CN-122025926-A - Lithium battery temperature control power limit management method and device

CN122025926ACN 122025926 ACN122025926 ACN 122025926ACN-122025926-A

Abstract

The embodiment of the application discloses a power limit management method and device for temperature control of a lithium battery, wherein the method comprises the steps of monitoring the temperature of a battery core, the air outlet temperature and the power demand fluctuation of a wireless blower in real time, calculating the temperature rise rate of the battery core based on the temperature of the battery core, and calculating the change rate of the air temperature based on the air outlet temperature; when the battery core temperature or the air outlet temperature is detected to exceed the corresponding threshold value, a power limiting coefficient is calculated based on the change rate amplitude of the temperature rise rate of the battery core or the change rate amplitude of the change rate of the air outlet temperature and the fluctuation of the power demand, and then the power limiting coefficient is applied to a heating module of the wireless blower to carry out heating power output limitation. Through temperature acquisition, threshold judgment, risk calculation and power control, self-adaptive heat management and power dynamic regulation and control of the wireless blower in a high-power running state are realized, and the problems of lag temperature control response and unstable power regulation in the prior art are overcome.

Inventors

LEI HONGJUN
YANG CHUNYOU
PENG JIANGPING

Assignees

东莞市腾威动力新能源有限公司

Dates

Publication Date: 20260512
Application Date: 20260129

Claims (8)

