Motor system electronic oil pump rotating speed control method and motor system controller

Abstract

The application discloses a motor system electronic oil pump rotating speed control method and a motor system controller, and belongs to the field of cooling, lubrication and thermal management of electric drive assemblies of new energy vehicles. The method comprises the following steps: obtaining a current temperature value of a motor winding temperature sensor; inquiring a first mapping relationship to obtain a first EOP request rotating speed, and setting a corresponding relationship between the motor winding temperature and the EOP request rotating speed; obtaining a current rotating speed and torque of a driving motor DM; inquiring a second mapping relationship to obtain an EOP rotating speed coefficient K value; multiplying the first EOP request rotating speed and the EOP rotating speed coefficient K value to obtain an initial EOP target rotating speed; comparing the initial EOP target rotating speed with a preset EOP minimum guarantee rotating speed, and taking the maximum value of the two as a final EOP target control rotating speed. The above method can adjust the rotating speed of the electronic oil pump according to the real-time demand of the motor system, and realize the minimum power consumption of the low-voltage power supply system of the vehicle.

Description

Technical Field

[0001] This invention belongs to the field of cooling, lubrication and thermal management of electric drive assemblies for new energy vehicles, and specifically relates to a method for controlling the speed of an electronic oil pump in a motor system and a motor system controller. Background Technology The primary goal of cooling and lubrication in an oil-cooled motor system is to ensure that the temperature of heat-generating components such as the motor, bearings, and gears is kept within a safe range. This, in turn, reduces power consumption and improves overall efficiency. The cooling and lubrication of the oil-cooled motor system, especially the cooling of the motor stator and rotor, achieves thermal equilibrium mainly through an electric oil pump providing cooling oil flow. This oil exchanges heat with the relevant components, carrying away heat from the heat-generating parts. The cooling oil then flows back to the oil pan of the motor system, forming a closed loop.

[0002] In pure electric vehicles, oil-cooled motor systems, lacking the noise masking effect of an engine, make the NVH performance of the electronic oil pump crucial in overall vehicle NVH acceptance testing. Studies have found that the higher the electronic oil pump's speed, the greater its noise, and the more easily it is perceived by vehicle occupants. Therefore, effective and reasonable control is paramount. Summary of the Invention

[0003] The purpose of this invention is to provide a method for controlling the speed of an electronic oil pump in a motor system and a controller for the motor system, so as to solve the above-mentioned technical problems pointed out in the prior art.

[0004] This invention provides a method for controlling the speed of an electronic oil pump in a motor system, comprising the following steps: S1. Obtain the current temperature value from the motor winding temperature sensor; S2. Based on the current temperature value, query the first mapping relationship to obtain the first EOP requested speed. The first mapping relationship is used to set and determine the correspondence between the motor winding temperature and the EOP requested speed with the motor system thermal balance control target. S3. Obtain the current speed and torque of the drive motor DM; S4. Based on the current speed and torque of the drive motor DM, query the second mapping relationship to obtain the EOP speed coefficient K value. The second mapping relationship is used to set and determine the correspondence between the speed and torque of the drive motor DM and the EOP speed coefficient K. S5. Multiply the first EOP requested speed by the EOP speed coefficient K value to obtain the initial EOP target speed; S6. Compare the initial EOP target speed with the preset minimum guaranteed EOP speed, and take the maximum value of the two as the final EOP target control speed; S7. Control the EOP operation by controlling the rotational speed according to the final EOP target.

[0005] Preferably, as an implementation method, after step S1 and before S2, the method further includes: It should be noted that in the above technical solution, considering that the EOP NVH problem is only prominent under high NTC Sensor temperature and low vehicle speed conditions, a new control target feasible solution is introduced, that is, when the NTC Sensor temperature is higher than or equal to a certain value (i.e., determining whether the current temperature value is ≥ the first temperature threshold), if so, steps S2 to S7 are executed; if not, the first EOP request speed obtained by querying the first mapping relationship based on the current temperature value is directly used as the final EOP target control speed, and step S7 is executed.

[0006] Preferably, as one possible implementation, the method is applied to a cooling and lubrication system comprising dual motors and solenoid valves, wherein step S1 specifically comprises: The current temperature value of the first motor winding temperature sensor (i.e., the TM NTC Sensor temperature) and the current temperature value of the second motor winding temperature sensor (i.e., the GM NTC Sensor temperature) are obtained, and the maximum value of the two is taken as the current temperature value. Step S2 specifically includes: S21. Obtain the current state of the solenoid valve; S22. If the solenoid valve is in the closed state, the third mapping relationship is queried according to the current temperature value to obtain the first EOP requested speed. If the solenoid valve is in the open state, the first mapping relationship is queried according to the current temperature value to obtain the first EOP requested speed. The third mapping relationship is used to define the correspondence between the motor winding temperature and the EOP requested speed in the solenoid valve closed and single motor cooling mode.

