CN-121984177-A - USB charging wire automatic power-off method and system based on short circuit detection

CN121984177ACN 121984177 ACN121984177 ACN 121984177ACN-121984177-A

Abstract

The invention relates to the technical field of electronics and electrics, in particular to a USB charging wire automatic power-off method and system based on short circuit detection, comprising the following steps: the method comprises the steps of confirming a charging detection environment based on a USB charging detection instruction, analyzing current and voltage of a current sampling unit and a MOS power-off unit by utilizing a microcontroller in a circuit control board to obtain a current transformation time sequence, a current mutation rate, a voltage transformation time sequence and a voltage collapse rate, calculating a circuit abnormality index according to the current mutation rate, the voltage collapse rate and a transient response time length, carrying out short circuit assessment on a basic parameter set based on a pre-constructed circuit analysis model to obtain a short circuit danger probability, calculating a short circuit state score according to the circuit abnormality index, the short circuit danger probability and the short circuit risk coefficient, and confirming a termination charging device based on the short circuit state score and a running charging device to complete automatic power off of a USB charging wire. The invention can identify the short circuit risk of the USB charging wire in advance and improve the accuracy and timeliness of automatic power off.

Inventors

YU WENMING
CHEN LIANWEI
CHENG RUNMING

Assignees

东莞市格邦电子有限公司

Dates

Publication Date: 20260505
Application Date: 20260112

Claims (10)

