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CN-121973672-A - Cooling system and method for back plate of new energy automobile

CN121973672ACN 121973672 ACN121973672 ACN 121973672ACN-121973672-A

Abstract

The invention discloses a new energy automobile backboard cooling system and a method, which relate to the technical field of new energy automobiles, the method comprises the steps of preprocessing vehicle attitude parameters and backboard region temperature parameters acquired in the new energy automobile backboard cooling system, and on the basis, a cooling capacity unbalance risk index Rcb is constructed, and the temperature difference between the high potential side area and the low potential side area of the backboard is quantitatively related to the gravity component caused by the vehicle posture inclination angle, so that the quantitative assessment of the cooling capacity unbalance risk of the backboard is realized. Compared with the existing cooling control method which is only regulated based on temperature or load, the method can identify the potential cooling capacity unbalance problem of the cooling liquid caused by gravity bias in advance when the vehicle gesture is obviously inclined, so that frequent intervention of cooling control under unnecessary working conditions is avoided, false triggering probability is reduced, and judgment accuracy and stability of a backboard cooling control strategy are improved.

Inventors

  • LI TIANZENG
  • CHU YANHONG

Assignees

  • 东莞市巨唯电子科技有限公司

Dates

Publication Date
20260505
Application Date
20260302

Claims (10)