[0007] It should be noted that in the above technical solution, the system controller checks whether there are two motor windings. It checks the temperatures of the TM NTC Sensor and GM NTC Sensor for both motor windings and takes the maximum of the two as the current temperature value. If the solenoid valve is open, it consults Table 1 based on the current check status and requests EOP speed control. If the solenoid valve is closed, it consults Table 2 based on the current check status and requests EOP speed control. The system controller simultaneously checks the current DM speed and torque, consults Table 3, and retrieves the K value based on the correspondence between DM speed, torque, and EOP speed coefficient K in Table 3. The requested EOP speed control value is multiplied by the EOP speed coefficient K value to obtain the controller's initial EOP target control speed. If this initial EOP target control speed is greater than the minimum EOP speed, the maximum of the two is taken as the controller's final EOP target control speed, which is then requested and implemented.

[0008] Preferably, as one possible implementation, the method further includes the following steps after S1 and before S21: Determine whether the current temperature value is greater than or equal to the first temperature threshold; If so, proceed with steps S21 to S7; If not, after executing steps S21 and S22, the first EOP requested speed obtained is directly used as the final EOP target control speed, and step S7 is executed.

[0009] Preferably, as one possible implementation, the construction logic of the first mapping relationship and / or the third mapping relationship includes: a) When the motor winding temperature is ≤ the second temperature threshold (A), the EOP requests the speed as the minimum guaranteed speed of the EOP; b) When the motor winding temperature is greater than the second temperature threshold (A) and less than the third temperature threshold (B), different control paths are selected based on the rate of temperature rise of the motor winding temperature: If the temperature rise rate is less than or equal to the rate threshold, then the first control path is selected, and the EOP requests the rotation speed to increase gradually with the temperature. If the temperature rise rate is greater than the rate threshold, the second control path is selected, and the EOP requests the rotation speed to increase rapidly. c) When the motor winding temperature is ≥ the fourth temperature threshold (C), the EOP requests the speed as the maximum permissible speed of the EOP.

[0010] Preferably, as one possible implementation, the first control path is used to control and adjust the EOP speed to ultimately achieve the lowest EOP power consumption, and the second control path is used to control the maximum EOP speed to ultimately meet the preset high power and high heat dissipation power operating conditions requirements of the motor system.

[0011] Preferably, as one possible implementation, the minimum guaranteed EOP speed is the EOP speed corresponding to the cooling oil flow rate required to ensure that the motor system meets the minimum cooling and lubrication requirements.

[0012] Preferably, as one possible implementation; the motor system is a dual-motor system of hybrid electric drive; it also includes adding an additional electromagnetic control valve to the cooling oil circuit of the electric drive assembly: the cooling oil circuit of the electric drive assembly includes a gearbox, an additional electromagnetic control valve, a heat exchanger, a filter press, a drive motor DM (or a traction motor TM), a generator GM (or a drive motor DM), an EOP, a suction filter, and an oil pan; The status of the additional electromagnetic control valve in the cooling oil circuit is detected, and the cooling flow rate is selected to supply to different motors according to the opening or closing status of the additional electromagnetic control valve. When the additional electromagnetic control valve is closed, the electronic oil pump only supplies cooling flow to the drive motor DM; When the additional electromagnetic control valve is opened, the electronic oil pump simultaneously supplies cooling flow to the drive motor DM (or traction motor TM) and the generator GM (or drive motor DM).

[0013] Preferably, as one possible implementation, the first mapping relationship, the second mapping relationship, the third mapping relationship, the first temperature threshold, the second temperature threshold (A), the third temperature threshold (B), the fourth temperature threshold (C), the rate threshold, and the minimum guaranteed rotational speed for EOP are preset values.

[0014] A motor system controller includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements a method for controlling the speed of an electronic oil pump in the motor system.

