Oil-cooled electrically-driven oil pump control strategy and system

Abstract

This invention provides a control strategy and system for an oil-cooled electric drive oil pump, belonging to the field of automotive technology. The control strategy includes: determining the operating states of a low-voltage power supply and a high-voltage power supply; determining the vehicle's gear mode when both the low-voltage and high-voltage power supplies are in an active state; and controlling and adjusting the oil pump system according to the vehicle's gear mode. Determining the vehicle's gear mode involves setting a control strategy that specifies the required oil pump speed for lubrication and cooling of the oil-cooled motor system under different operating modes. Based on the actual operating conditions of the vehicle and the motor's heat dissipation and cooling, this invention refines the control of the oil pump according to the vehicle's efficiency requirements, NVH requirements, heat dissipation, and lubrication requirements. The oil pump control strategy of this invention satisfies lubrication and cooling needs while also improving system efficiency, enhancing NVH performance, reducing oil pump energy consumption, and increasing battery range.

Description

Technical Field

[0001] This invention relates to the field of automotive technology, and more specifically to a control strategy and system for an oil-cooled electrically driven oil pump. Background Technology

[0002] Currently, the main oil pump control strategies on the market are as follows: Control based on the rated speed of the oil pump is relatively simple, but the energy consumption of the oil pump is high and NVH problems are more obvious; Obtain the vehicle's operating mode, motor heating power, radiator inlet oil temperature, and motor speed. When the operating mode is any of torque mode, pulse heating mode, or DC boost mode, determine the first oil pump speed for the corresponding operating mode based on the motor heating power and radiator inlet oil temperature; Determine the second oil pump speed based on the motor speed and radiator inlet oil temperature, and use the larger value between the first and second oil pump speeds as the target required speed of the oil pump. This control method mainly relies on previously calibrated data for control. For mass-produced products, if there is a large variation, it can easily lead to motor overheating.

[0003] The existing oil-cooled electric drive oil pump control strategy does not consider the control methods of the oil pump under conditions such as stall heating, ASC, and follow-up operation; the existing oil-cooled electric drive control strategy does not consider the robustness of the control strategy when the product consistency deviation is large; the existing oil-cooled electric drive control strategy does not define the control target of the motor temperature sensor. Summary of the Invention

[0004] The purpose of this invention is to provide a control strategy and system for an oil-cooled electric drive oil pump, which solves the problem of oil pump control methods that do not consider conditions such as stall heating, ASC, and follow-up operation. It defines the control target of the motor temperature sensor and improves the efficiency of the oil pump system.

[0005] To achieve the above objectives, the present invention provides a control strategy for an oil-cooled electrically driven oil pump, the control strategy comprising:

[0006] Determine the operating status of the low-voltage and high-voltage power supplies;

[0007] When both the low-voltage power supply and the high-voltage power supply are in the starting state, determine the vehicle's gear mode.

[0008] The oil pump system is controlled and adjusted according to the vehicle's gear mode.

[0009] Optionally, the control strategy includes:

[0010] When the low-voltage power supply is in standby mode, determine whether the vehicle is in ASC mode;

[0011] If the vehicle is determined to be in ASC mode, adjust the speed of the oil pump system to the peak speed;

[0012] If it is determined that the vehicle is not in ASC mode, the oil pump system is controlled to enter standby mode, and the speed of the oil pump system is adjusted to a first speed value.

[0013] Optionally, the vehicle's gear mode is determined, including:

[0014] Determine whether the vehicle is in any of the following gears: P, D, N, R, 0-100 km / h acceleration, or vehicle heating.

[0015] If the vehicle is in any of the following gears: P, D, N, R, 0-100 km / h acceleration, or vehicle heating, then the vehicle's gear mode is determined to be torque mode.

[0016] Optionally, the gear mode includes one or more of the following: torque mode, stall heating mode, coasting mode, and phase mode before power-off sleep mode.

[0017] Optionally, controlling the adjustment of the oil pump system according to the gear mode of the vehicle includes:

[0018] When the vehicle is in torque mode, the motor loss and temperature control target value of the motor system are determined based on the motor speed and torque.

