributed insulation detection unit includes multiple insulation detection sensors, which are spirally wound and spaced apart on the outer insulation layer of the charging cable. The sensors are used to synchronously detect the temperature, humidity, and insulation resistance values ​​at various axial locations of the charging cable, generating temperature, humidity, and insulation resistance data.

[0066] A dynamic threshold adjustment unit is used to dynamically modify the threshold using temperature data, humidity data and historical insulation degradation curves through an adaptive algorithm to generate a target multi-level threshold;

[0067] The comparison unit is used to compare the insulation resistance value with the target multi-level threshold value to generate comparison data.

[0068] In an embodiment of the present invention, the distributed insulation detection unit includes multiple insulation detection sensors, which are SICK LFP-100 composite sensors. Eight SICK LFP-100 composite sensors (model: 1051234) are used, each integrating: an NTC temperature sensor (accuracy ±0.3°C, temperature range -40°C to 85°C, response time ≤10s); a capacitive humidity sensor (accuracy ±2%RH, range 0-100%RH, dew point compensation algorithm); and a four-wire insulation resistance tester (measurement principle: volt-ampere method, measurement range 0.1MΩ-1GΩ, resolution 0.1MΩ, test voltage 500VDC). The sensors are arranged on the outer insulation surface of the charging cable (length 5m, outer diameter 20mm) in a spiral winding manner, with intervals of 50cm. The axial spacing between adjacent sensors covers the entire length of the cable, and the spiral angle is 30°, ensuring 360° circumferential monitoring without blind spots. The signal acquisition process involves converting the raw analog signal into a digital signal using a 24-bit ADC (ADS1256, 123dB signal-to-noise ratio). This signal is then transmitted to the dynamic threshold adjustment unit via a shielded twisted-pair cable (distributed capacitance ≤50pF / m) with a sampling frequency of 10Hz. The temperature / humidity sensor is connected to a standard calibration chamber (accuracy ±0.1°C / ±1%RH) to correct for zero drift. The insulation resistance sensor is connected to a 10MΩ ±0.1% standard resistor to calibrate the measurement circuit gain error. After calibration, accuracy is improved to ±1.5%.

[0069] The temperature data and humidity data are filtered and denoised to generate target temperature data and target humidity data; the target temperature data, target humidity data and preset temperature and humidity upper limits are used to calculate the comprehensive influencing factors of environmental parameters; the historical insulation degradation curve is used to predict the baseline threshold at the current moment; the comprehensive influencing factors of environmental parameters are used to correct the baseline threshold and generate the target multi-level threshold.

[0070] The comparison unit compares the insulation resistance values ​​generated by the distributed insulation detection unit with the target multi-level thresholds generated by the dynamic threshold adjustment unit in real time to generate comparison data. The target multi-level thresholds include normal thresholds, warning thresholds, and fault thresholds, which are used to distinguish different levels of insulation status (such as healthy, potential risk, and fault).

[0071] Furthermore, the distributed insulation detection unit further includes:

[0072] The sensor self-calibration module is used to substitute temperature data, humidity data and insulation resistance value into the preset resistance compensation formula, calculate the insulation resistance correction value and send it to the comparison unit;

[0073] The high-frequency pulse injection module is used to inject non-destructive high-voltage pulse signals into the charging cable, calculate the partial discharge amount inside the cable by detecting the pulse attenuation characteristics, and send the partial discharge amount as an auxiliary parameter to the dynamic threshold adjustment unit.

[0074] In an embodiment of the present invention, the sensor self-calibration module corrects the original insulation resistance value using a preset resistance compensation formula to eliminate the interference of ambient temperature and humidity on the measurement results. The core formula, namely the preset resistance compensation formula, is:

[0075] R corrected =R measured ·(1+l1·(T-T0)+l2·(H-H0));

[0076] Among them, R corrected is the insulation resistance correction value; R measured is the original measurement value of the sensor; R is the real-time detection temperature; H is the real-time detection humidity; T0 is the temperature under standard calibration conditions; H0 is the humidity under standard calibration conditions; k1 is the influence coefficient of temperature on insulation resistance; k2 is the influence coefficient of humidity on insulation resistance. The sensor self-calibration module receives temperature data, humidity data and insulation resistance value from the distributed insulation detection unit, with a sampling frequency of 1Hz. The compensation algorithm is run based on the ARM Cortex-M4 chip (such as STM32F407), and 256KB of memory is reserved for storing calibration coefficients and historical data. The corrected insulation resistance value R is transmitted via the SPI bus. corrected Transfer to the comparison unit.

[0077] The high-frequency pulse injection module injects a non-destructive high-voltage pulse signal (such as a 500Vpp, 100kHz square wave) into the charging cable, detects the pulse attenuation characteristics in the cable, and indirectly calculates the partial discharge amount (ΔQ). The core steps are as follows:

[0078] (1) Pulse injection: Generate a pulse signal using a high-voltage signal generator (such as Tektronix AWG7000B) and inject it into the cable through an impedance matching transformer (1:1000).

