Oil cooling motor oil pump control method

Abstract

The invention belongs to the technical field of new energy automobile electric driving system thermal management, and particularly discloses an oil cooling motor oil pump control method which comprises the steps that a plurality of driving modes are set through first design parameters of a motor, and a plurality of working modes are set through second design parameters of an oil pump; constructing a first mapping relation between the driving mode and the working mode according to the target energy consumption of the oil pump; in each working mode, constructing a second mapping relation between the thermal management interval of the motor and a second design parameter; according to the current first working parameter and temperature state of the motor, through the first mapping relation and the second mapping relation, the working mode of the oil pump driving the heat conduction oil and the second working parameter are determined; the method has the following advantages that through double mapping of the driving mode and the working mode and heat management interval constraint, fine adjustment of the rotating speed of the oil pump under multiple working conditions is achieved, locked-rotor heating efficiency and energy consumption optimization are both considered, and the overheating risk of the motor is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy vehicle electric drive system thermal management, in particular to an oil-cooled motor oil pump control method. BACKGROUND

[0002] With the continuous increase of power density and torque density of new energy vehicle drive motors, motor loss and temperature rise continue to increase, and oil cooling technology with higher heat dissipation efficiency has gradually become a development trend. The oil-cooled motor oil pump control strategy needs to consider both rapid heating and system safety, and its core is to precisely adjust the oil pump speed to uniformly heat the motor under different operating conditions and avoid local overheating or mechanical damage. However, the existing oil-cooled motor oil pump control strategy mostly presets control logic for limited operating conditions, and the applicable scenarios are limited, which is difficult to cover all vehicle operating conditions and lacks universality; at the same time, the oil pump speed control is not fine enough, and the power consumption under some operating conditions is not optimal, resulting in large oil pump energy consumption, especially under low pressure conditions such as motor locked-rotor heating, there is a lack of special control mechanism for power consumption optimization, and it is difficult to balance the locked-rotor heating efficiency and vehicle energy consumption control.

[0003] Therefore, an oil-cooled motor oil pump control method is proposed to solve the above problems. SUMMARY

[0004] The present application aims to provide an oil-cooled motor oil pump control method to solve or improve the above technical problems of limited operating conditions, non-fine speed control, and difficulty in balancing heating efficiency and energy consumption optimization under low pressure conditions such as locked-rotor heating.

[0005] Therefore, the first aspect of the present application provides an oil-cooled motor oil pump control method.

[0006] The second aspect of the present application provides a system.

[0007] The third aspect of the present application provides an electronic device.

[0008] The fourth aspect of the present application provides a computer-readable storage medium.

[0009] The first aspect of the present application provides an oil-cooled motor oil pump control method, comprising the following steps: setting a plurality of driving modes through a first design parameter of a motor, and setting a plurality of working modes through a second design parameter of an oil pump; constructing a first mapping relationship between the driving modes and the working modes according to a target energy consumption of the oil pump; constructing a second mapping relationship between a thermal management interval of the motor and the second design parameter in each of the working modes; and determining a working mode and a second working parameter of the oil pump driving heat conducting oil according to a current first working parameter of the motor and the temperature state through the first mapping relationship and the second mapping relationship.

[0010] The second aspect of the present application provides a system, comprising: a mode setting module, configured to set a plurality of driving modes through a first design parameter of a motor, and set a plurality of working modes through a second design parameter of an oil pump; a mapping relationship constructing module, configured to construct a first mapping relationship between the driving modes and the working modes according to a target energy consumption of the oil pump, and configured to construct a second mapping relationship between a thermal management interval of the motor and the second design parameter in each of the working modes; and an oil pump control module, configured to determine a working mode and a second working parameter of the oil pump driving heat conducting oil according to a current first working parameter of the motor and the temperature state through the first mapping relationship and the second mapping relationship. The third aspect of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned oil-cooled motor oil pump control method when executing the computer program.

[0011] The fourth aspect of the present application provides a computer readable storage medium, which stores a computer program, wherein the computer program is executed by a processor to implement the steps of the above-mentioned oil-cooled motor oil pump control method.

[0012] Compared with the prior art, the present application has the following beneficial effects: By setting a plurality of driving modes through a first design parameter of a motor, and setting a plurality of working modes through a second design parameter of an oil pump, and then constructing a first mapping relationship between the driving modes and the working modes in combination with a target energy consumption of the oil pump, the oil pump control is no longer dependent on fixed logic of a single or a small number of working conditions, but can cover a plurality of running working conditions of the whole vehicle, realize one-to-one or conditional correspondence between the driving modes and the working modes, and thus improve the universality and adaptability of the control strategy. By further constructing a second mapping relationship between the motor thermal management interval and the second design parameter in each working mode, and jointly determining the working mode and the second working parameter of the oil pump driven heat conducting oil according to the current first working parameter and temperature state in the running process by using the first mapping relationship and the second mapping relationship, the oil pump speed and its boost rate can be finely adjusted with the changes of the motor temperature and the heat conducting oil temperature, compared with the existing control mode of using only rough grading or fixed threshold, the fine degree of speed control is improved, the oil pump is closer to the target energy consumption under various working conditions on the premise of meeting the heat dissipation or heating demand, and the oil pump energy consumption optimization is realized. By introducing the constraint of temperature state and thermal management interval, the working mode and the second working parameter can increase, maintain or reduce the motor temperature under different driving modes, guide the temperature to stably converge in the preset temperature interval associated with the first working parameter, and in the low pressure working condition such as locked rotor heating, the target component coupled by the heat conducting oil can be efficiently heated by the controllable waste heat of the motor, and the waste of oil pump power consumption caused by excessive speed or redundant flow is avoided, so that the locked rotor heating efficiency and vehicle energy consumption control are considered, and the risk of local overheating and mechanical damage of the motor is reduced.

