New energy power system electronic pump control method

Abstract

The invention discloses a new energy power system electronic pump control method and belongs to the technical field of motor cooling. The method comprises the following steps: the MCU collects a motor state signal in real time; the MCU calculates the cooling demand flow of the electronic pump according to the collected motor state signal, sends a cooling demand flow instruction to the electronic pump to activate the electronic pump, and then sends an operation enable signal to the electronic pump; the MCU communicates with the electronic pump through a CAN bus to realize cooperative control; according to the vehicle operation mode, the corresponding electronic pump control strategy is executed to dynamically adjust the flow output of the electronic pump, the mechanical pump is assisted to achieve the cooling effect on the motor, and it is ensured that the temperature of the motor is within the safe range. According to the method, a rotating speed-torque combined table look-up and temperature compensation mechanism is adopted, a multi-operation-mode differential control strategy is combined, the problem of insufficient cooling or redundant energy consumption caused by traditional static threshold value control is effectively solved, and the system energy efficiency is remarkably improved.

Description

Technical Field

[0001] The invention relates to a new energy power system electronic pump control method, belonging to the technical field of motor cooling. Background Art

[0002] In the field of new energy vehicle technology, the efficiency of the motor cooling system plays a decisive role in the reliability and performance of the vehicle's powertrain. Traditional cooling control strategies typically use static control logic based on fixed temperature thresholds or preset single operating condition parameters. These design limitations make dynamic adaptation difficult under complex and changing operating conditions. Specifically, existing technical solutions have the following technical deficiencies: 1. The electronic pump control logic in traditional cooling systems lacks a deep coupling mechanism with the motor's real-time operating status (such as core component temperature, speed, and output torque). This results in a significant mismatch between the cooling medium flow rate and the actual heat load demand. This static threshold control mode can easily lead to insufficient cooling under sudden changes in motor load or sustained high load conditions, resulting in the risk of local overheating. Under low-load conditions, excessive cooling leads to unnecessary increases in system energy consumption.

[0003] 2. Existing cooling systems generally use a centralized flow supply solution, lacking a dynamic flow distribution mechanism based on the heat load distribution characteristics of various motor components. This design flaw prevents the cooling medium from accurately matching the real-time heat dissipation needs of key heat sources (such as stator windings and power modules), potentially causing localized heat accumulation and inefficient energy utilization due to excessive cooling in unnecessary areas.

[0004] 3. New energy vehicle powertrains typically include multiple operating modes, including pure electric drive (EV mode) and hybrid parallel drive. The motor's power output characteristics, heat loss distribution, and continuous operating time vary significantly across these modes. Traditional cooling strategies fail to establish differentiated control models to account for these mode differences. This can lead to delayed response or redundant control during mode switching, directly impacting the smoothness and economy of the vehicle's power output. Summary of the Invention

[0005] In order to solve the problems existing in the background technology, the present invention provides a new energy power system electronic pump control method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a new energy power system electronic pump control method, the method comprising the following steps: S1: MCU collects motor status signals in real time; S2: The MCU calculates the cooling flow rate of the electronic pump based on the collected motor status signal, sends a cooling flow rate instruction to the electronic pump to activate the electronic pump, and then sends an operation enable signal to the electronic pump; S3: MCU communicates with the electronic pump via the CAN bus to achieve coordinated control; S4: Based on the vehicle operating mode, the corresponding electronic pump control strategy is executed to dynamically adjust the flow output of the electronic pump to assist the mechanical pump in cooling the motor and ensure that the motor temperature is within a safe range.

[0007] Furthermore, the cooling demand flow of the electronic pump described in S2 is calculated by dynamically selecting the maximum value as the final demand through a two-dimensional lookup table of GM and TM motor speeds and torques or an independent lookup table of stator temperature.

[0008] Furthermore, the operation enabling conditions of the electronic pump described in S2 include: the vehicle high-voltage system is powered on, the MCU receives the Ready set 1 signal, the generator speed is lower than 6000 rpm, the C1 clutch is not engaged, and the motor stator temperature is higher than -25°C.

