Temperature control method and device of electric driving system, vehicle and storage medium

Abstract

The invention provides a temperature control method and device of an electric driving system, a vehicle and a storage medium. The method comprises the following steps: respectively acquiring resistance values and temperature change rates of a first temperature sensor arranged on a main drive motor and a second temperature sensor arranged on a main drive motor controller; when the resistance value of any temperature sensor meets a first preset condition or the temperature change rate of any temperature sensor meets a second preset condition, the power of the electric driving system is limited according to the control duration; and when the speed of the vehicle is smaller than the preset speed, the electric driving system is turned off. The output power of the electric driving system can be flexibly reduced, the reliability of the electric driving system is improved, and then the running safety of the vehicle is improved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a temperature control method, device, vehicle and storage medium for an electric drive system. Background Art

[0002] Electric vehicles have increasingly higher performance requirements, especially the power density requirements of electric drive systems. The most economical way to improve their power density is to make the electric drive system work in a reasonable temperature environment and control the electric drive system to work in a high-efficiency area to improve its working efficiency and ultimately increase the power density.

[0003] The electric drive system mainly includes the main drive motor and the main drive motor controller. Due to the temperature sensitivity of the IGBT set in the main drive motor controller, the temperature of the main drive motor controller must be monitored in real time during the operation of the main drive motor, and controlled according to the collected temperature to ensure that the main drive motor controller operates within the allowable temperature range. However, traditional temperature control is relatively simple, resulting in poor reliability of the electric drive system and low vehicle safety. Summary of the invention

[0004] Embodiments of the present invention provide a temperature control method, device, vehicle and storage medium for an electric drive system to solve the problem of low reliability of temperature control in the prior art.

[0005] In a first aspect, an embodiment of the present invention provides a temperature control method for an electric drive system, wherein a first temperature sensor is provided on a main drive motor in the electric drive system, and a second temperature sensor is provided on a main drive motor controller. The temperature control method for the electric drive system includes:

[0006] Respectively obtaining the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor;

[0007] When the resistance value of any temperature sensor meets the first preset condition, or the temperature change rate of any temperature sensor meets the second preset condition, the power of the electric drive system is limited according to the control time;

[0008] When the vehicle speed is less than a preset speed, the electric drive system is turned off.

[0009] In a possible implementation, when the resistance value of any temperature sensor meets the first preset condition, or the temperature change rate of any temperature sensor meets the second preset condition, limiting the power of the electric drive system according to the control time includes:

[0010] When the resistance value of any temperature sensor obtained in real time is infinite or zero for a preset time, or the temperature change rate of any temperature sensor is greater than or equal to a first temperature change rate threshold, the power of the electric drive system is limited according to the control time.

[0011] In a possible implementation manner, after respectively acquiring the resistance values ​​and the temperature change rates of the first temperature sensor and the second temperature sensor, the method further includes:

[0012] When the temperature change rate of any temperature sensor is less than a first temperature change rate threshold, the cooling system of the vehicle is controlled to be turned on according to the temperature of any temperature sensor, and the power of the electric drive system is linearly limited.

[0013] In a possible implementation, limiting the power of the electric drive system according to the control duration includes:

[0014] controlling the electric drive system to limit power to a first power within a first preset time period from the start of control, the first power being less than the power;

[0015] Controlling the electric drive system to limit power to a second power within a second preset time period from the start of control, wherein the second preset time period is greater than the first preset time period, and the second power is less than the first power;

[0016] The electric drive system is controlled to limit the vehicle speed to the preset vehicle speed within a third preset time period from the start of control, and the third preset time period is greater than the second preset time period.

[0017] In a possible implementation, controlling the vehicle cooling system to start according to the temperature of any one of the temperature sensors, and linearly limiting the power of the electric drive system, includes:

[0018] When the temperature of any temperature sensor is greater than or equal to the corresponding first temperature threshold, controlling the cooling system of the vehicle to start;

[0019] When the temperature of any of the temperature sensors is greater than or equal to a corresponding second temperature threshold, the power of the corresponding main drive motor or main drive motor controller is controlled to be linearly limited, and the second temperature threshold is greater than the first temperature threshold;

[0020] When the temperature of any temperature sensor is greater than or equal to the corresponding third temperature threshold, the corresponding main drive motor or main drive motor controller is controlled to stop power and a fault alarm is issued, and the third temperature threshold is greater than the second temperature threshold.

[0021] In a possible implementation, after controlling the vehicle's cooling system to start according to the temperature of any one of the temperature sensors and linearly limiting the power of the electric drive system, the method further includes:

[0022] When the temperature of any of the temperature sensors is less than or equal to a corresponding fourth temperature threshold, controlling the corresponding main drive motor or main drive motor controller to restore power to the power before the power limiting operation, the fourth temperature threshold being greater than the first temperature threshold and less than the second temperature threshold;

[0023] When the temperature of any temperature sensor is less than or equal to a corresponding fifth temperature threshold, the cooling system of the vehicle is controlled to be turned off, and the fifth temperature threshold is less than the first temperature threshold.