[0015] Compared with the prior art, the embodiments of the present invention have at least the following technical advantages: Analysis of the above-mentioned method for controlling the speed of an electronic oil pump in a motor system provided by the present invention shows that, in specific applications, S1, the current temperature value of the motor winding temperature sensor is obtained; S2, based on the current temperature value, a first mapping relationship is queried to obtain the first EOP requested speed, wherein the first mapping relationship is used to set and determine the correspondence between the motor winding temperature and the EOP requested speed with the motor system thermal balance control target; S3, the current speed and torque of the drive motor DM are obtained; S4. Based on the current speed and torque of the drive motor DM, query the second mapping relationship to obtain the EOP speed coefficient K value. The second mapping relationship is used to set and determine the correspondence between the speed and torque of the drive motor DM and the EOP speed coefficient K. S5. Multiply the first EOP requested speed by the EOP speed coefficient K value to obtain the initial EOP target speed; S6. Compare the initial EOP target speed with the preset EOP minimum guaranteed speed, and take the maximum value of the two as the final EOP target control speed; S7. Control the EOP to run according to the final EOP target control speed.

[0016] Analysis of the above steps reveals that this invention provides a method for controlling the speed of an electronic oil pump in a motor system by introducing an EOP speed coefficient K, which is related to the speed and torque of the motor's damping system (DM). When the DM is operating at low speed and low torque, the motor's heat generation power is low, and the demand for cooling flow and pressure is also low. At this time, K is set to a coefficient less than 1 by looking up a table. Multiplying the temperature-based requested speed by this K value (less than 1) results in an initial target speed that is actively reduced. As long as the reduced speed is not lower than the minimum speed, the controller will operate the EOP at this lower speed. Under the premise of meeting basic cooling requirements, the unnecessary high speed is actively reduced by the coefficient K, directly reducing the power consumption of the electronic oil pump and thus optimizing the power consumption of the entire system.

[0017] Meanwhile, this invention provides a method for controlling the speed of an electronic oil pump in a motor system, which adopts a progressive and multi-condition targeted control approach. Steps S1-S7 are the most core and basic method, and other control methods are detailed in subsequent solutions. Attached Figure Description

[0018] Figure 1 This is one of the feasible schemes for EOP speed control target in a motor system electronic oil pump speed control method. Figure 2 The second logical block diagram of a feasible scheme for EOP speed control target of an electronic oil pump speed control method for a motor system; Figure 3 The third logical block diagram of a feasible scheme for EOP speed control target of an electronic oil pump speed control method for a motor system; Figure 4 The fourth logical block diagram of a feasible scheme for EOP speed control target of an electronic oil pump speed control method for a motor system; Figure 5 This is a schematic diagram of the cooling oil flow direction in an electric drive cooling and lubrication system, representing a method for controlling the speed of an electronic oil pump in an electric motor system. Figure 6 This corresponds to the NTC Sensor temperature versus EOP rotation speed curve in Table 1; Figure 7 This corresponds to the NTC Sensor temperature versus EOP rotation speed curve in Table 2; Figure 8This is a schematic diagram of the main structure of a motor system controller.

[0019] Labels: 10 - memory, 20 - processor, 30 - computer program. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0022] This invention mainly provides a method for controlling the speed of an electronic oil pump in a motor system. Based on meeting the basic cooling and lubrication requirements of an oil-cooled motor system, the method can adjust the speed of the electronic oil pump according to the real-time needs of the motor system to minimize the power consumption of the vehicle's low-voltage power supply system. At the same time, the method can adjust the speed coefficient of the electronic oil pump according to the current state of the vehicle and the motor system to achieve optimal NVH performance of the electronic oil pump.

[0023] Compared with other application cases, the electric oil pump speed control method for motor systems provided by this invention has the following advantages: lower verification cost in the early stage of strategy formulation; simpler control logic and higher reliability due to the single control objective; and strong scalability due to the simple control logic, which can be used not only for single motor systems, but also for dual motor systems of pure electric drive or hybrid electric drive.

[0024] In this embodiment, the electronic oil pump is (EOP); the NTC sensor is an NTC thermistor temperature sensor; the drive motor is abbreviated as DM; the traction motor is abbreviated as TM; and the generator motor is abbreviated as GM.

[0025] Example 1 like Figure 1-8 As shown, Embodiment 1 of the present invention provides a method for controlling the speed of an electronic oil pump in a motor system, comprising the following operational steps: S1. Obtain the current temperature value from the motor winding temperature sensor; S2. Based on the current temperature value, query the first mapping relationship to obtain the first EOP requested speed. The first mapping relationship is used to set and determine the correspondence between the motor winding temperature and the EOP requested speed with the motor system thermal balance control target. S3. Obtain the current speed and torque of the drive motor DM; S4. Based on the current speed and torque of the drive motor DM, query the second mapping relationship to obtain the EOP speed coefficient K value. The second mapping relationship is used to set and determine the correspondence between the speed and torque of the drive motor DM and the EOP speed coefficient K. S5. Multiply the first EOP requested speed by the EOP speed coefficient K value to obtain the initial EOP target speed; S6. Compare the initial EOP target speed with the preset minimum guaranteed EOP speed, and take the maximum value of the two as the final EOP target control speed; S7. Control the EOP operation by controlling the rotational speed according to the final EOP target.

