Automatic over-temperature and over-voltage protection device and system of power adapter

Abstract

The invention relates to the field of power electronics, and discloses an automatic over-temperature and over-voltage protection device for a power adapter, and the device comprises an input voltage collection module which collects the internal input voltage of the power adapter; the input current detection module is used for detecting internal input current of the power adapter; the temperature sensing module is used for monitoring the environment temperature of the device in real time; the load power analysis module is respectively connected with the input voltage acquisition module and the input current detection module and is used for analyzing the load power of the device; and the dynamic threshold calculation module is respectively connected with the input current detection module and the temperature sensing module, and dynamically generates a standard voltage and an overvoltage threshold based on the input current, the total load power and the environment temperature. The dynamic standard voltage and the overvoltage threshold are calculated based on the load power, the input current and the environment temperature, the threshold is adjusted along with the load and the environment, the overvoltage judgment precision is improved to + / -0.5%, and the environmental adaptability is expanded to-40 DEG C to + 85 DEG C.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and specifically to an automatic over-temperature and over-voltage protection device and system for a power adapter. Background Art

[0002] In the current field of power adapters, with the wide application of electronic devices and the increase in complex working environments, higher requirements are put forward for the over-temperature and over-voltage protection performance of power adapters.

[0003] Most traditional automatic over-temperature and over-voltage protection devices for power adapters adopt a fixed threshold scheme. In actual work, the load power is not constant, and the ambient temperature is also constantly changing. Since the fixed threshold cannot be adjusted according to the dynamic changes of the load and the environment, when the load fluctuates, for example, at the moment when some high-power devices start, the load power will suddenly increase. At this time, the fixed over-voltage threshold may not be able to accurately judge the real working state, resulting in misjudgment; and when the ambient temperature changes, for example, in a cold -40°C or hot +85°C environment, the performance of circuit components will change, which will also cause the fixed threshold to mismatch with the actual required threshold, and finally the misjudgment rate is as high as 15% - 20%.

[0004] At the same time, in terms of over-voltage detection, traditional protection devices either only focus on the sampling speed or only pursue the detection accuracy, and it is difficult to balance both. Simple high-frequency sampling can quickly obtain data, but the accuracy is insufficient; high-precision sampling cannot guarantee fast response, which leads to a long response time when facing over-voltage situations, and in a complex electromagnetic environment, the misjudgment rate is high, and reliable protection cannot be achieved.

[0005] In addition, in the case of sudden load changes, traditional devices lack effective countermeasures. When connecting or disconnecting some high-power loads, due to the output impedance not being able to be adjusted in real time, it will cause severe voltage fluctuations and voltage dips, which not only affect the normal operation of the equipment, but also may trigger chain misoperations. Especially in strong interference scenarios such as industrial frequency conversion equipment, the system stability is extremely poor.

[0006] Finally, the parameter adjustment of traditional devices depends on manual experience and is difficult to adapt to complex and changeable working conditions. During the entire life cycle of the power adapter, as the usage time increases and the working environment changes, the original parameter settings gradually cannot meet the protection requirements, but cannot be automatically updated and optimized, resulting in a high mis-triggering rate and it is difficult to guarantee the high-temperature compensation accuracy, which greatly affects the service life of the equipment. Summary of the Invention

[0007] In view of the deficiencies of the prior art, the present invention provides an automatic over-temperature and over-voltage protection device and system for a power adapter, which solves the problems in the prior art that the output impedance cannot be adjusted in real time, resulting in severe voltage fluctuations and voltage drops, which not only affect the normal operation of the device but may also cause chain misoperations.

[0008] To achieve the above objectives, the present invention is realized through the following technical solutions: An automatic over-temperature and over-voltage protection device for a power adapter, comprising: An input voltage acquisition module for acquiring the input voltage inside the power adapter; An input current detection module for detecting the input current inside the power adapter; A temperature sensing module for real-time monitoring of the device ambient temperature; A load power analysis module, connected to the input voltage acquisition module and the input current detection module respectively, for analyzing the device load power; A dynamic threshold calculation module, connected to the input current detection module and the temperature sensing module respectively, for dynamically generating a standard voltage and an over-voltage threshold based on the input current, the total load power, and the ambient temperature; A dual-time-window voltage comparison module, connected to the input voltage acquisition module, for jointly determining the over-voltage state through a rough detection stage and a fine detection stage; A non-linear temperature correction module, connected to the temperature sensing module, for generating a corrected temperature value by combining the ambient temperature and the internal temperature; A power disturbance isolation module, connected to the input voltage acquisition module and the load power analysis module respectively, for suppressing voltage fluctuations caused by load mutations; A protection execution module, connected to the dual-time-window voltage comparison module and the non-linear temperature correction module respectively, for triggering protection actions in grades according to the over-voltage or over-temperature determination results.

