CN-121671375-B - Parallel battery pack charging control method, battery management system and aircraft

CN121671375BCN 121671375 BCN121671375 BCN 121671375BCN-121671375-B

Abstract

The application discloses a parallel battery pack charging control method, a battery management system and an aircraft, and relates to the technical field of charging control. The parallel battery pack charging control method comprises the steps of obtaining sampling charging currents of battery packs, determining current distribution ratios of the sampling charging currents compared with total charging currents, wherein the total charging currents are the sum of the sampling charging currents of the battery packs, and determining total charging request currents meeting overcurrent prevention conditions at least based on the current distribution ratios of the battery packs and maximum allowable charging currents. The application effectively avoids the risk of thermal runaway under the condition of approaching the theoretical limit value as far as possible, and ensures the charging safety.

Inventors

XUE SONGBAI
LI QING
Zhai Zhushan
Xie Shaiming
WANG KE
Sun Zixia
XIAO RENCHAO
CHEN MENGJI

Assignees

四川沃飞长空科技发展有限公司
浙江吉利控股集团有限公司

Dates

Publication Date: 20260508
Application Date: 20260212

Claims (8)

1. A parallel battery pack charge control method, characterized by comprising: Obtaining sampling charging current of each battery pack; determining a current distribution ratio of each sampled charging current to a total charging current, wherein the total charging current is a sum of the sampled charging currents of each battery pack; determining a total charging request current meeting an overcurrent prevention condition based at least on the current distribution ratio and a maximum allowable charging current of each battery pack; The determining the current distribution ratio of each sampling charging current compared with the total charging current comprises the following steps: determining a present current distribution ratio of each of the sampled charging currents compared to the total charging current; determining the current distribution ratio change condition of each battery pack based on the current distribution ratio, wherein the current distribution ratio change condition is a current distribution ratio change rate; judging whether the current battery state of the parallel battery pack meets a distribution ratio updating condition or not at least based on the current distribution ratio change condition of part of the battery packs; And updating the current distribution ratio based on the present current distribution ratio for each of the battery packs, if the distribution ratio update condition is satisfied.
2. The parallel battery pack charge control method according to claim 1, wherein the determining whether the current battery state of the parallel battery pack satisfies a distribution ratio update condition based at least in part on the current distribution ratio change condition of the battery pack comprises: under the condition that the change rate of at least one current distribution ratio is larger than a preset change threshold value, determining that the current battery state of the parallel battery pack meets a current distribution ratio updating condition; And under the condition that all the current distribution ratio change conditions are smaller than or equal to the preset change threshold value, determining that the current battery state of the parallel battery pack does not meet the current distribution ratio update condition.
3. The parallel battery pack charge control method according to claim 1 or 2, wherein the determining a total charge request current that satisfies an overcurrent prevention condition based at least on the current distribution ratio of each of the battery packs and a maximum allowable charge current includes: determining a total charging request current predicted value corresponding to the overcurrent prevention condition based on the corresponding maximum allowable charging current and the current distribution ratio for each battery pack; And determining the minimum value of all the predicted values of the total charging request current as the total charging request current.
4. The parallel battery pack charge control method according to claim 3, wherein after the minimum value among all the predicted values of the total charge request current is determined as the total charge request current, the method further comprises: Determining current feedback information of each battery pack; And performing closed-loop control on the total charging request current based on at least part of the current feedback information.
5. The method for parallel battery pack charge control according to claim 4, wherein determining current feedback information of each of the battery packs includes regarding, for each of the battery packs, a current margin of the battery pack as the current feedback information, the current margin being a value obtained by subtracting the corresponding sampling charging current from the maximum allowable charging current corresponding to the battery pack; and/or the number of the groups of groups, The closed-loop control of the total charge request current based on at least a portion of the current feedback information includes: and performing closed-loop control on the total charging request current based on the minimum value in all the current feedback information.
6. The parallel battery pack charge control method according to claim 1 or 2, wherein before the obtaining of the sampled charge current of each battery pack, the method further comprises: And under the condition that the pressure difference among all the battery packs is smaller than or equal to a preset risk threshold value, charging the parallel battery packs.
7. A battery management system comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the computer program being configured to implement the steps of the parallel battery pack charge control method of any one of claims 1 to 6.
8. An aircraft, characterized in that, the aircraft comprises: an aircraft body having a charging interface; a parallel battery pack provided to the aircraft body, and The battery management system of claim 7, the battery management system being disposed on the aircraft body, the battery management system being connected with the parallel battery pack, and the battery management system being adapted to be connected with a charging device through the charging interface.