[0026] In traditional control schemes, the EOP speed is often strongly correlated only with temperature. While it provides sufficient cooling under high loads, it may lead to "overcooling" under medium and low loads, where the flow rate and pressure provided by the oil pump exceed actual needs, resulting in unnecessary energy consumption. Embodiment 1 of this invention provides a method for controlling the speed of an electronic oil pump in a motor system by introducing an EOP speed coefficient K, which is related to the speed and torque of the motor's damper (DM). When the DM is operating at low speed and low torque, the motor's heat output is low, and the demand for cooling flow rate and pressure is also low. At this time, K is set to a coefficient less than 1 by looking up a table. Multiplying the temperature-based requested speed by this K value (less than 1) results in an initial target speed that is actively reduced. As long as this reduced speed is not lower than the minimum speed, the controller will operate the EOP at this lower speed. By actively reducing unnecessary high speeds through the coefficient K while meeting basic cooling requirements, the energy consumption of the electronic oil pump is directly reduced, thereby optimizing the overall system power consumption.

[0027] Embodiment 1 of the present invention provides a method for controlling the speed of an electronic oil pump in a motor system. It adopts a progressive and multi-condition targeted control approach. Steps S1-S7 are the most core and basic method scheme. Other control methods are detailed in subsequent schemes.

[0028] Preferably, as an implementation method, after step S1 and before step S2, the method further includes: It should be noted that in the above technical solution, considering that the EOP NVH problem is only prominent under high NTC Sensor temperature and low vehicle speed conditions, a new control target feasible solution is introduced, that is, when the NTC Sensor temperature is higher than or equal to a certain value (i.e., whether the current temperature value is ≥ the first temperature threshold), if so, steps S2 to S7 are executed; if not, the first EOP request speed obtained by querying the first mapping relationship based on the current temperature value is used as the final EOP target control speed, and step S7 is executed. In other words, the entire control operation is summarized as follows: first, determine whether the current temperature value is greater than or equal to the first temperature threshold. If so, proceed to steps S2 to S7; If not, the first EOP request speed obtained by querying the first mapping relationship based on the current temperature value is directly used as the final EOP target control speed, and step S7 is executed.

[0029] In a specific embodiment of the present invention, a technical solution is introduced that balances targeted NVH optimization with economic efficiency: the coefficient K is only activated for speed adjustment when the temperature is ≥ the first temperature threshold; otherwise, the first EOP request speed obtained by querying the first mapping relationship based on the current temperature value is directly used as the final EOP target control speed, and step S7 is executed.

[0030] Preferably, as one possible implementation, the method is applied to a cooling and lubrication system comprising dual motors and solenoid valves, wherein step S1 specifically comprises: The current temperature value of the first motor winding temperature sensor (i.e., the TM NTC Sensor temperature) and the current temperature value of the second motor winding temperature sensor (i.e., the GM NTC Sensor temperature) are obtained, and the maximum value of the two is taken as the current temperature value. Step S2 specifically includes: S21. Obtain the current state of the solenoid valve; S22. If the solenoid valve is in the closed state, the third mapping relationship is queried according to the current temperature value to obtain the first EOP requested speed. If the solenoid valve is in the open state, the first mapping relationship is queried according to the current temperature value to obtain the first EOP requested speed. The third mapping relationship is used to define the correspondence between the motor winding temperature and the EOP requested speed in the solenoid valve closed and single motor cooling mode.

[0031] It should be noted that in the above technical solution, the system controller checks whether there are two motor windings. It checks the temperatures of the TM NTC Sensor and GM NTC Sensor for both motor windings and takes the maximum of the two as the current temperature value. If the solenoid valve is open, it consults Table 1 based on the current check status and requests EOP speed control. If the solenoid valve is closed, it consults Table 2 based on the current check status and requests EOP speed control. The system controller simultaneously checks the current DM speed and torque, consults Table 3, and retrieves the K value based on the correspondence between DM speed, torque, and EOP speed coefficient K in Table 3. The requested EOP speed control value is multiplied by the EOP speed coefficient K value to obtain the controller's initial EOP target control speed. If this initial EOP target control speed is greater than the minimum EOP speed, the maximum of the two is taken as the controller's final EOP target control speed, which is then requested and implemented.