[0019] Determine whether the motor loss is less than the first loss value;

[0020] If it is determined that the motor loss is less than the first loss value, it is determined whether the current motor NTC temperature is less than the first temperature control target value;

[0021] If the current motor NTC temperature is determined to be lower than the first temperature control target value, the motor NTC temperature is adjusted by speed control.

[0022] Determine whether the NTC temperature of the speed-regulated motor is lower than the first temperature control target value for the first time;

[0023] If the NTC temperature of the speed-regulated motor is found to be less than the first temperature control target value for the first time, it is determined whether the difference between the current torque of the vehicle and the over-temperature torque is less than or equal to the first threshold and whether the current power of the vehicle is less than the corresponding rated value.

[0024] If the difference between the current torque and the over-temperature torque of the vehicle is less than or equal to the first threshold and the current power of the vehicle is less than the corresponding rated value, output the lookup table oil pump command speed.

[0025] If the difference between the current torque and the over-temperature torque of the vehicle is greater than the first threshold or the current power of the vehicle is greater than the corresponding rated value, the speed is compensated and corrected according to the current output speed.

[0026] If the NTC temperature of the speed-regulated motor is greater than or equal to the first temperature control target value for the first time, the lookup table oil pump command speed is output.

[0027] Optionally, controlling the adjustment of the oil pump system according to the gear mode of the vehicle includes:

[0028] If the current motor NTC temperature is determined to be greater than the first temperature control target value, record an over-temperature torque and determine whether the current motor NTC temperature is greater than the second temperature value.

[0029] If the current motor NTC temperature is determined to be greater than the second temperature value, determine whether the current motor NTC temperature is greater than the third temperature value.

[0030] If the current motor NTC temperature is determined to be greater than the third temperature value, adjust the oil pump speed to the peak speed.

[0031] If the current motor NTC temperature is determined to be less than the third temperature value, and the current motor NTC temperature is greater than the second temperature value, the oil pump speed is incremented by the first accumulated value every second until the peak speed is reached.

[0032] If the current motor NTC temperature is determined to be lower than the second temperature value, the previous oil pump speed is output.

[0033] Optionally, controlling the adjustment of the oil pump system according to the gear mode of the vehicle includes:

[0034] When the vehicle is in torque mode, the motor loss and temperature control target value of the motor system are determined based on the motor speed and torque.

[0035] Determine whether the motor loss is greater than the first loss value;

[0036] If it is determined that the motor loss is greater than the first loss value, it is determined whether the current motor NTC temperature is less than the second temperature control target value;

[0037] If the current motor NTC temperature is determined to be lower than the second temperature control target value, the motor NTC temperature is adjusted by speed control.

[0038] Determine whether the NTC temperature of the speed-regulated motor is lower than the second temperature control target value for the first time;

[0039] If the NTC temperature of the speed-regulated motor is found to be less than the second temperature control target value for the first time, it is determined whether the difference between the current torque and the over-temperature torque of the vehicle is less than or equal to the second threshold and whether the current power of the vehicle is less than the corresponding rated value.

[0040] If the difference between the current torque and the over-temperature torque of the vehicle is less than or equal to the second threshold and the current power of the vehicle is less than the corresponding rated value, output the lookup table oil pump command speed.

[0041] If the difference between the current torque and the over-temperature torque of the vehicle is greater than the second threshold or the current power of the vehicle is greater than the corresponding rated value, the speed is compensated and corrected according to the current output speed.

[0042] If the NTC temperature of the speed-regulated motor is greater than or equal to the second temperature control target value for the first time, the lookup table oil pump command speed is output.

[0043] Optionally, controlling the adjustment of the oil pump system according to the gear mode of the vehicle includes:

[0044] If the current motor NTC temperature is determined to be greater than the second temperature control target value, record an over-temperature torque and determine whether the current motor NTC temperature is greater than the fourth temperature value.

[0045] If the current motor NTC temperature is determined to be greater than the fourth temperature value, determine whether the current motor NTC temperature is greater than the third temperature value.

[0046] If the current motor NTC temperature is determined to be greater than the third temperature value, adjust the oil pump speed to the peak speed.