Description

Parallel battery pack charging control method, battery management system and aircraft Technical Field The application relates to the technical field of charging control, in particular to a parallel battery pack charging control method, a battery management system and an aircraft. Background With the severe demands of vehicles such as new energy automobiles, eVTOL (ELECTRIC VERTICAL TAKE-off AND LANDING, electric vertical landing aircrafts) and electric ships for quick charging, the conventional constant-current-constant-voltage (CC-CV) charging strategy of a single battery pack has been difficult to cope with complex working conditions, and the adoption of a multi-battery pack parallel charging technology becomes a better choice. However, due to the variability of the manufacturing process of the battery core, the gradient change of the ambient temperature and the difference of the cyclic aging degree, the internal resistance of each battery pack presents dynamic nonlinear characteristics, so that the shunt current of each battery pack presents non-uniform distribution characteristics in the charging process, and the thermal runaway risk is caused. Disclosure of Invention The application mainly aims to provide a parallel battery pack charging control method, a battery management system and an aircraft, and aims to solve the technical problem that thermal runaway risks exist when parallel multi-battery packs are charged. In order to achieve the above object, the present application provides a parallel battery pack charge control method, including: Obtaining sampling charging current of each battery pack; Determining the current distribution ratio of each sampling charging current compared with the total charging current, wherein the total charging current is the sum of the sampling charging currents of each battery pack; and determining the total charging request current meeting the overcurrent prevention condition at least based on the current distribution ratio of each battery pack and the maximum allowable charging current. In one embodiment, determining a current sharing ratio of each sampled charging current compared to the total charging current includes: Determining a present current distribution ratio of each sampled charging current compared to the total charging current; The current distribution ratio is updated for each battery pack based on the present current distribution ratio. In an embodiment, updating the current distribution ratio based on the present current distribution ratio for each battery pack includes: judging whether the current battery state of the parallel battery pack meets the distribution ratio updating condition or not; in the case where the distribution ratio update condition is satisfied, the current distribution ratio is updated based on the current distribution ratio for each battery pack. In one embodiment, determining whether the current battery state of the parallel battery pack satisfies the distribution ratio update condition includes: Determining the current distribution ratio change condition of each battery pack based on the current distribution ratio; and judging whether the current battery states of the parallel battery packs meet distribution ratio updating conditions or not at least based on the current distribution ratio change condition of part of the battery packs. In an embodiment, the current distribution ratio change condition is a current distribution ratio change rate; Based at least on the current distribution ratio change condition of partial battery packs, judging whether the current battery state of the parallel battery packs meets the distribution ratio update condition or not, comprising: under the condition that the change rate of at least one current distribution ratio is larger than a preset change threshold value, determining that the current battery state of the parallel battery pack meets the current distribution ratio updating condition; and under the condition that all current distribution ratio change conditions are smaller than or equal to a preset change threshold value, determining that the current battery state of the parallel battery pack does not meet the current distribution ratio updating condition. In one embodiment, determining the total charge request current that satisfies the overcurrent protection condition based at least on the current distribution ratio of each battery pack and the maximum allowable charge current includes: determining a total charging request current predicted value corresponding to the overcurrent prevention condition based on the corresponding maximum allowable charging current and current distribution ratio for each battery pack; The minimum value of all the predicted values of the total charge request current is determined as the total charge request current. In an embodiment, after determining the minimum value of all the predicted values of the total charging request current as the total charging re