[0024] In a possible implementation manner, before respectively acquiring the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor, the method further includes:

[0025] The electronic fan in the cooling system of the vehicle is controlled to reverse for a preset time.

[0026] In a second aspect, an embodiment of the present invention provides a temperature control device for an electric drive system, wherein a first temperature sensor is provided on a main drive motor in the electric drive system, and a second temperature sensor is provided on a main drive motor controller, and the temperature control device for the electric drive system comprises:

[0027] An acquisition module, used to respectively acquire the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor;

[0028] A control module, configured to limit the power of the electric drive system according to a control duration when a resistance value of any temperature sensor meets a first preset condition or a temperature change rate of any temperature sensor meets a second preset condition;

[0029] The control module is also used to shut down the electric drive system when the vehicle speed is less than a preset speed.

[0030] In a third aspect, an embodiment of the present invention provides a vehicle, comprising a controller, the controller comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the steps of the temperature control method of the electric drive system as described in the first aspect or any possible implementation method of the first aspect.

[0031] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the temperature control method of the electric drive system as described in the first aspect or any possible implementation method of the first aspect are implemented.

[0032] The embodiment of the present invention provides a temperature control method, device, vehicle and storage medium for an electric drive system. The resistance value and temperature are collected by temperature sensors respectively arranged on a main drive motor and a main drive motor controller. When the resistance value of any temperature sensor meets a first preset condition, or the temperature change rate of any temperature sensor meets a second preset condition, the power of the electric drive system is limited according to the control time. When the vehicle speed is less than the preset speed, the electric drive system is shut down. Therefore, when the electric drive system is abnormal, power limitation can be performed according to the control time, the output power can be gradually reduced to reduce the vehicle speed, and when the vehicle speed is less than the preset speed, the electric drive system can be shut down again, thereby realizing flexible reduction of the output power of the electric drive system, improving the reliability of the electric drive system, and further improving the safety of vehicle operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 is a flow chart of a temperature control method for an electric drive system provided by an embodiment of the present invention;

[0035] Figure 2 is a schematic diagram of an electric drive system provided by an embodiment of the present invention;

[0036] Figure 3 is a schematic diagram of an electric drive system provided by another embodiment of the present invention;

[0037] Figure 4 is a schematic structural diagram of a temperature control device for an electric drive system provided by an embodiment of the present invention;

[0038] Figure 5 is a schematic diagram of a terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0041] Figure 1 The present invention provides a flow chart of a temperature control method for an electric drive system. The electric drive system includes a main drive motor and a main drive motor controller. The main drive motor controller is a motor control unit (MCU).

[0042] The main drive motor controller can be a separate controller or an integrated controller. The main drive motor controller and the auxiliary drive motor controller and other control units are integrated together, which is called an integrated controller or an all-in-one controller.

[0043] The main drive motor generally has a strong tolerance to temperature, but the main drive motor controller has a weak tolerance to temperature. The specifications of the controller's electronic components generally require that the cooling water temperature cannot be raised. Otherwise, the long-term high cooling water temperature will not only affect the controller's power output, but also the life of the main drive motor components. In theory, the main drive motor and the main drive motor controller work in their respective optimal temperature ranges, which is more effective. However, in order to improve the integration and lightweight of the vehicle's thermal management system, facilitate layout and installation in a limited space, and reduce the complexity of thermal management and vehicle costs, the entire electric drive system uses the same cooling system for centralized cooling.

[0044] like Figure 2 and Figure 3 In the schematic diagram of the electric drive system shown in the figure, the main drive motor is provided with a first temperature sensor, denoted as T1, which is generally provided inside the winding with higher heat generation; the main drive motor controller is provided with a second temperature sensor, denoted as T2, which is generally provided on the power module IGBT with higher heat generation. The electric drive system also includes a vehicle control unit (VCU), an electronic fan, an electronic fan controller, a cooling water pump, a cooling water pump controller, and a power supply for cooling the execution load. The cooling system mentioned below is a system consisting of an electronic fan, an electronic fan controller, a cooling water pump, and a cooling water pump controller.

[0045] Figure 2In the figure, the third temperature sensor set on the cooling water inlet pipe of the main drive motor controller is denoted as T3; the fourth temperature sensor set on the cooling water outlet pipe of the main drive motor controller is denoted as T4. The power supply of the cooling execution load is generally 24V, such as general electric commercial vehicles; but some electric passenger vehicles have a cooling execution load power supply of 12V.