1. A power limit management method for lithium battery temperature control, applied to a wireless blower, comprising the following steps: step S10, monitoring the temperature of a battery cell, the air outlet temperature and the power demand fluctuation of the wireless blower in real time, calculating the temperature rise rate of the battery cell based on the temperature of the battery cell, and calculating the change rate of the air temperature based on the air outlet temperature; step S20, judging whether the temperature of the battery cell exceeds a preset first temperature threshold or whether the temperature of the air outlet exceeds a preset second temperature threshold, if so, entering step S30, otherwise, maintaining the current working power and returning to step S10; Step S30, when the battery cell temperature or the air outlet temperature is detected to exceed a corresponding threshold value, calculating a corresponding power limiting coefficient based on the change rate amplitude of the battery cell temperature rise rate or the change rate amplitude of the air outlet temperature change rate and the power demand fluctuation; Step S40, the power limiting coefficient is applied to a heating module of the wireless blower to limit heating power output.
2. The method of claim 1, wherein in step S10, the method further comprises: Acquiring the temperature of a battery core through a first temperature sensor arranged in a battery pack, acquiring the temperature of the battery core at the current acquisition time and the temperature of the battery core at the last acquisition time, calculating the temperature difference value of the battery core between the two acquisition times, and dividing the temperature difference value of the battery core by the time interval of the two acquisition to obtain the temperature rise rate of the battery core; acquiring air outlet temperature through a second temperature sensor arranged in an air outlet channel, acquiring the air outlet temperature at the current acquisition time and the air outlet temperature at the last acquisition time, calculating the air outlet temperature difference between the two acquisition times, and dividing the air outlet temperature difference by the time interval of the two acquisition to obtain the air outlet temperature change rate; the method comprises the steps of collecting real-time discharge current and discharge voltage of a battery through a current sensor and a voltage sensor, calculating a real-time power value based on the discharge current and the discharge voltage, and calculating a difference value between the real-time power value and a preset power reference value to obtain power demand fluctuation.
3. The method of claim 1, wherein in step S20, the method further comprises: Comparing the temperature of the battery cell acquired in real time with a preset first temperature threshold value, and comparing the air-out temperature acquired in real time with a preset second temperature threshold value; when the temperature of the battery cell is greater than or equal to the first temperature threshold value or the temperature of the air outlet is greater than or equal to the second temperature threshold value, judging that the corresponding threshold value is exceeded and entering step S30; and when the temperature of the battery cell is smaller than the first temperature threshold and the temperature of the air outlet is smaller than the second temperature threshold, if the corresponding threshold is not exceeded, the current working power is maintained, and the step S10 is returned to for continuous monitoring.
4. The method of claim 1, wherein in step S30, the method further comprises: When the temperature of the battery cell exceeds the first temperature threshold, calculating the difference value between the temperature of the battery cell and the first temperature threshold to obtain the range of the change rate of the battery cell, and carrying out weighted summation on the range of the change rate of the battery cell and the temperature rise rate of the battery cell to obtain a risk value of the temperature of the battery cell; When the air outlet temperature exceeds the second temperature threshold value, calculating a difference value between the air outlet temperature and the second temperature threshold value to obtain an air outlet change rate amplitude, and carrying out weighted summation on the air outlet change rate amplitude and the air outlet temperature change rate to obtain an air outlet temperature risk value; Taking the larger value of the battery cell temperature risk value and the air outlet temperature risk value as a comprehensive temperature risk value, performing dynamic scaling treatment on the comprehensive temperature risk value to obtain a temperature risk factor, and performing normalization treatment on the power demand fluctuation to obtain a power demand stabilizing factor; substituting the temperature risk factor and the power demand stabilization factor into a preset power limiting coefficient calculation formula to obtain a power limiting coefficient.
5. The method for managing power limitation of lithium battery temperature control according to claim 4, wherein the step of performing dynamic scaling processing on the integrated temperature risk value to obtain a temperature risk factor, and performing normalization processing on the power demand fluctuation to obtain a power demand stability factor comprises: Comparing the comprehensive temperature risk value with a preset risk threshold interval, setting the temperature risk factor to 0 when the comprehensive temperature risk value is smaller than or equal to the minimum threshold of the risk threshold interval, and setting the temperature risk factor to 1 when the comprehensive temperature risk value is larger than or equal to the maximum threshold of the risk threshold interval; when the comprehensive temperature risk value is located between the maximum threshold value and the minimum threshold value of the risk threshold value interval, calculating a difference value between the comprehensive temperature risk value and the minimum threshold value, and dividing the difference value by a difference value between the maximum threshold value and the minimum threshold value of the risk threshold value interval to obtain a risk ratio; substituting the risk ratio into a nonlinear mapping function to perform dynamic scaling treatment to obtain a temperature risk factor; And obtaining a plurality of power demand fluctuation values in a preset time window, calculating an average value of the plurality of power demand fluctuation values as smoothed power demand fluctuation, and dividing the smoothed power demand fluctuation by a preset maximum power demand fluctuation value to obtain a power demand stability factor.
6. The method for power limit management of lithium battery temperature control according to claim 4, wherein the power limit coefficient calculation formula is as follows: Wherein, the As a factor of the power limit, As a temperature risk factor, the temperature of the material is, As a power demand stabilizing factor, As a temperature risk weighting coefficient, Is a power demand weight coefficient.
7. The method of claim 1, wherein in step S40, the method further comprises: Obtaining the current target heating power of the heating module, multiplying the target heating power by the power limiting coefficient to obtain the limited heating power; And regulating the PWM duty ratio of the heating module or regulating the power supply voltage according to the limited heating power, so that the actual output power of the heating module is reduced to the limited heating power, and the limitation on the heating power output is realized.
8. A lithium battery temperature controlled power limit management device for use in a wireless blower, comprising: The monitoring module is used for monitoring the temperature of the battery cell, the air outlet temperature and the power demand fluctuation of the wireless blower in real time, calculating the temperature rise rate of the battery cell based on the temperature of the battery cell and calculating the change rate of the air temperature based on the air outlet temperature; the judging module is used for judging whether the temperature of the battery cell exceeds a preset first temperature threshold value or whether the temperature of the air outlet exceeds a preset second temperature threshold value, if so, entering the calculating module, and if not, maintaining the current working power and returning to the monitoring module; the calculation module is used for calculating a corresponding power limiting coefficient based on the change rate amplitude of the temperature rise rate of the battery cell or the change rate amplitude of the change rate of the air outlet temperature and the power demand fluctuation when the battery cell temperature or the air outlet temperature is detected to exceed a corresponding threshold value; and the limiting module is used for limiting the heating power output by applying the power limiting coefficient to the heating module of the wireless blower.