[0032] In a specific embodiment of the present invention, for a dual-motor system, the maximum temperature of both motors is taken as the input; and a solenoid valve status judgment is added, and different temperature-speed mapping relationships (first mapping relationship or third mapping relationship) are selected according to its opening / closing.

[0033] The above control method targets the motor with the highest temperature among the two motors, ensuring that the hottest component always receives sufficient cooling. When the solenoid valve is closed (only a single motor operates, such as in pure electric drive or engine direct drive mode), the cooling circuit serves only one motor. In this case, a third mapping relationship is selected, which can calibrate the EOP speed based on the heat dissipation requirements of a single motor, and can request a lower speed at the same temperature than the first mapping relationship serving both motors.

[0034] Preferably, as one possible implementation, the method further includes the following steps after S1 and before S21: Determine whether the current temperature value is greater than or equal to the first temperature threshold; If so, proceed with steps S21 to S7; If not, after executing steps S21 and S22, the first EOP requested speed is directly used as the final EOP target control speed, and step S7 is executed.

[0035] Preferably, as one possible implementation, the construction logic of the first mapping relationship and / or the third mapping relationship includes: a) When the motor winding temperature is ≤ the second temperature threshold (A), the EOP requests the speed as the minimum guaranteed speed of the EOP; b) When the motor winding temperature is greater than the second temperature threshold (A) and less than the third temperature threshold (B), different control paths are selected based on the rate of temperature rise of the motor winding temperature: If the temperature rise rate is less than or equal to the rate threshold, then the first control path is selected, and the EOP requests the rotation speed to increase gradually with the temperature. If the temperature rise rate is greater than the rate threshold, the second control path is selected, and the EOP requests the rotation speed to increase rapidly. c) When the motor winding temperature is ≥ the fourth temperature threshold (C), the EOP requests the speed as the maximum permissible speed of the EOP.

[0036] Preferably, as one possible implementation, the first control path is used to control and adjust the EOP speed to ultimately achieve the lowest EOP power consumption, and the second control path is used to control the maximum EOP speed to ultimately meet the preset high power and high heat dissipation power operating conditions requirements of the motor system.

[0037] In all the above implementation methods, the underlying setting logic of Table 1 or Table 2 looked up by the motor system controller is one of the core inventive points of this invention: The following table 1 or table 2, and its corresponding curve relationship diagram ( Figure 6 , Figure 7 As shown in the figure, when the NTC Sensor temperature of the motor winding is less than or equal to a certain temperature value A, the EOP speed is set to the minimum EOP speed to ensure the minimum cooling and lubrication requirements of the motor system.

[0038] When the NTC Sensor temperature of the motor winding is within a certain range (e.g., A℃ < NTC Sensor temperature < B℃), two paths are set for EOP speed control: when the NTC Sensor temperature rise rate is less than a certain value (e.g., <5℃ / 10s), path 1 is selected, and the EOP speed is adjusted in a timely manner to achieve the lowest EOP power consumption; when the NTC Sensor temperature rise rate is greater than a certain value (e.g., >5℃ / 10s), path 2 is selected, and the EOP speed is rapidly increased to meet the large heat dissipation power requirements of the motor system during sudden changes.

[0039] When the NTC Sensor temperature of the motor winding is greater than or equal to a certain temperature value C, the motor system is in a high-power, high-heat-dissipation-power operating condition. Set the EOP (Extreme Operating Speed) to fully cool the motor system and ensure that the motor can operate at full power with good performance.

[0040] Tables 1, 2, and 3 contain NTC Sensor temperature, EOP speed, TM (DM) speed, and EOP speed coefficient K value, all of which were obtained through calibration tests.

[0041] Preferably, as one possible implementation, the minimum guaranteed EOP speed is the EOP speed corresponding to the cooling oil flow rate required to ensure that the motor system meets the minimum cooling and lubrication requirements.

[0042] Preferably, as one possible implementation; the motor system is a multi-motor system; it further includes acquiring the winding temperature parameters of the motor system in real time through a controller, and querying the speed control value of the electronic oil pump based on the winding temperature parameters, specifically including: The controller acquires the winding temperature parameters of multiple motor units in real time, and takes the maximum value as the winding temperature parameter; it detects the status of the control valve in the cooling oil circuit, selects different speed control correspondences according to the opening or closing status of the control valve, and queries the speed control value of the electronic oil pump. When the control valve is closed, the electric oil pump supplies cooling flow to a single motor unit; when the control valve is open, the electric oil pump supplies cooling flow to multiple motor units simultaneously.