[0047] If the current motor NTC temperature is determined to be less than the fifth temperature value, and the current motor NTC temperature is greater than the fourth temperature value, the oil pump speed is incremented by a second accumulated value every second until the peak speed is reached.

[0048] If the current motor NTC temperature is determined to be lower than the fourth temperature value, the previous oil pump speed is output.

[0049] Optionally, adjusting the speed of the oil pump system according to the motor speed and temperature includes:

[0050] Determine whether the corrected oil pump speed is greater than or equal to the peak speed;

[0051] If it is determined that the corrected oil pump speed is greater than or equal to the peak speed, the duration for which the corrected oil pump speed is greater than or equal to the peak speed is determined.

[0052] Determine whether the duration is greater than or equal to a preset first time threshold;

[0053] If the duration is determined to be greater than or equal to the first time threshold, the oil pump command speed is determined based on the corrected oil pump speed.

[0054] Determine whether the oil pump command speed is greater than a preset first oil pump command speed threshold or whether the vehicle has entered ASC mode;

[0055] If the oil pump command speed is determined to be greater than the preset first oil pump command speed threshold or the vehicle enters ASC mode, the oil pump system speed is determined to be the rated speed.

[0056] If the duration is determined to be less than the first time threshold, the rotational speed of the oil pump system is determined to be the peak speed;

[0057] If it is determined that the corrected oil pump speed is less than the peak speed, the speed of the oil pump system is determined to be the corrected oil pump speed.

[0058] Select the larger of the corrected oil pump speed, peak speed, and rated speed, and adjust the oil pump speed of the oil pump system according to the oil pump speed slope.

[0059] On the other hand, the present invention provides an oil-cooled electrically driven oil pump control system, the control system including a controller for executing any of the above-described control strategies.

[0060] Through the above technical solution, the vehicle's gear modes are determined, and control strategies are set for the required oil pump speeds for lubrication and cooling of the oil-cooled motor system under different operating modes. Based on the actual operating conditions of the vehicle and the motor's heat dissipation and cooling, this invention refines the control of the oil pump according to the vehicle's efficiency requirements, NVH requirements, heat dissipation, and lubrication requirements. The oil pump control strategy of this invention not only meets the needs of lubrication and cooling but also improves system efficiency, enhances NVH performance, reduces oil pump energy consumption, and increases battery range. Attached Figure Description

[0061] Figure 1 This is a flowchart of a control strategy for an oil-cooled electrically driven oil pump according to an embodiment of the present invention;

[0062] Figure 2 This is a partial flowchart of a control strategy for an oil-cooled electrically driven oil pump according to an embodiment of the present invention;

[0063] Figure 3 This is a partial flowchart of a control strategy for an oil-cooled electrically driven oil pump according to an embodiment of the present invention;

[0064] Figure 4This is a partial flowchart of a control strategy for an oil-cooled electrically driven oil pump according to an embodiment of the present invention;

[0065] Figure 5 This is a partial flowchart of a control strategy for an oil-cooled electrically driven oil pump according to an embodiment of the present invention. Detailed Implementation

[0066] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0067] In the embodiments of this application, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used to describe the relative positional relationships of components in relation to the directions shown in the accompanying drawings or in relation to the vertical, perpendicular, or gravitational directions.

[0068] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0069] like Figure 1 The diagram shows a flowchart of a control strategy for an oil-cooled electrically driven oil pump according to an embodiment of the present invention. Figure 1 In this context, the control strategy may include the following steps:

[0070] In step S1, the operating states of the low-voltage power supply and the high-voltage power supply are determined;

[0071] In step S2, when both the low-voltage power supply and the high-voltage power supply are in the starting state, the vehicle's gear mode is determined.

[0072] In step S3, the oil pump system is controlled and adjusted according to the vehicle's gear mode.

[0073] In Figure 1In this process, step S1 is used to determine the operating status of the low-voltage power supply and the high-voltage power supply, thereby determining whether the vehicle's fuel pump system needs to be adjusted. Since both the low-voltage and high-voltage power supplies draw power from the vehicle's engine, if both the low-voltage and high-voltage power supplies are in the starting state, it indicates that the fuel pump system is in the starting state. Therefore, steps S2 and S3 can be used to control and adjust the fuel pump system according to the vehicle's current gear mode.