1. An automatic power-off method of a USB charging wire based on short circuit detection is characterized by comprising the following steps: Receiving a USB charging detection instruction, and confirming a charging detection environment based on the USB charging detection instruction, wherein the charging detection environment comprises an intelligent USB charging wire, an off-line integrated device, a charging end and a device to be charged, the intelligent USB charging wire comprises a VBUS main wire and a circuit control board, and the circuit control board comprises a circuit input end, a circuit output end, a MOS power-off unit, a current sampling unit and a microcontroller; based on the intelligent USB charging wire, the charging end and the device to be charged, the operation USB charging wire and the operation charging device are confirmed; the microcontroller in the circuit control board is utilized to conduct current and voltage analysis on the current sampling unit and the MOS power-off unit, and current transformation time sequence, current mutation rate, voltage transformation time sequence and voltage collapse rate are obtained; Confirming transient response time based on the current transformation time sequence and the voltage transformation time sequence, and calculating average equivalent impedance and impedance fluctuation variance according to the current transformation time sequence and the voltage transformation time sequence; calculating a circuit abnormality index according to the current mutation rate, the voltage collapse rate and the transient response time length; Constructing a basic parameter set based on an intelligent USB charging wire, average equivalent impedance and impedance fluctuation variance, and carrying out short circuit evaluation on the basic parameter set based on a pre-constructed circuit analysis model to obtain short circuit danger probability; extracting environmental characteristics of the running USB charging line by using an off-line integrated device to obtain a short circuit risk coefficient; Calculating a short circuit state score according to the circuit abnormality index, the short circuit risk probability and the short circuit risk coefficient, and completing automatic power-off of the USB charging wire based on the short circuit state score and the confirmation of stopping the charging device by operating the charging device.
2. The method of claim 1, wherein the VBUS main line in the charging detection environment comprises a power supply input end, a power supply output end, a charging input end and a charging output end, the charging end is connected with the power supply input end of the VBUS main line, the device to be charged is connected with the charging output end of the VBUS main line, the circuit input end of the circuit control board is connected with the power supply output end of the VBUS main line, the circuit output end of the circuit control board is connected with the charging input end of the VBUS main line, the microcontroller is electrically connected with the current sampling unit and the MOS power-off unit on the circuit control board, the current sampling unit and the MOS power-off unit are connected in series between the circuit input end and the circuit output end of the circuit control board, the off-line integrated device comprises a micro Hall sensor, a micro temperature sensor and a micro humidity sensor, and the micro Hall sensor in the off-line integrated device are all arranged on the outer surface of the intelligent USB charging line.
3. The method for automatically powering off the USB charging wire based on short circuit detection according to claim 2, wherein the step of performing the current-voltage analysis on the current sampling unit and the MOS power-off unit by using the microcontroller in the circuit control board to obtain the current transformation timing sequence, the current abrupt change rate, the voltage transformation timing sequence and the voltage collapse rate comprises the steps of: confirming a sampling resistor of a current sampling unit; the method comprises the steps of respectively monitoring a current sampling unit and an MOS power-off unit based on a preset monitoring interval, a preset monitoring time and a microcontroller in a circuit control board to obtain a unit voltage difference time sequence and a voltage conversion time sequence, wherein the unit voltage difference time sequence comprises a plurality of unit voltage differences, the voltage conversion time sequence comprises a plurality of output end voltages, and the unit voltage differences correspond to the output end voltages one by one; The following is performed for each cell voltage value in the cell voltage difference sequence: calculating the current of the current circuit according to the cell voltage difference and the sampling resistor; Summarizing the current circuit currents to obtain a plurality of current circuit currents, and sequencing the plurality of current circuit currents according to the sequence of the unit voltage values corresponding to the current circuit currents in the unit voltage difference time sequence to obtain a current conversion time sequence; Identifying a maximum circuit current and a minimum circuit current based on the plurality of present circuit currents; Respectively confirming a first serial number and a second serial number of the maximum circuit current and the minimum circuit current in a current conversion time sequence; calculating a current mutation rate according to the maximum circuit current, the minimum circuit current, the first sequence number, the second sequence number and the monitoring interval; the voltage collapse rate is confirmed based on the plurality of output voltages in the voltage transition sequence.
4. The method for automatically powering down a USB charging wire based on short circuit detection according to claim 3, wherein the step of identifying a transient response time based on a current transition time sequence and a voltage transition time sequence comprises: respectively extracting an ith current circuit current, an ith+1th current circuit current, an ith output end voltage and an ith+1th output end voltage from a current conversion time sequence and a voltage conversion time sequence, wherein the initial value of i is 1; calculating an instantaneous current difference value according to the ith current circuit current and the (i+1) th current circuit current, wherein the instantaneous current difference value is an absolute difference value of the ith current circuit current and the (i+1) th current circuit current; calculating an instantaneous voltage difference value according to the ith output end voltage and the (i+1) th output end voltage; Calculating a circuit fluctuation rate according to the instantaneous current difference value and the instantaneous voltage difference value, wherein the circuit fluctuation rate is the product of the instantaneous current difference value and the instantaneous voltage difference value; Comparing the circuit fluctuation rate with a preset fluctuation threshold, if the circuit fluctuation rate is greater than the preset fluctuation threshold, making I=i+1, taking I as I, and returning to the step of extracting the ith current circuit current, the (i+1) th current circuit current, the (I) th output terminal voltage and the (i+1) th output terminal voltage from the current conversion time sequence and the voltage conversion time sequence respectively until the circuit fluctuation rate is less than or equal to the fluctuation threshold or I=m, and confirming the stable serial number of the ith current circuit current in the current conversion time sequence, wherein m is the number of the current circuit currents in the current conversion time sequence; And calculating the transient response time according to the stable sequence number and the monitoring interval.
