Protection control method of electric drive system and related equipment

Abstract

The invention discloses a protection control method of an electric drive system and related equipment, and relates to the technical field of automobile thermal management, and the method comprises the following steps: obtaining first temperature data of a first target component in a front drive system and second temperature data of a second target component in a rear drive system; on the basis of the first temperature data, the second temperature data and a first temperature threshold value, identifying a target driving system with abnormal temperature; determining a target protection level of the target driving system based on the target temperature data of the target driving system and a preset temperature threshold; and determining a control strategy corresponding to the target driving system according to the target protection level. Through the multi-stage protection control strategy, graded gradual over-temperature protection is achieved, intervention can be conducted in advance through derating torque output at the initial stage of temperature abnormity, and vehicle stall caused by direct cutting off of power is avoided.

Description

Technical Field

[0001] The present application relates to the field of automotive thermal management technology, and in particular to a protection control method and related equipment for an electric drive system. Background Art

[0002] In the field of thermal management for electric drive systems in new energy vehicles, traditional overtemperature protection methods typically rely on setting a fixed temperature threshold within the electric drive system. When the temperature reaches that threshold, power output is cut off to protect the system. This method provides basic overtemperature protection in two-wheel drive mode, but has significant drawbacks in four-wheel drive mode.

[0003] For electric drive systems in four-wheel drive mode, when the front or rear drive system cuts off power due to overheating, the continued operation of the other drive system will cause the faulty drive system to passively rotate. When the passive rotation speed reaches the weakening magnetic speed, the motor controller will inject a weakening magnetic current to maintain the speed, which will cause the temperature of the faulty drive system to continue to rise, causing damage to the controller or motor, and even posing a safety hazard. Traditional fixed-threshold protection strategies cannot solve the problem of passive weakening magnetic temperature rise in four-wheel drive mode. Therefore, a protection and control method for electric drive systems is urgently needed to address the technical problems mentioned above. Summary of the Invention

[0004] The Summary of the Invention introduces a series of simplified concepts that will be further described in the Detailed Description of the Invention. The Summary of the Invention of this application is not intended to limit the key features and essential technical features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0005] This application aims to solve the problem of passive magnetic weakening heating in four-wheel drive mode in the existing technology. It realizes graded and progressive over-temperature protection through a multi-level protection control strategy, and can intervene in advance by reducing the torque output at the early stage of temperature abnormality to avoid vehicle stalling caused by direct power cut-off.

[0006] In a first aspect, the present application provides a protection control method for an electric drive system, wherein the electric drive system includes a front drive system and a rear drive system, including:

[0007] Acquiring first temperature data of a first target component in the front drive system and second temperature data of a second target component in the rear drive system, wherein the first target component and the second target component are of the same component type;

[0008] Identifying a target drive system having a temperature abnormality based on the first temperature data, the second temperature data, and the first temperature threshold;

[0009] determine a target protection level of the target driving system based on the target temperature data of the target driving system and the preset temperature threshold, wherein the target temperature data of the target driving system is the first temperature data of the front driving system or the second temperature data of the rear driving system;

[0010] determine a control strategy corresponding to the target driving system according to the target protection level.

[0011] In some embodiments, the first temperature data of the first target component in the front driving system and the second temperature data of the second target component in the rear driving system are obtained, comprising:

[0012] obtain a first monitoring point set of the first target component of the front driving system;

[0013] collect current temperature data of each monitoring point in the first monitoring point set to generate a first temperature data set;

[0014] perform a maximum value screening operation on the first temperature data set, and take the maximum current temperature data in the first temperature data set as the first temperature data;

[0015] obtain a second monitoring point set of the second target component of the rear driving system;

[0016] collect current temperature data of each monitoring point in the second monitoring point set to generate a second temperature data set;

[0017] perform a maximum value screening operation on the second temperature data set, and take the maximum current temperature data in the second temperature data set as the second temperature data.

[0018] In some embodiments, the target driving system includes the front driving system or the rear driving system, and the target driving system with temperature abnormality is identified based on the first temperature data, the second temperature data and the first temperature threshold, comprising:

[0019] when the first temperature data is greater than or equal to the first temperature threshold, the front driving system is determined as the target driving system with temperature abnormality; or,

[0020] when the second temperature data is greater than or equal to the first temperature threshold, the rear driving system is determined as the target driving system with temperature abnormality.

[0021] In some embodiments, the preset temperature threshold includes a first temperature threshold, a second temperature threshold and a third temperature threshold, the third temperature threshold is greater than the second temperature threshold, and the second temperature threshold is greater than the first temperature threshold. The target protection level includes a first protection level, a second protection level and a third protection level, and the target protection level of the target driving system is determined based on the target temperature data of the target driving system and the preset temperature threshold, comprising:

[0022] determining that the target protection level of the target driving system is the first protection level when the target temperature data is greater than or equal to the first temperature threshold and less than the second temperature threshold;

[0023] determining that the target protection level of the target driving system is the second protection level when the target temperature data is greater than or equal to the second temperature threshold and less than the third temperature threshold;

[0024] determining that the target protection level of the target driving system is the third protection level when the target temperature data is greater than or equal to the third temperature threshold and the temperature change rate of the target driving system is greater than or equal to a preset change rate threshold.

[0025] In some embodiments, according to the target protection level, a control strategy corresponding to the target driving system is determined, including:

[0026] calculating a maximum output torque of the target driving system based on the target temperature data, the first temperature threshold and the second temperature threshold when the target protection level is the first protection level;

[0027] controlling the target driving system to perform a de-rating torque output operation based on the maximum output torque;

[0028] controlling the target driving system to perform a zero torque output operation and determining a highest vehicle speed of the whole vehicle as a first target speed when the target protection level is the second protection level, wherein the first target speed satisfies that a passive rotating speed of the target driving system is lower than a field weakening rotating speed of the target driving system under a standard voltage working condition of the power battery;

[0029] controlling the target driving system to perform a zero torque output operation and determining a highest vehicle speed of the whole vehicle as a second target speed when the target protection level is the third protection level, wherein the second target speed satisfies that the passive rotating speed of the target driving system is lower than the field weakening rotating speed of the target driving system under a minimum voltage working condition of the power battery, and the first target speed is greater than the second target speed.

