A new energy automobile motor cooling system control method and system

Abstract

The application provides a new energy automobile motor cooling system control method and system, relates to the motor cooling technical field, and determines the alternate duration of the bidirectional alternate operation of the motor cooling pump by identifying that the motor of the new energy automobile enters the frequent start-stop operation condition; the cooling pump is controlled to operate bidirectionally and alternately according to the alternate duration, a low-temperature buffer section is constructed in the connecting pipeline between the motor water outlet and the external heat exchanger; the heat dissipation time window in which the external cooling circuit is allowed to intervene is calculated; in the heat dissipation time window, the main valve connecting the motor internal cooling flow channel and the external cooling circuit is controlled to be opened, the cooling pump is controlled to start at a second rotating speed, and the motor is rapidly cooled; when the current average temperature of the low-temperature buffer section rises to a preset threshold value, the main valve is controlled to be closed, and the bidirectional alternate operation step is repeatedly executed to rebuild the low-temperature buffer section. The application can realize the heat dissipation control of the residual heat accumulation of the new energy automobile motor under the frequent start-stop condition.

Description

Technical Field

[0001] This application relates to the field of motor cooling technology, and more specifically, to a control method and system for a new energy vehicle motor cooling system. Background Technology

[0002] The thermal management performance of the drive motor in new energy vehicles directly affects the overall vehicle power performance and operational safety. Motor cooling technology is the core support for ensuring the continuous and stable operation of the motor. Liquid cooling solutions are widely used in the heat dissipation systems of new energy vehicle motors due to their advantages of high heat dissipation efficiency and precise temperature control. By rationally designing the cooling channels and regulating the circulation of the cooling medium, the working heat of core components such as the motor stator and windings can be effectively dissipated, reducing the risk of thermal decay, improving the power density and service life of the motor, and providing key guarantees for the power output and reliability of new energy vehicles.

[0003] In scenarios such as urban traffic congestion, the motors of new energy vehicles are often in a state of frequent start-stop operation. Under this condition, residual heat is prone to accumulate. Traditional motor cooling control strategies mostly adopt fixed operating modes, which are poorly adapted to the dynamic operating conditions of frequent start-stop and are difficult to efficiently dissipate locally accumulated residual heat. Most existing cooling systems do not have a reasonable heat dissipation regulation mechanism for dynamic residual heat, and the timing and rhythm of external heat dissipation circuit intervention lack flexible planning, which can easily lead to heat accumulation that cannot be dissipated in time, thereby affecting the motor's operating stability and component lifespan. Therefore, how to achieve heat dissipation control of residual heat accumulation under the frequent start-stop conditions of new energy vehicle motors has become a challenge for the industry. Summary of the Invention

[0004] This application provides a control method and system for a cooling system of a new energy vehicle motor, which can realize heat dissipation control of residual heat accumulation under frequent start-stop conditions of the new energy vehicle motor.

[0005] In a first aspect, this application provides a control method for a new energy vehicle motor cooling system, the motor cooling system control method comprising the following steps:

[0006] The method identifies when the motor of a new energy vehicle enters a frequent start-stop operation condition. The motor is a liquid-cooled motor with a layered cooling channel. The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined based on the start-stop frequency and single running duration of the motor under the frequent start-stop operation condition.

[0007] The cooling pump is controlled to operate in both directions alternately for alternating durations to transfer the residual heat in the stator, rotor and winding areas of the motor to the external pipeline side. At the same time, a low-temperature buffer section formed by low-temperature coolant is constructed in the connecting pipeline between the motor outlet and the external heat exchanger.

[0008] Detect the current length and current average temperature of the low-temperature buffer section in the connecting pipeline, and calculate the heat dissipation time window that allows the external cooling circuit to intervene;

[0009] During the heat dissipation time window, the main valve connecting the internal cooling channel of the motor and the external cooling circuit is opened, and the cooling pump is started at the second speed to quickly dissipate heat from the motor.

[0010] When the current average temperature of the cryogenic buffer section rises to a preset threshold, the main control valve closes and repeats the bidirectional alternating operation steps to rebuild the cryogenic buffer section.

[0011] In this embodiment, identifying the frequent start-stop operation of the motor in a new energy vehicle specifically includes:

[0012] Collect start-stop signals from the motors of new energy vehicles;

[0013] Extract the adjacent time intervals and temporal entropy values ​​of all motor start and stop actions from the start and stop action signals;

[0014] The motor is determined to be in a frequent start-stop operation condition based on the adjacent time intervals and timing entropy values ​​of all motor start-stop actions.

[0015] In this embodiment, determining the alternation duration of the bidirectional alternating operation of the motor cooling pump based on the start-stop frequency and single-run duration of the motor under frequent start-stop conditions specifically includes:

[0016] Obtain the start-stop frequency and single-run duration of the motor under frequent start-stop conditions;

[0017] The heat dissipation ratio of the stratified cooling channel is matched according to the start-stop frequency of the motor under frequent start-stop conditions, and the forward and reverse operation of the motor cooling pump.

[0018] The two-way duration allocation weight of the adaptation ratio is derived by correcting the winding thermal accumulation gradient corresponding to the single running time of the motor under frequent start-stop conditions.

[0019] The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined based on the revised bidirectional duration allocation weight.

[0020] In this embodiment, controlling the cooling pump to operate alternately in both directions for alternating durations to dissipate residual heat from the motor stator, rotor, and winding areas to the external piping side specifically includes:

[0021] Control the cooling pump to perform forward pumping action;

[0022] The driving coolant flows forward along the stratified cooling channels, carrying away residual heat from the motor stator and winding areas;

[0023] After the alternation period is reached, the cooling pump direction is switched to perform reverse pumping action;

[0024] The coolant is driven to flow in the reverse direction along the stratified cooling channels, dissipating residual heat in the motor rotor area to the external piping side.

[0025] In this embodiment, the construction of a low-temperature buffer section formed by low-temperature coolant in the connecting pipe between the motor outlet and the external heat exchanger specifically includes:

[0026] While the cooling pump performs bidirectional alternating operation and switches to reverse operation according to the alternating duration, the entire section of the connecting pipeline between the motor outlet and the external heat exchanger is locked.

[0027] Drive the cooling pump to run in reverse, so that the high-temperature coolant in the connecting pipe near the motor outlet flows back into the motor, while the low-temperature coolant in the connecting pipe near the external heat exchanger remains in the connecting pipe.

[0028] During the duration of the cooling pump's reverse operation, the flow of the low-temperature coolant remaining in the connecting pipe to the motor or the external heat exchanger is continuously blocked, causing the low-temperature coolant to form a continuous liquid column section in the connecting pipe.

[0029] When the cooling pump completes its reverse rotation and switches back to forward rotation, the connecting pipe remains locked, allowing the continuous liquid column to remain in the connecting pipe during the forward rotation of the cooling pump, and the continuous liquid column formed by the low-temperature coolant in the connecting pipe serves as a low-temperature buffer section.

[0030] In this embodiment, detecting the current length and current average temperature of the low-temperature buffer section in the connecting pipeline, and calculating the heat dissipation time window that allows the external cooling circuit to intervene, specifically includes:

[0031] The current length and average temperature of the low-temperature buffer section in the connecting pipeline are detected.

[0032] The effective cold storage capacity of the low-temperature buffer section is determined based on its current length and current average temperature.

[0033] Based on the heat generation power of the motor under frequent start-stop conditions and the effective cold energy reserve value, the thermal response analysis of the low temperature buffer section after the intervention of the external cooling circuit is carried out to obtain the critical time of thermal penetration of the low temperature buffer section after the intervention of the external cooling circuit.