  1. 1. A cooling method for a back plate of a new energy automobile is characterized by comprising the following steps: S1, setting an acquisition point through a new energy automobile backboard and cooling equipment, acquiring cooling data in real time, transmitting the cooling data to a thermal management controller, and preprocessing to obtain a preprocessing feature vector; s2, calculating and outputting a cooling capacity unbalance risk index Rcb based on the preprocessing feature vector, and carrying out preliminary comparison evaluation on a preset risk threshold Rth and the cooling capacity unbalance risk index Rcb to judge the cooling capacity unbalance risk; And S3, triggering a cooling capacity redistribution mechanism based on the preliminary comparison evaluation result, calculating a re-balance pump rotation reference Ncb based on the cooling capacity unbalance risk index Rcb, and executing a cooling capacity redistribution control strategy by taking the re-balance pump rotation reference Ncb as a center.
  2. 2. The method for cooling a back panel of a new energy automobile according to claim 1, wherein S1 comprises S11; S11, setting a plurality of acquisition points around a back plate and cooling equipment of the new energy automobile, acquiring cooling data in real time through a vehicle-mounted self-contained sensor in each acquisition point, and transmitting the cooling data to a thermal management controller through a vehicle-mounted communication gateway; the collecting points comprise attitude angle collecting points, cooling liquid interface collecting points, back plate area temperature collecting points and pump state collecting points; The cooling data comprise a longitudinal pitch angle Jp, a transverse roll angle Jr, a cooling liquid inlet temperature Tin, a cooling liquid outlet temperature Tout, a back plate high potential side area temperature Tbp, a high back plate low potential side temperature Tbp, low and a pump rotating speed feedback np; The attitude angle acquisition points acquire longitudinal pitch angles Jp and transverse roll angles Jr of the vehicle in the running process through an inertial measurement unit IMU and an attitude resolving function which are arranged in an electronic stability system controller ESC and are arranged in the electronic stability system controller ESC; The cooling liquid interface acquisition point acquires cooling liquid inlet temperature Tin and cooling liquid outlet temperature Tout through temperature sensors respectively arranged at the inlet position and the outlet position of the cooling liquid loop; The temperature acquisition points of the back plate area are divided into a temperature acquisition point set close to the back plate high potential side area and a temperature acquisition point set close to the back plate low potential side area according to the internal structure of the battery pack and the back plate space direction in the calibration stage, and the temperature Tbp, high and the temperature Tbp and low of the back plate high potential side area are respectively obtained in operation; The pump state acquisition point is arranged at the interface of the electronic water pump controller, and the pump rotating speed feedback np is acquired through the feedback channel of the electronic water pump controller.
  3. 3. The method for cooling a back panel of a new energy automobile according to claim 2, wherein S1 further comprises S12; S12, preprocessing the received cooling data in a thermal management controller to obtain a preprocessing feature vector; The pretreatment comprises a first pretreatment step PP1, a second pretreatment step PP2, a third pretreatment step PP3 and a fourth pretreatment step PP4; The first preprocessing step PP1 converts the collected longitudinal pitch angle Jp and the collected transverse roll angle Jr into preset angle units in a unified mode through a unit unified processing technology, carries out filtering processing on the longitudinal pitch angle Jp and the transverse roll angle Jr through a first-order low-pass filtering technology, suppresses transient attitude fluctuation caused by road surface jolt in the running process of a vehicle, and obtains a filtered longitudinal pitch angle Jpf and a filtered transverse roll angle Jrf; The second preprocessing step PP2 compares the filtered longitudinal pitch angle Jpf and the filtered transverse roll angle Jrf with a corresponding longitudinal threshold Jpth and a corresponding transverse threshold Jrth respectively through a gesture duration thold judging technology, starts a gesture timer and accumulates gesture duration thold when any condition of | Jpf | Jpth and | Jrf |gtoreq Jrth is satisfied, and clears the gesture duration thold when the condition is not satisfied to obtain the gesture duration thold; the third preprocessing step PP3 carries out outlier rejection processing on the temperature Tbp of the high potential side of the backboard and the temperature Tbp of the low potential side of the backboard obtained by the temperature acquisition point of each backboard area through a temperature effectiveness screening technology; The method comprises the steps of carrying out validity screening on temperature acquisition points of each backboard region, judging invalidity when out-of-range and jump occur, and constructing rules based on valid temperature data through a region representative value, wherein the representative value constructing rules are that a temperature maximum value is selected from a backboard high potential side region temperature acquisition point set to serve as backboard high potential side region valid temperatures Tbp, high and eff, and a temperature minimum value is selected from a backboard low potential side region temperature acquisition point set to serve as backboard low potential side region valid temperatures Tbp, low and eff; The fourth preprocessing step PP4 performs a difference calculation according to the cooling liquid inlet temperature Tin and the cooling liquid outlet temperature Tout through a cooling circuit temperature rise stabilization processing technology, obtains a cooling circuit temperature rise delta Tloop, and compares the cooling circuit Wen Sheng Tloop with a preset temperature rise lower limit delta Tmin; The lower temperature rise limit Δtmin is employed as the cooling circuit effective Wen Sheng Tloop, eff when the cooling circuit Wen Sheng Tloop is Yu Wen liters lower limit Δtmin; When the cooling circuit Wen Sheng Tloop is not smaller than the temperature rise lower limit delta Tmin, the cooling circuit temperature rise delta Tloop is adopted as the cooling circuit effective Wen Sheng Tloop and eff; And integrating the filtered longitudinal pitch angle Jpf, the filtered transverse roll angle Jrf, the gesture duration thold, the effective temperature Tbp of the high potential side area of the back plate, the effective temperature Tbp of the eff and the low potential side area of the back plate, the low effective temperature, the eff, the cooling loop effective Wen Sheng Tloop, the eff and the pump rotating speed feedback np to obtain a preprocessing feature vector.
  4. 4. The method for cooling a back panel of a new energy automobile according to claim 3, wherein S2 comprises S21; S21, extracting effective temperatures Tbp, high and eff of a high potential side area of the backboard, effective temperatures Tbp, low and eff of a low potential side area of the backboard and effective temperatures Wen Sheng Tloop and eff of a cooling loop based on the obtained preprocessing feature vector, and calculating the normalized quantity of temperature difference of the backboard area; and calculating the combined quantity of the attitude gravity components through the longitudinal pitch angle Jpf after filtering and the transverse roll angle Jrf after filtering, and performing product calculation on the normalized quantity of the temperature difference of the back plate area and the combined quantity of the attitude gravity components to obtain a cooling capacity unbalance risk index Rcb, and quantitatively analyzing the unbalance degree of the cooling capacity between the back plate high potential side area and the back plate low potential side area under the action of the attitude gravity components of the vehicle.