[0030] In some embodiments, further comprising:

[0031] determining a target flow value of the liquid cooling system based on a preset flow gain coefficient and a current flow value of the liquid cooling system when the target protection level is the second protection level and the liquid cooling system is effective, and controlling the liquid cooling pump to perform a rotating speed adjusting operation based on the target flow value so that the current flow value of the liquid cooling system is increased to the target flow value;

[0032] calculating a target shunt value of the battery cooling loop based on a preset shunt ratio when the target protection level is the third protection level and the liquid cooling system is ineffective, and controlling a three-way valve of the battery cooling loop to perform an opening adjusting operation based on the target shunt value so that the battery cooling loop allocates the coolant to the target electric driving system at the preset shunt ratio.

[0033] In some embodiments, further comprising:

[0034] obtaining ambient temperature data of the electric drive system;

[0035] based on the ambient temperature data, dynamically compensating and correcting the preset temperature threshold to generate a compensated temperature threshold;

[0036] based on the target temperature data of the target drive system and the compensated temperature threshold, determining a target protection level of the target drive system.

[0037] In a second aspect, the present application provides a protection control device for an electric drive system, the electric drive system comprising a front drive system and a rear drive system, comprising:

[0038] a temperature data acquisition unit, configured to acquire first temperature data of a first target component in the front drive system and second temperature data of a second target component in the rear drive system, wherein the first target component and the second target component are of the same component type;

[0039] an abnormal system identification unit, configured to identify a target drive system having a temperature abnormality based on the first temperature data, the second temperature data, and a first temperature threshold;

[0040] a protection level determination unit, configured to determine a target protection level of the target drive system based on target temperature data of the target drive system and a preset temperature threshold, wherein the target temperature data of the target drive system is the first temperature data of the front drive system or the second temperature data of the rear drive system;

[0041] a control strategy execution unit, configured to determine a control strategy corresponding to the target drive system according to the target protection level.

[0042] In a third aspect, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor is configured to implement the steps of the protection control method of the electric drive system according to any one of the first aspect when executing the computer program stored in the memory.

[0043] In a fourth aspect, the present application provides a computer readable storage medium, storing a computer program, wherein the computer program is executable by a processor to implement the protection control method of the electric drive system according to any one of the first aspect.

[0044] In summary, the application obtains temperature data of the same type of components in the front drive system and the rear drive system, identifies an abnormal drive system based on the temperature data and a threshold value, and determines a corresponding control strategy according to a target protection level. The application realizes a graded and progressive over-temperature protection, can intervene in advance by reducing the torque output at the initial stage of temperature anomaly, avoids vehicle stall caused by direct power cut-off, prevents the problem of field weakening temperature rise caused by passive rotation in four-wheel drive mode through the matching of multiple temperature thresholds and protection levels, and combines a dynamic speed limit strategy, effectively prevents the problem of field weakening temperature rise caused by passive rotation in four-wheel drive mode, and adjusts the flow of the liquid cooling system or the cooling circuit shunt according to the protection level, improves the thermal management efficiency, balances the power performance and driving experience of the vehicle to the greatest extent on the premise of ensuring the safety of the electric drive system. BRIEF DESCRIPTION OF DRAWINGS

[0045] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are merely illustrative and are not intended to be limiting upon the scope of the present description. Moreover, the same reference numerals are intended to refer to same components throughout the drawings. In the drawings:

[0046] Figure 1 A protection control method flowchart of an electric drive system provided by an embodiment of the application;

[0047] Figure 2 A protection control device structure schematic diagram of an electric drive system provided by an embodiment of the application;

[0048] Figure 3 A protection control device structure schematic diagram of an electric drive system provided by an embodiment of the application. DETAILED DESCRIPTION

[0049] The terms "first", "second", "third", "fourth" and the like in the description and claims of the application and in the above drawings, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the use of these terms in the description and the claims of the application is merely intended to distinguish the various features or aspects of the embodiments from each other and is not intended to limit the scope of each embodiment to the features or aspects being described. It will be further understood that the scope of the application is not limited to the embodiments described but can be practiced with modification and alteration within the scope and spirit of the appended claims. Furthermore, the above-mentioned description and the following description of the embodiments of the application are merely intended to illustrate the technical solutions of the application and not to limit the scope of the application. The scope of the application is defined by the appended claims.

[0050] Please refer to Figure 1 A protection control method flowchart of an electric drive system is provided for the embodiments of the present application. The electric drive system includes a front drive system and a rear drive system, and specifically can include:

[0051] S110, acquiring first temperature data of a first target component in the front drive system and second temperature data of a second target component in the rear drive system, wherein the first target component and the second target component are of the same component type;

[0052] For example, the thermal failure risk of the electric drive system mainly focuses on two core components, power semiconductors (such as IGBT modules, Insulated Gate Bipolar Transistor Modules) and motor windings. The IGBT module, as the core switching device of the motor controller, generates concentrated heat due to switching loss under high load conditions; the motor winding forms a distributed heat source due to the current Joule effect. Abnormal temperature rise of both will directly lead to insulation aging, magnetic performance decay, and even permanent damage. Therefore, this step locates the thermal risk source by synchronously collecting temperature data of target components (such as IGBT or winding) of the same type in the front drive system and the rear drive system.

[0053] In four-wheel drive mode, the front drive system and the rear drive system work independently in a mechanically decoupled but electrically coupled state. Over-temperature of either system may trigger a passive field weakening temperature vicious cycle due to continuous driving of the other system (such as a faulty bridge being dragged to rotate to the field weakening speed by a healthy bridge). Traditional single-point monitoring cannot distinguish the abnormal heat source belonging to the drive bridge, and this step provides a data basis for subsequent identification of the specific fault drive system (front or rear) by independently acquiring temperature data of the double systems and associating the component type, which is the primary condition for blocking the four-wheel drive thermal runaway chain.

[0054] S120, identifying a target drive system with temperature abnormality based on the first temperature data, the second temperature data, and a first temperature threshold;

[0055] For example, in a four-wheel electric drive system, the first temperature threshold (T1) serves as a basic warning threshold, which is set based on the temperature boundary (such as the lower limit of the safe working temperature of the IGBT module or the motor winding) when the electric drive system is normally running. When the acquired first temperature data of the front drive system or the second temperature data of the rear drive system exceeds T1, it indicates that the core component of the corresponding drive system has entered the temperature abnormality interval. This judgment logic compares the real-time temperature data with the preset safety threshold, realizes the preliminary positioning of the abnormal drive system, and provides a trigger condition for the subsequent hierarchical protection strategy.