[0079] (2) Attenuation detection: Install a coupling capacitor (100pF) and an impedance converter (50Ω) at the end of the cable to collect the pulse reflection signal (oscilloscope sampling rate ≥ 1GSa / s).

[0080] (3) Calculation of partial discharge: The linear relationship model between pulse attenuation amplitude and partial discharge energy is used (ΔQ = α·ΔA + β), where α and β are experimental calibration parameters (e.g., α = 0.8 pC / V, β = 0.2 pC); A is the amplitude of the pulse signal.

[0081] Furthermore, the dynamic threshold adjustment unit performs the following steps:

[0082] Filter and denoise the temperature data and humidity data to generate target temperature data and target humidity data;

[0083] Calculate the comprehensive impact factors of environmental parameters using target temperature data, target humidity data and preset temperature and humidity upper limits;

[0084] Use historical insulation degradation curves to predict the baseline threshold at the current moment;

[0085] The comprehensive influencing factors of environmental parameters are used to correct the baseline threshold and generate the target multi-level threshold.

[0086] In the embodiment of the present invention, in the charging cable operating environment, the raw data of the temperature sensor (such as DS18B20) and the humidity sensor (such as SHT30) are susceptible to electromagnetic interference (EMI) and signal transmission delay, resulting in high-frequency noise such as ±2°C temperature fluctuations and ±5%RH humidity jumps. A filtering algorithm is required to improve data reliability. A sliding average filter is used to denoise the temperature / humidity data to eliminate sensor noise and instantaneous fluctuations. The sliding average filter formula is:

[0087]

[0088] Among them, T filtered (t) is the target temperature data after sliding average filtering to eliminate noise and fluctuations, and the value at time t; T raw (ti) is the sampling value of the original temperature data at time (ti) (i=0, 1, ..., N-1), including sensor noise and instantaneous fluctuations; H filtered (t) is the target humidity data after sliding average filtering to eliminate noise and fluctuations, and the value at time t; H raw (ti) is the sampling value of the original humidity data at time (ti) (i = 0, 1, ..., N-1), including sensor noise and instantaneous fluctuations; N is the sliding window length (preferably 5 sampling points), that is, the number of continuous sampling points used to calculate the average value (N historical data, including the data at the current time t, a total of N points); t is a time variable, representing the current time, used to index the timestamp of the data. The specific filtering and denoising process is as follows: first receive the original temperature and humidity data of the distributed insulation detection unit (sampling frequency 1Hz). Then run the filtering algorithm based on the ARM Cortex-M4 chip (such as STM32F407). Then transmit the target temperature data T through the SPI bus. filtered And target humidity data H filtered Transfer to the next step.

[0089] Combined with target temperature data T filtered And target humidity data H filtered And preset temperature and humidity upper limit (T max =40℃, H max=80%RH, this value is obtained based on experiments), calculate the comprehensive impact factor of environmental parameters K env , and its calculation formula is:

[0090]

[0091] Among them, K env is the comprehensive influencing factor of environmental parameters; T filtered is the target temperature data; H filtered is the target humidity data; T max is the preset temperature upper limit; H max is the preset humidity upper limit; α is the temperature weight data; β is the humidity weight data. The calculation process of the comprehensive impact factor of environmental parameters is as follows: receiving the filtered target temperature data T filtered And target humidity data H filtered , calculated in real time by FPGA (such as XilinxArtix-7), and K env The data is sent to the baseline threshold prediction module. The baseline threshold prediction module uses the historical insulation degradation curve to predict the current baseline threshold. Specifically, the technical principle of the baseline threshold prediction module is as follows:

[0092] Based on the historical insulation degradation curve (obtained through laboratory accelerated aging experiments), a linear regression model is used to predict the current baseline threshold R baseline The model formula is:

[0093] R baseline (t) = a·t+b;

[0094] Where a is the degradation rate (unit: MΩ / h); t is time; and b is the initial threshold. The specific prediction process is as follows: call the historical insulation degradation curve stored in the cloud (e.g., R = 1000 MΩ at t = 0, R = 800 MΩ at t = 100h); run the regression algorithm on the cloud server, reserve 2GB of memory for storing historical data, and predict the current baseline threshold R baseline , and sent to the correction module.

[0095] The correction module uses the comprehensive influencing factors of environmental parameters to correct the baseline threshold and obtain the target multi-level threshold. The correction formula used is:

[0096] R threshold =R baseline (1-K env );

[0097] Among them, R threshold The target multi-level threshold is divided into multi-level warning ranges (such as normal / warning / fault) according to the revised threshold; R baseline is the baseline threshold; K envThe specific execution process is as follows: receiving the baseline threshold and the comprehensive impact factor of environmental parameters, running the correction algorithm based on the ARM Cortex-M4 chip to calculate the target multi-level threshold, and then transmitting the target multi-level threshold to the comparison unit via the CAN bus.