[0013] Additional aspects and advantages of embodiments according to the present application will become apparent from the following description with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0014] The above and / or additional aspects and advantages of the present application will become apparent and more readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings in which: Figure 1 The method flowchart of the present application is shown in the figure; Figure 2 The system logic diagram of the present application is shown in the figure; Figure 3 The structure diagram of an electronic device according to the present application is shown in the figure. DETAILED DESCRIPTION

[0015] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the following further describes the present application in conjunction with the drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0016] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0017] Please refer to Figures 1-3The oil-cooled motor oil pump control method, system, electronic device, and computer readable storage medium of some embodiments of the present application are described below.

[0018] Embodiments of the first aspect of the present application propose an oil-cooled motor oil pump control method. In some embodiments of the present application, as shown in Figure 1 The method comprises the following steps: S101, set a plurality of driving modes by the first design parameters of the motor, and set a plurality of working modes by the second design parameters of the oil pump.

[0019] Here, in the control strategy calibration stage, first, the first design parameters of the motor are obtained, which at least include the rated speed, the maximum speed, the rated power, the rated torque of the motor, and the preset torque when running at the maximum speed, and can also include a plurality of temperature thresholds and thermal management intervals related to the thermal safety of the motor. Based on the above first design parameters, the typical running states of the motor in the whole vehicle use process are classified and abstracted, and the running states covering different scenes such as vehicle starting, low-speed cruising, medium-high speed driving, high-load acceleration, and locked-rotor heating are divided into a plurality of driving modes. Each driving mode corresponds to a type of motor running condition with similar speed range, torque level, output power interval, and thermal load level, so that subsequent control can be differentiated at the mode level, avoiding rough control based on a single working condition.

[0020] The second design parameters of the oil pump are obtained, which at least include the minimum speed, the maximum speed, the speed increase step length available in different temperature intervals, and the indicators related to the energy consumption and response capability of the oil pump, and based on the above second design parameters, the working states of the oil pump under different target energy consumption levels and different thermal management requirements are divided into a plurality of working modes, so that each working mode corresponds to a group of control parameters matched with the speed range, speed change gradient, and energy consumption level of the oil pump.

[0021] As can be seen from the above, the mode abstraction of the motor side running characteristics and the mode abstraction of the oil pump side working state are completed in advance, which provides a clear structural basis for subsequent selection of driving modes according to the vehicle working condition, mapping of driving modes to corresponding working modes, and further refinement to specific speed instructions, thereby ensuring that the oil-cooled motor oil pump control method can cover a variety of running conditions from the beginning of the design, and laying a premise for energy consumption optimization and locked-rotor heating efficiency improvement.

[0022] In any of the above embodiments, the first design parameter includes a rated speed, a maximum speed, a rated torque and a preset torque of the motor, and the second design parameter includes a minimum speed, a maximum speed and a speed increasing rate of the oil pump.

[0023] In this embodiment, when calibrating and designing the oil-cooled motor oil pump control method, first, the rated speed of the motor is determined based on the motor prototype and the vehicle design requirements. The rated speed represents the upper limit speed range of the motor under long-term continuous working conditions. The rated speed corresponds to the typical working point of the motor when the efficiency, temperature rise, mechanical strength and other indicators reach a balanced state. On this basis, the maximum speed of the motor is further determined according to the mechanical structural strength of the motor, the resistance and safety margin of the rotor and stator components. The maximum speed is used as the upper limit of the extreme speed of the motor under short-time or controlled working conditions, for boundary constraint of high-speed working conditions in the control strategy. At the same time, the rated torque of the motor is determined through experiments and design calculations. The rated torque is used as a reference to measure the continuous output capacity of the motor under rated working conditions, for distinguishing low-load and high-load working conditions.

[0024] The preset torque is determined according to the torque capacity of the motor at the maximum speed. The preset torque is used as a characteristic torque when running at the maximum speed, for jointly forming the judgment boundary of different load intervals with the rated torque, so that the control logic can more accurately identify whether the current working condition belongs to low-load, medium-high load or overload trend working condition by comparing the relationship between the current torque and the rated torque, the preset torque, thereby providing a basis for subsequent driving mode division.

[0025] In the determination of the second design parameter, the minimum speed of the oil pump is first determined according to the structure specification and the minimum controllable output capacity of the electronic oil pump. The minimum speed is used as the basic running speed when the motor is in a low-temperature, low-load working condition or an initial locked-rotor heating working condition, so as to reduce the energy consumption of the oil pump as much as possible while ensuring that the lubricating oil can form a basic flow and heat exchange channel. At the same time, the maximum speed of the oil pump is determined according to the rated performance and mechanical limit of the oil pump. The maximum speed is used as the maximum working point that can be used when the motor temperature approaches the upper limit or in the later stage of locked-rotor heating, for providing sufficient heat conduction oil flow under the scene of large heat load or the need to quickly raise the battery temperature.

[0026] Further, by analyzing the vehicle test data and simulation results, and combining the thermal response characteristics of the motor and oil circuit in different temperature intervals, the speed increasing rate of the oil pump under different working conditions is determined, which is part of the second design parameter, used to describe the dynamic adjustment gradient of the oil pump speed when the motor temperature or lubricating oil temperature changes. For example, in the low load driving condition, a smaller speed increasing rate is used to gradually increase the speed of the oil pump when the motor temperature rises slowly, so as to balance the heat dissipation demand and energy consumption control; while in the medium and high load driving condition or the locked rotor heating condition, a larger speed increasing rate is used to quickly increase the speed of the oil pump when the temperature changes rapidly, so as to increase the heat conduction oil flow and avoid local overheating of the motor winding or core.

[0027] Specifically, the step of setting multiple driving modes through the first design parameter of the motor includes: The first determination interval is determined by the rated speed and the maximum speed, and the second determination interval is determined according to the rated torque and the preset torque.

[0028] At least one first stage is respectively determined in the first determination interval and the second determination interval, and multiple driving modes are generated according to all the first stages of the first determination interval and the second determination interval.