[0009] Preferably, the working logic of the dynamic threshold calculation module includes: Calculating the standard voltage according to the ratio of the sum of the rated powers of several connected load devices to the input current, and performing efficiency compensation on the standard voltage in combination with the ambient temperature; The over-voltage threshold is a linear combination of the standard voltage and the rate of change of the input current.

[0010] Preferably, the execution method of the dual-time-window voltage comparison module is: In the rough detection stage, continuously detect whether the output voltage exceeds the over-voltage threshold at the first sampling frequency. If over-voltage is detected three times in a row, start the fine detection stage; During the fine inspection stage, verification is carried out at the second sampling frequency. If the over-limit ratio exceeds the set threshold, the overvoltage state is confirmed, where the first sampling frequency is higher than the second sampling frequency.

[0011] Preferably, the working method of the power disturbance isolation module includes: When it is detected that the instantaneous change rate of the total load power exceeds the preset ratio of the total power, the voltage comparison process is frozen and the Kalman filter is activated to smooth the output voltage; Dynamic impedance matching is achieved by adjusting the resistance value of the digital potentiometer to suppress the voltage fluctuation caused by power mutation.

[0012] Preferably, the correction process of the non-linear temperature correction module includes: Calculating the thermal effect compensation value based on the internal temperature of the adapter and the thermal resistance model; Periodically correcting the compensation value according to the ambient temperature to generate the final corrected temperature.

[0013] Preferably, the hierarchical protection strategy of the protection execution module is: When the overvoltage determination is established, first reduce the output power to the first preset ratio. If the over-limit continues, completely cut off the output; When the corrected temperature exceeds the second preset value of the reference temperature, first limit the output current. If the temperature continues to rise, turn off the power supply.

[0014] In addition, the present invention also provides an automatic over-temperature and over-voltage protection system for a power adapter, including: A verification module, configured to periodically detect whether the output voltage and temperature return to the safe range after the protection action is triggered, and adjust the protection release condition according to the recovery situation.

[0015] Preferably, the working method of the verification module includes: After the overvoltage protection is triggered, detect whether the output voltage is lower than the third preset ratio of the standard voltage at every set time interval; If the detection is qualified for multiple consecutive times, gradually restore the output power until full-load operation.

[0016] Preferably, it further includes: A self-learning module, configured to record the load power, ambient temperature, and protection response data of historical overvoltage and over-temperature events, and dynamically optimize the efficiency compensation coefficient and overvoltage threshold adjustment parameters in the dynamic threshold calculation module.

[0017] Preferably, the protection action delay time of the system is: The response time from the establishment of the overvoltage determination to the execution of the power reduction action does not exceed 15 ms, and the response time from the establishment of the over-temperature determination to the execution of the current limiting action does not exceed 1 s.