[0043] Preferably, as one possible implementation, the first mapping relationship, the second mapping relationship, the third mapping relationship, the first temperature threshold, the second temperature threshold (A), the third temperature threshold (B), the fourth temperature threshold (C), the rate threshold, and the minimum guaranteed rotational speed for EOP are preset values, which are all determined through testing and verification experience during the development phase, and will not be elaborated further.

[0044] This invention provides a feasible implementation method for controlling the speed of an electronic oil pump in a motor system. Based on meeting the basic cooling and lubrication requirements of an oil-cooled motor system, the method adjusts the electronic oil pump speed according to the real-time needs of the motor system to minimize power consumption in the vehicle's low-voltage power supply system. Simultaneously, it adjusts the electronic oil pump speed coefficient based on the current state of the vehicle and motor system to achieve optimal NVH performance. In summary, the electronic oil pump speed control method used in this invention employs targeted and feasible control solutions for various operating conditions and required settings. These various feasible control solutions can be illustrated in the control logic diagram below; for details, please refer to the control logic diagram. Figures 1-4 ; Regarding control logic Figure 1 : Figure 1 This is one of the logic block diagrams for a feasible solution to the EOP speed control target; namely, implementation method ①, such as... Figure 1As shown. The motor system controller checks the current NTC sensor temperature of the motor windings to determine the control target for achieving thermal balance in the motor system. Based on the current check status, it consults Table 1 to request the EOP speed control value. Simultaneously, the motor system controller checks the current DM speed and consults Table 3. Based on the correspondence between DM speed, torque, and EOP speed coefficient K in Table 3, it retrieves the K value. The requested EOP speed control value is multiplied by the EOP speed coefficient K value to obtain the controller's initial EOP target control speed. This initial EOP target control speed is greater than the minimum EOP speed; the larger of the two is used as the controller's final EOP target control speed, which is then requested and implemented.

[0045] The minimum operating point (EOP) speed is the EOP speed value that ensures the minimum cooling and lubrication requirements of the motor system, and it is determined by calibration tests during the development phase.

[0046] The introduction of the EOP speed coefficient K value is mainly to correct the EOP speed in real time under high NTC sensor temperature, medium and low vehicle speed and low power driving conditions, so as to ensure the power and economy of the whole vehicle, while optimizing low voltage power consumption and optimizing the physical experience of the whole vehicle passengers on EOP NVH.

[0047] Regarding control logic Figure 2 ; Figure 2 The second feasible logic block diagram for EOP speed control target; Implementation method ② builds upon implementation method ①. Considering that EOP NVH issues are only prominent under high NTC Sensor temperatures and low vehicle speeds, a logic for judging the NTC Sensor temperature is added to the feasible control target scheme. Only when the NTC Sensor temperature is higher than or equal to a certain value (e.g., ≥100℃) will Tables 1 and 3 be consulted, the product and ratio calculated, and the controller's final EOP target speed control requested and implemented. Otherwise, Table 1 is directly consulted to request and implement the controller's final EOP target speed control. Figure 2 As shown.

[0048] Implementation method ③ is a further step based on implementation method ①. Considering the expansion of this implementation method from a single DM motor system to a pure electric drive assembly and hybrid electric drive system with dual motors, a switching solenoid valve control logic is added to the cooling and lubrication circuit structure.

[0049] Regarding control logic Figure 3 ; Figure 3 The third feasible solution logic block diagram for EOP speed control target; such as Figure 3As shown, the motor system controller checks the current NTC sensor temperatures of the two motor windings, TM and GM, and takes the maximum value as the control target for achieving thermal balance in the motor system. Simultaneously, the controller checks the current solenoid valve status (open or closed). If the solenoid valve is open, it consults Table 1 based on the current status and requests EOP speed control; if the solenoid valve is closed, it consults Table 2 based on the current status and requests EOP speed control. The motor system controller synchronously checks the current DM speed and torque, consults Table 3, and retrieves the K value based on the correspondence between DM speed, torque, and EOP speed coefficient K in Table 3. The requested EOP speed control value is multiplied by the EOP speed coefficient K value to obtain the controller's initial EOP target control speed. This initial EOP target control speed is greater than the minimum EOP speed; the maximum of the two is taken as the controller's final EOP target control speed, which is then requested and implemented.