5. The method for automatically powering down a USB charging wire based on short circuit detection according to claim 4, wherein calculating average equivalent impedance and impedance fluctuation variance according to current transformation timing and voltage transformation timing comprises: the following is performed for each present circuit current in the current transformation sequence: recording the corresponding output end voltage of the current circuit current in the voltage conversion time sequence as the current circuit voltage; Dividing the current circuit voltage by the current circuit current to obtain unit equivalent impedance; summarizing the unit equivalent impedance to obtain a plurality of unit equivalent impedance; And calculating average equivalent impedance and impedance fluctuation variance according to the plurality of unit equivalent impedances, wherein the average equivalent impedance and the impedance fluctuation variance are respectively the average value and the variance of the plurality of unit equivalent impedances.
6. The method for automatically powering down a USB charging wire based on short circuit detection according to claim 5, wherein the constructing a basic parameter set based on the intelligent USB charging wire, the average equivalent impedance, and the variance of impedance fluctuation comprises: identifying the length and diameter of the USB wire of the intelligent USB charging wire; and summarizing the average equivalent impedance, the impedance fluctuation variance, the USB line length and the USB line diameter to obtain a basic parameter set.
7. The method for automatically powering off a USB charging wire based on short circuit detection according to claim 6, wherein the performing environmental feature extraction on the operating USB charging wire by using the off-line integrated device to obtain a short circuit risk coefficient comprises: The method comprises the steps that a miniature Hall sensor and a miniature temperature sensor in an off-line integrated device are used for respectively collecting current circuit magnetic flux leakage and current wire temperature of a USB charging wire, time for obtaining the current wire temperature is used as a starting point, time is recorded in real time, environment monitoring time is obtained, and when the environment monitoring time reaches a preset environment monitoring interval, the miniature Hall sensor and the miniature temperature sensor in the off-line integrated device are used for respectively collecting updated circuit magnetic flux leakage and updated wire temperature of the USB charging wire; collecting current environmental humidity by using a miniature humidity sensor in the off-line integrated device; Calculating a short-circuit risk coefficient according to the current circuit magnetic leakage, the updated circuit magnetic leakage, the current wire temperature, the updated wire temperature, the current environment humidity and the environment monitoring interval, wherein the calculation formula is as follows: Wherein, the As a risk factor for the short-circuit, And The current circuit magnetic flux leakage and the updated circuit magnetic flux leakage are respectively, And The current wire temperature and the updated wire temperature are respectively, For the current ambient humidity level to be the current ambient humidity level, For the environmental monitoring interval, Is a natural logarithm of the number of the pairs, The absolute value is taken.
8. The method for automatically powering off a USB charging wire based on short circuit detection according to claim 7, wherein the calculation formula of the short circuit state score is as follows: Wherein, the The short-circuit condition is scored as such, In order to be a short-circuit hazard probability, As an index of the abnormality of the circuit, As a function of the hyperbolic tangent, Is a natural constant.
9. The method for automatically powering down a USB charging wire based on short circuit detection according to claim 8, wherein said determining to terminate the charging device based on the short circuit state scoring and operating the charging device comprises: comparing the short circuit state score with a preset dangerous threshold, if the short circuit state score is greater than or equal to the dangerous threshold, marking the running USB charging wire as a marked charging wire, taking the time of the marked charging wire as a starting point, recording the time in real time, obtaining waiting buffer time until the waiting buffer time reaches the preset waiting time threshold, and confirming updated state scores based on the marked charging wire, the off-line integrated device and a circuit analysis model; Comparing the updated state score with a dangerous threshold, and if the updated state score is greater than or equal to the dangerous threshold, executing power-off operation on the MOS power-off unit in the marked charging wire by using the microcontroller to obtain a power-off charging wire; confirming that the charging device is terminated based on the power-off charging wire and the operation charging device; If the updated state score is smaller than the dangerous threshold, taking the marked charging wire as an operation USB charging wire, and returning to the step of analyzing the current and the voltage of the current sampling unit and the MOS power-off unit by utilizing the microcontroller in the circuit control board; And if the short-circuit state score is smaller than the dangerous threshold value, returning to the step of analyzing the current and the voltage by utilizing the microcontroller in the circuit control board to the current sampling unit and the MOS power-off unit until receiving a pre-built charging stopping instruction, and confirming to terminate the charging device based on the operation USB charging wire and the operation charging device.
10. A USB charging wire auto-power-off system based on short circuit detection, the system comprising: The charging environment confirmation module is used for receiving a USB charging detection instruction and confirming a charging detection environment based on the USB charging detection instruction, wherein the charging detection environment comprises an intelligent USB charging wire, an off-line integrated device, a charging end and a device to be charged, the intelligent USB charging wire comprises a VBUS main wire and a circuit control board, and the circuit control board comprises a circuit input end, a circuit output end, a MOS power-off unit, a current sampling unit and a microcontroller; The current and voltage monitoring module is used for confirming the operation of the USB charging wire and the operation of the charging device based on the intelligent USB charging wire, the charging end and the device to be charged, and performing current and voltage analysis on the current sampling unit and the MOS power-off unit by utilizing a microcontroller in the circuit control board to obtain a current transformation time sequence, a current mutation rate, a voltage transformation time sequence and a voltage collapse rate; The short-circuit state evaluation module is used for confirming transient response time based on the current transformation time sequence and the voltage transformation time sequence, calculating average equivalent impedance and impedance fluctuation variance according to the current transformation time sequence and the voltage transformation time sequence, calculating circuit abnormality indexes according to the current mutation rate, the voltage collapse rate and the transient response time sequence, constructing a basic parameter set based on the intelligent USB charging wire, the average equivalent impedance and the impedance fluctuation variance, carrying out short-circuit evaluation on the basic parameter set based on a pre-constructed circuit analysis model to obtain short-circuit risk probability, and carrying out environmental feature extraction on the operation USB charging wire by utilizing the off-line integrated device to obtain a short-circuit risk coefficient; and the automatic power-off judging module is used for calculating a short circuit state score according to the circuit abnormality index, the short circuit risk probability and the short circuit risk coefficient, and finishing the automatic power-off of the USB charging wire based on the short circuit state score and the confirmation of the termination of the charging device by operating the charging device.