[0056] Because the front drive system and the rear drive system are independent in mechanical structure but coupled in power transmission in the four-wheel drive mode, if the temperature of a single drive system is not identified in time, passive rotation may be caused by the continuous operation of the other system. When the abnormal drive system is identified, a protection mechanism can be started to avoid the passive field weakening temperature rise caused by the failure to locate the fault source in time. This abnormal identification based on the temperature threshold value ensures the accuracy and timeliness of fault location through independent comparison of the temperature data of the two systems, and is the core prerequisite for realizing the hierarchical protection.

[0057] In S130, a target protection level of the target drive system is determined based on the target temperature data of the target drive system and a preset temperature threshold value, where the target temperature data of the target drive system is the first temperature data of the front drive system or the second temperature data of the rear drive system.

[0058] For example, in the protection control logic of the electric drive system, the preset temperature threshold value is designed in three levels (a first temperature threshold value T1, a second temperature threshold value T2, and a third temperature threshold value T3, and T3>T2>T1), corresponding to the first to third protection levels. This hierarchical mechanism is set based on the thermal tolerance characteristics of the core components of the electric drive system (such as IGBT modules and motor windings). T1 is used as a warning threshold value, corresponding to the temperature of the component starting to deviate from the safe interval. T2 is used as a secondary protection threshold value, corresponding to the thermal stress of the component close to the critical value. T3 is used as an emergency protection threshold value, corresponding to the risk of thermal failure of the component. By comparing the real-time temperature data of the target drive system with the three threshold values, the severity level of the current temperature abnormality can be determined.

[0059] In the four-wheel drive mode, the determination of the target protection level combines the dual dimensions of temperature absolute value and thermal risk trend: when the target temperature is in the interval [T1, T2), it is determined as a preliminary warning (the first protection level) to avoid premature power cut-off; when the temperature enters the interval [T2, T3), it is upgraded to the second protection level to balance the safety intervention and the vehicle endurance; when the temperature is greater than or equal to T3 and the temperature change rate exceeds a preset threshold value, the third emergency protection is triggered, at which time the component temperature has shown an out-of-control trend. This hierarchical mechanism provides protection strength matching the degree of temperature crisis through gradual threshold matching, and avoids the defects of the non-gradual protection logic of the traditional single threshold strategy, and can also address the passive field weakening temperature rise risk that may occur in the four-wheel drive system.

[0060] In S140, a control strategy corresponding to the target drive system is determined according to the target protection level.

[0061] Exemplarily, in the protection control system of the electric drive system, the target protection level is in a gradient mapping relationship with the control strategy, and the protection strength is dynamically matched according to the severity of the temperature anomaly. After determining the protection level of the target drive system, the control strategy needs to balance the heat risk suppression, power performance adjustment and driving safety. For the passive field weakening temperature risk that may occur in the four-wheel drive mode, a hierarchical strategy is needed to block the heat runaway chain.

[0062] The first protection level (primary warning) corresponds to the temperature preliminary abnormal interval, and the control strategy takes the dynamic derating torque output as the core, maintains the basic driving ability of the vehicle by reserving part of the power output, and reduces the thermal load at the same time; when the second protection level (secondary protection) is triggered, the target drive system executes zero torque output and limits the maximum vehicle speed, at this time the speed limit value needs to be set to meet the passive speed lower than the field weakening speed under the standard voltage working condition of the power battery, so as to fundamentally avoid the generation of field weakening current; the third protection level (emergency protection) adopts the most stringent speed limiting measure, sets a lower speed limit value in combination with the minimum voltage working condition of the power battery, and cooperates with the flow regulation of the liquid cooling system or the cooling loop shunt, to prevent component thermal failure through multi-dimensional thermal management means. This hierarchical control strategy not only guarantees the safety of the electric drive system, but also maximizes the impact on the driving experience.

[0063] In summary, the embodiment of the present application obtains the temperature data of the same type target components in the front drive system and the rear drive system, identifies the target drive system with temperature anomaly based on the temperature data and the first temperature threshold, determines the target protection level according to the temperature data of the target drive system and the preset multi-level temperature threshold, and then adopts the corresponding control strategy according to different protection levels, realizing the graded and progressive over-temperature protection. The torque output can be intervened in advance at the initial stage of temperature anomaly to avoid vehicle stall caused by direct power cut-off; through the matching of multi-level temperature threshold and protection level, in combination with the dynamic speed limiting strategy set according to the voltage working condition of the power battery, the passive rotating speed of the target drive system is ensured to be lower than the field weakening speed, effectively preventing the field weakening temperature rise problem caused by passive rotation in the four-wheel drive mode; at the same time, the liquid cooling system flow or the cooling loop shunt is adjusted according to the protection level, and the preset temperature threshold is dynamically compensated and corrected according to the environmental temperature, improving the thermal management efficiency, balancing the power performance and driving experience of the vehicle to the greatest extent on the premise of ensuring the safety of the electric drive system.

[0064] In some examples, obtaining the first temperature data of the first target component in the front drive system and the second temperature data of the second target component in the rear drive system includes:

[0065] Obtaining a first monitoring point set of the first target component of the front drive system;

[0066] Collecting the current temperature data of each monitoring point in the first monitoring point set to generate a first temperature data set;

[0067] performing a maximum value screening operation on the first temperature data set, and taking the maximum current temperature data in the first temperature data set as the first temperature data;

[0068] obtaining a second set of monitoring points of a second target component of the rear drive system;

[0069] collecting current temperature data of each monitoring point in the second set of monitoring points to generate a second temperature data set;

[0070] performing a maximum value screening operation on the second temperature data set, and taking the maximum current temperature data in the second temperature data set as the second temperature data.

[0071] For example, in the thermal safety monitoring of the electric drive system, the key heat generating areas of the target component need to be covered by the preset monitoring points. For the front drive system, based on the physical structure and thermal distribution characteristics of the first target component (such as the chip hotspot area of the IGBT module or the end turn inter-turn area of the motor winding), a first set of monitoring points is defined in advance, which includes a plurality of physical monitoring positions arranged in the heat-sensitive area of the target component. Similarly, for the rear drive system, a second set of monitoring points is defined on the second target component according to the same selection logic as the first target component (such as the same thermal simulation model or failure analysis data). The monitoring point position and quantity are calibrated through component thermal simulation and accelerated aging test to ensure that the temperature extreme value area under the most severe working condition is covered.