[0029] For the above specific description, the rated speed and the maximum speed of the motor are first obtained in the calibration stage, wherein the rated speed is used to represent the upper limit speed of the motor under the long-term continuous operation condition, and the maximum speed is used to represent the limit speed of the motor under the constraints of structural strength, mechanical stress and safety margin. Based on the above two speed parameters, a first determination interval for distinguishing different speed conditions is constructed on the speed axis, for example, the area below the rated speed is regarded as the low speed side, the area between the rated speed and the maximum speed is regarded as the medium and high speed side, and the area above the maximum speed is regarded as the prohibited operation or protection interval, thereby forming the first determination interval covering the available speed range of the motor.

[0030] The control method also constructs a second judgment interval on the torque axis based on a rated torque of the motor and a preset torque, the rated torque being used to represent a stable torque output capability of the motor under a rated working condition, and the preset torque being used to represent a characteristic torque level of the motor when running at a highest speed, by taking the rated torque and the preset torque as a boundary on the torque axis, the motor load can be divided into a low load interval, an interval close to a characteristic load at the highest speed, and an interval close to a rated load or a high load, thereby forming the second judgment interval for distinguishing different load working conditions. By constructing the first judgment interval and the second judgment interval on the speed axis and the torque axis respectively, when subsequently identifying the actual running state of the motor, the current working condition can be classified and positioned from the speed dimension and the torque dimension at the same time, thereby providing clear and engineering-based boundary conditions for generating multiple driving modes.

[0031] In the first judgment interval, the control method subdivides the interval according to different speed levels, divides the first judgment interval into at least one first stage, for example, one or more first stages are demarcated in the region below the rated speed to represent a low-speed running zone, and one or more first stages are demarcated in the region between the rated speed and the highest speed to represent a medium-high speed running zone; similarly, in the second judgment interval, the control method subdivides the interval according to different torque levels, divides the second judgment interval into at least one first stage, for example, one or more first stages are demarcated in the region below the rated torque to represent a low-load running zone, and one or more first stages are demarcated in the region between the preset torque and the rated torque to represent a medium-high load running zone.

[0032] A plurality of first stages for subdividing the speed state and the load state are formed in the first judgment interval and the second judgment interval respectively, each first stage representing a specific speed subinterval or torque subinterval. Subsequently, the control method generates multiple driving modes according to the combination relationship of all first stages of the first judgment interval and the second judgment interval, that is, by combining the first stages on the speed dimension with the first stages on the torque dimension, the combination of each speed interval and each torque interval corresponds to an independent driving mode. For example, when the speed is in the first stage below the rated speed, and the torque is in the first stage below the rated torque, a driving mode for low-speed low-load running can be generated; when the speed is in the first stage between the rated speed and the highest speed, and the torque is in the first stage between the preset torque and the rated torque, a driving mode for medium-high speed medium-high load running can be generated; when the speed and / or torque is close to the upper limit boundary defined by the rated speed, the highest speed, the rated torque and the preset torque, a driving mode for high-load or near-limit working condition running can be generated.

[0033] It can be known from the above that, through the gradual construction mode of the judgment interval, the first stage, and the driving mode, the division of the plurality of driving modes not only covers the main working conditions of the motor in the whole vehicle running process, but also each driving mode corresponds to a clear combination of speed interval and torque interval, which facilitates subsequent quick identification of the current driving mode in the control logic according to the current first working parameter, and further mapping with the working mode of the oil pump and the second working parameter, so as to realize fine configuration and dynamic switching of the oil pump speed control strategy.

[0034] Specifically, the step of setting a plurality of working modes through the second design parameter of the oil pump includes: The output interval is determined by the minimum speed and the maximum speed.

[0035] A plurality of working modes are generated according to the output interval and the speed increasing rate.

[0036] For the above specific description, when calibrating the oil-cooled motor oil pump control method, first, based on the structural capacity of the oil pump and the whole vehicle thermal management demand, the minimum speed and the maximum speed of the oil pump are determined, the former usually corresponds to the low temperature or low load working condition, and the minimum stable running speed allowed to ensure that the heat transfer oil forms a basic circulation and reduces energy consumption as much as possible, and the latter corresponds to the high temperature, heavy load or blocked heating later stage, and the maximum safe speed allowed to ensure that the heat can be quickly transferred from the motor side to the battery side. Through these two boundary values, a continuous output interval is constructed on the oil pump speed axis, which covers all the speed levels that the oil pump may adopt in actual application, and provides range constraints for subsequent flexible selection of specific speed sections in different working conditions. On this basis, the output interval can be further divided into several subintervals according to the fineness of the actual thermal management strategy, for example, a subinterval for low-power operation near the minimum speed, an intermediate subinterval for regular heat dissipation as the temperature gradually rises, and a high-speed subinterval for high-load heat dissipation or blocked heating near the maximum speed, thereby reserving corresponding speed activity space for different types of working modes, so that each type of working mode runs within its corresponding output interval without exceeding the boundary.

[0037] The speed-up rate of the rotating speed, as one of the second design parameters, is used to represent the response gradient of the rotating speed of the oil pump to the temperature change in the process that the temperature of the motor or the lubricating oil changes over time. For example, it can be calibrated to increase by 100 rpm per 10℃ increase, or to increase by 200 rpm per 10℃ increase, or different speed-up rates can be used in different temperature intervals. When multiple working modes are generated, the control strategy combines the above parameters into several representative rotating speed control strategies according to different sub-sections in the output interval and the rotating speed-up rate set for different working conditions, and each rotating speed control strategy corresponds to a working mode. For example, a combination covering the low-speed sub-interval and using a small rotating speed-up rate can be defined as a low-power consumption priority working mode, so that the oil pump runs at a lower rotating speed when the motor is at low temperature and low load, and the rotating speed increases at a gentler gradient when the temperature slowly rises, thereby reducing the power consumption of the oil pump as much as possible while meeting the basic heat exchange demand; a combination covering the middle output interval and using a medium rotating speed-up rate can be defined as a regular heat dissipation working mode, so that the oil pump can moderately increase the rotating speed as the temperature rises when the motor is in a near-rated working condition, and the balance between heat dissipation capacity and energy consumption is considered; and a combination covering the output interval close to the highest rotating speed and using a large rotating speed-up rate can be defined as a strengthened heat dissipation or locked-rotor heating working mode, so that the oil pump can quickly increase to a high rotating speed or even the highest rotating speed when the temperature of the motor or the lubricating oil is close to the high-temperature interval, thereby prioritizing the heat transfer efficiency and the safety boundary of the motor and the battery.