[0074] When the low-voltage power supply or high-voltage power supply is in a non-starting state (standby state), the following can be performed: Figure 2 The method shown in the diagram. Figure 2 In this method, the steps may be further included:

[0075] In step S4, when the low-voltage power supply is in standby mode, it is determined whether the car is in ASC (Active Short Circuit) mode.

[0076] In step S5, if it is determined that the car is in ASC mode, the speed of the oil pump system is adjusted to the peak speed;

[0077] In step S6, if it is determined that the car is not in ASC mode, the oil pump system is controlled to enter standby mode, and the speed of the oil pump system is adjusted to the first speed value.

[0078] In Figure 2 In the illustrated method, when the low-voltage power supply is in standby mode, the system considers whether the vehicle is in ASC mode. If the vehicle is in ASC mode, the continuous current generated by the back electromotive force of the low-voltage power supply may cause the motor to overheat. Overheating can lead to demagnetization of the rotor magnets and can also cause the inverter to overheat, potentially damaging it. Therefore, the oil pump system speed is adjusted to its peak speed. When the vehicle is not in ASC mode, the oil pump system is controlled to enter standby mode, and its speed is adjusted to a first speed value. This first speed value can be calculated by determining whether the basic lubrication requirements of the bearings are met. In one example of this invention, this first speed can be 800 rpm.

[0079] When the low-voltage power supply or high-voltage power supply is in the startup state, the following can be performed: Figure 3 The method shown. In this Figure 3 In this method, the steps may be further included:

[0080] In step S200, it is determined whether the vehicle is in any of the following gears: P, D, N, R, 0-100 km / h acceleration, or vehicle heating.

[0081] In step S201, if it is determined that the car is in any of the following gears: P, D, N, R, 0-100 km / h acceleration, or vehicle heating, the car's gear mode is determined to be torque mode.

[0082] In this embodiment, such as Figure 2 and Figure 3 As shown, existing oil-cooled electric drive oil pump control strategies do not consider oil pump control methods under conditions such as stall heating, ASC, coasting mode, and pre-dormant mode after power-off. They simply control based on the rated speed of the oil pump, which is relatively simple but results in high energy consumption and significant NVH issues. Therefore, the gear mode can be one of several modes known to those skilled in the art. In the embodiments of this invention, the gear mode includes one or more of the following: torque mode, stall heating mode, coasting mode, and pre-dormant mode after power-off. When the vehicle is in coasting mode, the first threshold temperature is 123°C. If the motor temperature exceeds the first threshold temperature of 123°C, the rated speed of the oil pump is output. If the motor temperature is below the first threshold temperature of 123°C, the oil pump speed is 800 rpm, and the oil pump flow rate is 3 L / min.

[0083] When the car's gear mode is in torque mode, the following can be performed: Figure 4 The method shown in the diagram. Figure 4 In this method, the steps may be further included:

[0084] In step S202, when the vehicle's gear mode is in torque mode, the motor loss and temperature control target of the motor system are determined based on the motor speed and torque.

[0085] In step S203, it is determined whether the motor loss is less than the first loss value;

[0086] In step S204, if it is determined that the motor loss is less than the first loss value, it is determined whether the current motor NTC temperature is less than the first temperature control target value.

[0087] In step S205, if it is determined that the current motor NTC temperature is less than the first temperature control target value, the speed adjustment motor NTC temperature operation is performed;

[0088] In step S206, it is determined whether the NTC temperature of the motor after speed regulation is lower than the first temperature control target value for the first time;

[0089] In step S207, if it is determined that the NTC temperature of the motor after speed regulation is less than the first temperature control target value for the first time, it is determined whether the temperature difference between the current torque and the over-temperature torque of the car is less than or equal to the first threshold and whether the current power of the car is less than the corresponding rated value.

[0090] In step S208, if the temperature difference between the current torque and the overheat torque of the vehicle is less than or equal to the first threshold and the current power of the vehicle is less than the corresponding rated value, the lookup table oil pump command speed is output.