Description

USB charging wire automatic power-off method and system based on short circuit detection Technical Field The invention relates to the technical field of electronics and electrics, in particular to an automatic power-off method and system for a USB charging wire based on short circuit detection. Background With the popularization of mobile electronic devices, a USB charging wire has become an indispensable accessory in daily life. The cable has complex use scene and high frequency, and long-term plugging, bending and environmental temperature and humidity change easily lead to abrasion of an insulating layer in the cable, conductor breakage or joint oxidation, so that potential safety hazards such as abnormal line impedance, local overheating and even short circuit can be caused. The existing USB charging line automatic power-off technology generally sets an overcurrent and overtemperature protection element, such as a fuse or a thermal switch, in a charging loop to cut off a circuit when a short circuit occurs or the circuit is abnormal. Although the prior art can complete automatic power-off of the USB charging wire, the existing automatic power-off technology is a post-response after short circuit, can not identify the abnormal condition of the circuit before short circuit in advance, and does not consider the characteristics of different cable specifications, and the protection of the USB charging wire lacks timeliness and accuracy. Therefore, an intelligent power-off protection method capable of monitoring the multi-dimensional short-circuit risk characteristics in real time, predicting the short-circuit state in advance and timely powering off is needed. Disclosure of Invention The invention provides an automatic power-off method of a USB charging wire based on short circuit detection and a computer readable storage medium, which mainly aim to identify the short circuit risk of the USB charging wire in advance and improve the accuracy and timeliness of automatic power-off. In order to achieve the above object, the present invention provides an automatic power-off method for a USB charging wire based on short circuit detection, including: Receiving a USB charging detection instruction, and confirming a charging detection environment based on the USB charging detection instruction, wherein the charging detection environment comprises an intelligent USB charging wire, an off-line integrated device, a charging end and a device to be charged, the intelligent USB charging wire comprises a VBUS main wire and a circuit control board, and the circuit control board comprises a circuit input end, a circuit output end, a MOS power-off unit, a current sampling unit and a microcontroller; based on the intelligent USB charging wire, the charging end and the device to be charged, the operation USB charging wire and the operation charging device are confirmed; the microcontroller in the circuit control board is utilized to conduct current and voltage analysis on the current sampling unit and the MOS power-off unit, and current transformation time sequence, current mutation rate, voltage transformation time sequence and voltage collapse rate are obtained; Confirming transient response time based on the current transformation time sequence and the voltage transformation time sequence, and calculating average equivalent impedance and impedance fluctuation variance according to the current transformation time sequence and the voltage transformation time sequence; calculating a circuit abnormality index according to the current mutation rate, the voltage collapse rate and the transient response time length; Constructing a basic parameter set based on an intelligent USB charging wire, average equivalent impedance and impedance fluctuation variance, and carrying out short circuit evaluation on the basic parameter set based on a pre-constructed circuit analysis model to obtain short circuit danger probability; extracting environmental characteristics of the running USB charging line by using an off-line integrated device to obtain a short circuit risk coefficient; Calculating a short circuit state score according to the circuit abnormality index, the short circuit risk probability and the short circuit risk coefficient, and completing automatic power-off of the USB charging wire based on the short circuit state score and the confirmation of stopping the charging device by operating the charging device. Optionally, the VBUS main line in the charging detection environment comprises a power supply input end, a power supply output end, a charging input end and a charging output end, the charging end is connected with the power supply input end of the VBUS main line, the device to be charged is connected with the charging output end of the VBUS main line, the circuit input end of the circuit control board is connected with the power supply output end of the VBUS main line, the circuit output end of the circuit control board is conn