[0034] The heat dissipation time window that allows external cooling circuit intervention is determined by the critical time of heat penetration and the thermal shock protection redundancy time of the motor.

[0035] In this embodiment, within the heat dissipation time window, controlling the main valve connecting the internal cooling channel of the motor and the external cooling circuit to open, and controlling the cooling pump to start at the second speed to rapidly dissipate heat from the motor specifically includes:

[0036] Verify the remaining effective duration of the heat dissipation time window;

[0037] Send a staged opening command to the main valve that connects the internal cooling channel of the motor and the external cooling circuit. First, control the main valve to open to the pre-calibrated pre-opening degree to balance the pipeline pressure difference, and then control the main valve to open fully to connect the internal cooling channel of the motor and the external cooling circuit.

[0038] Determine the second speed of the motor cooling pump;

[0039] After the main valve is fully opened, the control cooling pump starts smoothly at the second speed, driving the low-temperature coolant from the external cooling circuit into the internal cooling channel of the motor to perform rapid heat dissipation on the motor.

[0040] During rapid heat dissipation, the remaining effective duration of the heat dissipation time window is monitored to ensure that the entire cooling process remains within the effective and controllable range of the heat dissipation time window.

[0041] In this embodiment, when the current average temperature of the cryogenic buffer section rises to a preset threshold, controlling the main valve to close and repeatedly executing the bidirectional alternating operation steps to rebuild the cryogenic buffer section specifically includes:

[0042] During the process of rapid heat dissipation by the intervention of the external cooling circuit, the current average temperature of the low temperature buffer section is continuously monitored, and the current average temperature is compared with the preset temperature threshold in real time.

[0043] When the current average temperature of the low-temperature buffer section rises to the preset threshold, it is determined that the low-temperature insulation capability of the low-temperature buffer section has failed, and an external cooling circuit exit command is generated.

[0044] Based on the external cooling circuit exit command, the cooling pump is controlled to stop running, and at the same time a closing command is sent to the main valve to control the main valve to close completely, cutting off the connection between the internal cooling channel of the motor and the external cooling circuit;

[0045] Trigger the cryogenic buffer zone reconstruction process, repeat the alternating operation of the cooling pumps, and rebuild the cryogenic buffer zone formed by cryogenic coolant within the connecting pipeline.

[0046] In this embodiment, based on the heat generation power of the motor under frequent start-stop conditions and the effective cooling capacity reserve, a thermal response analysis is performed on the low-temperature buffer section after the external cooling circuit intervention. The specific thermal penetration critical time of the low-temperature buffer section after the external cooling circuit intervention includes:

[0047] By analyzing the heat generation power of the motor under frequent start-stop conditions and the effective cold energy reserve value, the thermal response delay of the low temperature buffer section after the intervention of the external cooling circuit is obtained through thermal response delay constraint conditions of the low temperature buffer section after the intervention of the external cooling circuit.

[0048] Based on the aforementioned thermal response delay constraint condition, the critical duration of thermal penetration of the low-temperature buffer section after the intervention of the external cooling circuit is constrained and analyzed to obtain the critical duration of thermal penetration of the low-temperature buffer section after the intervention of the external cooling circuit.

[0049] Secondly, this application provides a control system for a new energy vehicle motor cooling system, used to execute a control method for a new energy vehicle motor cooling system, the motor cooling system control system comprising:

[0050] The motor frequent start-stop identification module is used to identify when the motor of a new energy vehicle enters the frequent start-stop operation condition. The motor is a liquid-cooled motor with a layered cooling channel. The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined according to the start-stop frequency and single running duration of the motor under the frequent start-stop operation condition.

[0051] The cooling pump bidirectional alternating operation module is used to control the cooling pump to operate bidirectionally alternately according to the alternating duration, so as to conduct the residual heat of the motor stator, rotor and winding area to the external pipeline side, and at the same time construct a low temperature buffer section formed by low temperature coolant in the connecting pipeline between the motor outlet and the external heat exchanger.

[0052] The heat dissipation time window calculation module is used to detect the current length and current average temperature of the low-temperature buffer section in the connecting pipeline, and calculate the heat dissipation time window that allows the external cooling circuit to intervene.

[0053] The motor rapid heat dissipation module is used to control the opening of the main valve connecting the internal cooling channel of the motor and the external cooling circuit during the heat dissipation time window, and to control the cooling pump to start at the second speed to rapidly dissipate heat from the motor.

[0054] The low-temperature buffer section reconstruction module is used to control the main valve to close and repeatedly execute bidirectional alternating operation steps to rebuild the low-temperature buffer section when the current average temperature of the low-temperature buffer section rises to a preset threshold.

[0055] The technical solutions provided by the embodiments disclosed in this application have the following beneficial effects:

[0056] The system identifies when the motor of a new energy vehicle enters a frequent start-stop operation condition. The motor is a liquid-cooled motor with a layered cooling channel. Based on the start-stop frequency and single-run duration of the motor under frequent start-stop conditions, the alternation duration of the motor cooling pump's bidirectional alternating operation is determined. The cooling pump is controlled to operate bidirectionally alternately according to the alternation duration, dissipating residual heat from the motor stator, rotor, and winding areas to the external pipeline side. Simultaneously, a low-temperature buffer section formed by low-temperature coolant is constructed in the connecting pipeline between the motor outlet and the external heat exchanger. The current length and current average temperature of the low-temperature buffer section in the connecting pipeline are detected, and a heat dissipation time window allowing the external cooling circuit to intervene is calculated. Within the heat dissipation time window, the main valve connecting the internal cooling channel of the motor and the external cooling circuit is opened, and the cooling pump is started at a second speed to quickly dissipate heat from the motor. When the current average temperature of the low-temperature buffer section rises to a preset threshold, the main valve is closed, and the bidirectional alternating operation steps are repeated to rebuild the low-temperature buffer section.

[0057] Therefore, in this application, when the current average temperature of the low-temperature buffer section rises to a preset threshold, the main valve is controlled to close and the bidirectional alternating operation steps are repeatedly executed to rebuild the low-temperature buffer section. Firstly, by identifying the frequent start-stop operation of the new energy vehicle motor and determining the alternation duration of the bidirectional alternating operation of the cooling pump based on the start-stop frequency and single-run duration, the cooling control strategy can accurately match the dynamic operating characteristics of the motor, solving the problem of poor adaptability of the traditional fixed cooling mode to frequent start-stop conditions. Secondly, controlling the cooling pump to operate bidirectionally and alternately according to the set alternation duration can effectively dissipate residual heat from the motor stator, rotor, and winding areas to the external pipeline side. Simultaneously, a low-temperature coolant buffer section is constructed in the connecting pipeline between the motor outlet and the external heat exchanger, which can efficiently dissipate locally accumulated residual heat and prevent excessive heat accumulation in the core components of the motor. Furthermore... By detecting the current length and average temperature of the low-temperature buffer section and calculating the heat dissipation time window, the timing of external cooling circuit intervention can be rationally planned. This compensates for the deficiencies in the existing cooling system's heat dissipation control mechanism and the inflexible planning of heat dissipation rhythm, ensuring that the timing of external heat dissipation intervention is adapted to dynamic waste heat changes. Subsequently, within the heat dissipation time window, the main valve is opened and the cooling pump is controlled to start at the second speed, enabling rapid heat dissipation of the motor through the external cooling circuit, timely dissipation of accumulated residual heat, and improvement of the heat dissipation efficiency of the liquid cooling system. Finally, when the average temperature of the low-temperature buffer section rises to the preset threshold, the main valve is closed and bidirectional alternating operation is repeated to rebuild the low-temperature buffer section. This forms a cyclical waste heat conduction and heat dissipation control mechanism, continuously suppressing the continuous accumulation of residual heat under frequent start-stop conditions, thereby ensuring the stability of motor operation and extending the service life of the motor's core components.