[0091] In step S209, if the difference between the current torque of the vehicle and the over-temperature torque is greater than the first threshold or the current power of the vehicle is greater than the corresponding rated value, the rotational speed is compensated and corrected according to the current output speed.

[0092] In step S210, when the NTC temperature of the speed-regulated motor is greater than or equal to the first temperature control target value for the first time, the lookup table oil pump command speed is output.

[0093] In this embodiment, the torque of the car is actually the torque output from the crankshaft of the engine. With a fixed power output, the torque of the car is inversely proportional to the engine speed. The faster the speed, the smaller the torque, and vice versa, reflecting the car's load-bearing capacity within a certain range. The torque and power of the car are among the main indicators of the engine, reflected in the car's performance, including acceleration, climbing ability, and suspension. Torque mode is a mode for controlling the output torque of the motor. By controlling the magnitude and phase of the current and voltage, precise control of the motor's output torque can be achieved. Torque mode can achieve constant torque control, speed control, and position control of the motor, and is a very important part of motor control. Torque mode control directly affects the motor's output torque and speed; the higher the control precision, the more stable the output torque and speed. Therefore, when the car's gear mode is in torque mode, the motor loss and temperature control target of the motor system are determined based on the motor speed and torque combined with a preset correspondence table. The first loss value can be any value known to those skilled in the art; in one embodiment of this invention, the first loss value is 1500W.

[0094] During energy conversion, motors experience internal losses. These losses affect the efficiency and economy of motor operation. Since the lost energy is ultimately converted into heat, the temperature of various motor components rises, affecting the lifespan of the insulation materials used and potentially even burning out the motor. Therefore, this invention sets a temperature control target. The first temperature control target value can be any value known to those skilled in the art. In one embodiment of this invention, the first temperature control target value is 120°C.

[0095] In step S211, if it is determined that the current motor NTC temperature is greater than the first temperature control target value, an over-temperature torque is recorded, and it is determined whether the current motor NTC temperature is greater than the second temperature value.

[0096] In step S212, if it is determined that the current motor NTC temperature is greater than the second temperature value, it is determined whether the current motor NTC temperature is greater than the third temperature value.

[0097] In step S213, if it is determined that the current motor NTC temperature is greater than the third temperature value, the oil pump speed is adjusted to the peak speed;

[0098] In step S214, if it is determined that the current motor NTC temperature is less than the third temperature value, and the current motor NTC temperature is greater than the second temperature value, the oil pump speed is increased by the first accumulated value every second until the peak speed is reached.

[0099] In step S215, if it is determined that the current motor NTC temperature is less than the second temperature value, the previous oil pump speed is output.

[0100] In this embodiment, such as Figure 4 As shown, the second temperature value can be any of the values ​​known to those skilled in the art. In one embodiment of the present invention, the second temperature value is 123°C. If the current motor loss is less than 1500W and the current motor NTC temperature is greater than 120°C, then it is determined whether the current motor NTC temperature is greater than 123°C. If the current motor NTC temperature is between 120°C and 123°C, the previous oil pump speed is output. The third temperature value can be any of the values ​​known to those skilled in the art. In one embodiment of the present invention, the third temperature value is 150°C. If the current motor NTC temperature exceeds 150°C, the oil pump speed is adjusted to the peak speed of 4500 rpm. If the current motor NTC temperature is between 123°C and 150°C, the oil pump speed is incremented by a first accumulated value every second until the peak speed of 4500 rpm is reached. The first accumulated value is 50 rpm.

[0101] In step S216, if it is determined that the motor loss is greater than the first loss value, it is determined whether the current motor NTC temperature is less than the second temperature control target value.

[0102] In step S217, if it is determined that the current motor NTC temperature is less than the second temperature control target value, the speed adjustment motor NTC temperature operation is performed;

[0103] In step S218, if it is determined that the NTC temperature of the motor after speed regulation is less than the second temperature control target value for the first time, it is determined whether the difference between the current torque of the car and the over-temperature torque is less than or equal to the second threshold and whether the current power of the car is less than the corresponding rated value.