[0046] The connection relationship between the devices is as follows: the main drive motor and the main drive motor controller are connected by a power harness, the four temperature sensors and the VCU are connected by a low-voltage acquisition harness, the main drive motor controller, the electronic fan controller and the cooling water pump controller are connected to the VCU by CAN communication lines, and each controller transmits the temperature signal to the VCU through the CAN communication line. The electronic fan controller and the cooling water pump controller are connected to the power supply by a power harness and a low-voltage acquisition harness respectively, and the electronic fan and the electronic fan controller, and the cooling water pump and the cooling water pump controller are connected by a low-voltage acquisition harness.

[0047] Among them, the power harness is represented by a dotted line, the low-voltage collection harness is represented by a black line, and the CAN communication line is represented by a thick black line.

[0048] Figure 3 In the example, the settings of T1 and T2 are the same as Figure 2 The same as in the figure, but T1 is connected to the main drive motor controller through a low-voltage acquisition harness or plug-in to transmit the temperature signal directly to the main drive motor controller. T3 and T4 are connected to the main drive motor controller through a low-voltage acquisition harness or plug-in to transmit the temperature signal directly to the main drive motor controller. The main drive motor controller transmits the temperature signals of T1, T2, T3 and T4 to the VCU through the CAN communication line. Figure 2 and Figure 3 The system architecture design and signal acquisition methods are different, but the control logic used is the same. The temperature control method of the electric drive system is performed by the VCU, as detailed below:

[0049] Step 101, respectively obtaining the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor.

[0050] The first temperature sensor and the second temperature sensor can collect temperature and resistance values ​​in real time according to the settings, and send the collected temperature and resistance values ​​to the VCU after processing. The VCU receives the resistance value and temperature sent by the first temperature sensor and the second temperature sensor in real time, and calculates the temperature change rate according to the temperature.

[0051] When calculating the temperature change rate here, the temperature change value collected at adjacent intervals is differentiated and the differential calculation result can be The temperature change is subsequently determined based on the temperature change rate.

[0052] In one embodiment, before respectively acquiring the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor, the method may further include:

[0053] Controls the electronic fan in the vehicle's cooling system to reverse for a preset time.

[0054] Each time the vehicle is started, the electronic fan is controlled to reverse at a preset speed to blow away debris on its surface in a reverse blowing manner to improve the heat dissipation effect of the electronic fan and improve the reliability of the cooling system. The electronic fan will stop working after a few seconds of reverse blowing.

[0055] Step 102 : when the resistance value of any temperature sensor meets the first preset condition, or the temperature change rate of any temperature sensor meets the second preset condition, the power of the electric drive system is limited according to the control time.

[0056] After obtaining the resistance value and temperature change rate of any temperature sensor, it is possible to determine whether the electric drive system is in normal mode or abnormal mode based on the resistance value and the temperature change rate, and adjust the power in different modes so that the electric drive system works in a high-efficiency area, thereby improving its working efficiency and ultimately improving the power density.

[0057] According to the control strategy, in this embodiment, the electric drive system is currently in normal mode or abnormal mode by judging the temperature change rate. Under normal circumstances, the temperature sensor is a thermal component, that is, a thermistor sensor, which corresponds to a certain resistance value, but its corresponding resistance value cannot be infinite or zero. In addition, the temperature sensor measures the temperature of the high-heat winding inside the main drive motor and the high-heat power module. Therefore, as the engine starts, the temperature should gradually increase, so the resistance value corresponding to the temperature cannot change suddenly. If a sudden change occurs, it is considered to be abnormal and in abnormal mode.

[0058] Here, the main types of thermistor sensors can be PT100, PT1000, etc. The larger the resistance value, the higher the temperature. Under normal circumstances, according to the type of thermistor sensor, the resistance representing the temperature value is in a normal range.

[0059] Abnormal mode conditions mainly include running detection and stationary detection. Running detection mainly refers to abnormal conditions detected during the operation of the vehicle after it has been powered on. At this time, it is judged by the temperature change rate; stationary detection mainly refers to abnormal conditions detected when the vehicle is just powered on. In this case, the corresponding temperature resistance value can be infinite resistance value or zero resistance value.

[0060] In one embodiment, when the resistance value of any temperature sensor meets the first preset condition, or the temperature change rate of any temperature sensor meets the second preset condition, limiting the power of the electric drive system according to the control time may include:

[0061] When the resistance value of any temperature sensor obtained in real time is infinite or zero for a preset time, or the temperature change rate of any temperature sensor is greater than or equal to a first temperature change rate threshold, the electric drive system is determined to be in abnormal mode, and the power of the electric drive system is limited according to the control time.

[0062] Among them, when the resistance value is infinite, it is determined that the corresponding temperature sensor or transmission path is broken, mainly because the temperature sensor and the signal transmission link are disconnected, and the resistance value of the temperature signal transmitted to the corresponding controller is infinite, which is mistakenly regarded as high temperature.