[0058] In summary, the technical solution adopted in this application can achieve heat dissipation control of residual heat accumulation under frequent start-stop conditions of new energy vehicle motors. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this embodiment of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 This is an exemplary flowchart of a control method for a new energy vehicle motor cooling system provided in this application;

[0061] Figure 2 It is a timing diagram of the bidirectional alternating operation of the cooling pump provided in this application;

[0062] Figure 3 This is a flowchart illustrating the reconstruction of the cryogenic buffer zone provided in this application;

[0063] Figure 4 This is a modular structure diagram of a control system for a new energy vehicle motor cooling system provided in this application. Detailed Implementation

[0064] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0065] This application provides a control method and system for a cooling system of a new energy vehicle motor. The core of this method is to identify when the motor of a new energy vehicle enters a frequent start-stop operation condition. The motor is a liquid-cooled motor with layered cooling channels. The alternation duration of the motor cooling pump's bidirectional alternating operation is determined based on the start-stop frequency and single-run duration under frequent start-stop conditions. The cooling pump is controlled to operate bidirectionally and alternately according to the alternation duration, dissipating residual heat from the motor stator, rotor, and winding areas to the external pipeline side. Simultaneously, a low-temperature buffer section formed by low-temperature coolant is constructed in the connecting pipeline between the motor outlet and the external heat exchanger. The current length and current average temperature of the low-temperature buffer section in the connecting pipeline are detected, and a heat dissipation time window allowing the external cooling circuit to intervene is calculated. Within the heat dissipation time window, the main valve connecting the internal cooling channels of the motor and the external cooling circuit is opened, and the cooling pump is started at a second speed to rapidly dissipate heat from the motor. When the current average temperature of the low-temperature buffer section rises to a preset threshold, the main valve is closed, and the bidirectional alternating operation steps are repeated to rebuild the low-temperature buffer section.

[0066] Example 1: To better understand the above technical solution, the following will provide a detailed description of the technical solution in conjunction with the accompanying drawings and specific implementation methods. (Refer to...) Figure 1 As shown in the figure, this is an exemplary flowchart of a control method for a new energy vehicle motor cooling system according to this embodiment of the present application. The motor cooling system control method includes the following steps:

[0067] In step S1, it is identified that the motor of the new energy vehicle has entered a frequent start-stop operation condition. The motor is a liquid-cooled motor with a layered cooling channel. The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined according to the start-stop frequency and single operation duration of the motor under the frequent start-stop operation condition.

[0068] In this embodiment, identifying the frequent start-stop operation of the motor in a new energy vehicle can be achieved through the following steps:

[0069] Collect start-stop signals from the motors of new energy vehicles;

[0070] Extract the adjacent time intervals and temporal entropy values ​​of all motor start and stop actions from the start and stop action signals;

[0071] The frequent start-stop operation condition of the motor in a new energy vehicle is determined based on the adjacent time intervals and time sequence entropy values ​​of all start-stop actions of the motor.

[0072] It should be noted that the motor described in this application is a liquid-cooled motor with layered cooling channels. A liquid-cooled motor refers to a motor that uses coolant as a heat exchange medium and achieves heat removal from the motor through the circulation of coolant. The layered cooling channels refer to a multi-region independent and interconnected cooling channel structure that is arranged in layers and zones to correspond to heat exchange in different heat-generating areas of the motor stator, rotor, and windings.

[0073] It should also be noted that the start-stop action signal mentioned in this application represents a set of electrical signals that can characterize the start-stop action state of the new energy vehicle motor; the adjacent time interval represents the time difference between two consecutive start-stop actions of the motor (start to stop or stop to start); the time sequence entropy value represents a quantitative index that characterizes the degree of disorder in the time sequence distribution of the start-stop action of the new energy vehicle motor, and is used to reflect the frequent and irregular start-stop action of the new energy vehicle motor.

[0074] In specific implementation, firstly, the start-stop control signals of the new energy vehicle motor are collected through the vehicle controller of the new energy vehicle. Secondly, a time series segmentation algorithm is used to process the collected start-stop action signals. First, the start and end times of each start-stop action are marked by a level transition detection method. Then, the difference between the start times of every two adjacent start-stop actions is calculated, and the obtained difference is used as the adjacent time interval of the corresponding start-stop action of the motor, thus obtaining the adjacent time interval of all start-stop actions of the motor. At the same time, the Shannon entropy algorithm is used to calculate the time entropy value. Specifically, the probability distribution of all adjacent time intervals is first counted. The probability distribution of each adjacent time interval is substituted into the Shannon entropy calculation process. First, the natural logarithm of each probability distribution is taken. Then, the product of each probability distribution and its corresponding natural logarithm is summed. Finally, the negative number of the sum is taken as the time entropy value of the motor start-stop action, thus obtaining the time entropy value of the motor start-stop action. The system first calculates the temporal entropy value for start-stop actions. Then, it presets an adjacent time interval threshold and a temporal entropy value threshold. The adjacent time interval threshold is set based on the initial dissipation time of residual heat after a single run of a liquid-cooled motor with a layered cooling channel. An adjacent start-stop interval less than this threshold indicates frequent start-stop operations. The temporal entropy value threshold is set based on statistical data from numerous experiments on frequent start-stop operations of liquid-cooled motors. A temporal entropy value greater than this threshold indicates irregular start-stop actions and falls into the category of frequent start-stop operations. All extracted adjacent time intervals are compared one by one with the preset adjacent time interval threshold. Simultaneously, the calculated temporal entropy value is compared with the preset temporal entropy value threshold. If five or more consecutive adjacent time intervals are less than the preset threshold, and the temporal entropy value is greater than the preset threshold, this determination is used as the basis for identifying the frequent start-stop operation condition of the new energy vehicle's motor, thus completing the identification of the frequent start-stop operation condition of the new energy vehicle's motor.

[0075] In this embodiment, the alternation duration of the bidirectional alternating operation of the motor cooling pump can be determined based on the start-stop frequency and single-run duration of the motor under frequent start-stop conditions using the following steps:

[0076] Obtain the start-stop frequency and single-run duration of the motor under frequent start-stop conditions;

[0077] The heat dissipation ratio of the stratified cooling channel is matched according to the start-stop frequency of the motor under frequent start-stop conditions, and the forward and reverse operation of the motor cooling pump.

[0078] The two-way duration allocation weight of the adaptation ratio is derived by correcting the winding thermal accumulation gradient corresponding to the single running time of the motor under frequent start-stop conditions.

[0079] The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined based on the revised bidirectional duration allocation weight.

[0080] It should be noted that, in this application, the start-stop frequency refers to the number of times the motor completes a start-stop cycle per unit time, used to quantify the intensity of frequent start-stop cycles; the single running duration refers to the time the motor runs continuously from start to stop each time it starts, used to reflect the heat accumulation of the motor during a single run; the heat extraction adaptation ratio refers to the proportion of the cooling pump's forward and reverse operation time, used to adapt to the heat extraction requirements of the layered cooling channel; the winding heat accumulation gradient refers to the rate of cumulative change of winding temperature over time within the single running duration of the motor, used to reflect the magnitude of the heat load during a single run; the bidirectional duration allocation weight refers to the allocation coefficient of the cooling pump's forward and reverse operation time after correction based on the heat extraction adaptation ratio; and the alternation duration refers to the duration of a single forward and reverse operation of the cooling pump.