  5. 5. The method for cooling a back panel of a new energy automobile according to claim 4, wherein S2 further comprises S22; S22, presetting a risk threshold Rth in a thermal management controller, and performing preliminary comparison evaluation on the risk threshold Rth and a cooling capacity unbalance risk index Rcb acquired in real time to judge a cooling capacity unbalance state, wherein the specific evaluation content is as follows: when the cooling capacity unbalance risk index Rcb is smaller than the risk threshold Rth, outputting a cooling capacity unbalance evaluation result as normal, and maintaining a conventional back plate cooling control mode; when the cooling capacity unbalance risk index Rcb is more than or equal to the risk threshold Rth, outputting a cooling capacity unbalance evaluation result as an unbalance risk, and triggering a cooling capacity redistribution control mechanism.
  6. 6. The method for cooling a back panel of a new energy automobile according to claim 5, wherein S3 comprises S31; s31, after the preliminary comparison evaluation triggers a cooling capacity redistribution control mechanism, the cooling pump reference rotating speed Nbase output by the thermal management control module in the conventional back plate cooling control mode is based on And correcting the reference rotation speed Nbase of the cooling pump by a linear proportional amplification calculation mode based on the cooling capacity unbalance risk index Rcb acquired in real time to acquire a heavy balance pump rotation reference Ncb, and taking the heavy balance pump rotation reference Ncb as a central reference value for regulating the rotation speed of the cooling pump in a cooling capacity redistribution control mode.
  7. 7. The method for cooling a back panel of a new energy automobile according to claim 6, wherein S3 further comprises S32; S32, after obtaining a re-balance pump rotation reference Ncb, executing a cooling capacity redistribution control strategy, wherein the cooling capacity redistribution control strategy comprises a pump output rhythm disturbance control strategy and a disturbance phase selection strategy related to a gesture direction; The pump output rhythm disturbance control strategy is characterized in that when the cooling capacity unbalance assessment result is an unbalance risk, the pump output rhythm disturbance control strategy takes a balance pump rotating speed reference Ncb as a center, adjusts the cooling pump output rotating speed through a rhythm disturbance control technology, and introduces low-frequency and small-amplitude periodic rotating speed disturbance in the upper and lower ranges of the balance pump rotating speed reference Ncb so as to periodically reconstruct a cooling liquid flow field in a back plate flow channel, thereby weakening a stable bias flow structure formed under the action of vehicle attitude gravity; The disturbance amplitude delta n of the periodic rotation speed disturbance is set to be 5% -12% of the maximum available rotation speed of the cooling pump, and the condition that the rotation speed standard Ncb of the heavy balance pump and the disturbance amplitude delta n are overlapped and then not more than the maximum allowable rotation speed of the cooling pump and are not less than the minimum stable rotation speed of the cooling pump after being overlapped is met; The disturbance frequency f of the periodic rotation speed disturbance is set to be 0.05 Hz-0.20 Hz so as to form low-frequency disturbance with the period of 5 s-20 s, and the rotation speed of the cooling pump is adjusted in a sine wave mode.
  8. 8. The method for cooling a back panel of a new energy automobile according to claim 7, wherein S32 further comprises S321; S321, determining the initial phase of the periodic rotation speed disturbance through the disturbance phase selection strategy associated with the gesture direction while executing the pump output rhythm disturbance control strategy; The disturbance phase selection strategy related to the gesture direction comprises a gesture direction judging mechanism, gesture quadrant division and a disturbance phase selection rule; The gesture direction judging mechanism and gesture quadrant division are used for judging based on the filtered longitudinal pitch angle Jpf and the filtered transverse roll angle Jrf, and accordingly dividing the vehicle gesture into gesture quadrants of ascending slope right inclination, ascending slope left inclination, descending slope right inclination and descending slope left inclination; the specific judgment content is as follows: When the filtered longitudinal pitch angle Jpf is more than 0 and the filtered transverse roll angle Jrf is more than 0, judging that the vehicle is inclined to the right on an ascending slope; When the filtered longitudinal pitch angle Jpf is more than 0 and the filtered transverse roll angle Jrf is less than 0, judging that the slope is inclined left; when the filtered longitudinal pitch angle Jpf <0 and the filtered transverse roll angle Jrf >0, determining that the slope is declined to the right; A downhill left roll is determined when the filtered longitudinal pitch angle Jpf <0 and the filtered lateral roll angle Jrf <0.
  9. 9. The method for cooling a back panel of a new energy automobile according to claim 8, wherein S32 further comprises S322; S322, when the gesture quadrant division is an unbalance risk through a cooling capacity unbalance evaluation result, and when the gesture duration thold reaches a preset duration threshold value of 30S, controlling periodic rotation speed disturbance to start from a rotation speed section higher than a rotation speed reference Ncb of the heavy balance pump, so that the initial output rotation speed of the cooling pump is the sum of the rotation speed reference Ncb of the heavy balance pump and the disturbance amplitude delta n, and forming rapid impact on a cooling liquid bias flow structure; When the unbalance evaluation result of the cooling capacity is unbalance risk and the gesture duration thold does not reach the preset duration threshold value for 30s, controlling periodic rotation speed disturbance to start from a rotation speed section lower than the rotation speed reference Ncb of the heavy balance pump, so that the initial output rotation speed of the cooling pump is the difference between the rotation speed reference Ncb of the heavy balance pump and the disturbance amplitude delta n to form gradual disturbance on a cooling liquid bias flow structure; The initial phase of the periodic rotation speed disturbance and the gesture quadrant are used together to enable the rotation speed disturbance direction and the gravity bias direction of the cooling liquid in the back plate flow channel to form reverse superposition.
  10. 10. A new energy automobile backboard cooling system which is applied to the new energy automobile backboard cooling method according to any one of claims 1-9, and is characterized by comprising a posture and cooling acquisition module, a capacity unbalance analysis module and a cooling capacity redistribution module; the attitude and cooling acquisition module is used for setting acquisition points through a new energy automobile backboard and cooling equipment, acquiring cooling data in real time, transmitting the cooling data to the thermal management controller, and preprocessing to obtain a preprocessing feature vector; The capacity unbalance analysis module calculates and outputs a cooling capacity unbalance risk index Rcb based on the preprocessing feature vector, and performs preliminary comparison evaluation on a preset risk threshold Rth and the cooling capacity unbalance risk index Rcb to judge the cooling capacity unbalance risk; The cooling capacity redistribution module triggers a cooling capacity redistribution mechanism based on the preliminary comparison evaluation result, calculates a re-balance pump rotation reference Ncb based on the cooling capacity unbalance risk index Rcb, and executes a cooling capacity redistribution control strategy by taking the re-balance pump rotation reference Ncb as a center.