[0038] As can be seen from the above, the multiple working modes generated according to the output interval and the rotating speed-up rate correspond to different energy consumption targets and thermal management targets, respectively, which provides a clear and hierarchical control basis for subsequent matching of the driving mode of the motor with the working mode of the oil pump through the first mapping relationship, and then selecting the corresponding rotating speed command under the specific temperature state through the second mapping relationship, so that the oil-cooled motor oil pump control method of the present application can cover multiple working conditions and achieve fine balance between the rotating speed of the oil pump and the energy consumption in actual operation.

[0039] S102, constructing a first mapping relationship between the driving mode and the working mode according to the target energy consumption of the oil pump; and constructing a second mapping relationship between the thermal management interval of the motor and the second design parameter in each working mode.

[0040] Here, after completing the setting of the plurality of driving modes and the plurality of working modes in step S101, in order to make the oil pump meet the motor cooling or heating demand in different driving modes and make the power consumption of the oil pump itself as much as possible within the target energy consumption range, first, based on the vehicle thermal management calibration demand, typical working condition test results, and the rated power and efficiency characteristics of the oil pump, the target energy consumption interval of the oil pump under various working conditions is determined. For example, a lower target energy consumption is set for a low-load driving working condition, a target interval considering cooling capacity and energy consumption is set for a medium-high load driving working condition, and a target energy consumption interval mainly guaranteeing heating efficiency is set for a special working condition such as locked-rotor heating.

[0041] Each type of pre-divided driving mode is analyzed one by one, the typical speed range, torque level, output power size and the resulting thermal load level of the motor in the driving mode are evaluated, and combined with the heat conduction oil flow rate and temperature response speed required by the oil pump under the corresponding working condition, the working mode that matches and can make the long-term running power consumption of the oil pump close to the target energy consumption interval is selected, thereby establishing a one-to-one or one-to-many first mapping relationship between the driving mode and the working mode. Through the first mapping relationship, when the driving mode to which the motor currently belongs is identified according to the first working parameter of the motor subsequently, the type of working mode of the oil pump that should be used can be quickly determined. For example, in a low-load driving mode where the motor speed is less than the rated speed and the torque is less than the rated torque, the working mode that runs at a low speed and has a slow speed increase gradient is preferentially mapped to; in a medium-high load driving mode where the motor speed is between the rated speed and the maximum speed or the torque is between the preset torque and the rated torque, the working mode that can provide greater flow and has a more aggressive speed increase is mapped to; in a locked-rotor heating mode, the working mode specially used for locked-rotor heating is mapped to, so as to ensure that the heating efficiency and the overall energy consumption under low pressure working condition are within the expected range.

[0042] Based on the NTC temperature collected at the end of the motor stator winding and the lubricating oil temperature, the thermal safety boundary and the heating and cooling demand of the motor under different temperature levels are divided, and the temperature range from low-temperature starting, normal working to high-temperature protection process is divided into several thermal management intervals. For example, multiple intervals are set, such as the motor temperature being lower than a first preset temperature, being between the first preset temperature and a second preset temperature, being between the second preset temperature and a third preset temperature, and being higher than the third preset temperature, and in the locked-rotor heating scene, the motor temperature interval and the lubricating oil temperature interval are combined and divided to form a more detailed two-dimensional thermal management interval grid.

[0043] For each working mode, in the corresponding thermal management interval of the working mode, in combination with the minimum speed, the maximum speed and the different temperature section allowed to adopt the speed increase step or the speed increase rate contained in the second design parameter of the oil pump, the corresponding target oil pump speed instruction or speed change rule in each thermal management interval is determined, and the above target speed instruction is associated with the second design parameter, forming a second mapping relationship between the motor thermal management interval and the second design parameter of the oil pump. For example, in the working mode suitable for low load driving, a lower oil pump speed is selected in the lower temperature interval and a smaller speed increase step is adopted to reduce the energy consumption of the oil pump; in the interval where the temperature is close to the upper limit of the motor safety, a larger speed increase gradient or a higher fixed speed is directly given to enhance the heat dissipation capacity; and in the locked rotor heating working mode, different gears and steps from the minimum speed to the maximum speed are selected according to different combinations of the lubricating oil temperature and the stator NTC temperature, so that the oil pump starts at a lower speed to reduce energy consumption when the oil temperature is low, the speed is increased at a set step when the oil temperature and the motor temperature gradually increase, and finally runs at the highest speed in the high temperature interval to ensure the heating efficiency.

[0044] As can be seen from the above, by establishing the above second mapping relationship in each working mode, the corresponding second design parameter can be found directly through the thermal management interval after identifying the current motor temperature state and the lubricating oil temperature, so as to obtain the accurate oil pump speed instruction, so that the method completes the matching of the driving mode to the working mode on the macro level through the first mapping relationship, and completes the fine mapping of the thermal management interval to the specific speed parameter on the micro level through the second mapping relationship, thereby realizing the effective control of the target energy consumption of the oil pump under the premise of ensuring the safety of the motor and the locked rotor heating efficiency.