[0072] Through the temperature sensors deployed at each monitoring point (such as the built-in NTC sensor for IGBT modules and the embedded thermocouple for motor windings), the current temperature data of each physical position in the first set of monitoring points is collected in real time. The sampling frequency is not less than 20 Hz to meet the transient temperature rise capture requirement. The multi-point data collected at the same time are classified according to the drive system to generate the first temperature data set of the front drive system; the second set of monitoring point data is collected synchronously to generate the second temperature data set of the rear drive system. The data set is stored in sequence according to the time stamp to provide original temperature data for subsequent processing.

[0073] Performing a maximum value screening operation on the generated first temperature data set, traversing the current temperature values of all monitoring points in the data set, and extracting the temperature point data with the maximum value as the first temperature data of the front drive system. This operation uses a real-time comparison algorithm to ensure that the output value is the highest local temperature of the target component of the front drive system at the current time. Similarly, the same maximum value screening logic is performed on the second temperature data set to output the second temperature data of the rear drive system. This design is based on the principle that the local hot spot determines the system risk, avoiding the concealment of key overheating points due to averaging processing, and ensuring that there is no missed detection of over-temperature risk.

[0074] It should be noted that the purpose of the maximum value screening strategy of the embodiment of the present application is to trigger the thermal failure of the electric drive system from the weakest point of the component (such as the junction temperature of the IGBT chip or the temperature of the winding insulation layer). By independently processing the data set of the dual-drive system and taking the temperature extreme value in each system as the representative value, the real thermal state of each system can be accurately reflected. The data acquisition process introduces a redundancy checking mechanism. If the temperature difference between the main and standby sensors of the same component exceeds 5℃, the system automatically switches to the standby data source and triggers fault diagnosis. The sampling frequency and the checking mechanism cooperate to ensure the real-time and reliability of the temperature data, and provide accurate input for abnormal system identification.

[0075] In summary, the embodiment of the present application solves the problem of easy omission of local overheating in traditional single-point monitoring through multi-point monitoring, high-frequency sampling and maximum value screening strategy, and ensures the accuracy and reliability of temperature data. On the one hand, multi-point collection based on the set of monitoring points can comprehensively cover the temperature distribution of the component, avoiding misjudgment caused by sensor arrangement deviation; on the other hand, the maximum value screening operation can accurately capture the highest temperature of the component, providing key data support for subsequent abnormal identification based on temperature threshold, protection level determination and control strategy execution, thereby effectively blocking the passive field weakening temperature rise risk caused by inaccurate temperature monitoring in four-wheel drive mode, and improving the safety and reliability of the electric drive system thermal management.

[0076] In some examples, the target drive system includes a front drive system or a rear drive system, and identifying the target drive system having a temperature abnormality based on the first temperature data, the second temperature data, and the first temperature threshold includes:

[0077] When the first temperature data is greater than or equal to the first temperature threshold, determining that the front drive system is the target drive system having a temperature abnormality; or,

[0078] When the second temperature data is greater than or equal to the first temperature threshold, determining that the rear drive system is the target drive system having a temperature abnormality.

[0079] Exemplarily, in the abnormality identification logic of the electric drive system, the first temperature threshold T1 is taken as a basic early warning threshold, the value of which is set based on the lower limit of the safe working temperature of the electric drive core components (such as IGBT modules or motor windings), and is calibrated by comprehensive marking of historical operation data and accelerated aging test. Specifically, T1 is usually set to be 10% to 20% higher than the peak temperature in normal working conditions, and the first temperature threshold T1 in the present application is set to 100°C to 120°C, so as to ensure that the early warning can be triggered when the temperature of the component begins to deviate from the safe interval. When the first temperature data of the front drive system obtained is greater than or equal to T1, it indicates that the target component of the front drive system has entered a temperature abnormal state; similarly, when the second temperature data of the rear drive system is greater than or equal to T1, it is determined that the rear drive system is an abnormal target system. This judgment logic realizes the preliminary positioning of the abnormal drive system through the direct comparison of real-time temperature data and the preset safety threshold, strictly follows the principle of independent judgment of the double systems, and ensures the accuracy of abnormal positioning.

[0080] In the four-wheel drive mode, the mechanically decoupled front drive system and rear drive system realize cooperative driving through electrical coupling. When a drive system is identified as a target drive system due to over-temperature, the system will immediately start the protection mechanism for the specific drive axle. This design directly blocks the vicious cycle caused by the failure to accurately locate the fault source in the traditional scheme, and the continuous operation of the healthy drive system drags the passive rotation of the fault system. Once the rotation speed of the fault system reaches the field weakening speed point, the controller will automatically inject field weakening current to cause additional heating (i.e. passive field weakening heating). By independently identifying the abnormal system and locking the protection target, this step provides accurate input for the subsequent hierarchical protection strategy, and fundamentally avoids the spread of thermal runaway risk.

[0081] In summary, the embodiments of the present application realize the accurate positioning and timely early warning of the fault drive system through the double-system independent comparison and threshold triggering mechanism. On the one hand, the setting of the T1 threshold ensures the early identification of abnormal temperature and avoids component damage caused by protection lag; on the other hand, for the characteristics of the four-wheel drive mode, the temperature states of the front drive system and the rear drive system are independently judged, which can effectively prevent the cross-axle thermal runaway problem caused by the abnormality of a single system. This identification method provides accurate trigger conditions for the subsequent hierarchical protection strategy, which not only guarantees the safe operation of the electric drive system, but also avoids the misjudgment or omission that may be caused by the traditional single threshold strategy, and improves the reliability and pertinence of the thermal management of the four-wheel drive system.

[0082] In some examples, the preset temperature threshold includes a first temperature threshold, a second temperature threshold, and a third temperature threshold, the third temperature threshold is greater than the second temperature threshold, and the second temperature threshold is greater than the first temperature threshold. The target protection level includes a first protection level, a second protection level, and a third protection level. The target protection level of the target drive system is determined based on the target temperature data of the target drive system and the preset temperature threshold, including:

[0083] determining that the target protection level of the target drive system is the first protection level when the target temperature data is greater than or equal to the first temperature threshold and less than the second temperature threshold;

[0084] determining that the target protection level of the target drive system is the second protection level when the target temperature data is greater than or equal to the second temperature threshold and less than the third temperature threshold;

[0085] determining that the target protection level of the target drive system is the third protection level when the target temperature data is greater than or equal to the third temperature threshold and the temperature change rate of the target drive system is greater than or equal to the preset change rate threshold.