[0009] Furthermore, the exit conditions of the electronic pump described in S2 are that the vehicle high-voltage system is powered off or the MCU receives the Ready set to 0 signal or the generator speed is greater than or equal to 6000 rpm or the C1 clutch is engaged or the motor stator temperature is less than or equal to -25°C or the electronic pump has a level 3 or above fault.

[0010] Furthermore, the signals of the CAN bus for implementing the collaborative control in S3 include: **MCU_0x06C_nSpdOilMotor**: electronic pump assembly speed command; **MCU_0x06C_bEnOilMotor**: Electronic pump operation enable signal, used to control the start and stop of the electronic pump; **Pump_stOilPumpErr**: electronic pump fault code, used for abnormal diagnosis; **Pump_stEOPfaultLevel**: Electronic pump fault level, used for abnormality diagnosis; **Pump_tOilPmpTemp**: electronic pump motor temperature; **MCU2_226_EngineStartr**: engine running request, used for engine start; **HCU_311_t_trsmOilTemp**: electronic pump oil temperature signal, used for flow demand calculation; **HCU_214_VEH_SPD**: Vehicle speed signal, used to participate in NVH optimization strategy.

[0011] Furthermore, the method further includes an NVH optimization strategy, wherein the NVH optimization strategy includes: Case 1: When the vehicle speed is ≤78km / h: If the motor temperature is less than 100°C and the torque is less than or equal to 230 Nm, the electronic pump speed is limited to 1600 rpm; If the temperature is within the limit, but the motor torque exceeds the limit of 1600 rpm and lasts for more than 2 seconds, the electronic pump speed limit of 1600 rpm will be cancelled; Case 1: When the vehicle speed is greater than 78km / h: If the motor temperature is less than 80°C and the torque is less than or equal to 150Nm, the electronic pump speed is limited to 1600rpm; If the temperature is within the limit, but the motor torque exceeds the limit of 1600 rpm and lasts for more than 2 seconds, the electronic pump speed limit of 1600 rpm is cancelled.

[0012] Furthermore, the control strategy of the electronic pump in the vehicle operation mode in S4 includes: EV mode: Based on the drive motor speed, torque and stator temperature, the flow demand is obtained by looking up the table, and the maximum flow demand is selected as the motor cooling flow demand; Idle power generation mode: Based on the generator speed, torque and stator temperature table lookup, the maximum flow demand is selected as the motor cooling flow demand; Parallel mode: When the generator speed is less than 6000 rpm and the C1 clutch is not engaged, the electronic pump is controlled in EV mode; when the speed is ≥ 6000 rpm or the C1 clutch is engaged, the electronic pump stops; Series mode: When the generator speed is less than 6000 rpm and the C1 clutch is not engaged, the flow rate requirements of the generator and drive motor are calculated based on their speed-torque requirements. If the sum exceeds 11 L / min, the flow rate is 11 L / min. When the generator speed is ≥6000 rpm, the electronic pump is controlled in EV mode. When the C1 clutch is engaged, the electronic pump stops working. Direct drive mode: the electronic pump stops working after the C1 clutch is engaged; Limp / Zero Torque Mode: Based on the dual motor temperature lookup table, the flow demand at the maximum temperature of the two is taken as the motor cooling flow demand; Fault mode: The electronic pump stops working immediately and requests the engine to start when the GM / TM speed is greater than 50rpm or the torque is greater than 20Nm; the electronic pump fault signal will be transmitted to the MCU in real time via the CAN bus.