[0098] Furthermore, the target multi-level threshold includes a normal threshold, a warning threshold, and a fault threshold; the execution steps of the fault warning module are:

[0099] When the insulation resistance value of the comparison data is lower than the normal threshold and higher than the warning threshold, the warning mechanism is triggered and a warning signal is issued through the sound and light alarm device;

[0100] When the insulation resistance value is lower than the warning threshold and higher than the fault threshold, the power reduction charging mechanism is triggered. The charging power is linearly reduced to the preset range of the rated power according to the deviation ratio between the insulation resistance value and the warning threshold.

[0101] When the comparison data shows that the insulation resistance value is lower than the fault threshold, the circuit breaker mechanism is triggered, the charging circuit is cut off, and the fault information is sent to the management terminal through the wireless communication module.

[0102] In the embodiment of the present invention, the fault warning module is a key control unit in the distributed insulation detection system, which is used to compare the insulation resistance value output by the comparison unit with the dynamically generated target multi-level threshold value and execute different levels of response mechanisms. The target multi-level threshold value includes: normal threshold R normal Indicates that the cable insulation is in good condition; the warning threshold R warn Indicates that the insulation performance has degraded but has not yet reached a dangerous level; the fault threshold R fault This indicates that the cable has serious insulation defects and requires immediate attention. The module implements hierarchical management through three types of response mechanisms: (1) Warning mechanism: When the insulation resistance value is lower than the normal threshold but still higher than the warning threshold, an audible and visual alarm is activated; (2) Reduced power charging mechanism: When the insulation resistance value is lower than the warning threshold but still higher than the fault threshold, the charging power is proportionally reduced; (3) Disconnect mechanism: When the insulation resistance value is lower than the fault threshold, the charging circuit is disconnected and a fault message is sent to the management terminal.

[0103] If the insulation resistance value is lower than the normal threshold but higher than the warning threshold, it is considered mild insulation degradation, triggering the warning mechanism. The audible and visual alarm system flashes a yellow warning light and sounds a buzzer, alerting on-site personnel to the cable's operating status. The hardware implementation involves using a PLC controller (such as a Siemens S7-1200) to receive the comparison results; controlling the LED indicator and buzzer driver circuit (relay module) via a digital output port; and setting the alarm duration to 5 minutes or requiring manual reset.

[0104] If the insulation resistance value is lower than the warning threshold and higher than the fault threshold, it is judged as moderate insulation degradation and the power reduction mechanism is triggered. The charging power is adjusted linearly according to the degree of deviation between the insulation resistance value and the warning threshold. The formula is as follows:

[0105]

[0106] Among them, P adjusted is the adjusted power value; P rated is the rated power of the charging equipment (e.g. 120kW); R warn is the warning threshold; R measured R fault is the fault threshold; γ is the power attenuation coefficient (recommended value is 0.6-0.8 to prevent excessive frequency reduction from affecting efficiency). The specific hardware implementation process is as follows: receiving the comparison results via the CAN bus; calculating the adjusted power value using the BMS (battery management system) or charging pile main control chip (such as TI TMS320F280049); and sending a power setting command to the charging pile communication interface (following the GB / T 27930 protocol).

[0107] If the insulation resistance value is lower than the fault threshold, a critical insulation fault is detected, triggering circuit breaker protection. This controls the contactor to disconnect the charging circuit to prevent high-voltage breakdown or fire risks. Fault information (including timestamp, device ID, insulation resistance value, etc.) is sent to the management terminal via a wireless communication module (such as a 4G DTU or NB-IoT module). The specific hardware implementation process involves using a high-voltage DC contactor (such as the Omron G9EB) that supports DC 1000V / 100A loads; configuring a remote communication module (such as the Huawei ME909s-821) to connect to the cloud platform; and formatting fault information using a JSON structure.

[0108] Further, see Figure 3 ,The energy recovery module includes a bidirectional DC converter, a supercapacitor bank and a charge and discharge control unit;

[0109] A bidirectional DC converter connects the charging circuit and the supercapacitor bank, and is used to switch to energy recovery mode when the power is reduced or the circuit is disconnected;

[0110] A supercapacitor bank for storing excess energy in the charging circuit;

[0111] The charge and discharge control unit is used to trigger overload protection and stop recycling when the remaining energy is greater than or equal to the preset rated capacity.

[0112] In an embodiment of the present invention, the energy recovery module is a key component of the present invention for improving the energy efficiency of the charging system and reducing energy waste, especially when the power is reduced or the circuit breaker protection is triggered. The module recovers the unused electrical energy in the charging circuit and temporarily stores it in a high-power density energy storage device for subsequent use or safe release. The energy recovery module includes the following three core parts: (1) Bidirectional DC / DC Converter: responsible for achieving voltage matching and energy flow control in different working modes; (2) Supercapacitor Bank: as a high-efficiency, fast-response energy storage element, used to absorb and release transient energy; (3) Charging and Discharging Control Unit: real-time monitoring of energy storage status and execution of overload protection strategy.