[0086] Exemplarily, in the protection control method of the electric drive system, the preset temperature threshold is designed in a three-level gradient, including a first temperature threshold (T1), a second temperature threshold (T2), and a third temperature threshold (T3), where the third temperature threshold is greater than the second temperature threshold, and the second temperature threshold is greater than the first temperature threshold (T3>T2>T1). The target protection level is divided into a first protection level, a second protection level, and a third protection level. The target protection level of the target drive system is determined by the following logic.

[0087] The first temperature threshold (T1) is used as a warning threshold, and the setting basis is that the historical peak temperature (for example, 90°C) of the electric drive system under normal working conditions is floated by 10% to 20% (i.e., the calibration range is 100°C to 120°C). When the target temperature data of the target drive system reaches or exceeds the first temperature threshold but is lower than the second temperature threshold (T1≤target temperature data<T2), it is determined that the target protection level is the first protection level. This stage indicates that the target drive system starts to have temperature abnormalities, but has not yet reached a high-risk state, and needs to start primary intervention measures.

[0088] The second temperature threshold (T2) is used as a protection threshold, and the setting reference is that the junction temperature limit (150°C) of the core components (such as IGBT modules) of the electric drive system is reserved by 10% safety margin (i.e., the calibration range is 130°C to 140°C), and is verified by accelerated aging test. When the target temperature data reaches or exceeds the second temperature threshold but is lower than the third temperature threshold (T2≤target temperature data<T3), it is determined that the target protection level is the second protection level. This stage indicates that the thermal stress of the target drive system is close to the critical value, and the protection strength needs to be upgraded to block the temperature rise trend.

[0089] The third temperature threshold (T3) is set as an emergency protection threshold, which is inversely deduced (the calibration range is 145-155°C) through a thermal failure experiment (such as the carbonization temperature of insulating material ≥160°C). When the target temperature data reaches or exceeds the third temperature threshold (target temperature data ≥ T3) and the temperature change rate (the amount of temperature change per unit time) of the target drive system reaches or exceeds the preset change rate threshold (3°C / s), it is determined that the target protection level is the third protection level. The introduction of the temperature change rate threshold solves the problem of too fast temperature rise rate under transient operating conditions (such as sudden acceleration). If the temperature change rate does not exceed the threshold, the second protection is maintained to avoid excessive intervention.

[0090] In summary, the embodiments of the present application realize fine management of electric drive system thermal protection through progressive threshold matching and dynamic risk assessment. On the one hand, the three-level threshold design gradually strengthens the protection measures with the degree of temperature abnormality, avoiding premature intervention affecting the driving experience, and at the same time, strengthening the protection in time when the temperature is critical. On the other hand, the temperature change rate is introduced as the trigger condition of the third protection level, which can dynamically predict the over-temperature risk and move the protection logic forward. Through the hierarchical protection mechanism, the safety and power performance are accurately balanced, and at the same time, the hierarchical trigger conditions are provided for subsequent strategies such as liquid cooling system cooperative control and dynamic speed limit, improving the reliability and flexibility of electric drive system thermal management.

[0091] In some examples, according to the target protection level, a control strategy corresponding to the target drive system is determined, including:

[0092] When the target protection level is the first protection level, the maximum output torque of the target drive system is calculated based on the target temperature data, the first temperature threshold and the second temperature threshold; and the target drive system is controlled to perform a derated torque output operation based on the maximum output torque;

[0093] When the target protection level is the second protection level, the target drive system is controlled to perform a zero-torque output operation and the highest vehicle speed of the whole vehicle is determined as a first target speed, wherein the first target speed satisfies that the passive rotating speed of the target drive system is lower than the field weakening speed of the target drive system under the standard voltage condition of the power battery;

[0094] When the target protection level is the third protection level, the target drive system is controlled to perform a zero-torque output operation and the highest vehicle speed of the whole vehicle is determined as a second target speed, wherein the second target speed satisfies that the passive rotating speed of the target drive system is lower than the field weakening speed of the target drive system under the minimum voltage condition of the power battery, and the first target speed is greater than the second target speed.

[0095] For example, when the target protection level is the first protection level, the maximum output torque of the target drive system is calculated based on the target temperature data (denoted as t) of the target drive system, the first temperature threshold (T1) and the second temperature threshold (T2). The specific calculation formula is maximum output torque = (second temperature threshold - current temperature) / (second temperature threshold - first temperature threshold) x rated torque. The essence of this calculation is to linearly reduce the maximum torque of the allowed output according to the relative position of the current temperature within the interval of T1 and T2. For example, if T1 = 100℃, T2 = 140℃, the current temperature t = 120℃, the maximum output torque is (140-120) / (140-100) x 100% = 50% rated torque. Based on the calculation result, the motor controller of the target drive system performs the derated torque output operation, that is, limits its actual output torque to not more than the maximum output torque value calculated. The healthy drive system still maintains full torque output in this stage, ensuring that the vehicle maintains basic driving ability, while suppressing the temperature rise trend by actively reducing the load of the faulty system.

[0096] When the target protection level is the second protection level, the target drive system is controlled to perform zero torque output operation, that is, the output torque of the target drive system is forced to zero through the motor controller. At the same time, the highest vehicle speed of the whole vehicle is determined as the first target vehicle speed (V1). The setting of V1 must strictly meet the following conditions: under the standard voltage condition of the power battery (typical working voltage when the battery temperature is greater than or equal to 25℃ and the SOC is 10%), the passive rotating speed of the target drive system caused by the healthy drive system dragging must be lower than its field weakening speed. The field weakening speed is obtained by experimental calibration, that is, the base speed point when the back electromotive force is equal to the standard voltage of the battery is determined by measuring the back electromotive force curve of the motor; the field weakening control parameters are adjusted to calibrate the speed point with the best field weakening effect. If the calibrated field weakening speed is 6000 rpm, the transmission ratio is 9:1, V1 must satisfy the converted vehicle speed ≤ (6000 ÷ 9) x tire circumference x 0.06 km / h (to ensure that the passive speed < 6000 rpm), wherein the field weakening speed divided by the transmission ratio represents the conversion of the motor speed to the wheel speed (assuming the transmission ratio is 9, that is, the motor rotates 9 times and the wheel rotates 1 time), x tire circumference represents the distance traveled by the wheel per revolution (unit: meters), x 0.06 represents the unit conversion factor (1 hour = 60 minutes, 1 kilometer = 1000 meters). This speed limit strategy avoids the generation of passive field weakening current from the root, and blocks the heat runaway chain.