[0081] In practice, firstly, the start-stop frequency and single-cycle duration of the motor under frequent start-stop conditions are obtained. Specifically, the total number of start-stop cycles completed by the motor within a continuous 30-minute period is counted, and the total number is divided by 30 minutes to obtain the start-stop frequency per unit time. At the same time, the time difference from the start time to the stop time of the motor in each start-stop cycle is extracted, and the arithmetic mean of all time differences is taken as the single-cycle duration of the motor. Secondly, three sets of adaptation ratio ranges are preset, with the adaptation ratio being the forward operation time of the cooling pump and the reverse operation time of the cooling pump. This preset adaptation ratio range can be set according to the characteristics of the liquid-cooled motor with layered cooling channels. That is, during forward operation, the coolant mainly flows through the stator and winding channels, and during reverse operation, it mainly flows through the rotor channel. The higher the start-stop frequency, the faster the rotor waste heat accumulates, so the proportion of reverse operation needs to be increased. For example, the start-stop frequency of 1-2 times / minute corresponds to an adaptation ratio of 6:4, 2-3 times / minute corresponds to 5:5, and more than 3 times / minute corresponds to 4:6. The obtained start-stop frequency is substituted into the adaptation ratio range to output the adaptation ratio of the motor cooling pump for forward and reverse operation to the layered cooling channel, and these ratios are used as the heat dissipation adaptation ratios of the motor cooling pump for forward and reverse operation to the layered cooling channel. Next, the winding temperature corresponding to a single running time under frequent start-stop conditions is obtained. From the initial winding temperature at the start time to the final winding temperature at the stop time, the temperature change is integrated to obtain the cumulative change value of the winding temperature. This cumulative change value is then divided by the single running time, and the result is used as the winding thermal accumulation gradient. The winding thermal accumulation gradient corresponding to all running times under frequent start-stop conditions is then normalized, and the normalized value is used as the correction coefficient for the corresponding single running time. When the winding thermal accumulation gradient is greater than the preset gradient threshold (which can be set as the safe thermal accumulation rate allowed for the liquid-cooled motor winding), the reverse running time weight of the thermal export adaptation ratio is corrected using the correction coefficient. When the winding thermal accumulation gradient is less than the preset threshold, the forward running time weight of the thermal export adaptation ratio is corrected using the correction coefficient. The ratio of the corrected forward running time to the reverse running time is used as the bidirectional time allocation weight of the thermal export adaptation ratio. Finally, the total cycle of the bidirectional alternating operation of the cooling pump is allocated to the forward and reverse operation according to the bidirectional duration weight, and the duration composed of the forward and reverse operation durations of the motor cooling pump is taken as the alternation duration of the bidirectional alternating operation of the motor cooling pump.

[0082] In step S2, the cooling pump is controlled to operate alternately in both directions for alternating durations to export the residual heat of the motor stator, rotor and winding areas to the external pipeline side. At the same time, a low-temperature buffer section formed by low-temperature coolant is constructed in the connecting pipeline between the motor outlet and the external heat exchanger.

[0083] In this embodiment, controlling the cooling pump to operate alternately in both directions for alternating durations to dissipate residual heat from the motor stator, rotor, and winding areas to the external piping side can be achieved through the following steps:

[0084] Control the cooling pump to perform forward pumping action;

[0085] The driving coolant flows forward along the stratified cooling channels, carrying away residual heat from the motor stator and winding areas;

[0086] After the alternation period is reached, the cooling pump direction is switched to perform reverse pumping action;

[0087] The coolant is driven to flow in the reverse direction along the stratified cooling channels, dissipating residual heat in the motor rotor area to the external piping side.

[0088] It should be noted that, in this application, the forward pumping action refers to the cooling pump rotating in the forward direction, driving the coolant to flow along the dedicated flow channels of the stator and windings; the forward flow of the layered cooling channels refers to the coolant flowing through the dedicated flow channels of the stator and windings; the reverse pumping action refers to the cooling pump rotating in the reverse direction, driving the coolant to flow along the dedicated flow channels of the rotor; the reverse flow of the layered cooling channels refers to the coolant flowing through the dedicated flow channels of the rotor area; and the external pipeline side refers to the connecting pipeline between the motor outlet and the external heat exchanger.

[0089] It should also be noted that the reference Figure 2 As shown in the figure, this is a timing diagram of the bidirectional alternating operation of the cooling pump provided in this application. The horizontal axis of the timing diagram is the time axis, marked with key timing nodes t0 to t6; the vertical axis is the operating state of the cooling pump, divided into three levels: forward operation, stop reversing, and reverse operation. The timing flow is as follows: In the t0-t1 stage, the cooling pump is in the forward operation state, directionally dissipating the residual heat in the stator and winding areas of the motor; in the t1-t2 stage, it enters the stop reversing state, completing the switching of the pump's operating direction; in the t2-t3 stage, the cooling pump switches to reverse operation, specifically dissipating the heat in the motor rotor area, and simultaneously building a low-temperature buffer section in the pipeline; in the t3-t4 stage, it enters the stop reversing state again, triggering the heat dissipation time window; in the t4-t6 stage, the cooling pump resumes forward operation, completing the reconstruction of the low-temperature buffer section and entering the next cycle.

[0090] In practice, firstly, based on the forward operation duration received by the cooling pump controller, a forward drive command is sent to the cooling pump to control it to perform forward pumping. Secondly, the forward operation of the cooling pump generates pumping pressure, driving the coolant to flow forward along the stator and winding dedicated flow channels in the layered cooling channel. The coolant exchanges heat with the residual heat in the stator and winding areas, absorbing heat and increasing in temperature. The coolant, having absorbed the residual heat from the stator and windings, acts as a waste heat carrier, thus removing the residual heat from the stator and winding areas. Next, when the forward pumping duration reaches a predetermined alternation duration, a direction switching command is immediately sent to control the cooling pump to stop forward operation and switch direction to perform reverse pumping. Finally, the reverse operation of the cooling pump drives the coolant to flow in reverse along the rotor dedicated flow channel in the layered cooling channel. After absorbing the residual heat in the rotor area, the coolant is driven to the motor outlet and introduced into the external pipeline side, thereby completing the removal of residual heat from all areas.

[0091] In this embodiment, the construction of a low-temperature buffer section formed by low-temperature coolant in the connecting pipe between the motor outlet and the external heat exchanger can be achieved by the following steps:

[0092] While the cooling pump performs bidirectional alternating operation and switches to reverse operation according to the alternating duration, the entire section of the connecting pipeline between the motor outlet and the external heat exchanger is locked.

[0093] Drive the cooling pump to run in reverse, so that the high-temperature coolant in the connecting pipe near the motor outlet flows back into the motor, while the low-temperature coolant in the connecting pipe near the external heat exchanger remains in the connecting pipe.

[0094] During the duration of the cooling pump's reverse operation, the flow of the low-temperature coolant remaining in the connecting pipe to the motor or the external heat exchanger is continuously blocked, causing the low-temperature coolant to form a continuous liquid column section in the connecting pipe.

[0095] When the cooling pump completes its reverse rotation and switches back to forward rotation, the connecting pipe remains locked, allowing the continuous liquid column to remain in the connecting pipe during the forward rotation of the cooling pump, and the continuous liquid column formed by the low-temperature coolant in the connecting pipe serves as a low-temperature buffer section.