[0013] Furthermore, the control strategy for the electronic pump gear switching in S4 includes: When the P / N gear is switched to the R / D gear, the electronic pump updates the motor cooling flow strategy according to the target mode; In the P / N gear, the motor cooling flow requirement is determined based on the maximum temperature of the dual motors and the vehicle speed.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts a speed-torque joint lookup table and temperature compensation mechanism, combined with a differentiated control strategy for multiple operating modes, to effectively solve the problems of insufficient cooling or redundant energy consumption caused by traditional static threshold control, and significantly improve the energy efficiency of the system; based on the CAN bus, the coordinated control of the electronic pump and the mechanical pump and the dynamic distribution of flow are realized, and a thermal load response mechanism for key components is established, which greatly improves the accuracy of heat dissipation and reduces the energy consumption of the system; the present invention integrates NVH optimization and fault redundancy protection functions, improves vibration and noise by speed limitation under low-speed and high-torque conditions, and automatically triggers the protection mechanism when the electronic pump fails, thereby comprehensively improving the system operation reliability; the transition control logic is designed according to the mode switching characteristics of the hybrid system to ensure that the cooling system can achieve seamless adaptation during the mode switching process, which is particularly suitable for the cooling needs of new energy power systems under complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic block diagram of the present invention; Figure 2 Schematic diagram of the hardware interface of the electronic pump used in the present invention; Figure 3 It is a front view of the electronic pump used in the present invention; Figure 4 yes Figure 3 side view. DETAILED DESCRIPTION

[0016] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] A method for controlling an electronic pump of a new energy power system, the method comprising the following steps: S1: The MCU (motor controller) collects motor status signals in real time, including motor stator temperature, motor speed, torque, clutch status, and vehicle control mode; S2: The MCU calculates the cooling flow rate of the electronic pump using a preset algorithm based on the collected motor status signal, and then sends a cooling flow rate instruction to the electronic pump to activate the electronic pump, and then sends an operation enable signal to the electronic pump; S3: MCU communicates with the electronic pump via the CAN bus to achieve coordinated control; S4: Based on the vehicle operating mode, the corresponding electronic pump control strategy is executed to dynamically adjust the flow output of the electronic pump to assist the mechanical pump in cooling the motor and ensure that the motor temperature is within a safe range.

[0018] Furthermore, the cooling demand flow of the electronic pump described in S2 is calculated by dynamically selecting the maximum value as the final demand through a two-dimensional lookup table of GM and TM motor speed and torque or an independent lookup table of stator temperature to ensure motor cooling.

[0019] Furthermore, the operation enabling conditions of the electronic pump described in S2 include: the vehicle high-voltage system is powered on, the MCU receives the Ready set 1 signal, the generator speed is lower than 6000 rpm, the C1 clutch is not engaged, and the motor stator temperature is higher than -25°C.

[0020] The above conditions must be met simultaneously to activate the electronic pump.

[0021] Furthermore, the exit conditions of the electronic pump described in S2 are that the vehicle high-voltage system is powered off or the MCU receives the Ready set to 0 signal or the generator speed is greater than or equal to 6000 rpm or the C1 clutch is engaged or the motor stator temperature is less than or equal to -25°C or the electronic pump has a level 3 or above fault.

[0022] Furthermore, the signals of the CAN bus for implementing the collaborative control in S3 include: **MCU_0x06C_nSpdOilMotor**: electronic pump assembly speed command, unit rpm; **MCU_0x06C_bEnOilMotor**: Electronic pump operation enable signal, used to control the start and stop of the electronic pump; **Pump_stOilPumpErr**: electronic pump fault code, used for abnormal diagnosis; **Pump_stEOPfaultLevel**: Electronic pump fault level, used for abnormality diagnosis; **Pump_tOilPmpTemp**: electronic pump motor temperature, unit ℃; **MCU2_226_EngineStartr**: engine running request, used for engine start; **HCU_311_t_trsmOilTemp**: electronic pump oil temperature signal, used for flow demand calculation; **HCU_214_VEH_SPD**: Vehicle speed signal, used to participate in NVH optimization strategy.