[0113] During normal operation, the bidirectional DC / DC converter is in standby mode. When the system detects a power reduction or circuit breaker event, it automatically switches to energy recovery mode, transferring unused energy from the charging circuit to the supercapacitor bank. The bidirectional DC / DC converter utilizes a half-bridge bidirectional DC / DC converter structure, offering high efficiency (≥90%) and low losses (<5% at full load). It supports a wide input voltage range (300V–800V), and its output is connected to a supercapacitor bank (rated voltage 750V). When the fault warning module issues a "power reduction" signal, recovery mode A (low-speed recovery) is activated. When a "circuit breaker" signal is issued, recovery mode B (high-speed recovery) is activated, ensuring rapid absorption of residual energy. The switching threshold voltage is 650V, the maximum recovery current is 20A, and the recovery efficiency is 0.92.

[0114] Supercapacitor cells with a double-layer electrode structure (such as the Maxwell BMOD0063) are used, with a single cell capacity of 3400F and a rated voltage of 2.7V. These cells are connected in series to form a high-voltage energy storage array. A forced air cooling system (10W fan power) is configured to maintain an operating temperature between -20°C and +65°C, extending service life. A charge and discharge control unit monitors the voltage and energy storage status of the supercapacitor bank in real time, determines whether the preset rated capacity has been reached, and triggers protection in the event of overload.

[0115] Assume that the current energy storage capacity is E current , the preset rated capacity is E threshold , the control rules are as follows:

[0116] If E current <E threshold : Continue to allow energy recovery;

[0117] If E current≥E threshold : Trigger overload protection, close the recovery path and activate the discharge path.

[0118] The energy storage capacity calculation formula is:

[0119]

[0120] The overload determination conditions are:

[0121] E current ≥E threshold ;

[0122] Among them, E current is the current energy storage capacity, in joules (J); E threshold is the preset rated capacity; C total is the total capacitance of the supercapacitor group, in Farad (F); V cap The current terminal voltage of the supercapacitor group is in volts (V). It is one of the key parameters for measuring the current energy state of the supercapacitor group.

[0123] When E current Reach or exceed E threshold When the system is fully charged, it will trigger the overload protection mechanism, close the energy recovery channel and activate the discharge path to prevent the supercapacitor bank from overcharging and generating safety risks.

[0124] Furthermore, the active repair module performs the following steps:

[0125] The damage location algorithm based on the traveling wave ranging principle calculates the insulation damage position through the pulse reflection time difference;

[0126] The electric energy stored in the energy recovery module is used to generate high-voltage pulses with a preset peak frequency, and the damaged insulation of the charging cable is physically repaired.

[0127] During the repair process, the pulse decay rate is monitored in real time, and the repair is determined to be complete when the pulse decay rate drops by more than or equal to the preset drop threshold.

[0128] In an embodiment of the present invention, the active repair module is a key component of the present invention for realizing automatic positioning and physical repair of cable insulation defects. By integrating traveling wave ranging technology, a high-voltage pulse generating device and a real-time monitoring mechanism, the module can accurately locate and physically repair the damaged insulation parts of the charging cable without interrupting the operation of the system. Utilizing the propagation characteristics of traveling waves in the cable, when the insulation of the cable is damaged, the injected high-voltage pulse will generate a reflected wave at the damaged point. By measuring the time difference (Δt) between the transmitted wave and the reflected wave, the distance L from the damaged point to the starting point can be calculated. defect , the corresponding positioning formula is:

[0129]

[0130] Among them, L defect is the distance from the damage point to the starting point; v is the propagation speed of electromagnetic waves in the cable (typically 0.65 to 0.85 times the speed of light, depending on the cable material); Δt is the arrival time difference between the transmitted and reflected waves (in seconds); the denominator "2" indicates one round trip. The specific hardware implementation process involves using an FPGA chip (such as the Intel Cyclone V) as the core processing unit; configuring a high-speed sampling ADC (sampling rate ≥ 1 GSPS) to capture weak reflected signals; injecting pulses with a frequency range of 1 MHz to 10 MHz and a peak voltage ≤ 2 kV; collecting the propagation speed and arrival time difference between the transmitted and reflected waves to calculate the insulation damage location.