[0096] It should be noted that, in this application, the connection pipeline locking refers to blocking the fluid flow channels at both ends of the pipeline by means of a pipeline control valve, so that the inside of the pipeline forms a closed area; the high-temperature coolant refers to the coolant whose temperature rises after absorbing residual heat from the motor; the low-temperature coolant refers to the coolant whose temperature decreases after being dissipated by an external heat exchanger; and the low-temperature buffer section refers to the low-temperature liquid column section that prevents direct heat exchange between the external high-temperature coolant and the internal flow channel of the motor under frequent start-stop conditions.

[0097] In practice, firstly, at the synchronous moment when the cooling pump switches from forward to reverse operation, the isolation valves at both ends of the connecting pipe are closed simultaneously, locking the entire connecting pipe between the motor outlet and the external heat exchanger. Secondly, the cooling pump is driven to continuously reverse, using the reverse pumping force to draw the high-temperature coolant near the motor outlet back into the motor's internal flow channel, while simultaneously keeping the low-temperature coolant near the external heat exchanger within the closed section of the pipe. Next, during the entire reverse operation period of the cooling pump, the isolation valves at both ends of the pipe remain closed, continuously blocking the flow path of the low-temperature coolant to the motor or the external heat exchanger, causing the low-temperature coolant to gather and form a continuous liquid column within the closed section of the pipe. Finally, when the cooling pump finishes reversing and switches back to forward operation, the isolation valves remain closed and locked, allowing the continuous liquid column to remain stably inside the connecting pipe. This continuous liquid column composed of low-temperature coolant serves as a low-temperature buffer section, thus completing the construction of the low-temperature buffer section.

[0098] In step S3, the current length and current average temperature of the low-temperature buffer section in the connecting pipeline are detected, and the heat dissipation time window that allows the external cooling circuit to intervene is calculated.

[0099] In this embodiment, detecting the current length and current average temperature of the low-temperature buffer section in the connecting pipeline and calculating the heat dissipation time window that allows the external cooling circuit to intervene can be achieved by the following steps:

[0100] The current length and average temperature of the low-temperature buffer section in the connecting pipeline are detected.

[0101] The effective cold storage capacity of the low-temperature buffer section is determined based on its current length and current average temperature.

[0102] Based on the heat generation power of the motor under frequent start-stop conditions and the effective cold energy reserve value, the thermal response analysis of the low temperature buffer section after the intervention of the external cooling circuit is carried out to obtain the critical time of thermal penetration of the low temperature buffer section after the intervention of the external cooling circuit.

[0103] The heat dissipation time window that allows external cooling circuit intervention is determined by the critical time of heat penetration and the thermal shock protection redundancy time of the motor.

[0104] It should be noted that, in this application, the current length of the low-temperature buffer section refers to the actual length of the continuous liquid column segment formed by the low-temperature coolant in the connecting pipeline; the effective cold energy reserve value refers to the total heat value that the low-temperature coolant in the low-temperature buffer section can absorb to maintain its low-temperature insulation capacity; the heating power refers to the amount of heat generated by the motor per unit time under frequent start-stop conditions; the critical time for heat penetration refers to the critical time when the low-temperature buffer section fails completely due to high-temperature heat penetration from a low-temperature state; the thermal shock protection safety redundancy time refers to the safety buffer time reserved to avoid thermal shock to the new energy vehicle motor; and the heat dissipation time window refers to the effective time range within which the external cooling circuit can safely intervene and rapidly dissipate heat from the new energy vehicle motor.

[0105] In specific implementation, firstly, the pipe coverage length of the low-temperature buffer section is detected by a pipe length detection sensor, and this pipe coverage length is taken as the current length of the low-temperature buffer section. Simultaneously, the arithmetic mean of the temperature data at each monitoring point in the low-temperature buffer section is taken as the current average temperature of the low-temperature buffer section. Secondly, the cross-sectional area parameters of the connecting pipes, calibrated at the factory, are retrieved. The current length of the low-temperature buffer section is multiplied by the cross-sectional area of ​​the pipe to obtain the actual volume occupied by the low-temperature coolant inside the low-temperature buffer section. This actual volume is taken as the effective volume of the low-temperature coolant. Simultaneously, the density and specific heat capacity parameters of the coolant, calibrated at the factory, are retrieved. The real-time temperature of the high-temperature coolant inside the motor is collected. The difference between the real-time temperature of the high-temperature coolant inside the motor and the current average temperature of the low-temperature buffer section is calculated to obtain the temperature difference. Using existing heat capacity... The method involves calculating the actual mass of the cryogenic coolant by multiplying its effective volume by its density. Then, the actual mass of the coolant, its specific heat capacity, and the temperature difference are multiplied to obtain the total heat that the coolant can absorb within the cryogenic buffer zone. This total heat value is used as the effective cooling capacity reserve of the cryogenic buffer zone. Next, based on the motor's heat generation power under frequent start-stop conditions and the effective cooling capacity reserve, a thermal response analysis is performed on the cryogenic buffer zone after the external cooling circuit intervenes, yielding the critical heat penetration time of the cryogenic buffer zone after the external cooling circuit intervenes. Finally, the thermal shock protection safety redundancy time calibrated at the motor's factory is retrieved, and this redundancy time is subtracted from the critical heat penetration time to obtain the effective time for the external cooling circuit to safely intervene. This effective time is used as the heat dissipation time window allowing the external cooling circuit to intervene.

[0106] In this embodiment, based on the heat generation power of the motor under frequent start-stop conditions and the effective cooling capacity reserve, a thermal response analysis is performed on the low-temperature buffer section after the external cooling circuit intervention. The critical time for heat penetration of the low-temperature buffer section after the external cooling circuit intervention can be obtained by the following steps:

[0107] By analyzing the heat generation power of the motor under frequent start-stop conditions and the effective cold energy reserve value, the thermal response delay of the low temperature buffer section after the intervention of the external cooling circuit is obtained through thermal response delay constraint conditions of the low temperature buffer section after the intervention of the external cooling circuit.

[0108] Based on the aforementioned thermal response delay constraint condition, the critical duration of thermal penetration of the low-temperature buffer section after the intervention of the external cooling circuit is constrained and analyzed to obtain the critical duration of thermal penetration of the low-temperature buffer section after the intervention of the external cooling circuit.

[0109] It should be noted that the thermal response delay constraint condition described in this application represents the core constraint parameter that enables the low-temperature buffer section to maintain its low-temperature insulation capability during the delay process; the thermal penetration critical time represents the critical time required for the low-temperature buffer section to be completely penetrated by high-temperature heat and fail to maintain its low-temperature insulation capability after the intervention of the external cooling circuit.