[0097] When the target protection level is the third protection level, the target drive system is also controlled to perform a zero-torque output operation, and the highest vehicle speed of the whole vehicle is determined as a second target vehicle speed (V2). The setting condition of V2 is more stringent than that of V1. Under the condition of the minimum voltage of the power battery (the minimum working voltage under low temperature or low SOC of the battery), the passive rotating speed of the target drive system must be lower than the field weakening speed thereof. Since the field weakening speed point will decrease when the battery voltage decreases (the lower the voltage, the greater the current under the same power, and the field weakening control will intervene earlier), V2 needs to recalibrate the field weakening speed according to the minimum voltage. For example, the field weakening speed is reduced to 4500 rpm under the condition of the minimum voltage, and then V2 needs to satisfy the condition that the converted vehicle speed is less than or equal to (4500 ÷ 9) × tire circumference × 0.06 km / h. At this time, the first target vehicle speed (V1) is greater than the second target vehicle speed (V2), for example, V1 = 60 km / h and V2 = 30 km / h. This design ensures that the risk of passive field weakening temperature rise can be blocked under the most adverse conditions.

[0098] In summary, the embodiment of the present application effectively solves the problem of passive field weakening temperature rise in four-wheel drive mode through a hierarchical and gradual intervention mechanism. The dynamic derated torque output of the first protection level avoids power interruption in the initial stage of temperature anomaly, ensuring driving continuity. The second protection level combines zero-torque output and speed limit V1 based on the standard voltage condition, completely blocking the passive field weakening temperature rise path in most scenarios. The third protection level uses the limit speed V2 under the condition of the minimum voltage, covering the most adverse conditions of battery voltage fluctuation, ensuring that there is no loophole in thermal runaway protection. Through the cooperation of three-level protection and dynamic speed limit, this strategy not only prevents cross-axle thermal runaway caused by single drive system anomaly, but also balances safety and driving experience through gradient power limitation. Compared with the traditional single threshold protection strategy, the reliability of the electric drive system thermal management is improved.

[0099] In some examples, further comprising:

[0100] When the target protection level is the second protection level and the liquid cooling system is effective, a target flow value of the liquid cooling system is determined based on a preset flow gain coefficient and a current flow value of the liquid cooling system; and a speed regulation operation of the liquid cooling pump is controlled based on the target flow value, so that the current flow value of the liquid cooling system is increased to the target flow value.

[0101] When the target protection level is the third protection level and the liquid cooling system is ineffective, a target shunt value of the battery cooling loop is calculated based on a preset shunt ratio; and an opening adjustment operation of the three-way valve of the battery cooling loop is controlled based on the target shunt value, so that the battery cooling loop distributes the cooling liquid to the target electric drive system at the preset shunt ratio.

[0102] For example, when the target protection level is determined as the second protection level (corresponding to the temperature reaching the second temperature threshold T2) and the liquid cooling system is operating normally, the liquid cooling system is executed to enhance heat dissipation. First, the target flow value is calculated based on the preset flow gain coefficient (the calibration range is 20% to 30%) and the current flow measured value of the liquid cooling system. Specifically, the target flow value = current flow value x (1 + preset flow gain coefficient). For example, if the current flow is 10 L / min and the gain coefficient is 25%, the target flow value is 12.5 L / min. Second, based on the calculated target flow value, the driving voltage or PWM duty cycle of the liquid cooling pump is adjusted to control the speed of the liquid cooling pump to increase, so that the actual flow value of the liquid cooling system reaches the target flow value. If the ambient temperature is lower than -10℃, the PTC heater is triggered to preheat the coolant to prevent the viscosity from increasing at low temperature, which affects the flowability. This process is calibrated in real time through the closed-loop flow sensor to ensure the accuracy of the flow increase.

[0103] When the target protection level is upgraded to the third protection level (temperature ≥ third temperature threshold T3 and temperature change rate ≥ 3℃ / s) and the liquid cooling system is detected to be invalid (the flow value fed back by the flow sensor for 3 seconds < 50% of the rated value), the battery cooling circuit shunting mechanism is enabled. First, the target shunt flow value of the battery cooling circuit is calculated based on the preset shunt ratio (calibrated as 1:1). The target shunt flow value = the current total flow of the battery cooling circuit x the preset shunt ratio. For example, if the total flow of the battery circuit is 8 L / min, the target shunt flow value is 4 L / min. Second, the three-way valve opening degree at the connection between the battery cooling circuit and the electric drive cooling circuit is adjusted to control the shunt flow, and based on the mapping relationship between the target shunt flow value and the valve flow characteristic curve, the target opening angle of the three-way valve is determined; the actual opening of the three-way valve is adjusted to the target opening angle through the motor drive unit, so that the battery cooling circuit distributes the coolant flow to the target electric drive system (i.e. the drive system with temperature anomaly) at a ratio of 1:1.

[0104] It should be noted that the three-way valve is connected to the output end of the battery cooling circuit, the main circulating pipeline of the electric drive cooling circuit and the heat dissipation interface of the target electric drive system, forming three fluid conveying paths, the first input end is connected to the coolant output pipeline of the battery cooling circuit, the second input end is connected to the main circulating output pipeline of the electric drive cooling circuit, and the output end is connected to the heat sink inlet of the target electric drive system (i.e. the drive system with temperature anomaly) through a branch pipeline; when the shunting operation is triggered, the three-way valve rotates the valve core angle, so that the coolant in the output end of the battery cooling circuit flows to the target electric drive system at a preset shunt ratio (1:1) through the output end, while the path of the electric drive cooling circuit main circulation to the target system is blocked, and the coolant circulation of the healthy drive system in the electric drive cooling circuit is not affected, so that the battery cooling circuit realizes directional emergency heat dissipation for the fault drive system when the liquid cooling fails.

[0105] The environmental temperature dynamic compensation is introduced in the operation of the liquid cooling system. The environmental temperature data in the electric drive cabin is acquired in real time before the speed of the liquid cooling pump is adjusted. If the environmental temperature is less than -10°C, a preheating instruction is sent to the PTC heater before the flow rate increasing instruction is issued, so that the cooling liquid temperature is raised to more than 5°C, thereby avoiding the decrease of the flowability of the cooling liquid caused by low temperature and affecting the heat dissipation efficiency. The environmental temperature data is collected by the NTC sensor arranged in the electric drive cabin, the sampling frequency is 1 Hz, and the data is used for decision-making after being filtered by the sliding average.