[0104] In step S219, if the difference between the current torque and the over-temperature torque of the vehicle is less than or equal to the second threshold and the current power of the vehicle is less than the corresponding rated value, the lookup table oil pump command speed is output.

[0105] In step S220, if the difference between the current torque of the vehicle and the over-temperature torque is greater than the second threshold or the current power of the vehicle is greater than the corresponding rated value, the rotational speed is compensated and corrected according to the current output speed.

[0106] In step S221, if it is determined that the NTC temperature of the motor after speed regulation is greater than or equal to the second temperature control target value for the first time, the lookup table oil pump command speed is output.

[0107] In this embodiment, such as Figure 4 As shown, the second temperature control target value can be one of several values ​​known to those skilled in the art. In one embodiment of the present invention, the second temperature control target value is 140°C. The present invention performs zoned control based on the magnitude of motor losses. When the losses are lower than the first loss value of 1500W, the temperature target is the first temperature control target value of 120°C. When the losses are greater than or equal to the first loss value of 1500W, the temperature target is the second temperature control target value of 140°C. Zoned control can significantly reduce the energy consumption of the oil pump, improve the NVH performance of the oil pump, and improve the overall efficiency of the electric drive system.

[0108] In step S222, if it is determined that the current motor NTC temperature is greater than the second temperature control target value, an over-temperature torque is recorded, and it is determined whether the current motor NTC temperature is greater than the fourth temperature value.

[0109] In step S223, if it is determined that the current motor NTC temperature is greater than the fourth temperature value, it is determined whether the current motor NTC temperature is greater than the third temperature value.

[0110] In step S224, if it is determined that the current motor NTC temperature is greater than the third temperature value, the oil pump speed is adjusted to the peak speed;

[0111] In step S225, if it is determined that the current motor NTC temperature is less than the fifth temperature value, and the current motor NTC temperature is greater than the fourth temperature value, the oil pump speed is increased by the second accumulated value every second until the peak speed is reached.

[0112] In step S226, if it is determined that the current motor NTC temperature is less than the fourth temperature value, the previous oil pump speed is output.

[0113] In this embodiment, the fourth temperature value can be any of the values ​​known to those skilled in the art. In one embodiment of the present invention, the fourth temperature value is 143°C. When the current motor NTC temperature is between 140°C and 143°C, the previous oil pump speed is output. When the current motor NTC temperature is between 143°C and 150°C, the oil pump speed is incremented by a second accumulated value every second until the peak speed is reached. The second accumulated value can be any of the values ​​known to those skilled in the art. In one embodiment of the present invention, the second accumulated value is 100 rpm, and the peak speed is 4500 rpm. When the current motor NTC temperature exceeds 150°C, the oil pump speed is adjusted to the peak speed.

[0114] Having determined the oil pump speed at different temperatures, the following can be executed: Figure 5 The method shown. In this Figure 5 In this method, the steps may be further included:

[0115] In step S301, it is determined whether the corrected oil pump speed is greater than or equal to the peak speed.

[0116] In step S302, if it is determined that the corrected oil pump speed is greater than or equal to the peak speed, the duration for which the corrected oil pump speed is greater than or equal to the peak speed is determined.

[0117] In step S303, it is determined whether the duration is greater than or equal to a preset first time threshold.

[0118] In step S304, if the duration is determined to be greater than or equal to the first time threshold, the oil pump command speed is determined based on the corrected oil pump speed.

[0119] In step S305, it is determined whether the oil pump command speed is greater than the preset first oil pump command speed threshold or whether the vehicle has entered ASC mode.

[0120] In step S306, if it is determined that the oil pump command speed is greater than the preset first oil pump command speed threshold or the vehicle enters ASC mode, the oil pump system speed is determined to be the rated speed.

[0121] In step S307, if the duration is less than the first time threshold, the rotational speed of the oil pump system is determined to be the peak speed.

[0122] In step S308, if it is determined that the corrected oil pump speed is less than the peak speed, the speed of the oil pump system is determined to be the corrected oil pump speed.