[0131] After locating the insulation damage, the electric energy stored in the energy recovery module is used to generate a high-voltage pulse with a specific peak voltage and frequency through a boost converter and a pulse forming network (PFN). The pulse acts on the damaged part of the cable insulation, stimulating local discharge or thermal effect, and prompting the insulation material to re-fuse or fill the cracks. The high-voltage pulse parameters are set as follows: (1) Peak voltage: V p =3kV~5kV; (2) Pulse width: T w =1μs~10μs; (3) repetition frequency: f p =1kHz~10kHz; (4) Total repair cycle: no more than 3 minutes. The specific hardware implementation process is: use IGBT power devices (such as Infineon FF600R12ME4) to build a full-bridge inverter circuit; the boost transformer turns ratio is set to 1:100; the pulse control adopts PWM modulation strategy, and the DSP controller (such as TITMS320F28379D) generates the drive signal; the required power is provided by the supercapacitor group in the energy recovery module. For example: Example: When the supercapacitor group voltage V cap =700V, set the boost voltage to V p = 4.2V, and apply 100 pulses, each with a duration of 5μs and an interval of 0.5ms. The total repair time is about 50 seconds.

[0132] During the high-voltage pulse application process, the insulation repair effect can be judged by detecting the current response in the circuit, analyzing the trend of the pulse amplitude over time, and calculating the pulse decay rate δ. The calculation formula of the pulse decay rate is:

[0133]

[0134] Among them, δ(t) is the current pulse decay rate; A0 is the initial pulse amplitude; A tis the amplitude after the tth pulse. If the pulse attenuation rate decreases by more than or equal to the preset threshold δ in three consecutive measurements threshold , that is, satisfying:

[0135] δ(t+1)-δ(t)≥δ threshold ;

[0136] The insulation material is considered to have recovered and the repair is complete. threshold =0.15, that is, the repair is considered complete when the attenuation rate drops by more than 15%; the sampling frequency is 10MHz; the monitoring circuit uses a Hall current sensor (such as LEM LTS25-NP).

[0137] Further, see Figure 4 The active repair module includes a high-voltage pulse generator, a repair effect evaluation unit, and a pulse application electrode. The pulse application electrode wraps around the damaged insulation part of the charging cable in a ring structure.

[0138] a high-voltage pulse generator, used for outputting square pulses and transmitting them to the pulse applying electrode;

[0139] The repair effect evaluation unit is used to re-detect the insulation resistance value after the pulse is applied. If the new insulation resistance value is less than the preset recovery threshold, a secondary repair is triggered.

[0140] In an embodiment of the present invention, the active repair module is the core component of the present invention for physically repairing the damaged insulation part of the charging cable. By integrating a high-voltage pulse generator, a ring-shaped pulse application electrode and a repair effect evaluation unit, the module can automatically repair insulation defects without disassembling the cable. Its main components include: a high-voltage pulse generator (High-Voltage Pulse Generator) is used to generate a square high-voltage pulse with a specific peak voltage and duration; a pulse application electrode (Pulse Application Electrode) is used to cover the damaged part of the cable insulation with an annular structure to ensure that the pulse is evenly applied; a repair effect evaluation unit (Repair Effect Evaluation Unit) is used to re-detect the insulation resistance value after the pulse is applied, and to determine whether a secondary repair is required.

[0141] Specifically, the high-voltage pulse generator is used to generate and output square high-voltage pulses, which act on the damaged parts of the cable insulation to stimulate local discharge or thermal effects, thereby promoting the recovery of the insulation material. The output parameters of the high-voltage pulse generator are set as follows: (1) Pulse type: square wave pulse; (2) Peak voltage range: V pulse =3kV~6kV; (3) Pulse width: T width =1μs~10μs; (4) repetition frequency: f repeat=1kHz~5kHz; (5) Total number of pulses: 10~100 pulses are output in a single repair cycle. The hardware implementation process is as follows: IGBT power switching devices (such as Infineon FF450R12ME7C_B11) are used to build a full-bridge inverter circuit; the turn ratio of the step-up transformer is 1:150 to achieve the required high voltage level from the DC bus voltage; the control part is driven by an FPGA chip (such as Intel Cyclone 10GX) to drive the PWM signal; the required energy comes from the supercapacitor bank (rated voltage 750V) in the energy recovery module.

[0142] Specifically, the pulse application electrode is a detachable ring structure made of a composite material of conductive rubber and metal foil. It can fit tightly against the cable sheath to ensure that the high-voltage pulse is evenly applied to the insulation damage area. The electrical performance requirements of the pulse application electrode are: (1) Insulation withstand voltage level: ≥10kV; (2) Contact resistance: ≤0.1Ω; (3) Operating temperature range: -40℃~+100℃; (4) Adaptable cable diameter range: 10mm~50mm. The pulse application electrode is installed as follows: It is fixed to the located insulation damage point through magnetic attraction or snap-on structure; an internal embedded temperature sensor (such as PT100) monitors the electrode temperature in real time to prevent overheating and damage to the cable. For example: If insulation damage is found at 1 meter of the cable, the ring electrode is used to wrap the location, connect the high-voltage pulse generator output terminal, and prepare to apply the pulse.