[0018] The present invention provides an automatic over-temperature and over-voltage protection device and system for a power adapter. It has the following beneficial effects: 1. Based on the load power, input current, and ambient temperature, the present invention calculates the dynamic standard voltage and over-voltage threshold in real time, introduces a quadratic function temperature efficiency compensation model, realizes the dynamic adjustment of the threshold with the load and the environment, improves the over-voltage determination accuracy to ±0.5%, expands the environmental adaptability to -40°C to +85°C. Compared with the traditional fixed-threshold scheme, the misjudgment rate is as high as 15% - 20% when the load fluctuates or the temperature changes, eliminates the threshold mismatch problem caused by environmental temperature drift and load mutation, and reduces the false trigger rate by 96%; 2. The present invention adopts two-level verification of rough detection (1kHz high-frequency sampling) and fine detection (100Hz high-precision sampling), combined with a dynamic threshold elevation strategy, to shorten the over-voltage response time to within 15ms, reduce the misjudgment rate to 0.3 times / hour, break through the contradiction between response speed and accuracy, and achieve reliable protection in a complex electromagnetic environment; 3. Based on the Kalman filter smoothing process and dynamic impedance matching algorithm, the present invention combines a digital potentiometer to adjust the output impedance in real time, suppresses the voltage fluctuation peak caused by load mutation to below 50mV, reduces the voltage drop by 76%, avoids the chain misoperation caused by power mutation, and improves the stability of the system in strong interference scenarios such as industrial frequency conversion equipment; 4. Based on the parameter dynamic optimization framework of reinforcement learning, the present invention periodically updates the efficiency compensation coefficient and threshold adjustment parameters. After 30 days of operation, the false trigger rate drops from 1.2% to 0.3%, and the high-temperature compensation accuracy is improved by 42%. It breaks through the limitation of manual experience parameter adjustment, realizes the adaptive optimization of the system's entire life cycle, and extends the service life of the equipment by 2 - 3 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the automatic over-temperature and over-voltage protection device of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0021] Please refer to the attached Figure 1 , the embodiment of the present invention provides an automatic over-temperature and over-voltage protection device for a power adapter, including: An input voltage acquisition module for acquiring the input voltage inside the power adapter; Specifically, the input voltage acquisition module, as the front-end sensing unit of the overvoltage protection system, is responsible for accurately obtaining the input voltage value of the power adapter in real time. This module forms a closed-loop data stream with the dynamic threshold calculation module and the dual-time-window voltage comparison module: the original voltage data collected is processed to provide a reference input for generating the dynamic threshold and, at the same time, serves as a real-time criterion for voltage comparison. The module design needs to balance high precision, fast response, and anti-interference capabilities to ensure that the measurement error is ≤±0.5% within a wide input range (90 - 264VAC / 12 - 48VDC).

[0022] In some embodiments, the specific implementation of the input voltage acquisition module is as follows: Hardware topology design: High-voltage side circuit: A resistor voltage division network is used to reduce the high input voltage to within the ADC range. The voltage division ratio is designed to be 1000:1, and high-precision metal film resistors (±0.1%) are selected: R1 = 900kΩ ±0.1% (with a breakdown voltage of 500V) R2 = 1kΩ ±0.1% Theoretical voltage division output: ; In the formula, is the theoretical voltage division, is the input voltage.

[0023] Protection circuit: A TVS diode (SMBJ30CA, breakdown voltage 33V) and a self-recovery fuse (60V / 0.5A) are connected in parallel to prevent surge voltage from damaging the backend circuit.

[0024] Signal conditioning unit: Low-pass filtering: A second-order Butterworth filter (cutoff frequency 1kHz), with resistor-capacitor values: R3 = R4 = 10kΩ, C1 = C2 = 15.9nF Transfer function: ; where is the complex frequency.

[0025] Op-amp buffer: A zero-drift op-amp AD8628 (offset voltage 2μV) is used and configured as a voltage follower to reduce the output impedance to below 50mΩ.

[0026] ADC conversion configuration: Device selection: A 16-bit Σ-Δ ADC (ADS8866), sampling rate 1MHz, INL ±2LSB.

[0027] Reference source: An external reference chip REF5040 (4.096V ±0.05%), with a temperature drift of 3ppm / °C.

[0028] Sampling trigger: Synchronized with the main control chip through the SPI interface, and the conversion result is read every 10 μs.

[0029] Real-time calibration mechanism: Power-on self-calibration: Short-circuit the input terminal during power-on to collect the zero-offset value and store it in the EEPROM.

[0030] Online compensation: Actual measured value is corrected according to the following formula: ; where is the unregulated voltage, is the temperature compensation coefficient, , is the temperature of the ADC chip, which is obtained through the built-in sensor.

[0031] As an option, the input voltage acquisition module also has an anti-interference design. It uses a voltage division network and the ADC input trace with a double-layer Faraday shield, the grounding impedance < 0.1 Ω, and the CMRR is configured > 120 dB in the differential input mode to suppress the common-mode interference of the power grid.

[0032] Input current detection module, which detects the input current inside the power adapter; Specifically, in this embodiment, the sampling resistance method based on Ohm's law is adopted. The sampling resistance is connected in series in the input power line of the power adapter. The two ends of the sampling resistance are respectively connected to the non-inverting input terminal and the inverting input terminal of the operational amplifier. In the feedback loop of the operational amplifier, a feedback resistance is connected. The resistance value of the feedback resistance is selected according to the required amplification factor. For example, if it is desired to amplify the sampling voltage by 100 times, the resistance value of the feedback resistance can be selected as (1 kΩ) (assuming the sampling resistance is (0.01 Ω). The output terminal of the operational amplifier is connected to the subsequent signal processing circuit, such as an analog-to-digital converter (ADC), to convert the analog voltage signal into a digital signal for processing and analysis by the central control unit.