[0063] When the resistance value is zero, it is determined that the corresponding temperature sensor or transmission path is short-circuited or short-circuited, causing the resistance value representing the temperature signal transmitted to the corresponding controller to be zero, which is mistakenly considered to be extremely low temperature.

[0064] It should be noted that temperature is a state quantity and it is impossible to have a sudden change. In addition, the temperature signal should be prevented from being unstable due to external reasons, such as abnormal phenomena such as poor contact of the temperature signal due to vibration, jitter, etc., or even instantaneous loss of the signal. Therefore, when judging and processing the temperature signal, it should be collected and controlled according to the duration period to ensure the stability of the temperature signal. Therefore, in this embodiment, when the resistance value of any temperature sensor obtained in real time is infinite or zero for a preset time, we can judge that the electric drive system is abnormal. The preset time of continuity should generally not be too short to avoid unstable signals and false alarm signals. It can generally be 5s, 6s, etc., that is, when the temperature sensor detects an open circuit state for 5 consecutive seconds, or if the temperature sensor detects a short circuit state for 5 consecutive seconds, it is judged that the electric drive system is abnormal.

[0065] In one embodiment, if the resistance value corresponding to the temperature sensor detected within a preset time returns to normal, it is determined that no abnormality occurs in the electric drive system, and the current temperature sensor short circuit or open circuit fault detection is exited.

[0066] Optionally, the first temperature change rate threshold can be set according to actual needs, but when setting its value, it should be noted that the first temperature change rate threshold is a sudden change threshold and will not be reached in the normal mode of the electric drive system.

[0067] When the electric drive system is determined to be in an abnormal mode, a temperature sensor open circuit or short circuit abnormality may be reported, and the power of the electric drive system may be limited according to the control duration.

[0068] In the above two abnormal conditions of open circuit and short circuit, the electric drive system is not in a real over-temperature condition, so special processing is required to ensure the safety of the whole vehicle. In one embodiment, the power of the electric drive system is limited according to the control time, which may include:

[0069] Controlling the electric drive system to limit power to a first power within a first preset time period from the start of control, the first power being less than the power;

[0070] Controlling the electric drive system to limit power to a second power within a second preset time period from the start of control, the second preset time period being greater than the first preset time period, and the second power being less than the first power;

[0071] The electric drive system is controlled to limit the vehicle speed to a preset vehicle speed within a third preset time period from the start of the control, and the third preset time period is greater than the second preset time period.

[0072] Optionally, the first preset time length and the second preset time length can be set according to requirements, for example, the first preset time length can be 10 seconds, and the second preset time length can be 20 seconds;

[0073] The first power and the second power can be set according to demand, for example, the current corresponding to the first power can be 80%*rated current, and power is equal to voltage multiplied by current. The current corresponding to the first power can be 50%*rated current.

[0074] That is, the power of the electric drive system is limited according to the control time, and the output power of the main drive motor can be limited to 80%*rated current within 10 seconds and to 50%*rated current within 20 seconds. In this way, the speed of the vehicle decreases as the power decreases.

[0075] The third preset time length can be set according to the demand, for example, the third preset time length can be 1 minute. That is, when the vehicle speed decreases, the vehicle speed needs to be limited to a safe speed within 1 minute.

[0076] It should be noted that during the power limiting process of the electric drive system, it is necessary to promptly control the alarm to sound an alarm so as to warn the driver to take measures, such as driving the vehicle to a safe position.

[0077] In one embodiment, after respectively obtaining the resistance values ​​and temperature change rates of the first temperature sensor and the second temperature sensor, the method further includes:

[0078] When the temperature change rate of any temperature sensor is less than a first temperature change rate threshold, the cooling system of the vehicle is turned on according to the temperature control of any temperature sensor, and the power of the electric drive system is linearly limited.

[0079] That is to say, when the temperature change rate of any temperature sensor is less than the first temperature change rate threshold, the electric drive system is determined to be in normal mode. In normal mode, the temperature of the electric drive system rises. In order to control the electric drive system to operate in the high-efficiency zone and improve its working efficiency, it is necessary to control the power of the electric drive system according to the temperature.

[0080] In normal mode, a linear temperature protection strategy is set according to the upper and lower temperature protection values, that is, the power output of the electric drive system is limited according to the lower temperature limit, and the power output of the electric drive system is protected to stop according to the upper temperature limit.

[0081] In one embodiment, controlling the vehicle's cooling system to start according to the temperature of any temperature sensor and linearly limiting the power of the electric drive system may include:

[0082] When the temperature of any temperature sensor is greater than or equal to the corresponding first temperature threshold, controlling the cooling system of the vehicle to start;

[0083] When the temperature of any temperature sensor is greater than or equal to the corresponding second temperature threshold, the power of the corresponding main drive motor or main drive motor controller is controlled to be linearly limited, and the second temperature threshold is greater than the first temperature threshold;

[0084] When the temperature of any temperature sensor is greater than or equal to the corresponding third temperature threshold, the corresponding main drive motor or main drive motor controller is controlled to stop power and a fault alarm is issued, and the third temperature threshold is greater than the second temperature threshold.