[0050] like Figure 5 As shown in the diagram, the section indicated by the dashed box A represents the cooling and lubrication system for a single-motor electric drive assembly. By adding a solenoid valve to the oil circuit, the cooling and lubrication system can be expanded to support the dual-motor system of a pure electric drive assembly or a hybrid electric drive system. When the solenoid valve is closed, the EOP supplies cooling oil flow to only one drive motor DM; when the solenoid valve is open, the EOP simultaneously supplies cooling flow to both the drive motor DM (or traction motor TM) and the generator GM (or drive motor DM). When the additional solenoid control valve is closed, the electronic oil pump supplies cooling flow only to the drive motor DM. Regarding control logic Figure 4 See also: Figure 4 The fourth part of the logic block diagram of the feasible scheme for EOP speed control target; Implementation method ④, based on implementation method ③ above and in conjunction with implementation method ②, further incorporates logic for determining the temperature level of the NTC Sensor. For example... Figure 4 As shown.

[0051] In all the above implementation methods, the underlying setting logic of Table 1 or Table 2 looked up by the motor system controller is one of the core inventive points of this invention: The following table 1 or table 2, and its corresponding curve relationship diagram ( Figure 6 , Figure 7 As shown in the figure, when the NTC Sensor temperature of the motor winding is less than or equal to a certain temperature value A, the EOP speed is set to the minimum EOP speed to ensure the minimum cooling and lubrication requirements of the motor system.

[0052] When the NTC Sensor temperature of the motor winding is within a certain range (e.g., A℃ < NTC Sensor temperature < B℃), two paths are set for EOP speed control: When the NTC Sensor temperature rise rate is less than a certain value (e.g., <5℃ / 10s), path 1 is selected (as shown by the dashed line in the curve relationship diagram), and the EOP speed is adjusted in a timely manner to achieve the lowest EOP power consumption; when the NTC Sensor temperature rise rate is greater than a certain value (e.g., >5℃ / 10s), path 2 is selected (as shown by the dashed line in the curve relationship diagram), and the EOP speed is rapidly increased to meet the large heat dissipation power requirements of the motor system during sudden changes.

[0053] When the NTC Sensor temperature of the motor winding is greater than or equal to a certain temperature value C, the motor system is in a high-power, high-heat-dissipation-power operating condition. Set the EOP (Extreme Operating Speed) to fully cool the motor system and ensure that the motor can operate at full power with good performance.

[0054] Tables 1, 2, and 3 contain NTC Sensor temperature, EOP speed, TM (DM) speed, and EOP speed coefficient K value, all of which were obtained through calibration tests.

[0055] Table 1: One of the Correspondences between NTC Sensor Temperature and EOP Speed ​​Control

[0056] Table 2: Correspondence between NTC Sensor Temperature and EOP Speed ​​Control (Part 2)

[0057] Table 3: Relationship between DM(TM) speed, torque and EOP speed coefficient K

[0058] Example 2 See Figure 8 Embodiment 2 of the present invention provides a motor system controller, including a memory 10, a processor 20, and a computer program 30 stored in the memory and executable on the processor. When the processor 20 executes the computer program, it implements a method for controlling the speed of an electronic oil pump in a motor system.

[0059] In summary, this invention constructs a dynamic index assessment method based on the fusion of multi-source heterogeneous data, enabling the continuous expression of the risk status of foundation pit engineering using a unified indicator system and calculation logic. Compared with traditional qualitative judgment methods based on static monitoring values ​​and manual inspections, this invention firstly significantly improves the completeness and accuracy of on-site status information through the fusion processing of multi-source data such as monitoring data and video inspection data; secondly, by introducing a dynamic weight model that automatically adjusts with the construction stage and indicator trend changes, the assessment results can truly reflect the changes in the dominant risk factors under different working conditions, thereby overcoming the limitations of fixed weights and static assessments that are difficult to apply to full-process management. Furthermore, by designing matching scoring methods for different types of indicators, various engineering entity risks, behavioral risks, and environmental risks can all be quantitatively incorporated into a unified model, significantly improving the accuracy and interpretability of the assessment. The resulting dynamic safety index can continuously reflect the risk evolution process, facilitating managers to promptly identify adverse trends and implement targeted measures. It also provides more reliable quantitative basis for engineering monitoring and early warning, construction organization optimization, and regulatory evaluation, thereby enhancing the scientific rigor and foresight of foundation pit engineering risk management.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art can modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for controlling the speed of an electronic oil pump in a motor system, characterized in that, The following steps are included: S1. Obtain the current temperature value from the motor winding temperature sensor; S2. Based on the current temperature value, query the first mapping relationship to obtain the first EOP requested speed. The first mapping relationship is used to set and determine the correspondence between the motor winding temperature and the EOP requested speed with the motor system thermal balance control target. S3. Obtain the current speed and torque of the drive motor DM; S4. Based on the current speed and torque of the drive motor DM, query the second mapping relationship to obtain the EOP speed coefficient K value. The second mapping relationship is used to set and determine the correspondence between the speed and torque of the drive motor DM and the EOP speed coefficient K. S5. Multiply the first EOP requested speed by the EOP speed coefficient K value to obtain the initial EOP target speed; S6. Compare the initial EOP target speed with the preset minimum guaranteed EOP speed, and take the maximum value of the two as the final EOP target control speed; S7. Control the EOP operation by controlling the rotational speed according to the final EOP target.