Description

Lithium battery temperature control power limit management method and device Technical Field The application relates to the technical field of lithium batteries, in particular to a power limit management method and device for temperature control of a lithium battery. Background With the popularity of wireless home appliances, portable wireless blowers are becoming an important product in the personal care area. The equipment generally provides working electric energy for the heating module and the fan through a built-in lithium battery, so that the free use without wire constraint is realized. However, the lithium battery is easy to generate heat accumulation effect in the high-power discharging process, especially in the continuous high-temperature air-out or long-time high-grade power running state, the temperature of the battery core is obviously increased, and if the temperature is controlled improperly, the battery performance is attenuated, the cycle life is reduced and even potential safety hazards exist. In the prior art, the temperature of the battery cell is usually detected in real time by arranging a temperature sensor inside the battery pack, and when the detected temperature exceeds a preset threshold value, the controller directly triggers the power reduction or turns off the heating module so as to prevent the battery from overheating. The part of the technical proposal is also combined with an external temperature sensor to monitor the temperature of the air outlet so as to assist in judging the thermal state of the whole machine, thereby executing power limitation or intermittent control when the temperature exceeds a safe range. Although basic overheat protection can be realized when the electric core or the air outlet temperature is detected to be out of limit through the threshold value judgment and the fixed power reduction control of the temperature sensor, when a user frequently cuts a gear shift, the temperature change of an air blowing environment is large or the thermal inertia of the electric core is strong, the real thermal risk of the electric core is difficult to be accurately reflected by a single threshold value judgment mode, the conditions of temperature response lag and excessive or insufficient power reduction control are easy to occur, and the problems of temperature control response lag and unstable power regulation exist. Disclosure of Invention In order to solve the problems of temperature control response lag and unstable power regulation in the prior art, the embodiment of the application provides a power limit management method and device for lithium battery temperature control. Other features and advantages of the application will be apparent from the following detailed description, or may be learned by the practice of the application. According to one aspect of the embodiment of the application, the power limit management method for temperature control of the lithium battery is provided and applied to a wireless blower, and comprises the steps of monitoring the battery cell temperature, the air outlet temperature and power demand fluctuation of the wireless blower in real time, calculating the battery cell temperature rise rate based on the battery cell temperature, calculating the air outlet temperature change rate based on the air outlet temperature, judging whether the battery cell temperature exceeds a preset first temperature threshold or whether the air outlet temperature exceeds a preset second temperature threshold, if so, entering the step S30, otherwise, maintaining the current working power and returning to the step S10, and when the battery cell temperature or the air outlet temperature is detected to exceed the corresponding threshold, calculating the corresponding power limit coefficient based on the change rate amplitude of the battery cell temperature rise rate or the change rate amplitude of the air outlet temperature change rate and the power demand fluctuation, and applying the power limit coefficient to a wireless heating module of the blower to carry out heating power output limit, wherein the step S40. In an embodiment of the application, the step S10 includes acquiring a core temperature through a first temperature sensor arranged in a battery pack, acquiring a core temperature at a current acquisition time and a core temperature at a last acquisition time, calculating a core temperature difference between the two acquisition times, dividing the core temperature difference by a time interval of the two acquisition to obtain a core temperature rise rate, acquiring an air-out temperature through a second temperature sensor arranged in an air-out channel, acquiring the air-out temperature at the current acquisition time and the air-out temperature at the last acquisition time, calculating an air-out temperature difference between the two acquisition times, dividing the air-out temperature difference by the time interval of the two acquisition