[0110] In practice, firstly, by analyzing the rate of change of winding temperature and stator core temperature per unit time, combined with the heat loss coefficient and heat dissipation coefficient specified by the motor manufacturer, the heat generation power of the motor under high load operation is calculated. The heat generation power under frequent start-stop conditions is taken as the input high-temperature heat value per unit time, and the effective cooling reserve value of the low-temperature buffer section is taken as the total heat insulation cooling capacity that the low-temperature buffer section can consume. The dynamic process of high-temperature heat gradually consuming the cooling capacity of the low-temperature buffer section is tracked in real time, reconstructing the entire process of high-temperature heat continuously transferring and consuming the total heat insulation cooling capacity of the low-temperature buffer section after the external cooling circuit intervenes. By continuously monitoring the temperature change of the low-temperature buffer section, the time from the intervention of the external cooling circuit to the first upward trend of the low-temperature buffer section temperature is recorded and taken as the thermal response delay time. The ratio between the effective cooling reserve value and the heat generation power of the motor under frequent start-stop conditions is calculated, and the obtained ratio is taken as the safe duration that the cooling capacity of the low-temperature buffer section can support. Then, the safe duration is compared with the thermal response delay time. The delay time serves as a constraint condition for the thermal response delay of the low-temperature buffer section after the intervention of the external cooling circuit. Secondly, based on the obtained thermal response delay constraint condition, the thermal response delay time of the thermal response delay constraint condition is used as the initial constraint stage where the low-temperature buffer section has no risk of thermal penetration. The safe duration that the cooling capacity can support under the thermal response delay constraint condition is used as the subsequent constraint stage where the cooling capacity of the low-temperature buffer section is gradually consumed and thermal penetration gradually occurs. A stage superposition method is used for dual constraints. Then, the real-time temperature change of the low-temperature buffer section after the intervention of the external cooling circuit is continuously monitored. The dual constraints of thermal response delay time and safe duration that the cooling capacity can support are strictly followed. The entire process of the temperature of the low-temperature buffer section gradually rising from the current average temperature is monitored in real time. When the temperature of the low-temperature buffer section rises to the failure critical temperature specified by the motor manufacturer, the total time from the start of the intervention of the external cooling circuit to the temperature of the low-temperature buffer section reaching the failure critical temperature is recorded. This total time is used as the critical time for thermal penetration of the low-temperature buffer section after the intervention of the external cooling circuit.

[0111] In step S4, within the heat dissipation time window, the main valve connecting the internal cooling channel of the motor and the external cooling circuit is opened, and the cooling pump is started at the second speed to quickly dissipate heat from the motor.

[0112] In this embodiment, within the heat dissipation time window, the main valve connecting the internal cooling channel of the motor and the external cooling circuit is opened, and the cooling pump is started at the second speed. The rapid heat dissipation of the motor can be achieved by the following steps:

[0113] Verify the remaining effective duration of the heat dissipation time window;

[0114] Send a staged opening command to the main valve that connects the internal cooling channel of the motor and the external cooling circuit. First, control the main valve to open to the pre-calibrated pre-opening degree to balance the pipeline pressure difference, and then control the main valve to open fully to connect the internal cooling channel of the motor and the external cooling circuit.

[0115] Determine the second speed of the motor cooling pump;

[0116] After the main valve is fully opened, the control cooling pump starts smoothly at the second speed, driving the low-temperature coolant from the external cooling circuit into the internal cooling channel of the motor to perform rapid heat dissipation on the motor.

[0117] During rapid heat dissipation, the remaining effective duration of the heat dissipation time window is monitored to ensure that the entire cooling process remains within the effective and controllable range of the heat dissipation time window.

[0118] It should be noted that, in this application, the remaining effective duration of the heat dissipation time window refers to the remaining time available for safe heat dissipation between the end of the heat dissipation time window and the current time; the graded opening command refers to the control command for controlling the opening degree of the main valve in stages, used to avoid sudden changes in pipeline pressure; the pre-opening degree is the intermediate opening value pre-calibrated by the main valve, used to balance the pipeline pressure difference between the internal and external cooling circuits of the motor; the second speed is the operating speed of the cooling pump adapted to the rapid heat dissipation of the motor without damaging the thermal insulation state of the low-temperature buffer section; the rapid heat dissipation refers to the heat dissipation method of quickly removing the residual heat inside the motor by using the low-temperature coolant of the external cooling circuit within the heat dissipation time window.

[0119] Send a staged opening command to the main valve that connects the internal cooling channels of the motor to the external cooling circuit.

[0120] In practice, firstly, the start time of the heat dissipation time window is obtained, and the remaining effective duration of the heat dissipation time window is calculated and verified. If the remaining effective duration is less than the preset minimum safety threshold, subsequent operations are terminated. If the remaining effective duration meets the requirements for rapid heat dissipation, the next step of sending instructions is initiated. Secondly, the valve control unit of the new energy vehicle motor controller sends a tiered opening instruction to the main valve connecting the internal cooling channel of the motor and the external cooling circuit. First, a pre-opening signal is sent to the main valve to control it to open to the pre-calibrated pre-opening degree. After the differential pressure sensor in the pipeline reports that the differential pressure has reached the equilibrium threshold, a fully opening signal is sent to the main valve to control it to fully open, thereby connecting the internal cooling channel of the motor and the external cooling circuit and avoiding the pipeline pressure shock caused by direct full opening. Thirdly, based on the current heat dissipation power of the motor, a step is taken to directly select... The factory-preset speed of the motor is used as the second speed of the cooling pump in the external cooling circuit. Then, after the main valve is fully opened, the pump start unit of the motor controller sends a smooth start command to the cooling pump in the external cooling circuit, controlling the cooling pump to start gradually and smoothly at the determined second speed. This avoids sudden changes in speed that could cause a sudden change in coolant flow, driving the low-temperature coolant in the external cooling circuit to smoothly enter the internal cooling channel of the motor and continuously circulate for rapid heat dissipation. Finally, during the rapid heat dissipation process, the remaining effective time is continuously monitored, and the real-time temperature of the low-temperature buffer section is also monitored. This double verification ensures that the cooling process is within the effective and controllable range of the heat dissipation time window throughout. If the remaining effective time is about to run out or the temperature of the low-temperature buffer section is close to the failure critical temperature, the cooling pump is immediately controlled to slow down and the main valve is closed, terminating the rapid heat dissipation process.

[0121] In step S5, when the current average temperature of the low-temperature buffer section rises to a preset threshold, the main valve is closed and the bidirectional alternating operation steps are repeated to rebuild the low-temperature buffer section.

[0122] Preferably, in this embodiment, when the current average temperature of the cryogenic buffer section rises to a preset threshold, the main valve is closed and the bidirectional alternating operation steps are repeated to rebuild the cryogenic buffer section. Figure 2 As shown in the figure, this is a schematic flowchart of the reconstruction of the cryogenic buffer segment in some embodiments of this application. In this embodiment, the reconstruction of the cryogenic buffer segment can be achieved by the following steps:

[0123] In step S51, during the process of rapid heat dissipation by the intervention of the external cooling circuit, the current average temperature of the low temperature buffer section is continuously monitored, and the current average temperature is compared with the preset temperature threshold in real time.

[0124] In step S52, when the current average temperature of the low temperature buffer section rises to a preset threshold, it is determined that the low temperature insulation capability of the low temperature buffer section has failed, and an external cooling circuit exit command is generated.

[0125] In step S53, based on the external cooling circuit exit command, the cooling pump is controlled to stop running, and at the same time a closing command is sent to the main valve to control the main valve to be completely closed, cutting off the connection between the internal cooling channel of the motor and the external cooling circuit;

[0126] In step S54, the cryogenic buffer section reconstruction process is triggered, and the alternating operation of the cooling pump is repeated to reconstruct the cryogenic buffer section formed by the cryogenic coolant in the connecting pipeline.

[0127] It should be noted that the preset temperature threshold mentioned in this application is the critical temperature at which the low-temperature insulation capacity of the low-temperature buffer section fails. The preset threshold is determined by actual measurement during the factory bench calibration test of the motor. Specifically, the temperature of the low-temperature buffer section is gradually increased on the bench, and the insulation performance of the low-temperature buffer section, the tolerance status of the pipeline material, and the operating temperature of the motor are monitored in real time. The lowest temperature value among the three—the failure of the low-temperature insulation capacity of the low-temperature buffer section, the critical tolerance of the pipeline material, and the upper limit of the safe operation of the motor—is taken as the final preset threshold. The external cooling circuit exit command is a cut-off command that controls the cooling pump to stop and the main valve to close. The low-temperature buffer section reconstruction process refers to the control process of forming a continuous low-temperature coolant column segment in the connecting pipeline again through the bidirectional alternating operation of the cooling pump. The alternating operation step of the cooling pump refers to the control step of the cooling pump pumping coolant alternately in the forward and reverse directions according to the previously determined alternation duration.