[0023] Furthermore, the method also includes an NVH optimization strategy, which dynamically limits the speed of the electronic pump by jointly determining vehicle speed, motor temperature, and torque parameters to avoid the generation of high-frequency noise. The NVH optimization strategy includes: Case 1: When the vehicle speed is ≤78km / h: If the motor temperature is less than 100°C and the torque is less than or equal to 230 Nm, the electronic pump speed is limited to 1600 rpm; If the temperature is within the limit, but the motor torque exceeds the limit of 1600 rpm and lasts for more than 2 seconds, the electronic pump speed limit of 1600 rpm will be cancelled to ensure that the motor does not overheat; Case 1: When the vehicle speed is greater than 78km / h: If the motor temperature is less than 80°C and the torque is less than or equal to 150Nm, the electronic pump speed is limited to 1600rpm; If the temperature is within the limit, but the motor torque exceeds the limit of 1600 rpm and lasts for more than 2 seconds, the electronic pump speed limit of 1600 rpm will be cancelled to ensure that the motor does not overheat; Furthermore, the control strategy of the electronic pump in the vehicle operation mode in S4 includes: EV mode: Based on the drive motor speed, torque and stator temperature, the flow demand is obtained by looking up the table, and the maximum flow demand is selected as the motor cooling flow demand; Idle power generation mode: Based on the generator speed, torque and stator temperature table lookup, the maximum flow demand is selected as the motor cooling flow demand; Parallel mode: When the generator speed is less than 6000 rpm and the C1 clutch is not engaged, the electronic pump is controlled in EV mode; when the speed is ≥ 6000 rpm or the C1 clutch is engaged, the electronic pump stops; Series mode: When the generator speed is less than 6000 rpm and the C1 clutch is not engaged, the flow rate requirements of the generator and drive motor are calculated based on their speed-torque requirements. If the sum exceeds 11 L / min, the flow rate is 11 L / min. When the generator speed is ≥6000 rpm, the electronic pump is controlled in EV mode. When the C1 clutch is engaged, the electronic pump stops working. Direct drive mode: the electronic pump stops working after the C1 clutch is engaged; Limp / Zero Torque Mode: Based on the dual motor temperature lookup table, the flow demand at the maximum temperature of the two is taken as the motor cooling flow demand; Fault mode: The electronic pump stops working immediately and requests the engine to start when the GM / TM speed is greater than 50rpm or the torque is greater than 20Nm; the electronic pump fault signal is transmitted to the MCU in real time via the CAN bus for further processing and decision-making.

[0024] Furthermore, the control strategy for the electronic pump gear switching in S4 includes: When the P / N gear is switched to the R / D gear, the electronic pump updates the motor cooling flow strategy according to the target mode; In the P / N gear, the motor cooling flow requirement is determined based on the maximum temperature of the dual motors and the vehicle speed.

[0025] The electronic pump used in the present invention includes the negative power supply pin 1 (rated operating current 25A / 12V, rated performance point, rated current), the positive power supply pin 2 (rated operating current 25A / 12V, rated performance point, rated current), the CAN_L pin 3 (communication interface), the CAN_H pin 4 (communication interface) and the KL15 pin 5 (ignition signal) to ensure stable signal transmission.

[0026] The hardware interfaces include: Connector pin definition: clearly define the pin assignments for power, ground, and CAN signals; Dimensional drawing: specifies the installation dimensions and interface position of the electronic pump; Network topology diagram: shows the CAN bus connection relationship between MCU, HCU, and electronic pump.

[0027] The connector models are as follows: Interface 1: KL31; Interface 2: KL30; Interface 3: CANL; Interface 4: CANH; Interface 5: KL15.

[0028] Table 1 Connector Definition It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0029] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A motor cooling control method for a new energy power system, characterized by: The method comprises the following steps: S1: MCU collects motor status signals in real time; S2: The MCU calculates the cooling flow rate of the electronic pump based on the collected motor status signal, sends a cooling flow rate instruction to the electronic pump to activate the electronic pump, and then sends an operation enable signal to the electronic pump; S3: MCU communicates with the electronic pump via the CAN bus to achieve coordinated control; S4: According to the vehicle operation mode, the corresponding electronic pump control strategy is executed to dynamically adjust the flow output of the electronic pump to assist the mechanical pump in cooling the motor and ensure that the motor temperature is within a safe range.

2. The motor cooling control method of a new energy power system according to claim 1, characterized in that: The calculation of the cooling demand flow of the electronic pump described in S2 is performed by dynamically selecting the maximum value as the final demand through a two-dimensional lookup table of the GM and TM motor speeds and torques or an independent lookup table of the stator temperature.

3. The motor cooling control method of a new energy power system according to claim 1, characterized in that: The operation enabling conditions of the electronic pump described in S2 include: the vehicle high-voltage system is powered on, the MCU receives the Ready set 1 signal, the generator speed is lower than 6000 rpm, the C1 clutch is not engaged, and the motor stator temperature is higher than -25°C.