[0085] The cooling system includes an electronic fan, an electronic fan controller, a cooling water pump, and a cooling water pump controller. Controlling the cooling system to start may include sending a start instruction to the electronic fan controller and the cooling water pump controller, and the electronic fan controller and the cooling water pump controller control the corresponding electronic fan and the cooling water pump to start running according to the start instruction, so as to reduce the temperature of the electric drive system. It may also include directly sending a control signal to the electronic fan and the cooling water pump to directly control the electronic fan and the cooling water pump to start running.

[0086] In addition, the cooling system may also include an intercooler, which can increase the heat dissipation area and facilitate heat dissipation.

[0087] Since the main drive motor and the main drive motor controller in the electric drive system have different temperature tolerances, generally the main drive motor has a stronger temperature tolerance and the main drive motor controller has a weaker temperature tolerance. Therefore, different temperature sensors correspond to different temperature thresholds, but the control strategies are the same.

[0088] For example, for the main drive motor, the first temperature threshold and the second temperature threshold may be t10 and t11 respectively, wherein t10<t11. In this embodiment, t11 refers to the maximum operating temperature point allowed by the main drive motor, that is, the temperature protection limit of the main drive motor, which is generally 140°C.

[0089] When the temperature of T1 rises to t10, the cooling system is started to dissipate heat; if T1 continues to heat up, the main drive motor temperature protection starts to control the linear power limit output of the main drive motor from t11.

[0090] The third temperature threshold may be t11+10°C, that is, when it reaches 150°C, the main drive motor is controlled to stop power output and an electric drive motor overtemperature fault is reported.

[0091] For example, for the main drive motor controller, the first temperature threshold and the second temperature threshold may be t20 and t22 respectively, wherein t20<t22. In this embodiment, t22 refers to the maximum operating temperature point allowed by the main drive motor, that is, the temperature protection limit of the main drive motor, which is generally 100°C.

[0092] When the temperature of T2 rises to t20, the cooling system is started to dissipate heat; if T2 continues to heat up, the main drive motor temperature protection starts to control the linear power limit output of the main drive motor from t22.

[0093] The third temperature threshold may be t22+10°C, that is, when it is 110°C, the main drive motor is controlled to stop power output and an electric drive motor controller overtemperature fault is reported.

[0094] When the output power of the electric drive system is limited, the temperature will decrease. Therefore, when the temperature of any temperature sensor is less than or equal to the corresponding fourth temperature threshold, the corresponding main drive motor or main drive motor controller is controlled to restore the power to the power before the power limiting operation, and the fourth temperature threshold is greater than the first temperature threshold and less than the second temperature threshold;

[0095] When the temperature of any temperature sensor is less than or equal to the corresponding fifth temperature threshold, the cooling system of the vehicle is controlled to be turned off, and the fifth temperature threshold is less than the first temperature threshold.

[0096] For the main drive motor, the fourth temperature threshold can be t11-10℃, that is, when the temperature drops to 130℃, the power is no longer limited, and the vehicle VCU instructions are restored. The fault can be reset automatically; the fifth temperature threshold can be t10-20℃, that is, when the temperature drops to t10-20℃, the cooling system stops cooling.

[0097] For the main drive motor controller, the fourth temperature threshold can be t22-10℃, that is, when the temperature drops to 90℃, the power is no longer limited, and the vehicle VCU instructions are restored. The fault can be reset automatically; the fifth temperature threshold can be t20-20℃, that is, when the temperature drops to t20-20℃, the cooling system stops cooling.

[0098] In one embodiment, when the electric drive system is in normal mode, during the power control of the electric drive system, the cooling fan and the cooling water pump can also be adjusted according to the temperature values ​​of T3 (temperature sensor on the cooling water inlet pipe of the motor controller) and T4 (temperature sensor on the water outlet pipe of the motor controller). When the temperature value of T3 and / or T4 is higher, the speed of the cooling fan and the cooling water pump is increased, and when the temperature value of T3 and / or T4 is lower, the speed of the cooling fan and the cooling water pump is reduced.

[0099] Optionally, when performing speed control, it can be frequency conversion control or control based on duty cycle.

[0100] In one embodiment, since the temperature change rate is calculated for the main drive motor or the main drive motor controller respectively, as long as one of the temperature change rates is abnormal, the power limitation processing of the electric drive system is performed according to the abnormal mode. When the electric drive system is determined to be in normal mode according to the temperature change rates of the two, when the specific control strategy is determined according to the temperature, control is performed according to the higher temperature limit. For example, if the temperature of the main drive motor is detected to be 110°C, the cooling system should be started according to the control method of the main drive motor, and the temperature of the main drive motor controller is 110°C, then the cooling system should be started according to the control method of the main drive motor controller, and the power of the main drive motor controller should be limited to zero. Therefore, the electric drive system is controlled according to the control method of the main drive motor controller to prevent the main drive motor controller from being damaged due to its weak ability to withstand temperature.