[0128] In practice, firstly, throughout the entire process of the external cooling circuit rapidly dissipating heat from the motor, the current average temperature of the low-temperature buffer section is monitored and continuously compared in real time with the motor's factory-preset temperature threshold. Secondly, when the comparison shows that the current average temperature of the low-temperature buffer section has risen to the preset temperature threshold, the main controller of the new energy vehicle's motor automatically determines that the low-temperature insulation capability of the low-temperature buffer section has failed, and then generates a control command to control the external cooling circuit to exit and transmits it to the execution unit. Thirdly, based on the generated external cooling circuit exit command, the pump control module of the motor controller controls the cooling pump of the external cooling circuit to smoothly stop operating, avoiding pipeline impact caused by sudden shutdown, and simultaneously, the valve control module controls the flow of water into the motor. The main valve of the internal cooling channel and the external cooling circuit sends a closing command to control the main valve to close smoothly and completely, completely cutting off the connection between the internal cooling channel and the external cooling circuit, preventing the external coolant from flowing back and interfering with the state of the internal cooling channel. Finally, the preset low-temperature buffer section reconstruction process is triggered, calling the bidirectional alternating operation time parameters of the cooling pump determined based on the frequent start-stop conditions of the motor, and repeating the steps of alternating forward and reverse operation of the cooling pump to drive the coolant to flow bidirectionally along the motor's layered cooling channel. At the same time, the connection pipeline range is locked, the loss of low-temperature coolant is blocked, and a continuous low-temperature coolant column segment is re-formed in the connection pipeline between the motor outlet and the external heat exchanger. This column segment is used as the reconstructed low-temperature buffer section to prepare for the next intervention of the external cooling circuit.

[0129] Therefore, in this application, when the current average temperature of the low-temperature buffer section rises to a preset threshold, the main valve is controlled to close and the bidirectional alternating operation steps are repeatedly executed to rebuild the low-temperature buffer section. Firstly, by identifying the frequent start-stop operation of the new energy vehicle motor and determining the alternation duration of the bidirectional alternating operation of the cooling pump based on the start-stop frequency and single-run duration, the cooling control strategy can accurately match the dynamic operating characteristics of the motor, solving the problem of poor adaptability of the traditional fixed cooling mode to frequent start-stop conditions. Secondly, controlling the cooling pump to operate bidirectionally and alternately according to the set alternation duration can effectively dissipate residual heat from the motor stator, rotor, and winding areas to the external pipeline side. Simultaneously, a low-temperature coolant buffer section is constructed in the connecting pipeline between the motor outlet and the external heat exchanger, which can efficiently dissipate locally accumulated residual heat and prevent excessive heat accumulation in the core components of the motor. Furthermore... By detecting the current length and average temperature of the low-temperature buffer section and calculating the heat dissipation time window, the timing of external cooling circuit intervention can be rationally planned. This compensates for the deficiencies in the existing cooling system's heat dissipation control mechanism and the inflexible planning of heat dissipation rhythm, ensuring that the timing of external heat dissipation intervention is adapted to dynamic waste heat changes. Subsequently, within the heat dissipation time window, the main valve is opened and the cooling pump is controlled to start at the second speed, enabling rapid heat dissipation of the motor through the external cooling circuit, timely dissipation of accumulated residual heat, and improvement of the heat dissipation efficiency of the liquid cooling system. Finally, when the average temperature of the low-temperature buffer section rises to the preset threshold, the main valve is closed and bidirectional alternating operation is repeated to rebuild the low-temperature buffer section. This forms a cyclical waste heat conduction and heat dissipation control mechanism, continuously suppressing the continuous accumulation of residual heat under frequent start-stop conditions, thereby ensuring the stability of motor operation and extending the service life of the motor's core components.

[0130] In summary, the technical solution adopted in this application can achieve heat dissipation control of residual heat accumulation under frequent start-stop conditions of new energy vehicle motors.

[0131] Example 2: This application provides a control system for a new energy vehicle motor cooling system, referencing... Figure 4 As shown in the figure, this is a modular structure diagram of a new energy vehicle motor cooling system control system according to this embodiment of the application. The motor cooling system control system includes:

[0132] The motor frequent start-stop identification module 100 is used to identify the motor of a new energy vehicle entering the frequent start-stop operation condition. The motor is a liquid-cooled motor with a layered cooling channel. The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined according to the start-stop frequency and single running duration of the motor under the frequent start-stop operation condition.

[0133] The cooling pump bidirectional alternating operation module 200 is used to control the cooling pump to operate bidirectionally alternately according to the alternating duration, so as to conduct the residual heat of the motor stator, rotor and winding area to the external pipeline side, and at the same time construct a low temperature buffer section formed by low temperature coolant in the connecting pipeline between the motor outlet and the external heat exchanger.

[0134] The heat dissipation time window calculation module 300 is used to detect the current length and current average temperature of the low temperature buffer section in the connecting pipeline, and calculate the heat dissipation time window that allows the external cooling circuit to intervene.

[0135] The motor rapid heat dissipation module 400 is used to control the opening of the main valve connecting the internal cooling channel of the motor and the external cooling circuit during the heat dissipation time window, and to control the cooling pump to start at the second speed to rapidly dissipate heat from the motor.

[0136] The low-temperature buffer section reconstruction module 500 is used to control the main valve to close and repeatedly execute bidirectional alternating operation steps to reconstruct the low-temperature buffer section when the current average temperature of the low-temperature buffer section rises to a preset threshold.

[0137] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0138] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, including read-only memory (ROM), random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-Erasable Programmable Read-Only Memory (EEPROM), compactdisc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium capable of carrying or storing data.

[0139] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

Claims

1. A control method for a cooling system of a new energy vehicle motor, characterized in that, The motor cooling system control method includes the following steps: The method identifies when the motor of a new energy vehicle enters a frequent start-stop operation condition. The motor is a liquid-cooled motor with a layered cooling channel. The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined based on the start-stop frequency and single running duration of the motor under the frequent start-stop operation condition. The cooling pump is controlled to operate in both directions alternately for alternating durations to transfer the residual heat in the stator, rotor and winding areas of the motor to the external pipeline side. At the same time, a low-temperature buffer section formed by low-temperature coolant is constructed in the connecting pipeline between the motor outlet and the external heat exchanger. Detect the current length and current average temperature of the low-temperature buffer section in the connecting pipeline, and calculate the heat dissipation time window that allows the external cooling circuit to intervene; During the heat dissipation time window, the main valve connecting the internal cooling channel of the motor and the external cooling circuit is opened, and the cooling pump is started at the second speed to quickly dissipate heat from the motor. When the current average temperature of the cryogenic buffer section rises to a preset threshold, the main control valve closes and repeats the bidirectional alternating operation steps to rebuild the cryogenic buffer section.

2. The control method for a new energy vehicle motor cooling system as described in claim 1, characterized in that, Identifying frequent start-stop operation of the motor in a new energy vehicle specifically includes: Collect start-stop signals from the motors of new energy vehicles; Extract the adjacent time intervals and temporal entropy values ​​of all motor start and stop actions from the start and stop action signals; The motor is determined to be in a frequent start-stop operation condition based on the adjacent time intervals and timing entropy values ​​of all motor start-stop actions.