4. The motor cooling control method of a new energy power system according to claim 1, characterized in that: The exit conditions of the electronic pump described in S2 are that the vehicle high-voltage system is powered off or the MCU receives the Ready set to 0 signal or the generator speed is greater than or equal to 6000 rpm or the C1 clutch is engaged or the motor stator temperature is less than or equal to -25°C or the electronic pump has a level 3 or above fault.

5. The motor cooling control method of a new energy power system according to claim 1, characterized in that: The signals of the CAN bus for realizing the coordinated control described in S3 include: **MCU_0x06C_nSpdOilMotor**: electronic pump assembly speed command; **MCU_0x06C_bEnOilMotor**: Electronic pump operation enable signal, used to control the start and stop of the electronic pump; **Pump_stOilPumpErr**: electronic pump fault code, used for abnormal diagnosis; **Pump_stEOPfaultLevel**: Electronic pump fault level, used for abnormality diagnosis; **Pump_tOilPmpTemp**: electronic pump motor temperature; **MCU2_226_EngineStartr**: engine running request, used for engine start; **HCU_311_t_trsmOilTemp**: electronic pump oil temperature signal, used for flow demand calculation; **HCU_214_VEH_SPD**: Vehicle speed signal, used to participate in NVH optimization strategy.

6. The motor cooling control method of a new energy power system according to claim 5, characterized in that: The method further includes an NVH optimization strategy, wherein the NVH optimization strategy includes: Case 1: When the vehicle speed is ≤78km / h: If the motor temperature is less than 100°C and the torque is less than or equal to 230 Nm, the electronic pump speed is limited to 1600 rpm; If the temperature is within the limit, but the motor torque exceeds the limit of 1600 rpm and lasts for more than 2 seconds, the electronic pump speed limit of 1600 rpm will be cancelled; Case 1: When the vehicle speed is greater than 78km / h: If the motor temperature is less than 80°C and the torque is less than or equal to 150Nm, the electronic pump speed is limited to 1600rpm; If the temperature is within the limit, but the motor torque exceeds the limit of 1600 rpm and lasts for more than 2 seconds, the electronic pump speed limit of 1600 rpm is cancelled.

7. The motor cooling control method of a new energy power system according to claim 5, characterized in that: The control strategy of the electronic pump in the vehicle operation mode of S4 includes: EV mode: The flow rate requirement is obtained by looking up the table based on the drive motor speed, torque and stator temperature, and the maximum flow rate requirement is selected as the motor cooling flow rate requirement; Idle power generation mode: Based on the generator speed, torque and stator temperature table lookup, the maximum flow demand is selected as the motor cooling flow demand; Parallel mode: When the generator speed is less than 6000 rpm and the C1 clutch is not engaged, the electronic pump is controlled in EV mode; when the speed is ≥ 6000 rpm or the C1 clutch is engaged, the electronic pump stops; Series mode: When the generator speed is less than 6000 rpm and the C1 clutch is not engaged, the flow rate requirements of the generator and drive motor are calculated based on their speed-torque requirements. If the sum exceeds 11 L / min, the flow rate is 11 L / min. When the generator speed is ≥6000 rpm, the electronic pump is controlled in EV mode. When the C1 clutch is engaged, the electronic pump stops working. Direct drive mode: the electronic pump stops working after the C1 clutch is engaged; Limp / Zero Torque Mode: Based on the dual motor temperature lookup table, the flow demand at the maximum temperature of the two is taken as the motor cooling flow demand; Fault mode: The electronic pump stops working immediately and requests the engine to start when the GM / TM speed is greater than 50rpm or the torque is greater than 20Nm; the electronic pump fault signal will be transmitted to the MCU in real time via the CAN bus.

8. The motor cooling control method of a new energy power system according to claim 5, characterized in that: The control strategy for the electronic pump gear switching in S4 includes: When the P / N gear is switched to the R / D gear, the electronic pump updates the motor cooling flow strategy according to the target mode; In the P / N gear, the motor cooling flow requirement is determined based on the maximum temperature of the dual motors and the vehicle speed.

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