[0033] Load power analysis module, which analyzes the load power of the device; Specifically, according to the power calculation formula: ; where is the power, is the voltage, Let \(I\) be the current. By measuring the voltage and current at the output of the power adapter in real time, the load power can be calculated. At the same time, trend analysis is carried out using this data to predict possible abnormal situations such as overload in advance.

[0034] To improve the calculation accuracy, the method of taking the average value by multiple samplings can be adopted. For example, sample once every 10 ms, and take the average value after 10 consecutive samplings as the current voltage and current values for power calculation.

[0035] The dynamic threshold calculation module dynamically generates a standard voltage and an overvoltage threshold based on the input current, the total load power, and the ambient temperature; The working logic of the dynamic threshold calculation module includes: Calculate the standard voltage according to the ratio of the sum of the rated powers of several connected load devices to the input current, and perform efficiency compensation on the standard voltage in combination with the ambient temperature; The overvoltage threshold is a linear combination of the standard voltage and the rate of change of the input current.

[0036] Specifically, the dynamic threshold calculation module, as the core decision-making unit of the protection system, is responsible for fusing multi-source data of the input current, the total load power, and the ambient temperature to generate an adaptive standard voltage and a dynamic overvoltage threshold . This module forms a closed loop with the input voltage acquisition module, the load power analysis module, and the temperature sensing module: receiving the real-time input current , the set of rated powers of load devices and the ambient temperature , and outputting the dynamic threshold to the double-time-window voltage comparison module to provide an intelligent benchmark for overvoltage determination.

[0037] In this embodiment, the specific implementation method of the dynamic threshold calculation module is as follows: Standard voltage calculation model: ; where is the sum of the rated powers of load devices (W), is the real-time measured value of the input current (A).

[0038] Temperature efficiency compensation: Introduce an efficiency correction coefficient related to the ambient temperature , and the final standard voltage is: ; where Calibrate the curve fitting through experiments: ; Temperature compensation range: -40°C to +85°C.

[0039] Compensation effect: for every 10°C increase in temperature, the standard voltage is reduced by 3.4%.

[0040] As an option, the dynamic threshold calculation module calculates the current change rate using a 10ms sliding window. The calculation formula is: ; Threshold adjustment formula: ; Wherein, is the adjustment coefficient, which is optimized and determined to be 0.05 through Monte Carlo simulation, is the 1-second moving average of the input current.

[0041] In a possible implementation, the real-time data interaction of the dynamic threshold calculation module is as follows: Input interface: Input current : The ADC conversion result from the input voltage acquisition module.

[0042] Load power : Obtained from the load power analysis module through the I 2 C bus.

[0043] Ambient temperature : Digital quantity from the temperature sensing module.

[0044] Output interface: Standard voltage : Transmitted to the dual-time window voltage comparison module as a reference.

[0045] Overvoltage threshold : Output as an analog signal modulated by PWM (0 - 5V corresponds to 0 - 30V threshold).

[0046] As an option, the dynamic threshold calculation module is also configured with an anti-saturation protection mechanism. When it detects / > 0.2 (severe load fluctuation), the threshold limiting is started: ; The dual-time window voltage comparison module collaboratively determines the overvoltage state through the rough detection stage and the fine detection stage; The execution mode of the dual-time window voltage comparison module is: In the rough detection stage, continuously detect whether the output voltage exceeds the overvoltage threshold at the first sampling frequency. If overvoltage is detected three times in a row, the fine detection stage is started; In the fine detection stage, verify at the second sampling frequency. If the overlimit ratio exceeds the set threshold, the overvoltage state is confirmed, where the first sampling frequency is higher than the second sampling frequency.

[0047] Specifically, the dual-time-window voltage comparison module adopts a two-stage detection mechanism of "quick screening - precise verification" to solve the pain point that it is difficult to balance the response speed and false judgment rate in traditional single-threshold detection. This module receives the real-time threshold from the dynamic threshold calculation module , and performs multi-band comparison with the output voltage of the input voltage acquisition module , and finally sends an overvoltage determination signal to the protection execution module. Its core innovation lies in the time-domain - frequency-domain collaborative analysis, achieving a microsecond-level fast response in the rough inspection stage and ensuring the determination accuracy in the precise inspection stage.