3. The control method for a new energy vehicle motor cooling system as described in claim 1, characterized in that, The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined based on the start-stop frequency and single-run duration of the motor under frequent start-stop conditions. Specifically, it includes: Obtain the start-stop frequency and single-run duration of the motor under frequent start-stop conditions; The heat dissipation ratio of the stratified cooling channel is matched according to the start-stop frequency of the motor under frequent start-stop conditions, and the forward and reverse operation of the motor cooling pump. The two-way duration allocation weight of the adaptation ratio is derived by correcting the winding thermal accumulation gradient corresponding to the single running time of the motor under frequent start-stop conditions. The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined based on the revised bidirectional duration allocation weight.

4. The control method for a new energy vehicle motor cooling system as described in claim 1, characterized in that, Controlling the cooling pump to operate alternately in both directions for alternating durations to dissipate residual heat from the motor stator, rotor, and winding areas to the external piping side specifically includes: Control the cooling pump to perform forward pumping action; The driving coolant flows forward along the stratified cooling channels, carrying away residual heat from the motor stator and winding areas; After the alternation period is reached, the cooling pump direction is switched to perform reverse pumping action; The coolant is driven to flow in the reverse direction along the stratified cooling channels, dissipating residual heat in the motor rotor area to the external piping side.

5. The control method for a new energy vehicle motor cooling system as described in claim 1, characterized in that, Meanwhile, a low-temperature buffer section formed by low-temperature coolant is constructed in the connecting pipe between the motor outlet and the external heat exchanger, specifically including: While the cooling pump performs bidirectional alternating operation and switches to reverse operation according to the alternating duration, the entire section of the connecting pipeline between the motor outlet and the external heat exchanger is locked. Drive the cooling pump to run in reverse, so that the high-temperature coolant in the connecting pipe near the motor outlet flows back into the motor, while the low-temperature coolant in the connecting pipe near the external heat exchanger remains in the connecting pipe. During the duration of the cooling pump's reverse operation, the flow of the low-temperature coolant remaining in the connecting pipe to the motor or the external heat exchanger is continuously blocked, causing the low-temperature coolant to form a continuous liquid column section in the connecting pipe. When the cooling pump completes its reverse rotation and switches back to forward rotation, the connecting pipe remains locked, allowing the continuous liquid column to remain in the connecting pipe during the forward rotation of the cooling pump, and the continuous liquid column formed by the low-temperature coolant in the connecting pipe serves as a low-temperature buffer section.

6. The control method for a new energy vehicle motor cooling system as described in claim 1, characterized in that, The current length and average temperature of the low-temperature buffer section in the connecting piping are detected, and the heat dissipation time window allowing external cooling circuit intervention is calculated, specifically including: The current length and average temperature of the low-temperature buffer section in the connecting pipeline are detected. The effective cold storage capacity of the low-temperature buffer section is determined based on its current length and current average temperature. Based on the heat generation power of the motor under frequent start-stop conditions and the effective cold energy reserve value, the thermal response analysis of the low temperature buffer section after the intervention of the external cooling circuit is carried out to obtain the critical time of thermal penetration of the low temperature buffer section after the intervention of the external cooling circuit. The heat dissipation time window that allows external cooling circuit intervention is determined by the critical time of heat penetration and the thermal shock protection redundancy time of the motor.

7. The control method for a new energy vehicle motor cooling system as described in claim 1, characterized in that, During the heat dissipation time window, the main valve connecting the internal cooling channel of the motor to the external cooling circuit is opened, and the cooling pump is started at the second speed to rapidly dissipate heat from the motor. Specifically, this includes: Verify the remaining effective duration of the heat dissipation time window; Send a staged opening command to the main valve that connects the internal cooling channel of the motor and the external cooling circuit. First, control the main valve to open to the pre-calibrated pre-opening degree to balance the pipeline pressure difference, and then control the main valve to open fully to connect the internal cooling channel of the motor and the external cooling circuit. Determine the second speed of the motor cooling pump; After the main valve is fully opened, the control cooling pump starts smoothly at the second speed, driving the low-temperature coolant from the external cooling circuit into the internal cooling channel of the motor to perform rapid heat dissipation on the motor. During rapid heat dissipation, the remaining effective duration of the heat dissipation time window is monitored to ensure that the entire cooling process remains within the effective and controllable range of the heat dissipation time window.

8. The control method for a new energy vehicle motor cooling system as described in claim 1, characterized in that, When the current average temperature of the cryogenic buffer section rises to a preset threshold, the main control valve closes and repeats the bidirectional alternating operation steps to rebuild the cryogenic buffer section. Specifically, this includes: During the process of rapid heat dissipation by the intervention of the external cooling circuit, the current average temperature of the low temperature buffer section is continuously monitored, and the current average temperature is compared with the preset temperature threshold in real time. When the current average temperature of the low-temperature buffer section rises to the preset threshold, it is determined that the low-temperature insulation capability of the low-temperature buffer section has failed, and an external cooling circuit exit command is generated. Based on the external cooling circuit exit command, the cooling pump is controlled to stop running, and at the same time a closing command is sent to the main valve to control the main valve to close completely, cutting off the connection between the internal cooling channel of the motor and the external cooling circuit; Trigger the cryogenic buffer zone reconstruction process, repeat the alternating operation of the cooling pumps, and rebuild the cryogenic buffer zone formed by cryogenic coolant within the connecting pipeline.

9. A control method for a new energy vehicle motor cooling system as described in claim 6, characterized in that, Based on the heat generation power of the motor under frequent start-stop conditions and the effective cooling capacity reserve, a thermal response analysis was performed on the low-temperature buffer section after the external cooling circuit intervention. The specific thermal penetration critical time of the low-temperature buffer section after the external cooling circuit intervention includes: By analyzing the heat generation power of the motor under frequent start-stop conditions and the effective cold energy reserve value, the thermal response delay of the low temperature buffer section after the intervention of the external cooling circuit is obtained through thermal response delay constraint conditions of the low temperature buffer section after the intervention of the external cooling circuit. Based on the aforementioned thermal response delay constraint condition, the critical duration of thermal penetration of the low-temperature buffer section after the intervention of the external cooling circuit is constrained and analyzed to obtain the critical duration of thermal penetration of the low-temperature buffer section after the intervention of the external cooling circuit.

10. A control system for a new energy vehicle motor cooling system, used to execute a control method for a new energy vehicle motor cooling system as described in any one of claims 1 to 9, characterized in that, The motor cooling system control system includes: The motor frequent start-stop identification module is used to identify when the motor of a new energy vehicle enters the frequent start-stop operation condition. The motor is a liquid-cooled motor with a layered cooling channel. The alternation duration of the bidirectional alternating operation of the motor cooling pump is determined according to the start-stop frequency and single running duration of the motor under the frequent start-stop operation condition. The cooling pump bidirectional alternating operation module is used to control the cooling pump to operate bidirectionally alternately according to the alternating duration, so as to conduct the residual heat of the motor stator, rotor and winding area to the external pipeline side, and at the same time construct a low temperature buffer section formed by low temperature coolant in the connecting pipeline between the motor outlet and the external heat exchanger. The heat dissipation time window calculation module is used to detect the current length and current average temperature of the low-temperature buffer section in the connecting pipeline, and calculate the heat dissipation time window that allows the external cooling circuit to intervene. The motor rapid heat dissipation module is used to control the opening of the main valve connecting the internal cooling channel of the motor and the external cooling circuit during the heat dissipation time window, and to control the cooling pump to start at the second speed to rapidly dissipate heat from the motor. The low-temperature buffer section reconstruction module is used to control the main valve to close and repeatedly execute bidirectional alternating operation steps to rebuild the low-temperature buffer section when the current average temperature of the low-temperature buffer section rises to a preset threshold.

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