[0045] Specifically, the step of constructing the second mapping relationship between the thermal management interval of the motor and the second design parameter comprises: determining at least one second stage of the speed increase rate in each output interval according to the thermal management interval; in each output interval, the numerical association between the thermal management interval and the speed increase rate is taken as the second mapping relationship.

[0046] According to the above specific description, first, after completing the division of the motor thermal management interval and the setting of the oil pump output interval, based on the heat dissipation requirement and the locked-rotor heating requirement of the motor under different temperature states, each thermal management interval is analyzed to determine the reasonable promotion gradient of the oil pump speed with temperature change in the corresponding output interval. The thermal management interval described here can include different intervals such as low-temperature starting range, normal working range, near temperature upper limit range, and high-temperature protection range of the motor temperature, and the motor temperature and the lubricating oil temperature can also be combined under the locked-rotor heating working condition to form a more detailed thermal management interval combination; and the output interval is a continuous range formed on the speed axis based on the minimum speed and the maximum speed of the oil pump, and multiple sub-intervals suitable for low-power running, medium-power running, and high-speed running are subdivided in the range.

[0047] For each output interval, in combination with the corresponding working mode and energy consumption target of the output interval, first, at least one speed promotion rate stage for responding to different thermal management intervals in the output interval is determined, that is, according to the temperature change trend from low to high in the same output interval, the speed promotion rate is divided into one or more second stages, for example, a smaller speed promotion rate is used in the thermal management interval with lower motor temperature, a medium or larger speed promotion rate is used when the temperature is close to the medium-high temperature interval, and a more aggressive speed promotion rate is used when the temperature is close to the safety upper limit or the later stage of locked-rotor heating, and the different speed promotion rate segments are defined as different second stages in numerical value, so that each output interval internally contains at least one second stage that changes with the thermal management interval.

[0048] For any given output interval, the control method corresponds the motor thermal management interval to the determined speed increase rate second stage one by one, so that each thermal management interval is explicitly associated with a specific speed increase rate value or a set of increase rules. For example, in a low-load, low-temperature thermal management interval, if the motor temperature is below the first preset temperature, the speed increase rate can be set to a smaller value in the corresponding output interval, so that the oil pump only increases the speed at a gentle slope similar to 100 rpm / 10°C as the temperature slowly rises, to control energy consumption; when the motor temperature enters the medium-temperature or near the second preset temperature thermal management interval, the speed increase rate can be switched to a higher second stage in the same output interval, so that the oil pump increases the speed at a larger gradient similar to 200 rpm / 10°C as the temperature continues to rise; and when the temperature is near the third preset temperature or above a certain high temperature threshold, the speed increase rate can be set to a higher second stage, or even directly correspond to a fixed high speed operation, to ensure the heat dissipation capacity or locked-rotor heating efficiency. In the locked-rotor heating working condition, the combination of the lubricating oil temperature interval and the motor temperature interval can also be divided into multiple thermal management interval combinations in the output interval, and different speed increase rate second stages are assigned to each combination. For example, the lowest increase rate is used in the combination interval where the oil temperature is low and the motor temperature is low, the increase rate gradually increases in the combination interval where the oil temperature and the motor temperature gradually increase, and the highest speed or the maximum increase rate is used when the oil temperature and the motor temperature are both high.

[0049] As can be seen from the above, the numerical association of the thermal management interval and the speed increase rate in each output interval is fixed as the second mapping relationship, so that in the actual control process, when it is detected that the current motor is in a certain thermal management interval and the oil pump needs to operate in a certain output interval, the corresponding speed increase rate second stage can be directly found through the second mapping relationship, so that the target speed or speed change rule currently should be used is calculated, realizing the fine matching between the motor thermal management interval and the oil pump second design parameter, so that the method of the present application can dynamically generate an oil pump speed control instruction that meets the heat dissipation and heating requirements and takes into account energy consumption optimization under different temperature states and different working conditions.

[0050] S103, according to the motor in the current first working parameter and temperature state, through the first mapping relationship and the second mapping relationship, determine the working mode of the oil pump driving the heat conducting oil and the second working parameter.

[0051] Here, in the actual running stage of the method, the control end first acquires the first working parameter of the motor at the current time in real time, the first working parameter including the current speed, output torque and output power of the motor and other physical quantities for representing the running state of the motor, and at the same time, acquires the temperature state information related to thermal management, the temperature state at least including the NTC temperature collected by the motor stator winding end and the lubricating oil temperature collected by the temperature sensor arranged in the oil circuit, and judges the thermal management interval in which the motor is located according to the above temperature signals, for example, judges whether the motor is in a low-temperature starting interval, a normal working interval, an interval close to an upper limit temperature or a locked-rotor heating interval.

[0052] The control end distinguishes and classifies the current first working parameter by using the judgment boundaries of the plurality of preset driving modes, determines the driving mode to which the current whole-vehicle electric drive system belongs by comparing the relationship between the current speed and the rated speed and the highest speed, and the relationship between the current torque and the preset torque and the rated torque, and combining the relationship between the current output power and the rated power, for example, judges as a low-load driving mode, a medium-high load driving mode or a locked-rotor heating mode, etc.

[0053] After identifying the current driving mode, the control end maps the driving mode to the corresponding oil pump working mode through the established first mapping relationship, thereby preliminarily determining the working mode type of the oil pump driving heat conducting oil, for example, maps the low-load driving mode to a working mode with low oil pump power consumption as the priority, maps the medium-high load driving mode to a working mode with enhanced heat dissipation and improved flow as the priority, and maps the locked-rotor heating mode to a special working mode optimized for low-voltage power consumption and taking into account heating efficiency. Then, after determining the working mode, the control end queries the second mapping relationship preliminarily constructed under the working mode according to the current temperature state information, retrieves the second design parameter matched with the temperature interval of the current motor stator NTC temperature and lubricating oil temperature in the mapping table or mapping rule between the thermal management interval corresponding to the working mode and the second design parameter, and calculates or directly reads out the corresponding second working parameter from the second design parameter, wherein the second working parameter at least includes the target speed, speed increase step and highest speed limit under certain working conditions of the oil pump.