[0048] In this embodiment, the hardware implementation method of the dual-time-window voltage comparison module is as follows: High-speed comparator array: Configure a 4-channel high-speed comparator (TLV3501, propagation delay 6 ns), corresponding to respectively: Channel 1: Main channel for rough inspection (threshold ); Channel 2: Main channel for precise inspection (threshold 1.02 ); Channels 3 / 4: Redundant backup channels (threshold dynamically follows the main channel) Dual-sampling-rate ADC system: Rough inspection ADC: ADS9224R (12 bits, 5 MSPS), dedicated to high-frequency sampling within a 10 ms window.

[0049] Precise inspection ADC: ADS131M08 (24 bits, 32 kSPS), used for high-precision sampling within a 100 ms window.

[0050] Logic control unit: The state machine control is implemented by FPGA (Xilinx Artix-7), and its main functions include: generating rough inspection trigger signals, timing for the precise inspection window, and cross-clock-domain data synchronization.

[0051] As an option, the specific process of the dual-time-window determination logic is as follows: Rough inspection stage: Sampling configuration: Frequency: , (period = 1 ms).

[0052] Window length: sampling points (covering 10 ms).

[0053] Trigger condition: ; And introduce hysteresis comparison as an anti-interference measure to prevent oscillation triggering caused by noise.

[0054] Precise inspection stage: Sampling configuration: Frequency: , (period = 10 ms).

[0055] Window length: sampling points (covering 100 ms).

[0056] Decision logic: ; Dynamic logic adjustment: In the fine inspection stage, the threshold is automatically increased by 2% to enhance robustness: ; State transition mechanism: Coarse inspection → fine inspection: When the coarse inspection is triggered continuously for 3 times, the FPGA starts the fine inspection counter in the next system clock cycle and locks the current value.

[0057] Timeout reset: If the confirmation condition is not reached within the fine inspection window, the state machine is automatically reset after 300 ms.

[0058] In a possible implementation, the real-time data interaction of the dual-time-window voltage comparison module is as follows: Interaction with the dynamic threshold module: Receive the updated value through the LVDS interface every 50 μs. When the detected mutation rate > 10% / ms, freeze the threshold input and trigger system diagnosis.

[0059] Interaction with the protection execution module: The overvoltage confirmation signal is transmitted to the MOSFET drive circuit through optocoupler isolation (TLP785). Protection action delay: The delay from fine inspection confirmation to execution instruction ≤ 2 μs.

[0060] Abnormal handling mechanism: ADC failure detection: Compare the data consistency of 4 channels. When the deviation > 5%, switch to the standby channel. Watchdog timer: Force reset if no heartbeat signal is received within 500 ms.

[0061] Temperature sensing module, which monitors the device environment temperature in real time; In this embodiment, a high-precision negative temperature coefficient thermistor is selected as the core temperature sensing element. In a relatively wide temperature range, the resistance value of this thermistor shows a good linear relationship with the temperature change, and it can accurately convert the temperature change into the resistance value change. The thermistor is closely attached to the surface of the main heating elements of the power adapter, such as power transistors, transformers, etc. To ensure good heat conduction, a thin layer of thermal grease is applied between the thermistor and the heating element to reduce the thermal resistance. At the same time, a high-temperature-resistant fixing glue is used to firmly fix the thermistor to prevent it from being displaced due to vibration and other factors during the operation of the power adapter, affecting the accuracy of temperature measurement.

[0062] The thermistor and a precision resistor form a voltage-dividing circuit, and the stable DC voltage provided by the power adapter serves as the voltage-dividing power supply. When the thermistor senses a temperature change, its resistance value changes, and the voltage output by the voltage-dividing circuit also changes accordingly. This voltage signal is first amplified by an operational amplifier to enhance the driving ability of the signal, and then passes through a low-pass filter circuit to filter out high-frequency interference signals, obtaining a stable and accurate voltage signal for subsequent transmission to the central control unit for processing. The low-pass filter circuit can adopt a first-order RC low-pass filter composed of a resistor R and a capacitor C. The parameters of the resistor and capacitor are reasonably selected according to actual requirements. For example, when R is taken as 10 kΩ and C is taken as 0.1 μF, high-frequency interference signals above 50 Hz can be effectively filtered out.

[0063] The non-linear temperature correction module combines the ambient temperature and the internal temperature to generate a corrected temperature value; The correction process of the non-linear temperature correction module includes: Calculating the thermal effect compensation value based on the internal temperature and thermal resistance model of the adapter; Periodically correcting the compensation value according to the ambient temperature to generate the final corrected temperature.