[0101] Step 103: when the vehicle speed is less than a preset speed, shut down the electric drive system.

[0102] When the power of the electric drive system is limited in step 102, the vehicle speed is reduced. When the vehicle speed is lower than the safe speed, the electric drive system can be shut down to reduce the temperature of the electric drive system and prevent the electric drive system from being damaged by high temperature. In addition, shutting down the electric drive system after the vehicle speed is reduced to the safe speed can protect the safety of people on the vehicle. Compared with the prior art of directly shutting down the electric drive system according to the temperature measured by the temperature sensor of the electric drive system, the control method of this embodiment is safer.

[0103] In one embodiment, the heat of the electric drive system can be used for other equipment in the vehicle, such as power battery heating or cab heating, so that heat can be recovered and the energy consumption of the entire vehicle can be reduced.

[0104] In one embodiment, the temperature control method of the electric drive system can be extended to other motor control systems of electric vehicles, such as steering motors and control systems, air pump motors and control systems, air conditioning compressors and control systems, to avoid false alarms, ensure the accuracy of temperature control, and reduce or minimize related faults. It can also be extended to power battery cooling system control. It can also be extended to special vehicles with lower requirements for air-cooled cooling systems, such as mobility scooters for the elderly, scenic sightseeing vehicles, etc., except that the temperature control only controls the cooling fan without a cooling water pump.

[0105] The embodiment of the present invention sets corresponding temperature sensors on the main drive motor and the main drive motor controller respectively. When the resistance value of any temperature sensor meets the first preset condition, or the temperature change rate of any temperature sensor meets the second preset condition, the power of the electric drive system is limited according to the control time; when the vehicle speed is less than the preset speed, the electric drive system is turned off, so that the temperature control of the electric drive system can be achieved through control without adding hardware. In addition, when the electric drive system is abnormal, the power is limited according to the control time, the output power is gradually reduced, and when the vehicle speed is less than the preset speed, the electric drive system is turned off again, so as to achieve flexible reduction of the output power of the electric drive system, thereby improving the vehicle operation safety and the reliability of the electric drive system.

[0106] The embodiment of the present invention can also control the vehicle's cooling system to start according to the temperature of any temperature sensor when the temperature change rate of any temperature sensor is less than the first temperature change rate threshold, and linearly limit the power of the electric drive system, so that the electric drive system can be reasonably controlled according to the temperature, so that the electric drive system works in the high-efficiency zone, improve the efficiency and power density of the electric drive system, and achieve energy saving for the whole vehicle. And the time to start the cooling system is determined according to the temperature, so that the invalid energy consumption of the electric drive system can be reduced, its invalid wear can be reduced to delay its use, and the reliability of the electric drive system can be improved.

[0107] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0108] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0109] Figure 4The schematic diagram of the structure of the temperature control device of the electric drive system provided by the embodiment of the present invention is shown. A first temperature sensor is arranged on the main drive motor in the electric drive system, and a second temperature sensor is arranged on the main drive motor controller. For the convenience of description, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0110] like Figure 4 As shown, the temperature control device 4 of the electric drive system includes: an acquisition module 41 and a control module 42 .

[0111] An acquisition module 41 is used to respectively acquire the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor;

[0112] A control module 42, configured to limit the power of the electric drive system according to a control duration when the resistance value of any temperature sensor meets a first preset condition or the temperature change rate of any temperature sensor meets a second preset condition;

[0113] The control module 42 is further configured to shut down the electric drive system when the vehicle speed is less than a preset speed.

[0114] In a possible implementation, when the resistance value of any temperature sensor meets the first preset condition, or the temperature change rate of any temperature sensor meets the second preset condition, the control module 42 limits the power of the electric drive system according to the control duration, and is used to:

[0115] When the resistance value of any temperature sensor obtained in real time is infinite or zero for a preset time, or the temperature change rate of any temperature sensor is greater than or equal to a first temperature change rate threshold, the power of the electric drive system is limited according to the control time.

[0116] In a possible implementation, after the acquisition module 41 respectively acquires the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor, the control module 42 is further configured to:

[0117] When the temperature change rate of any temperature sensor is less than a first temperature change rate threshold, the cooling system of the vehicle is turned on according to the temperature control of any temperature sensor, and the power of the electric drive system is linearly limited.