[0123] In step S309, the larger of the corrected oil pump speed, peak speed, and rated speed is selected, and the oil pump speed of the oil pump system is controlled and adjusted according to the oil pump speed slope.

[0124] In this embodiment, the first time threshold can be any of several values ​​known to those skilled in the art. In one embodiment of the present invention, the first time threshold is 15 seconds. Considering the operating conditions where the motor switches between high and low throttle, speed slope control is applied to the rise and fall of the oil pump speed, thereby improving the safety of the system.

[0125] On the other hand, the present invention provides an oil-cooled electrically driven oil pump control system, the control system including a controller for executing any of the above-described control strategies.

[0126] Through the above technical solution, the vehicle's gear modes are determined, and control strategies are set for the required oil pump speeds for lubrication and cooling of the oil-cooled motor system under different operating modes. Based on the actual operating conditions of the vehicle and the motor's heat dissipation and cooling, this invention refines the control of the oil pump according to the vehicle's efficiency requirements, NVH requirements, heat dissipation, and lubrication requirements. The oil pump control strategy of this invention not only meets the needs of lubrication and cooling but also improves system efficiency, enhances NVH performance, reduces oil pump energy consumption, and increases battery range.

[0127] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0128] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not describe the various possible combinations separately.

[0129] Furthermore, various different embodiments of the present invention can be combined arbitrarily, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A control strategy for an oil-cooled electrically driven oil pump, characterized in that, The control strategy includes: Determine the operating status of the low-voltage and high-voltage power supplies; When both the low-voltage power supply and the high-voltage power supply are in the starting state, the vehicle's gear mode is determined. The oil pump system is controlled and adjusted according to the gear mode of the vehicle. The control strategy includes: When the low-voltage power supply is in standby mode, determine whether the vehicle is in ASC mode; If the vehicle is determined to be in ASC mode, adjust the speed of the oil pump system to the peak speed; If it is determined that the vehicle is not in ASC mode, the oil pump system is controlled to enter standby mode, and the speed of the oil pump system is adjusted to a first speed value. Determine the car's gear mode, including: Determine whether the vehicle is in any of the following gears: P, D, N, R, 0-100 km / h acceleration, or vehicle heating. If it is determined that the vehicle is in any of the following gears: P, D, N, R, 0-100 km / h acceleration, or vehicle heating, then the vehicle's gear mode is determined to be torque mode. The gear mode includes one or more of the following: torque mode, stall heating mode, coasting mode, and phase mode before power-off sleep mode.

2. The control strategy according to claim 1, characterized in that, The oil pump system is controlled and adjusted according to the vehicle's gear mode, including: When the vehicle is in torque mode, the motor loss and temperature control target value of the motor system are determined based on the motor speed and torque. Determine whether the motor loss is less than the first loss value; If it is determined that the motor loss is less than the first loss value, it is determined whether the current motor NTC temperature is less than the first temperature control target value; If the current motor NTC temperature is determined to be lower than the first temperature control target value, the motor NTC temperature is adjusted by speed control. Determine whether the NTC temperature of the motor after speed adjustment is lower than the first temperature control target value for the first time; If the NTC temperature of the speed-regulated motor is found to be less than the first temperature control target value for the first time, it is determined whether the difference between the current torque of the vehicle and the over-temperature torque is less than or equal to the first threshold and whether the current power of the vehicle is less than the corresponding rated value. If the difference between the current torque and the over-temperature torque of the vehicle is less than or equal to the first threshold and the current power of the vehicle is less than the corresponding rated value, output the lookup table oil pump command speed. If the difference between the current torque and the over-temperature torque of the vehicle is greater than the first threshold or the current power of the vehicle is greater than the corresponding rated value, the speed is compensated and corrected according to the current output speed. If the NTC temperature of the speed-regulated motor is greater than or equal to the first temperature control target value for the first time, the lookup table oil pump command speed is output.