2. The method according to claim 1, characterized in that, The process includes, after step S1 and before step S2: determining whether the current temperature value is greater than or equal to a first temperature threshold. If so, proceed to steps S2 to S7; If not, the first EOP request speed obtained by querying the first mapping relationship based on the current temperature value is directly used as the final EOP target control speed, and step S7 is executed.

3. The method according to claim 2, characterized in that, The method is applied to a cooling and lubrication system that includes dual motors and solenoid valves. Step S1 specifically involves: The current temperature value of the first motor winding temperature sensor and the current temperature value of the second motor winding temperature sensor are obtained, and the maximum value of the two is taken as the current temperature value. Step S2 specifically includes: S21. Obtain the current state of the solenoid valve; S22. If the solenoid valve is in the closed state, the third mapping relationship is queried according to the current temperature value to obtain the first EOP requested speed. If the solenoid valve is in the open state, the first mapping relationship is queried according to the current temperature value to obtain the first EOP requested speed. The third mapping relationship is used to define the correspondence between the motor winding temperature and the EOP requested speed in the solenoid valve closed and single motor cooling mode.

4. The method according to claim 3, characterized in that, The steps following step S1 and before step S21 also include: Determine whether the current temperature value is greater than or equal to the first temperature threshold; If so, proceed with steps S21 to S7; If not, after executing steps S21 and S22, the first EOP requested speed is directly used as the final EOP target control speed, and step S7 is executed.

5. The method according to claim 3, characterized in that, The construction logic for the first mapping relationship and / or the third mapping relationship includes: When the motor winding temperature is less than or equal to the second temperature threshold, the EOP requests the minimum guaranteed speed of the EOP. When the motor winding temperature is greater than the second temperature threshold and less than the third temperature threshold, different control paths are selected according to the temperature rise rate of the motor winding temperature: if the temperature rise rate is less than or equal to the rate threshold, the first control path is selected, and the EOP requests the speed to rise slowly with the temperature; if the temperature rise rate is greater than the rate threshold, the second control path is selected, and the EOP requests the speed to rise rapidly. When the motor winding temperature is greater than or equal to the fourth temperature threshold, the EOP requests the maximum permissible speed of the EOP.

6. The method according to claim 5, characterized in that, The first control path is used to control and adjust the EOP speed to achieve the lowest EOP power consumption, and the second control path is used to control the maximum EOP speed to meet the preset high power and high heat dissipation power operating conditions of the motor system.

7. The method according to claim 6, characterized in that, The minimum guaranteed EOP speed is the EOP speed corresponding to the required cooling oil flow rate to ensure that the motor system meets the minimum cooling and lubrication requirements.

8. The method according to claim 1, characterized in that, The motor system is a dual-motor system for hybrid electric drive; it also includes an additional electromagnetic control valve added to the cooling oil circuit of the electric drive assembly: the cooling oil circuit of the electric drive assembly includes a gearbox, an additional electromagnetic control valve, a heat exchanger, a filter press, a drive motor DM, a generator GM, an EOP, a suction filter, and an oil pan; The status of the additional electromagnetic control valve in the cooling oil circuit is detected, and the cooling flow rate is selected to supply to different motors according to the opening or closing status of the additional electromagnetic control valve. When the additional electromagnetic control valve is closed, the electronic oil pump only supplies cooling flow to the drive motor DM; When the additional electromagnetic control valve is opened, the electronic oil pump simultaneously supplies cooling flow to the drive motor DM and the generator GM.

9. The method according to any one of claims 1 to 8, characterized in that, The first mapping relationship, the second mapping relationship, the third mapping relationship, the first temperature threshold, the second temperature threshold, the third temperature threshold, the fourth temperature threshold, the rate threshold, and the minimum guaranteed rotational speed for EOP are preset values.

10. A motor system controller, characterized in that, The method includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method for controlling the speed of an electronic oil pump in a motor system as described in any one of claims 1 to 8.

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