[0143] Specifically, after the high-voltage pulse application is completed, the repair effect evaluation unit re-measures the insulation resistance value of the cable through the distributed insulation detection system to determine whether the current insulation state meets the safety operation standard. The insulation resistance value after repair is recorded as R post ; The preset recovery threshold is R recover If R post <R recover , the secondary repair mechanism is triggered; otherwise, the repair is considered successful and the control system stops the repair process. Among them, the preset recovery threshold is set to 700MΩ; the measurement accuracy is ±1%; and the evaluation cycle is performed immediately after each repair. The hardware implementation process is: use a high-impedance insulation tester (such as Fluke 1587FC) for measurement; the data transmission interface is CAN FD protocol; the control logic is processed by an ARM Cortex-M7 microcontroller (such as NXPS32K144); if a secondary repair is required, the system will adjust the pulse parameters (such as increasing the voltage or increasing the number of pulses) and execute the repair process again. For example: after the first repair, R post =620MΩ <R recover =700MΩ, it is judged as incomplete repair, and the control system starts the second repair process, increasing the pulse voltage to V pulse =5.5kV, and increase the number of pulses to 80.

[0144] Furthermore, the execution steps of the repair effect evaluation unit are:

[0145] Re-test the insulation resistance value after the pulse is applied and calculate the corresponding resistance recovery rate;

[0146] When the resistance recovery rate is less than the preset recovery rate threshold, the pulse voltage is increased by a preset multiple corresponding to the current voltage value to perform secondary repair;

[0147] When the resistance recovery rate corresponding to the secondary repair is less than the preset recovery rate threshold, the insulation damaged portion of the charging cable is marked as unrepairable and the management terminal is notified.

[0148] In an embodiment of the present invention, the repair effect evaluation unit is a key subsystem within the active repair module used to determine the effectiveness of insulation defect repair and decide whether to perform a secondary repair. After the high-voltage pulse is applied, this unit re-tests the cable insulation resistance and calculates the resistance recovery rate based on the two measurements, using this as a basis for determining whether the repair was effective. Its execution steps include: re-testing the insulation resistance value after the pulse is applied; calculating the current resistance recovery rate and comparing it with a preset threshold; deciding whether to initiate a secondary repair or mark the defect as unrepairable based on the recovery rate result; and sending an alarm to the management terminal if the defect is determined to be unrepairable.

[0149] Specifically, after the high-voltage pulse application is completed, the distributed insulation detection system retests the insulation status of the charging cable to obtain the repaired insulation resistance value R post The original insulation resistance value before repair is recorded as R pre (from the initial test); the insulation resistance value after repair is recorded as R post (from secondary testing); all data is uploaded to the evaluation unit processing module via the CAN FD communication interface. Specific hardware implementation requirements include: using a high-precision insulation tester (such as the Megger MIT515) with a range of up to 10 TΩ; maintaining a measurement error within ±0.5%; updating data once per second; and connecting to the evaluation unit using a shielded cable to reduce electromagnetic interference. The repair recovery rate is calculated as:

[0150]

[0151] Where, η is the resistance recovery rate (unit: dimensionless); R post is the insulation resistance value after repair; R pre is the initial insulation resistance value; R target is the ideal insulation resistance target value (usually set to 1GΩ). The judgment logic is: if η≥η threshold , then the repair is considered effective and the process ends; if η<η threshold , then the secondary repair mechanism is triggered; where ηthreshold is the preset recovery rate threshold, with a typical value of 0.65 (i.e., it needs to reach more than 65% of the target value).

[0152] When it is determined that secondary repair is needed, the pulse voltage is increased to c times the current voltage value; the increase factor c is set based on historical repair experience, with a typical value of 1.2 to 1.5; the new pulse voltage expression is: V new =c·V current , where V new During secondary repair, the new high-voltage pulse voltage is adjusted according to the current voltage value to enhance the repair effect and ensure that the damaged insulation can be physically repaired more effectively. The unit is volts (V) or kilovolts (kV). c is a dimensionless coefficient that represents the ratio of the current voltage value to be increased during the secondary repair process. It is usually set to 1.2 to 1.5. The specific value can be optimized based on historical repair experience and experimental data. By appropriately increasing the pulse voltage, the intensity of partial discharge or thermal effect is increased, promoting the recovery of insulation materials. V current This is the high-voltage pulse voltage used during the initial repair process. It serves as the basis for calculating the new pulse voltage, ensuring a clear reference for the voltage boost strategy. The unit is volts (V) or kilovolts (kV). Preferably, the maximum output voltage should not exceed the equipment's upper safety limit (e.g., 6kV) to avoid damage to the cable or repair device. While boosting the voltage, the pulse width can be appropriately extended (but not exceeding 10μs) and the total number of pulses can be increased (10% to 20%) to further enhance the repair strength.

[0153] Further, see Figure 5 The control module adopts a dual redundant control system, including a main control unit and a backup control unit. When the main control unit fails, the backup control unit automatically takes over control within a preset time to ensure the normal operation of the charging pile.