[0064] Specifically, in this embodiment, the non-linear temperature correction module realizes high-precision temperature correction by fusing the internal temperature detection data of the adapter and the ambient temperature monitoring value, and adopting a thermal resistance model and a periodic ambient compensation algorithm. The module first collects the internal temperature of the adapter in real time through a high-precision NTC thermistor (model MF52-103, β value 3950K ± 1%) , and synchronously obtains the external ambient temperature , and calculates the thermal effect compensation value based on the thermodynamic steady-state model : ; Among them, is the equivalent thermal resistance of the adapter, is the total load power, is the standard output voltage, is the system running time (seconds). The first term represents the temperature rise caused by the power density, and the second term introduces a periodic disturbance factor to simulate the heat dissipation fluctuation.

[0065] The ambient temperature correction is realized through a dynamic weight function: ; The weight function takes the maximum value of 0.5 at 40 °C and decays exponentially with the deviation of the ambient temperature. When is detected, the emergency compensation mode is activated, and at A 3°C offset is forced to be superimposed to prevent high - temperature failure. The module updates the correction value every 200 ms and shares the data bus with the overtemperature protection module. When it exceeds 85°C continuously for 5 times, the secondary shutdown protection is triggered. Experiments show that within the temperature range of - 20°C to 70°C, this scheme reduces the temperature detection error from ±5.2°C of the traditional scheme to ±1.1°C, and the anti - instantaneous thermal interference ability is increased by 3.6 times.

[0066] The power disturbance isolation module suppresses the voltage fluctuation caused by load mutation; The working method of the power disturbance isolation module includes: When the instantaneous change rate of the total load power is detected to exceed the preset ratio of the total power, freeze the voltage comparison process and activate the Kalman filter to smooth the output voltage; Realize dynamic impedance matching by adjusting the resistance value of the digital potentiometer to suppress the voltage fluctuation caused by power mutation.

[0067] In this embodiment, the power disturbance isolation module monitors the instantaneous change rate of the total load power in real - time (defined as / , where is the power difference between adjacent 1 - ms intervals, = 1 ms). When the change rate is detected to exceed the preset threshold (the typical value is 20% of the total power), immediately trigger a three - level response mechanism: First, freeze the decision logic of the voltage comparison module for 500 μs to avoid misoperation caused by transient fluctuations; then activate the discrete Kalman filter to perform recursive smoothing on the output voltage. Its state equation and observation equation are respectively: ; ; where, is the system state at the k - th moment, is the process noise.

[0068] is the observed value at the k - th moment, is the observation noise; Through dynamic adjustment of the Kalman gain (update period 50 μs), suppress the peak value of the output voltage noise to below 50 mV. Synchronously start the dynamic impedance matching of the digital potentiometer (AD5272, 128 - step, I 2 C interface), and adjust the resistance value according to the power mutation direction: When > 0, the resistance value is increased according to: ; increases ( is the perturbation delay time, with a typical value of 2 ms), otherwise it decreases linearly, enabling the output impedance to match the load change within 5 ms. Measured results show that it can reduce the voltage drop caused by sudden loading from 12% to 3.2%. The module has a built-in self-check function. When the adjustment exceeds the potentiometer range for three consecutive times, it automatically switches to the MOSFET parallel shunt mode to forcibly stabilize the output voltage.

[0069] The protection execution module triggers protection actions in levels according to the overvoltage or overtemperature determination results.

[0070] The hierarchical protection strategy of the protection execution module is as follows: When the overvoltage determination is established, first reduce the output power to the first preset ratio. If it continues to exceed the limit, completely cut off the output. When the corrected temperature exceeds the second preset value of the reference temperature, first limit the output current. If the temperature continues to rise, turn off the power supply.

[0071] Specifically, in this embodiment, the protection execution module adopts a hierarchical progressive protection strategy, and designs a multi-level response mechanism for two types of faults: overvoltage and overtemperature. When the overvoltage determination is triggered (based on the confirmation result of the dual-time window module), the module first linearly reduces the duty cycle of the switching power supply to the preset 70% (the first preset ratio) within 5 ms through the PWM controller. If the output voltage still exceeds the dynamic threshold after 200 ms, then activate the hardware-level fast shutdown circuit, pull down the gate voltage of the GaNMOSFET to 0 V within 2 μs, cut off the feedback loop, and at the same time adjust the resistance value of the digital potentiometer (AD5272) to the maximum value through the I 2 C bus to isolate the load. For the overtemperature scenario (based on the non-linear corrected temperature ), when (the second preset value), the module decays the output current according to an exponential curve through the dynamic current limiting algorithm: ; where is the maximum output current.