[0054] After obtaining the working mode and the second working parameter, the control end outputs the second working parameter as a control instruction of the oil pump to an oil pump execution unit, so that the oil pump drives the heat conducting oil to circulate between the motor and the battery according to the current working condition requirement: in the low load and low temperature working condition, the oil pump operates at a low speed to reduce energy consumption and take into account the uniform heating of the motor; in the medium and high load and gradually increasing temperature working condition, the oil pump speed is gradually increased by a predetermined step according to the temperature state, so as to enhance the heat exchange capacity and avoid local overheating of the motor; in the locked rotor heating working condition, the oil pump gradually increases the speed according to a predetermined rule according to the combination interval of the lubricating oil temperature and the motor stator temperature, until it operates at the highest speed in the high temperature interval, so as to realize efficient heating of the battery system under low pressure conditions, while avoiding the waste of power consumption caused by blindly running at high speed in the initial stage of low temperature.

[0055] As can be seen from the above, by periodically and continuously repeating the above process in step S103, the oil-cooled motor oil pump control method can dynamically adjust the working mode and the second working parameter of the oil pump driving the heat conducting oil according to the real-time running state and temperature state of the motor in the whole working condition range of the vehicle, so as to realize fine control and overall optimization of the oil pump energy consumption under the premise of meeting the requirements of motor thermal safety and locked rotor heating efficiency.

[0056] In any of the above embodiments, the temperature state includes the motor temperature and the heat conducting oil temperature.

[0057] In this embodiment, the motor temperature is used to represent the real-time thermal state of the motor body, especially the motor stator winding area. For example, the temperature signal of the stator winding end can be obtained by arranging an NTC temperature sensor at the end of the stator winding, and the temperature signal is used as the motor temperature to participate in the division of the thermal management interval and the determination of the current working condition; the heat conducting oil temperature is used to represent the actual temperature level of the heat conducting oil in the oil cooling circuit. For example, the temperature signal of the lubricating oil or heat conducting oil at different positions can be collected in real time by the temperature sensor arranged on the oil circuit, and the temperature signal is input as the heat conducting oil temperature into the control logic.

[0058] By introducing the motor temperature and the heat conducting oil temperature at the same time, the temperature state formed by the two together is taken as the basic parameter of thermal management, which can reflect the heating intensity and safety margin of the motor on the one hand, and the heat carrying and transferring capacity of the heat conducting oil on the other hand, so that the subsequent determination of the thermal management interval of the motor, the selection of the corresponding output interval and the matching of the speed increasing rate can comprehensively consider the heating condition of the motor itself and the heat exchange capacity of the heat conducting oil circuit. For example, when the motor temperature is high but the heat conducting oil temperature is still at a low level, the control method can enhance heat exchange by increasing the oil pump speed, thereby accelerating the removal of motor heat; when the motor temperature and the heat conducting oil temperature are both high, the temperature state can be used to determine that the current has approached the upper limit interval of thermal management, so as to increase the oil pump speed to a high speed or even the highest speed, in order to prioritize the thermal safety of the motor and the heated object (such as the battery).

[0059] By including the motor temperature and the heat conducting oil temperature in the temperature state, the present application no longer relies on a single temperature parameter when controlling the oil pump speed, but makes a comprehensive determination based on the coupled thermal state of the motor and the heat conducting oil, thereby achieving fine adjustment of the oil pump energy consumption and heating efficiency in the locked rotor heating condition and the conventional driving condition of the oil-cooled motor.

[0060] Specifically, the working mode and the second working parameter are used to adjust the motor at the current temperature state to increase, maintain or decrease to the preset temperature interval associated with the first working parameter.

[0061] For the above specific description, after the current working mode to be adopted has been determined according to the first mapping relationship and the corresponding second working parameter has been obtained through the second mapping relationship, the control end jointly takes the working mode and the second working parameter as the basis for executing the oil pump control strategy, so that the oil pump drives the heat conducting oil to circulate in a matched manner under the current temperature state, thereby actively adjusting the thermal state of the motor and its surrounding components. The temperature state described herein includes the motor temperature and the heat conducting oil temperature, which can comprehensively reflect the heating intensity of the motor itself and the heat carrying capacity of the heat conducting oil, and the first working parameter includes the current speed, torque, power and other operating state quantities of the motor, and a preset temperature interval matched therewith is determined accordingly. For example, a lower target temperature interval is corresponding to a low speed and low load condition, a moderate target temperature interval is corresponding to a medium speed and medium load condition, and a higher target temperature interval is corresponding to a locked rotor heating condition which can efficiently transfer heat to the battery.

[0062] In the actual control process, when the temperature state is lower than the preset temperature interval associated with the current first working parameter, the working mode and the second working parameter jointly act to make the oil pump run at a higher speed raising rate to increase the flow of the heat conducting oil, thereby accelerating the heating of the motor and the heat conducting oil, and moving the temperature state to the target interval; when the temperature state has fallen into the preset temperature interval, the working mode will cooperate with the relatively gentle second working parameter to make the oil pump run at a relatively stable speed or a smaller speed raising rate to maintain the temperature of the motor and the heat conducting oil in the target interval to avoid excessive cooling or excessive heating; when the temperature state is higher than the upper limit of the preset temperature interval, the second working parameter is adjusted to make the oil pump run at a higher speed or a higher speed raising rate in the current working mode to enhance the heat dissipation capacity, so that the temperature of the motor and the heat conducting oil gradually decreases to return to the preset temperature interval corresponding to the first working parameter.