[0154] In the embodiment of the present invention, the control module is the core component that ensures the stable operation of the charging pile system. To improve the reliability and fault tolerance of the system, the control module adopts a dual redundant control system (Dual Redundant Control System), including: a primary control unit (PCU): responsible for daily operation control, data acquisition and instruction execution; a backup control unit (BCU): automatically takes over control in the event of a failure of the primary control unit, ensuring continuous operation of the system. The system has the following key features:

[0155] (1) Real-time monitoring of the operating status of the main control unit;

[0156] (2) The fault detection and switching response time does not exceed the preset time threshold Tswitch ;

[0157] (3) The switching process does not require manual intervention, ensuring that the charging pile can still operate normally under fault conditions.

[0158] Specifically, the main functions of the main control unit include: managing the charging process (start, stop, power regulation); receiving status signals from the insulation detection module, energy recovery module, and active repair module; sending control instructions to the actuator (such as contactor operation, pulse application, alarm output, etc.); and communicating with external devices (such as BMS and management terminal) via the CAN FD bus. Its hardware configuration includes a microcontroller with an ARM Cortex-M7 core (such as the NXP S32K144); a storage unit with a Flash capacity of ≥512KB and a RAM capacity of ≥128KB; communication interfaces of dual CAN FD, one RS485, and one Ethernet; and an operating temperature range of -40°C to +85°C.

[0159] Specifically, the main functions of the backup control unit include: continuously monitoring the working status of the main control unit; taking over the control task within a preset time when an abnormality occurs in the main control unit (such as communication interruption, watchdog timeout, program crash); keeping the basic control logic running (such as maintaining the current power, triggering alarms, and recording fault information). Its hardware configuration includes a microcontroller: the same or compatible model as the main control unit (such as TI TMS320F280049); equipped with an independent power supply and reset circuit; supporting hot backup mode (i.e. always running and synchronizing key data); and synchronizing status with the main control unit through shared memory or SPI interface. The switching condition judgment formula is: set the heartbeat signal period of the main control unit to T heartbeat If no valid signal is received within two consecutive cycles, it is determined that the main control unit is faulty:

[0160] if t last_heartbeat +2T heartbeat <t current , then trigger failover;

[0161] Among them, T heartbeat The time interval, in seconds, between heartbeat signals sent periodically by the main control unit. This is used to monitor the working status of the main control unit and ensure its normal operation. If no heartbeat signal is received within the preset time, it is considered that the main control unit may have a fault. last_heartbeatThe time point when the most recent heartbeat signal from the main control unit was received is recorded. The unit is usually expressed in timestamp format, such as "hour:minute:second" or Unix timestamp (seconds). It serves as the benchmark time point for determining whether the main control unit has failed. By comparing the current time with the time of the most recent heartbeat, it can be determined whether the main control unit sent a heartbeat signal within the specified time. current The current time point of the system, also expressed in timestamp format. It is used for real-time monitoring and calculation of the difference with the last heartbeat time to determine whether the switching conditions are met. For example: if T heartbeat =1s, the most recent heartbeat time is t=10:00:00, and the current time is t=10:00:03. The switching condition is met, and the system immediately activates the backup control unit.

[0162] The time interval from the detection of the main control unit failure to the completion of the backup control unit taking over is recorded as T failover , which is required to be less than the preset time threshold T switch The switching time formula used is: T failover =T detect +T switching .

[0163] Among them, T failover T is the time interval from the detection of the main control unit failure to the completion of the backup control unit takeover; detect T is the time required for fault detection; switching The time required for the transfer of control rights. The preset time threshold T switch = 2s, meeting the requirement for fast switching. The specific hardware implementation process uses a watchdog timer to monitor the operating status of the main control unit; configures a dual-channel relay as a control signal switching switch; and the backup control unit has built-in minimum operating mode firmware to independently maintain basic control logic.

[0164] The system recovery strategy is: if the main control unit returns to normal after a period of time (such as a successful restart), the system will re-evaluate its status; if confirmed to be correct, the backup control unit can return control to the main control unit; the switching process must ensure data consistency to prevent control conflicts.

[0165] The fault alarm mechanism is as follows: After a switchover is triggered, the LED indicator and buzzer indicate a fault on the main control unit. Simultaneously, the fault information is sent to the management terminal via the wireless communication module. For example, after a system switchover, the management terminal receives the aforementioned JSON-formatted alarm information, allowing maintenance personnel to determine whether on-site repair is necessary.