[0072] If the temperature continues to rise within 10 seconds and the rate exceeds 1.5 °C / s, then trigger the fusing mechanism, use the shape memory alloy (SMA) actuator to physically cut off the main power supply circuit, and at the same time start the standby LDO circuit to maintain the power supply of the control unit. The module integrates a status self-check function, automatically tests the response delay of the protection path every 24 hours (required ≤ 15 μs). In case of abnormality, it switches to the redundant control chip (dual MCU architecture). Measured data shows that this strategy shortens the average recovery time of overvoltage faults from 320 ms in the traditional scheme to 85 ms, and there is no arc generation during the overtemperature shutdown process. It can withstand ≥ protection actions within the life cycle.

[0073] In addition, the present invention also provides an automatic over-temperature and over-voltage protection system for a power adapter, comprising: A verification module, configured to periodically detect whether the output voltage and temperature have returned to the safe range after a protection action is triggered, and adjust the protection release condition according to the recovery situation.

[0074] The working method of the verification module includes: After over-voltage protection is triggered, detect whether the output voltage is lower than a third preset ratio of the standard voltage at regular time intervals; If the detection is qualified for multiple consecutive times, gradually restore the output power until full-load operation.

[0075] Specifically, in this embodiment, the verification module adopts an adaptive recovery strategy to ensure the safe restart of the system. After over-voltage protection is triggered, the module uses the initial interval to periodically collect the output voltage , and compare it with the standard voltage generated by the dynamic threshold module: when it is detected continuously for 3 times (the third preset ratio), start a four-stage power recovery process - first, increase the output power to 50% (adjusted step by step through the PWM duty cycle, with an increase of 5% per second), and then decrease the detection period by 50% every (down to a minimum of 1 second). If over-voltage is not triggered during this period, gradually restore it in three stages: 25%, 75%, and 100%, and each stage requires continuous detection and verification twice; when or temperature is detected during the recovery process, immediately roll back to the previous safe power level and extend the detection period to 8 seconds. The module integrates a historical status buffer to record the timestamps, recovery progress, and exception codes of the last 10 protection events, and dynamically optimizes the recovery parameters through the exponentially weighted moving average algorithm. Experiments show that this solution shortens the average recovery time of the system by 62% and reduces the secondary failure rate to 0.7%.

[0076] The automatic over-temperature and over-voltage protection system further includes: A self-learning module, configured to record the load power, ambient temperature, and protection response data of historical over-voltage and over-temperature events, and dynamically optimize the efficiency compensation coefficient and over-voltage threshold adjustment parameters in the dynamic threshold calculation module.

[0077] Specifically, in this embodiment, the self-learning module records the load power , ambient temperature , protection response delay , and action effectiveness indicators (such as overshoot voltage ), and adopts a dynamic optimization framework based on reinforcement learning to generate parameter update strategies every 24 hours. The specific process is as follows: 1) In the data preprocessing stage, perform wavelet denoising on and normalize it to the interval [0, 1], and perform periodic decomposition on to extract the trend term; 2) In the feature engineering stage, construct sliding window statistics; 3) In the model training stage, use the DQN (DeepQ-Network) algorithm to optimize the efficiency compensation coefficient in , parameters and the overvoltage threshold adjustment coefficient , and the objective function is to minimize the weighted sum of the protection false trigger rate and the false alarm rate in historical events (weight ratio 6:4); 4) In the online deployment stage, write the increment of the trained parameters into the FRAM configuration area of the dynamic threshold module after passing the security check, and at the same time retain the previous version for abnormal rollback. Experiments show that after 30 days of self-learning optimization, the false trigger rate of the system in the fluctuating load scenario drops from the initial 1.2% to 0.3%, and the efficiency compensation accuracy in the high-temperature environment is improved by 42%. The module is set with a self-learning enable switch, allowing users to select to enable / disable the adaptive optimization function according to the application scenario.

[0078] The protection action delay time of the system is: The response time from the overvoltage determination being established to the power reduction action being executed does not exceed 15 ms, and the response time from the overtemperature determination being established to the current limiting action being executed does not exceed 1 s.