Description

Cooling system and method for back plate of new energy automobile Technical Field The invention relates to the technical field of new energy automobiles, in particular to a new energy automobile backboard cooling system and a new energy automobile backboard cooling method. Background Along with the development of new energy automobiles to the directions of high energy density and high power output, the heat generated by a power battery in the processes of charge and discharge and high-load operation is obviously increased, and higher requirements are put on the heat dissipation capacity and heat balance performance of a battery system. In the existing new energy automobile, the power battery is usually subjected to heat management in a cooling liquid circulation mode, wherein a back plate structure arranged on the back of the battery pack is used as an important heat transfer interface between cooling liquid and a battery module, and the cooling effect directly influences the overall temperature distribution and the working safety of the battery pack. Therefore, how to realize effective and uniform cooling of the back plate of the new energy automobile under different working conditions becomes a key problem in the heat management technology of the new energy automobile. In the existing back panel cooling system of the new energy automobile, the cooling control strategy is generally uniformly adjusted based on the temperature of the cooling liquid, the temperature of the battery or the load working condition, for example, the whole heat dissipation capacity is improved by adjusting the rotating speed of a cooling pump or starting a corresponding cooling loop. However, most of the control strategies described above assume that the vehicle is in a condition with little change in level or attitude, and do not adequately take into account changes in longitudinal pitch and lateral roll attitude of the vehicle during actual travel, particularly on mountain roads, on ramp sections, or under complex terrain conditions. When the vehicle posture is obviously inclined, the distribution of the cooling liquid in the back plate flow channel can be influenced by the change of the gravity direction, so that the bias flow or layering phenomenon is generated, and the existing control strategy is difficult to adjust in a targeted manner according to the posture change. Because the existing back plate cooling control method generally ignores the influence of the vehicle posture inclination angle on the flowing state of the cooling liquid, when the vehicle is in an ascending, descending or transverse inclination working condition for a long time, the cooling liquid is easy to gather to the low potential side in the back plate flow channel, so that the cooling capacity of a high potential side area is reduced, and the condition of uneven temperature distribution of the back plate area is formed. The unbalance of the cooling capacity not only can cause heat accumulation in the local area of the back plate, but also can cause expansion of temperature difference between the battery modules, influence the consistency of the battery performance, and even trigger overheat protection or safety risk of the battery when serious. In addition, because the problems have certain concealment and working condition correlation, the problems are difficult to be effectively solved by simply increasing the rotation speed of the cooling pump or enhancing the overall cooling capacity, and on the contrary, new problems such as energy consumption increase, unstable control and the like can be brought. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a new energy automobile backboard cooling system and a new energy automobile backboard cooling method, and solves the problems in the background art. In order to achieve the above purpose, the invention is realized by the following technical scheme that the method comprises the following steps: S1, setting an acquisition point through a new energy automobile backboard and cooling equipment, acquiring cooling data in real time, transmitting the cooling data to a thermal management controller, and preprocessing to obtain a preprocessing feature vector; s2, calculating and outputting a cooling capacity unbalance risk index Rcb based on the preprocessing feature vector, and carrying out preliminary comparison evaluation on a preset risk threshold Rth and the cooling capacity unbalance risk index Rcb to judge the cooling capacity unbalance risk; And S3, triggering a cooling capacity redistribution mechanism based on the preliminary comparison evaluation result, calculating a re-balance pump rotation reference Ncb based on the cooling capacity unbalance risk index Rcb, and executing a cooling capacity redistribution control strategy by taking the re-balance pump rotation reference Ncb as a center. Preferably, the S1 includes S11; S11, setting a plurality of acquisition point