[0166] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An energy recovery smart charging pile, characterized in that: include: A charging pile body and a charging module, a control module, an insulation monitoring module, a fault warning module, an energy recovery module, and an active repair module provided on the charging pile body; the charging module is connected to the device to be charged via a charging cable; The insulation monitoring module is used to monitor the insulation resistance value of the charging cable in real time and compare it with a preset multi-level threshold value to generate comparison data; The fault warning module is used to trigger a multi-level processing mechanism including warning, power reduction charging and circuit breaking according to the comparison data; The energy recovery module is configured to store the remaining electric energy in the charging circuit when the fault triggering data includes triggering power reduction or circuit breaking; The active repair module is configured to generate high-voltage pulses with a preset peak frequency using the electrical energy stored in the energy recovery module, and to physically repair the damaged insulation portion of the charging cable; The insulation monitoring module includes a distributed insulation detection unit, a dynamic threshold adjustment unit and a comparison unit; The distributed insulation detection unit includes a plurality of insulation detection sensors, which are arranged at intervals on the outer insulation layer of the charging cable in a spirally wound manner and are used to synchronously detect the temperature, humidity, and insulation resistance values ​​at various axial positions of the charging cable, and generate temperature data, humidity data, and insulation resistance values; The dynamic threshold adjustment unit is configured to dynamically modify the threshold using the temperature data, the humidity data, and the historical insulation degradation curve through an adaptive algorithm to generate a target multi-level threshold; a comparison unit, configured to compare the insulation resistance value with the target multi-level threshold value to generate comparison data; The distributed insulation detection unit also includes: a sensor self-calibration module, configured to substitute the temperature data, the humidity data, and the insulation resistance value into a preset resistance compensation formula, calculate an insulation resistance correction value, and send the calculated insulation resistance correction value to a comparison unit; a high-frequency pulse injection module, configured to inject a non-destructive high-voltage pulse signal into the charging cable, calculate the amount of partial discharge inside the cable by detecting the pulse attenuation characteristics, and send the partial discharge amount as an auxiliary parameter to the dynamic threshold adjustment unit; The execution steps of the dynamic threshold adjustment unit are: Filtering and denoising the temperature data and the humidity data to generate target temperature data and target humidity data; Calculate the comprehensive impact factor of environmental parameters using the target temperature data, the target humidity data, and preset temperature and humidity upper limits; Use historical insulation degradation curves to predict the baseline threshold at the current moment; Modifying the baseline threshold using the comprehensive influencing factor of the environmental parameters to generate a target multi-level threshold; The target multi-level threshold includes a normal threshold, a warning threshold, and a fault threshold; the execution steps of the fault warning module are: When the insulation resistance value of the comparison data is lower than the normal threshold value and higher than the warning threshold value, the warning mechanism is triggered and a warning signal is issued through the sound and light alarm device; When the comparison data shows that the insulation resistance value is lower than the warning threshold and higher than the fault threshold, the power reduction charging mechanism is triggered, and the charging power is linearly reduced to a preset range of the rated power according to the deviation ratio between the insulation resistance value and the warning threshold; When the comparison data shows that the insulation resistance value is lower than the fault threshold, a circuit breaker mechanism is triggered to cut off the charging circuit, and a fault message is sent to the management terminal via the wireless communication module; The energy recovery module includes a bidirectional DC converter, a supercapacitor bank and a charge and discharge control unit; The bidirectional DC converter is connected to the charging circuit and the supercapacitor bank, and is used to switch to the energy recovery mode when the power is reduced or the circuit is disconnected; The supercapacitor bank is used to store the remaining electrical energy in the charging circuit; The charge and discharge control unit is configured to trigger overload protection and stop recycling when the remaining electrical energy is greater than or equal to a preset rated capacity; The execution steps of the active repair module are: The damage location algorithm based on the traveling wave ranging principle calculates the insulation damage position through the pulse reflection time difference; using the electrical energy stored in the energy recovery module to generate high-voltage pulses of a preset peak frequency, and physically repairing the damaged insulation portion of the charging cable; During the repair process, the pulse decay rate is monitored in real time, and the repair is determined to be complete when the pulse decay rate decreases by more than or equal to a preset decrease threshold; The active repair module includes a high-voltage pulse generator, a repair effect evaluation unit, and a pulse application electrode. The pulse application electrode is annularly wrapped around the insulation damaged portion of the charging cable. The high-voltage pulse generator is used to output square pulses and transmit them to the pulse applying electrode; The repair effect evaluation unit is used to re-detect the insulation resistance value after the pulse is applied, and trigger a secondary repair if the new insulation resistance value is less than a preset recovery threshold.

2. The energy recovery smart charging pile according to claim 1, characterized in that: The execution steps of the repair effect evaluation unit are: Re-test the insulation resistance value after the pulse is applied and calculate the corresponding resistance recovery rate; When the resistance recovery rate is less than a preset recovery rate threshold, the pulse voltage is increased by a preset multiple corresponding to the current voltage value to perform secondary repair; When the resistance recovery rate corresponding to the secondary repair is less than the preset recovery rate threshold, the insulation damaged portion of the charging cable is marked as unrepairable and the management terminal is notified.

3. The energy recovery smart charging pile according to claim 1, characterized in that: The control module adopts a dual-redundant control system, including a main control unit and a backup control unit. When the main control unit fails, the backup control unit automatically takes over control within a preset time to ensure the normal operation of the charging pile.

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