[0079] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An automatic over-temperature and over-voltage protection device for a power adapter, characterized in that: include: An input voltage acquisition module is used to collect the internal input voltage of the power adapter; An input current detection module detects the internal input current of the power adapter; Temperature sensing module, to monitor the device ambient temperature in real time; A load power analysis module, connected to the input voltage acquisition module and the input current detection module respectively, and used to analyze the load power of the device; A dynamic threshold calculation module, connected to the input current detection module and the temperature sensing module respectively, and dynamically generates a standard voltage and an overvoltage threshold based on the input current, the total load power and the ambient temperature; A dual time window voltage comparison module is connected to the input voltage acquisition module and collaboratively determines the overvoltage state through a rough inspection stage and a fine inspection stage; A nonlinear temperature correction module is connected to the temperature sensing module and generates a correction temperature value in combination with the ambient temperature and the internal temperature; A power disturbance isolation module, connected to the input voltage acquisition module and the load power analysis module respectively, and used to suppress voltage fluctuations caused by load mutations; The protection execution module is connected to the dual-time window voltage comparison module and the nonlinear temperature correction module respectively, and triggers the protection action in stages according to the overvoltage or overtemperature determination result.

2. The automatic over-temperature and over-voltage protection device for a power adapter according to claim 1, characterized in that: The working logic of the dynamic threshold calculation module includes: Calculating a standard voltage according to a ratio of a total rated power of a plurality of connected load devices to an input current, and performing efficiency compensation on the standard voltage in combination with an ambient temperature; The overvoltage threshold is a linear combination of the standard voltage and the input current change rate.

3. The automatic over-temperature and over-voltage protection device for a power adapter according to claim 1, characterized in that: The dual time window voltage comparison module is implemented as follows: In the rough detection stage, the output voltage is continuously detected at the first sampling frequency to see whether it exceeds the overvoltage threshold, and if the overvoltage is detected three times in a row, the fine detection stage is started; In the fine inspection stage, verification is performed at the second sampling frequency, and if the over-limit ratio exceeds a set threshold, an overvoltage state is confirmed, wherein the first sampling frequency is higher than the second sampling frequency.

4. The automatic over-temperature and over-voltage protection device for a power adapter according to claim 1, characterized in that: The working method of the power disturbance isolation module includes: When it is detected that the instantaneous rate of change of the total load power exceeds a preset proportion of the total power, the voltage comparison process is frozen and the Kalman filter is activated to smooth the output voltage; Dynamic impedance matching is achieved by adjusting the resistance value of the digital potentiometer to suppress voltage fluctuations caused by power mutations.

5. The automatic over-temperature and over-voltage protection device for a power adapter according to claim 1, characterized in that: The correction process of the nonlinear temperature correction module includes: Calculate the thermal effect compensation value based on the internal temperature of the adapter and the thermal resistance model; The compensation value is periodically corrected according to the ambient temperature to generate a final correction temperature.

6. The automatic over-temperature and over-voltage protection device for a power adapter according to claim 1, characterized in that: The hierarchical protection strategy of the protection execution module is: When the overvoltage is determined, the output power is first reduced to a first preset ratio, and if the limit is continuously exceeded, the output is completely cut off; When the calibrated temperature exceeds a second preset value of the reference temperature, the output current is limited first, and if the temperature continues to rise, the power supply is turned off.

7. An automatic over-temperature and over-voltage protection system for a power adapter, characterized in that: An automatic over-temperature and over-voltage protection device for a power adapter according to any one of claims 1 to 6, comprising: The verification module is used to periodically detect whether the output voltage and temperature have recovered to a safe range after the protection action is triggered, and adjust the protection release conditions according to the recovery situation.

8. The automatic over-temperature and over-voltage protection system for a power adapter according to claim 7, characterized in that: The working method of the verification module includes: After the overvoltage protection is triggered, detecting whether the output voltage is lower than a third preset ratio of the standard voltage at every set time interval; If the test is qualified for multiple times in a row, the output power will be gradually restored until it runs at full load.

9. The automatic over-temperature and over-voltage protection system for a power adapter according to claim 7, characterized in that: Also includes: The self-learning module is used to record the load power, ambient temperature and protection response data of historical overvoltage and overtemperature events, and dynamically optimize the efficiency compensation coefficient and overvoltage threshold adjustment parameters in the dynamic threshold calculation module.

10. The automatic over-temperature and over-voltage protection system for a power adapter according to claim 7, characterized in that: The protection action delay time of the system is: The response time from the establishment of overvoltage judgment to the execution of power reduction action shall not exceed 15ms, and the response time from the establishment of overtemperature judgment to the execution of current limiting action shall not exceed 1s.

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