[0106] In summary, the embodiment of the application improves the robustness and safety of the thermal management of the electric drive system through the hierarchical collaborative control of the liquid cooling system. In the second protection level, the liquid cooling flow rate is increased by a preset gain coefficient, directly enhancing the heat dissipation intensity of the faulty system and inhibiting the temperature rise rate; in combination with the PTC preheating mechanism triggered by the environmental temperature, the negative impact of low temperature on the flowability is eliminated, and the heat dissipation efficiency is guaranteed. In the extreme scenario of the third protection level and liquid cooling failure, the cooling liquid is diverted by the battery cooling circuit in a 1:1 ratio to provide an emergency cooling path for the faulty system, thereby avoiding thermal runaway. The closed-loop control of the flow rate and the valve opening degree ensures the operation accuracy, and the liquid cooling failure determination logic combined with multiple parameters effectively prevents false triggering. Ultimately, the collaborative mechanism enables the electric drive system to maintain the thermal safety boundary under multiple risk working conditions such as high temperature and liquid cooling failure, thereby providing key heat dissipation protection for the hierarchical protection strategy.

[0107] In some examples, further comprising:

[0108] Acquiring environmental temperature data of the electric drive system;

[0109] Based on the environmental temperature data, dynamically compensating and correcting the preset temperature threshold to generate a compensated temperature threshold;

[0110] Based on the target temperature data of the target drive system and the compensated temperature threshold, determining a target protection level of the target drive system.

[0111] Exemplary, through the ambient temperature sensor deployed in the electric drive cabin, the ambient temperature data of the electric drive system is collected in real time, the sampling frequency is 1Hz, and the data is processed by sliding average filtering to eliminate transient interference. Based on the ambient temperature data, the preset temperature threshold is dynamically compensated and corrected, when the ambient temperature exceeds the preset high temperature threshold (such as 35℃), due to the decrease of heat dissipation efficiency, the first temperature threshold (T1), the second temperature threshold (T2) is corrected downward by the preset temperature compensation value (3℃ to 5℃), and the compensated temperature threshold is generated. The specific correction formula is compensated temperature threshold = original temperature threshold - preset temperature compensation value. For example, if the original T1 = 110℃, the ambient temperature is 40℃, and the compensated T1' = 107℃ (taking the compensation value of 3℃). On the contrary, when the ambient temperature is lower than the preset low temperature threshold (such as-10℃), due to the decrease of the flowability of the cooling liquid, T1 and T2 are corrected upward by the same compensation value (such as T1' = 113℃). The size of the compensation value is determined by thermal simulation calibration, and the compensation value increases by 1℃ for every 10℃ increase in high temperature environment, and the compensation value increases by 1℃ for every 15℃ decrease in low temperature environment.

[0112] Based on the generated compensated temperature threshold (T1', T2', T3 remains unchanged), the protection level determination logic is re-executed, and the target temperature data of the target drive system is compared with the compensated threshold. If the target temperature data is ≥T1' and <T2', it is determined as the first protection level; if ≥T2' and <T3, it is the second protection level; if ≥T3 and the temperature change rate is ≥3℃ / s, it is the third protection level. This process automatically triggers threshold update when the ambient temperature changes more than 2℃ each time, ensuring that the protection triggering condition always matches the current heat dissipation environment.

[0113] Please refer to Figure 2 A protection control device structure diagram of an electric drive system is provided for the embodiments of the application, the electric drive system includes a front drive system and a rear drive system, which includes:

[0114] The temperature data acquisition unit 21 is configured to acquire first temperature data of a first target component in the front drive system and second temperature data of a second target component in the rear drive system, wherein the first target component and the second target component are of the same type of component.

[0115] The abnormal system identification unit 22 is configured to identify the target drive system with temperature abnormality based on the first temperature data, the second temperature data and the first temperature threshold.

[0116] The protection level determination unit 23 is configured to determine the target protection level of the target drive system based on the target temperature data of the target drive system and the preset temperature threshold, wherein the target temperature data of the target drive system is the first temperature data of the front drive system or the second temperature data of the rear drive system.

[0117] The control strategy execution unit 24 is configured to determine a control strategy corresponding to the target drive system according to the target protection level.

[0118] Please refer to Figure 3 The embodiment of the present application further provides an electronic device 300, which comprises a memory 310, a processor 320, and a computer program 311 stored in the memory 310 and capable of running on the processor, and the processor 320 implements the steps of the protection control method of the electric drive system when executing the computer program 311.

[0119] Since the electronic device introduced in the embodiment is the device used by the protection control device of the electric drive system in the embodiment of the present application, the specific implementation of the electronic device in the embodiment and various changes thereof can be understood by the person skilled in the art based on the method introduced in the embodiment of the present application, and therefore, how the electronic device implements the method in the embodiment of the present application is not described in detail here, as long as the device used by the person skilled in the art to implement the method in the embodiment of the present application belongs to the scope of the present application.

[0120] In the specific implementation process, the computer program 311 can implement any implementation manner in the embodiment of the first aspect when executed by the processor.

[0121] It should be noted that in the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0122] Those skilled in the art should understand that the embodiments of the present application can provide methods, systems or computer program products. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer readable storage media containing computer readable program codes.

[0123] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system) and computer program product according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded computer or other programmable data processing devices to produce a machine, so that the instructions executed by the computer or other programmable data processing devices produce a device for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 The device for implementing the functions specified in one flow or multiple flows and / or blocks. Figure 1 The device for implementing the functions specified in one flow or multiple flows and / or blocks.

[0124] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flow Figure 1 one or more flow or block Figure 1 one or more flow or block

[0125] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions executed on the computer or other programmable apparatus provide steps for implementing the flow Figure 1 one or more flow or block Figure 1 one or more flow or block

[0126] The embodiments of the present application also provide a computer program product, which comprises computer software instructions, when the computer software instructions are run on a processing device, the processing device executes the flow Figure 1 of the protection control method of the electric drive system in the corresponding embodiments.

[0127] The computer program product comprises one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of the present application is produced. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired or wireless means. The computer readable storage medium can be any available medium that the computer can store or be integrated into a data storage device such as a server, data center, etc. containing one or more available media sets. The available media can be magnetic media, optical media or semiconductor media, etc.

[0128] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0129] In several embodiments provided in the present application, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other manners. For example, the embodiments of the apparatus described above are merely schematic. For example, the division of the units is only a logical function division. There can be another division manner for the actual implementation, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between the units can be indirect couplings or communication connections through some interfaces, devices or units, and can be electrical, mechanical or in other forms.

[0130] The units described as separated components can or can not be physically separated, and the components displayed as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purposes of the embodiments of the present application.