3. The control strategy according to claim 2, characterized in that, The oil pump system is controlled and adjusted according to the vehicle's gear mode, including: If the current motor NTC temperature is determined to be greater than the first temperature control target value, record an over-temperature torque and determine whether the current motor NTC temperature is greater than the second temperature value. If the current motor NTC temperature is determined to be greater than the second temperature value, determine whether the current motor NTC temperature is greater than the third temperature value. If the current motor NTC temperature is determined to be greater than the third temperature value, adjust the oil pump speed to the peak speed. If the current motor NTC temperature is determined to be less than the third temperature value, and the current motor NTC temperature is greater than the second temperature value, the oil pump speed is incremented by the first accumulated value every second until the peak speed is reached. If the current motor NTC temperature is determined to be lower than the second temperature value, the previous oil pump speed is output.

4. The control strategy according to claim 3, characterized in that, The oil pump system is controlled and adjusted according to the vehicle's gear mode, including: When the vehicle is in torque mode, the motor loss and temperature control target value of the motor system are determined based on the motor speed and torque. Determine whether the motor loss is greater than the first loss value; If it is determined that the motor loss is greater than the first loss value, it is determined whether the current motor NTC temperature is less than the second temperature control target value; If the current motor NTC temperature is determined to be lower than the second temperature control target value, the motor NTC temperature is adjusted by speed control. Determine whether the NTC temperature of the speed-regulated motor is lower than the second temperature control target value for the first time; If the NTC temperature of the speed-regulated motor is found to be less than the second temperature control target value for the first time, it is determined whether the difference between the current torque of the vehicle and the over-temperature torque is less than or equal to the second threshold and whether the current power of the vehicle is less than the corresponding rated value. If the difference between the current torque and the over-temperature torque of the vehicle is less than or equal to the second threshold and the current power of the vehicle is less than the corresponding rated value, output the lookup table oil pump command speed. If the difference between the current torque and the over-temperature torque of the vehicle is greater than the second threshold or the current power of the vehicle is greater than the corresponding rated value, the speed is compensated and corrected according to the current output speed. If the NTC temperature of the speed-regulated motor is greater than or equal to the second temperature control target value for the first time, the lookup table oil pump command speed is output.

5. The control strategy according to claim 4, characterized in that, The oil pump system is controlled and adjusted according to the vehicle's gear mode, including: If the current motor NTC temperature is determined to be greater than the second temperature control target value, record an over-temperature torque and determine whether the current motor NTC temperature is greater than the fourth temperature value. If the current motor NTC temperature is determined to be greater than the fourth temperature value, determine whether the current motor NTC temperature is greater than the third temperature value. If the current motor NTC temperature is determined to be greater than the third temperature value, adjust the oil pump speed to the peak speed. If the current motor NTC temperature is determined to be less than the fifth temperature value, and the current motor NTC temperature is greater than the fourth temperature value, the oil pump speed is incremented by a second accumulated value every second until the peak speed is reached. If the current motor NTC temperature is determined to be lower than the fourth temperature value, the previous oil pump speed is output.

6. The control strategy according to claim 5, characterized in that, Adjusting the speed of the oil pump system according to the motor speed and temperature includes: Determine whether the corrected oil pump speed is greater than or equal to the peak speed; If it is determined that the corrected oil pump speed is greater than or equal to the peak speed, the duration for which the corrected oil pump speed is greater than or equal to the peak speed is determined. Determine whether the duration is greater than or equal to a preset first time threshold; If the duration is determined to be greater than or equal to the first time threshold, the oil pump command speed is determined based on the corrected oil pump speed. Determine whether the oil pump command speed is greater than a preset first oil pump command speed threshold or whether the vehicle has entered ASC mode; If the oil pump command speed is determined to be greater than the preset first oil pump command speed threshold or the vehicle enters ASC mode, the oil pump system speed is determined to be the rated speed. If the duration is determined to be less than the first time threshold, the rotational speed of the oil pump system is determined to be the peak speed; If it is determined that the corrected oil pump speed is less than the peak speed, the speed of the oil pump system is determined to be the corrected oil pump speed. Select the larger of the corrected oil pump speed, peak speed, and rated speed, and adjust the oil pump speed of the oil pump system according to the oil pump speed slope.

7. A control system for an oil-cooled electrically driven oil pump, characterized in that, The control system includes a controller for executing the control strategy as described in any one of claims 1 to 6.

Images