[0118] In a possible implementation, when the control module 42 limits the power of the electric drive system according to the control duration, it is used to:

[0119] Controlling the electric drive system to limit power to a first power within a first preset time period from the start of control, the first power being less than the power;

[0120] Controlling the electric drive system to limit power to a second power within a second preset time period from the start of control, the second preset time period being greater than the first preset time period, and the second power being less than the first power;

[0121] The electric drive system is controlled to limit the vehicle speed to a preset vehicle speed within a third preset time period from the start of the control, and the third preset time period is greater than the second preset time period.

[0122] In a possible implementation, the control module 42 controls the vehicle cooling system to start according to the temperature of any temperature sensor, and linearly limits the power of the electric drive system, to:

[0123] When the temperature of any temperature sensor is greater than or equal to the corresponding first temperature threshold, controlling the cooling system of the vehicle to start;

[0124] When the temperature of any temperature sensor is greater than or equal to the corresponding second temperature threshold, the power of the corresponding main drive motor or main drive motor controller is controlled to be linearly limited, and the second temperature threshold is greater than the first temperature threshold;

[0125] When the temperature of any temperature sensor is greater than or equal to the corresponding third temperature threshold, the corresponding main drive motor or main drive motor controller is controlled to stop power and a fault alarm is issued, and the third temperature threshold is greater than the second temperature threshold.

[0126] In a possible implementation, after the control module 42 controls the vehicle's cooling system to start according to the temperature of any temperature sensor and linearly limits the power of the electric drive system, it is further configured to:

[0127] When the temperature of any temperature sensor is less than or equal to the corresponding fourth temperature threshold, the corresponding main drive motor or main drive motor controller is controlled to restore power to the power before the power limiting operation, and the fourth temperature threshold is greater than the first temperature threshold and less than the second temperature threshold;

[0128] When the temperature of any temperature sensor is less than or equal to the corresponding fifth temperature threshold, the cooling system of the vehicle is controlled to be turned off, and the fifth temperature threshold is less than the first temperature threshold.

[0129] In a possible implementation, before respectively acquiring the resistance values ​​and the temperature change rates of the first temperature sensor and the second temperature sensor, the control module 42 is further configured to:

[0130] Controls the electronic fan in the vehicle's cooling system to reverse for a preset time.

[0131] The temperature control device of the electric drive system is configured with corresponding temperature sensors on the main drive motor and the main drive motor controller. When the resistance value of any temperature sensor meets the first preset condition, or the temperature change rate of any temperature sensor meets the second preset condition, the control module limits the power of the electric drive system according to the control time. When the vehicle speed is less than the preset speed, the control module shuts down the electric drive system, thereby realizing the temperature control of the electric drive system through control without adding hardware. In addition, when the electric drive system is abnormal, the power is limited according to the control time, the output power is gradually reduced, and when the vehicle speed is less than the preset speed, the electric drive system is shut down again, thereby realizing flexible reduction of the output power of the electric drive system, thereby improving the vehicle operation safety and the reliability of the electric drive system.

[0132] When the temperature change rate of any temperature sensor is less than the first temperature change rate threshold, the control module can control the vehicle's cooling system to start according to the temperature of any temperature sensor, and linearly limit the power of the electric drive system, so that the electric drive system can be reasonably controlled according to the temperature, so that the electric drive system works in the high-efficiency zone, improve the efficiency and power density of the electric drive system, and achieve energy saving for the whole vehicle. And the time to start the cooling system is determined according to the temperature, so as to reduce the ineffective energy consumption of the electric drive system, reduce its ineffective wear to delay its use, and improve the reliability of the electric drive system.

[0133] An embodiment of the present invention further provides a vehicle, including a controller, Figure 5 is a schematic diagram of a controller provided by an embodiment of the present invention. Figure 5 As shown, the controller 5 of this embodiment includes: a processor 50, a memory 51, and a computer program 52 stored in the memory 51 and executable on the processor 50. When the processor 50 executes the computer program 52, the steps in the above-mentioned temperature control method embodiments of the electric drive system are implemented, such as Figure 1 Alternatively, when the processor 50 executes the computer program 52, the functions of each module / unit in the above-mentioned device embodiments are realized, for example, Figure 4 The functions of each module / unit are shown.

[0134] Exemplarily, the computer program 52 may be divided into one or more modules / units, which are stored in the memory 51 and executed by the processor 50 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 52 in the controller 5. For example, the computer program 52 may be divided into Figure 4The modules / units shown.

[0135] The controller 5 may include, but is not limited to, a processor 50 and a memory 51. Those skilled in the art will appreciate that Figure 5 It is only an example of the controller 5 and does not constitute a limitation of the controller 5. The controller may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the controller may also include input and output devices, network access devices, buses, etc.

[0136] The processor 50 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0137] The memory 51 may be an internal storage unit of the controller 5, such as a hard disk or memory of the controller 5. The memory 51 may also be an external storage device of the controller 5, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the controller 5. Further, the memory 51 may include both an internal storage unit of the controller 5 and an external storage device. The memory 51 is used to store the computer program and other programs and data required by the controller. The memory 51 may also be used to temporarily store data that has been output or is to be output.