[0063] As can be seen from the above, the working mode is used to macroscopically define the type of thermal management strategy adopted under different operating conditions, and the second working parameter is used to microscopically finely depict the speed of the oil pump and its variation law, and the two jointly act to dynamically raise, maintain or lower the motor to the preset temperature interval associated with the current first working parameter under different temperature states, so as to realize the controllability of the thermal management process and the optimization of the oil pump energy consumption under the premise of meeting the safety and locked-rotor heating requirements of the motor.

[0064] Another embodiment of the first aspect of the application proposes a first specific implementation of the oil-cooled motor oil pump control method. In some embodiments of the application, the first specific implementation determines the current oil pump speed output map according to the vehicle working mode, the power, the torque, the speed, the lubricating oil temperature and the motor temperature of the motor; different motor oil pump maps are output under different working modes to ensure optimal oil pump energy consumption; the driving mode is: ① When the motor speed is less than the rated speed and the motor torque is less than the rated torque, the oil pump speed is output according to map1, specifically, when the motor temperature is less than the first preset temperature, the oil pump runs at the lowest speed, when the motor temperature is between the first preset temperature and the second preset temperature, the oil pump raises the speed at a rate of 100 rpm / 10℃, when the motor temperature is between the second preset temperature and the third preset temperature, the oil pump raises the speed at a rate of 200 rpm / 10℃, and when the motor temperature exceeds the third preset temperature, the oil pump runs at the highest 50% speed, it is particularly noted that the motor temperature is the NTC temperature collected at the end of the motor stator winding, and the first preset temperature is less than the second preset temperature which is less than the third preset temperature; 2. When the motor speed is between the rated speed and the maximum speed, or the torque is between the preset torque and the rated torque, and the motor output power is less than the rated power, the oil pump speed is output according to map2, the oil pump output power is adjusted according to the motor temperature change, the working condition 2 is greater than the working condition 1, and the corresponding oil pump speed rising rate is higher than that of the working condition 1, and it is particularly pointed out that the preset torque is the motor torque when the motor runs at the maximum speed for a long time; 3. When the motor power is greater than the rated power, or the output torque is greater than the rated torque, and the motor temperature is greater than the second preset temperature, the oil pump runs at the maximum speed; 4. The stall heating mode meets the conditions to enter the stall heating mode, the lubricating oil temperature and the motor temperature are detected, and the oil pump speed is output according to map3.

[0065] Another embodiment of the first aspect of the present application proposes a second specific implementation mode of the oil-cooled motor oil pump control method. In some embodiments of the present application, as shown in Figures 1-3 In this second specific implementation mode, the oil-cooled motor stall heating is realized by using the large amount of heat generated by the motor in the stall state to direct the heat to the battery system through the heat transfer capacity of the oil cooling system, so as to improve or maintain the battery temperature (especially in a low temperature environment). When the motor is in stall, the winding generates high temperature, the lubricating oil absorbs heat, and the heat is transferred to the cooling liquid through the oil cooler, and the cooling liquid flows through the battery, so that the controllable waste heat of the motor heats the battery, thereby improving the low temperature charging efficiency. Through a more refined oil pump control strategy, the power consumption of the whole vehicle is reduced.

[0066] The driving mode specific implementation mode is specifically shown as follows: 1. The motor speed is less than the rated speed, and the motor torque is less than the rated torque: When the motor temperature is less than -20℃, the oil pump runs at a speed of 500 rpm; When the motor temperature is greater than -20℃ and less than 80℃, the oil pump speed rises at a rate of 100 rpm@10℃; When the motor temperature is greater than 80℃ and less than 120℃, the oil pump speed rises at a rate of 200 rpm@10℃; When the motor temperature is greater than 120℃, the oil pump runs at a speed of 2000 rpm (50% of the maximum speed of the oil pump) When the motor runs at low load, the oil pump rising rate is adjusted according to the motor temperature, and the oil pump speed is low 2. When the motor speed is between the rated speed and the maximum speed, or the torque is between the preset torque and the rated torque, and the motor output power is less than the rated power When the motor temperature is less than -20℃, the oil pump runs at a speed of 500 rpm; When the motor temperature is greater than -20℃ and less than 60℃, the oil pump speed rises at a rate of 100 rpm@10℃ When the motor temperature is greater than 60℃ and less than 120℃, the oil pump speed increases at a rate of 200rpm@5℃ When the motor temperature is greater than 120℃, the oil pump runs at a speed of 4000rpm (the highest speed of the oil pump) When the motor is running at high load, the oil pump speed is adjusted according to the motor temperature, and the oil pump speed is high 3. When the motor power is greater than the rated power, or the output torque is greater than the rated torque, and the motor temperature is greater than the second preset temperature, the oil pump runs at the highest speed; 4. The specific implementation of the locked-rotor heating condition is as follows: When the oil temperature is less than 0℃ and the motor temperature is less than -20℃, the oil pump runs at the lowest speed, such as 500rpm; When the oil temperature is less than 0℃ and the motor temperature is greater than -20℃ and less than 0℃, the oil pump speed increases at a rate of 100rpm@10℃; When the oil temperature is greater than 0℃ and less than 30℃, and the motor temperature is greater than 0℃ and less than 60℃, the oil pump speed increases at a rate of 200rpm@10℃; When the oil temperature is greater than 30℃ and less than 90℃, and the motor temperature is greater than 60℃ and less than 120℃, the oil pump speed increases at a rate of 300rpm@10℃; When the oil temperature is greater than 90℃ and the motor temperature is greater than 120℃, the oil pump runs at the highest speed.

[0067] Specifically, the first mapping relationship and the second mapping relationship determined by the oil pump speed instruction are as follows: Table 1 includes:

[0068] Table 2 includes:

[0069] Table 3 includes:

[0070] Embodiments of the second aspect of the application propose a system 2. In some embodiments of the application, as shown in the figure, the system 2 includes: Figure 2 Mode setting module 201, for setting a plurality of driving modes by a first design parameter of a motor, and setting a plurality of working modes by a second design parameter of an oil pump. Mode setting module 201, for setting a plurality of driving modes by a first design parameter of a motor, and setting a plurality of working modes by a second design parameter of an oil pump.