[0131] In addition, each functional unit in the embodiments of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The integrated unit can be in the form of hardware and / or software function unit.

[0132] If the integrated unit is in the form of software function unit and is sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such an understanding, the technical solutions of the present application essentially or the part contributing to the prior art or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes several instructions for causing a computer device to perform all or part of the steps of the methods in the embodiments of the present application. The foregoing storage medium includes: U disk, mobile hard disk, read-only memory, magnetic disk or optical disk, and various other media that can store program codes.

[0133] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and these modifications or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

[0134] Although the preferred embodiments of this specification have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of this specification.

[0135] Obviously, those skilled in the art may make various changes to this specification without departing from the spirit and scope of this specification. Thus, if such changes to this specification fall within the scope of the claims and their equivalents, this specification is intended to include such changes.

Claims

1. A protection and control method for an electric drive system, wherein the electric drive system includes a front drive system and a rear drive system, characterized in that: include: Acquiring first temperature data of a first target component in the front drive system and second temperature data of a second target component in the rear drive system, wherein the first target component and the second target component are of the same component type; identifying a target drive system having a temperature abnormality based on the first temperature data, the second temperature data, and a first temperature threshold; determining a target protection level of the target drive system based on target temperature data of the target drive system and a preset temperature threshold, wherein the target temperature data of the target drive system is the first temperature data of the front drive system or the second temperature data of the rear drive system; A control strategy corresponding to the target drive system is determined according to the target protection level.

2. The method according to claim 1, characterized in that The acquiring first temperature data of a first target component in the front drive system and second temperature data of a second target component in the rear drive system includes: Acquire a first monitoring point set of the first target component of the front drive system; Collecting current temperature data of each monitoring point in the first monitoring point set to generate a first temperature data set; performing a maximum value screening operation on the first temperature data set, and taking the maximum current temperature data in the first temperature data set as the first temperature data; Acquire a second monitoring point set of the second target component of the rear drive system; Collecting current temperature data of each monitoring point in the second monitoring point set to generate a second temperature data set; A maximum value screening operation is performed on the second temperature data set, and the maximum current temperature data in the second temperature data set is used as the second temperature data.

3. The method according to claim 1, characterized in that The target drive system includes the front drive system or the rear drive system, and identifying the target drive system having a temperature abnormality based on the first temperature data, the second temperature data, and the first temperature threshold includes: When the first temperature data is greater than or equal to the first temperature threshold, determining that the front drive system is a target drive system with a temperature abnormality; or, When the second temperature data is greater than or equal to the first temperature threshold, the rear drive system is determined to be a target drive system with abnormal temperature.

4. The method according to claim 1, wherein The preset temperature threshold includes a first temperature threshold, a second temperature threshold, and a third temperature threshold, the third temperature threshold is greater than the second temperature threshold, and the second temperature threshold is greater than the first temperature threshold, the target protection level includes a first protection level, a second protection level, and a third protection level, and determining the target protection level of the target drive system based on the target temperature data of the target drive system and the preset temperature threshold includes: When the target temperature data is greater than or equal to the first temperature threshold and less than the second temperature threshold, determining that the target protection level of the target drive system is the first protection level; When the target temperature data is greater than or equal to the second temperature threshold and less than the third temperature threshold, determining that the target protection level of the target drive system is the second protection level; When the target temperature data is greater than or equal to the third temperature threshold and the temperature change rate of the target driving system is greater than or equal to a preset change rate threshold, the target protection level of the target driving system is determined to be the third protection level.

5. The method according to claim 4, characterized in that The determining, according to the target protection level, a control strategy corresponding to the target drive system includes: When the target protection level is the first protection level, calculating the maximum output torque of the target drive system based on the target temperature data, the first temperature threshold, and the second temperature threshold; Based on the maximum output torque, controlling the target drive system to perform a derated torque output operation; When the target protection level is the second protection level, controlling the target drive system to perform a zero torque output operation and determining the maximum vehicle speed to be a first target vehicle speed, wherein the first target vehicle speed satisfies that, under a standard power battery voltage operating condition, the passive rotation speed of the target drive system is lower than the field weakening speed of the target drive system; When the target protection level is the third protection level, the target drive system is controlled to perform zero torque output operation and the maximum vehicle speed is determined to be the second target speed, wherein the second target speed satisfies that under the minimum voltage operating condition of the power battery, the passive rotation speed of the target drive system is lower than the weak magnetic speed of the target drive system, and the first target speed is greater than the second target speed.

6. The method according to claim 4, characterized in that Also includes: When the target protection level is the second protection level and the liquid cooling system is valid, determining a target flow value of the liquid cooling system based on a preset flow gain coefficient and a current flow value of the liquid cooling system; Based on the target flow value, controlling the liquid cooling pump to perform a speed adjustment operation so that the current flow value of the liquid cooling system is increased to the target flow value; When the target protection level is the third protection level and the liquid cooling system fails, calculating a target diversion value for a battery cooling circuit based on a preset diversion ratio; Based on the target diversion value, the three-way valve of the battery cooling circuit is controlled to perform an opening adjustment operation so that the battery cooling circuit distributes coolant to the target electric drive system at the preset diversion ratio.

7. The method according to claim 1, characterized in that Also includes: Acquiring ambient temperature data of the electric drive system; Based on the ambient temperature data, dynamically compensating and correcting the preset temperature threshold to generate a compensated temperature threshold; A target protection level of the target driving system is determined based on the target temperature data of the target driving system and the compensation temperature threshold.

8. A protection and control device for an electric drive system, the electric drive system comprising a front drive system and a rear drive system, characterized in that: include: a temperature data acquisition unit, configured to acquire first temperature data of a first target component in the front drive system and second temperature data of a second target component in the rear drive system, wherein the first target component and the second target component are of the same component type; an abnormal system identifying unit, which identifies a target drive system having a temperature abnormality based on the first temperature data, the second temperature data, and a first temperature threshold; a protection level determining unit, configured to determine a target protection level of the target drive system based on target temperature data of the target drive system and a preset temperature threshold, wherein the target temperature data of the target drive system is the first temperature data of the front drive system or the second temperature data of the rear drive system; A control strategy execution unit is used to determine a control strategy corresponding to the target drive system according to the target protection level.

9. An electronic device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor is configured to implement the steps of the protection control method for an electric drive system as claimed in any one of claims 1 to 7 when executing the computer program stored in the memory.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the protection control method of the electric drive system according to any one of claims 1 to 7 is implemented.

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