[0138] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0139] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0140] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0141] In the embodiments provided by the present invention, it should be understood that the disclosed devices / controllers and methods can be implemented in other ways. For example, the device / controller embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0142] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0143] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0144] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the temperature control method embodiment of each electric drive system can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium.

[0145] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A temperature control method for an electric drive system, characterized in that: A first temperature sensor is provided on a main drive motor in an electric drive system, and a second temperature sensor is provided on a main drive motor controller. The temperature control method of the electric drive system includes: Respectively obtaining the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor; When the resistance value of any temperature sensor meets the first preset condition, or the temperature change rate of any temperature sensor meets the second preset condition, the power of the electric drive system is limited according to the control time; When the vehicle speed is less than a preset speed, the electric drive system is turned off.

2. The temperature control method of the electric drive system according to claim 1, characterized in that: When the resistance value of any temperature sensor meets the first preset condition, or the temperature change rate of any temperature sensor meets the second preset condition, the power of the electric drive system is limited according to the control time, including: When the resistance value of any temperature sensor obtained in real time is infinite or zero for a preset time, or the temperature change rate of any temperature sensor is greater than or equal to a first temperature change rate threshold, the power of the electric drive system is limited according to the control time.

3. The temperature control method of the electric drive system according to claim 2, characterized in that: After respectively obtaining the resistance values ​​and temperature change rates of the first temperature sensor and the second temperature sensor, the method further includes: When the temperature change rate of any temperature sensor is less than a first temperature change rate threshold, the cooling system of the vehicle is controlled to be turned on according to the temperature of any temperature sensor, and the power of the electric drive system is linearly limited.

4. The temperature control method of the electric drive system according to claim 1 or 2, characterized in that: The power of the electric drive system is limited according to the control duration, including: controlling the electric drive system to limit power to a first power within a first preset time period from the start of control, the first power being less than the power; Controlling the electric drive system to limit power to a second power within a second preset time period from the start of control, wherein the second preset time period is greater than the first preset time period, and the second power is less than the first power; The electric drive system is controlled to limit the vehicle speed to the preset vehicle speed within a third preset time period from the start of control, and the third preset time period is greater than the second preset time period.

5. The temperature control method of the electric drive system according to claim 3, characterized in that: Controlling the vehicle's cooling system to start according to the temperature of any one of the temperature sensors, and linearly limiting the power of the electric drive system, including: When the temperature of any temperature sensor is greater than or equal to the corresponding first temperature threshold, controlling the cooling system of the vehicle to start; When the temperature of any of the temperature sensors is greater than or equal to a corresponding second temperature threshold, the power of the corresponding main drive motor or main drive motor controller is controlled to be linearly limited, and the second temperature threshold is greater than the first temperature threshold; When the temperature of any temperature sensor is greater than or equal to the corresponding third temperature threshold, the corresponding main drive motor or main drive motor controller is controlled to stop power and a fault alarm is issued, and the third temperature threshold is greater than the second temperature threshold.

6. The temperature control method of the electric drive system according to claim 5, characterized in that: After controlling the vehicle's cooling system to start according to the temperature of any one of the temperature sensors and linearly limiting the power of the electric drive system, the method further includes: When the temperature of any of the temperature sensors is less than or equal to a corresponding fourth temperature threshold, controlling the corresponding main drive motor or main drive motor controller to restore power to the power before the power limiting operation, the fourth temperature threshold being greater than the first temperature threshold and less than the second temperature threshold; When the temperature of any temperature sensor is less than or equal to a corresponding fifth temperature threshold, the cooling system of the vehicle is controlled to be turned off, and the fifth temperature threshold is less than the first temperature threshold.

7. The temperature control method of the electric drive system according to claim 1, characterized in that: Before respectively acquiring the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor, the method further includes: The electronic fan in the cooling system of the vehicle is controlled to reverse for a preset time.

8. A temperature control device for an electric drive system, characterized in that: A first temperature sensor is arranged on the main drive motor in the electric drive system, a second temperature sensor is arranged on the main drive motor controller, and the temperature control device of the electric drive system includes: An acquisition module, used to respectively acquire the resistance value and the temperature change rate of the first temperature sensor and the second temperature sensor; A control module, configured to limit the power of the electric drive system according to a control duration when a resistance value of any temperature sensor meets a first preset condition or a temperature change rate of any temperature sensor meets a second preset condition; The control module is also used to shut down the electric drive system when the vehicle speed is less than a preset speed.

9. A vehicle, comprising a controller, the controller comprising a memory and a processor, the memory being used to store a computer program, the processor being used to call and run the computer program stored in the memory, characterized in that: When the processor executes the computer program, the steps of the temperature control method of the electric drive system as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the temperature control method of the electric drive system as described in any one of claims 1 to 7 are implemented.

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