[0071] The mapping relationship construction module 202 is configured to construct a first mapping relationship between the driving mode and the working mode according to the target energy consumption of the oil pump, and to construct a second mapping relationship between the thermal management interval of the motor and the second design parameter in each working mode.

[0072] The oil pump control module 203 is configured to determine the working mode and the second working parameter of the oil pump driving the heat conducting oil according to the current first working parameter and the temperature state of the motor through the first mapping relationship and the second mapping relationship.

[0073] The system provided in the second aspect of the application,

[0074] The electronic device provided in the third aspect of the application is shown in some embodiments of the application, Figure 3 The electronic device 3 can include but not limited to a processor 301 and a memory 302. Those skilled in the art can understand that, Figure 3 The electronic device 3 shown in the figure is only an example and does not constitute a limitation on the electronic device 3, and can include more or fewer components or different components than those shown in the figure.

[0075] The processor 301 can be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 301 can be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0076] The memory 302 can be an internal storage unit of the electronic device 3, for example, a hard disk or a memory of the electronic device 3. The memory 302 can also be an external storage device of the electronic device 3, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 3. The memory 302 can also include both the internal storage unit and the external storage device of the electronic device 3. The memory 302 is used to store computer programs and other programs and data required by the electronic device.

[0077] The embodiments of the fourth aspect of the present application provide computer readable storage media. In some embodiments of the present application, computer readable storage media is provided, which, when executed by the processor 301, implements the steps of the above method, so the computer readable storage media provided by the fourth aspect of the present application has all the technical effects of the above steps, which will not be described here.

[0078] The integrated modules / units, if implemented in the form of software function units and sold or used as independent products, can be stored in a computer readable storage medium. Based on such understanding, the present disclosure implements all or part of the processes in the above-mentioned embodiment methods, which can also be completed by instructing related hardware through a computer program. The computer program can be stored in a computer readable storage medium, and the computer program, when executed by a processor, can implement the steps of each method embodiment described above. The computer program can include computer program code, which can be in the form of source code, object code, executable file, or some intermediate form, etc. The computer readable medium can include any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (Read Only Memory, ROM), random access memory (Random Access Memory, RAM), electrical carrier signal, telecommunication signal, and software distribution medium, etc. It should be noted that the content contained in the computer readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunication signals.

[0079] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some technical features; and the above modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure, and should be included in the protection scope of the present disclosure.​

Claims

1. A method of controlling an oil-cooled electric machine oil pump, characterized by, The method comprises the following steps: a plurality of driving modes are set by first design parameters of the motor, and a plurality of working modes are set by second design parameters of the oil pump; a first mapping relationship between the driving modes and the working modes is constructed according to a target energy consumption of the oil pump; a second mapping relationship between a thermal management interval of the motor and the second design parameters is constructed in each of the working modes; a working mode and a second working parameter of the oil pump driving the heat conducting oil are determined according to the current first working parameter of the motor and the temperature state by the first mapping relationship and the second mapping relationship.

2. The oil-cooled electric machine oil pump control method of claim 1, wherein, The first design parameters comprise a rated speed, a maximum speed, a rated torque and a preset torque of the motor, and the second design parameters comprise a minimum speed, a maximum speed and a speed increasing rate of the oil pump.

3. The oil-cooled electric machine oil pump control method of claim 2, wherein, The step of setting a plurality of driving modes by the first design parameters of the motor comprises: a first judgment interval is determined by the rated speed and the maximum speed, and a second judgment interval is determined according to the rated torque and the preset torque; at least one first stage is respectively demarcated in the first judgment interval and the second judgment interval, and a plurality of driving modes are generated according to all the first stages in the first judgment interval and the second judgment interval.

4. The oil-cooled electric machine oil pump control method of claim 2, wherein, The step of setting a plurality of working modes by the second design parameters of the oil pump comprises: an output interval is determined by the minimum speed and the maximum speed; a plurality of working modes are generated according to the output interval and the speed increasing rate.

5. The oil-cooled electric machine oil pump control method of claim 4, wherein, The step of constructing the second mapping relationship between the thermal management interval of the motor and the second design parameters comprises: at least one second stage of the speed increasing rate in each of the output intervals is determined according to the thermal management interval; and in each of the output intervals, a numerical correlation between the thermal management interval and the speed increasing rate is taken as the second mapping relationship.

6. The oil-cooled motor oil pump control method according to claim 1, characterized by, The temperature state comprises a motor temperature and a heat conducting oil temperature.

7. The oil-cooled electric machine oil pump control method of any one of claims 2-6, wherein, The working mode and the second working parameter are used to adjust the motor in the current temperature state to improve, maintain or reduce to a preset temperature interval associated with the first working parameter.

8. A system for implementing the oil-cooled electric machine oil pump control method of any one of claims 1-7, characterized in that, The method comprises: a mode setting module for setting a plurality of driving modes by first design parameters of the motor and setting a plurality of working modes by second design parameters of the oil pump; a mapping relationship constructing module for constructing a first mapping relationship between the driving modes and the working modes according to a target energy consumption of the oil pump, and for constructing a second mapping relationship between a thermal management interval of the motor and the second design parameters in each of the working modes; an oil pump control module for determining a working mode and a second working parameter of the oil pump driving the heat conducting oil according to the current first working parameter of the motor and the temperature state by the first mapping relationship and the second mapping relationship.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that, The processor executes the computer program to realize the steps of the oil-cooled motor oil pump control method in any one of claims 1 to 7. The processor executes the computer program to realize the steps of the oil-cooled motor oil pump control method in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, the computer program comprising instructions that, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 9. The computer program, which is executed by a processor, implements the steps of the oil-cooled electric machine oil pump control method according to any one of claims 1 to 7.

Images