Method for setting rotational speed of coolant pump

Abstract

The invention discloses a method for setting the rotating speed of a coolant pump, and the coolant pump is used for conveying coolant to a coolant flow path of an electric drive system of a vehicle so as to cool the electric drive system. And the rotating speed of the coolant pump is set to be the rotating speed determined according to the following conditions: the rotating speed of the motor, the torque of the motor and the temperature of the motor and / or the temperature of the coolant. In the invention, when the electric driving system is not in the safe state, various factors (namely, the rotating speed and the torque of the motor and the temperature of the motor and / or the temperature of the cooling liquid) capable of influencing the heat dissipation requirement of the electric driving system are considered when the rotating speed of the cooling liquid pump is set, and the rotating speed of the cooling liquid pump is set according to the factors; therefore, the rotating speed of the cooling liquid pump adapts to the heat dissipation requirement of the electric drive system, and the energy consumption of the cooling liquid pump and the energy consumption of the whole vehicle are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles and electronic control, and in particular to a method for setting a rotation speed of a coolant pump. Background Art

[0002] At present, in order to meet the high requirements of new energy vehicles for the power density, speed and efficiency of the three-electric system, the cooling scheme of the electric drive system has been improved from water cooling to oil cooling, and the electric drive system can share cooling oil with the reducer. During the operation of the electric drive system, it is necessary to control the speed of the coolant pump used to transport coolant (for example, cooling water or cooling oil) in the coolant flow path of the electric drive system, so as to control the flow rate of the coolant. At present, the speed control of the coolant pump is relatively simple. Generally, the power of the coolant pump is always set to the maximum power, so that the coolant pump runs at the maximum speed. However, in fact, in most cases, the coolant pump does not need to run at the maximum speed. Therefore, this control method will cause the energy consumption of the coolant pump to be too high, resulting in excessive energy consumption of the entire vehicle. Summary of the invention

[0003] The starting point of the present invention is to provide a method for setting the rotation speed of a coolant pump, thereby solving the above-mentioned problems in the prior art.

[0004] An embodiment of the present invention provides a method for setting a rotation speed of a coolant pump, wherein the coolant pump is used to deliver coolant to a coolant flow path of an electric drive system of a vehicle to cool the electric drive system, wherein the electric drive system includes a motor, and the method includes:

[0005] When the electric drive system is in a safe state, setting the rotation speed of the coolant pump to a predetermined rotation speed corresponding to the safe state; and

[0006] When the electric drive system is not in the safe state, the rotation speed of the coolant pump is set to a rotation speed determined according to the following conditions: the rotation speed of the motor, the torque of the motor, and the temperature of the motor and / or the temperature of the coolant.

[0007] Optionally, the security state is an ASC state or a FreeWheeling state.

[0008] Optionally, when the electric drive system is not in the safe state, the rotation speed of the coolant pump is set to a rotation speed determined according to the rotation speed of the motor, the torque of the motor and the temperature of the motor.

[0009] Optionally, when the electric drive system is not in the safe state, the rotation speed of the coolant pump is set to a rotation speed determined according to the rotation speed of the motor, the torque of the motor and the temperature of the coolant.

[0010] Optionally, when the electric drive system is not in the safe state, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor and one selected from the temperature of the motor and the temperature of the coolant according to a set rule.

[0011] Optionally, the set rule is:

[0012] Selecting the greater of the temperature of the motor and the temperature of the coolant, or

[0013] The smaller one of the temperature of the motor and the temperature of the coolant is selected.

[0014] Optionally, if the temperature of the motor is selected from the temperature of the motor and the temperature of the coolant according to a set rule, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor and the temperature of the motor.

[0015] Optionally, if the temperature of the coolant is selected from the temperature of the motor and the temperature of the coolant according to a set rule, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor and the temperature of the coolant.

[0016] Optionally, setting the rotation speed of the coolant pump to a rotation speed determined according to the rotation speed of the motor, the torque of the motor and the temperature of the motor includes:

[0017] Searching for a first mapping result corresponding to the rotation speed of the motor and the torque of the motor in a first mapping relationship diagram;

[0018] A second mapping result corresponding to the first mapping result and the temperature of the motor is searched in the second mapping relationship diagram, where the second mapping result is the determined rotation speed.

[0019] Optionally, setting the rotation speed of the coolant pump to a rotation speed determined according to the rotation speed of the motor, the torque of the motor and the temperature of the coolant includes:

[0020] Searching the first mapping result corresponding to the rotation speed of the motor and the torque of the motor in the first mapping relationship diagram,

[0021] A third mapping result corresponding to the first mapping result and the temperature of the coolant is searched in a third mapping relationship diagram, where the third mapping result is the determined rotation speed.

[0022] The method for setting the rotation speed of a coolant pump according to an embodiment of the present invention has at least the following advantages:

[0023] In the present invention, when the electric drive system is not in a safe state, various factors that may affect the heat dissipation requirements of the electric drive system (i.e., the speed of the motor, the torque, and the temperature of the motor and / or the temperature of the coolant) are taken into consideration when setting the speed of the coolant pump, and the speed of the coolant pump is set based on these factors so that the speed of the coolant pump is adapted to the heat dissipation requirements of the electric drive system, thereby saving energy consumption of the coolant pump and the energy consumption of the entire vehicle.

[0024] In the present invention, when the electric drive system is in a safe state, the speed of the coolant pump is set to a predetermined speed corresponding to the safe state, so that the speed of the coolant pump is adapted to the heat dissipation requirement of the electric drive system in the safe state, thereby saving the energy consumption of the coolant pump and the energy consumption of the entire vehicle.

[0025] In the present invention, the larger one of the temperature of the motor and the temperature of the coolant can be taken into consideration when setting the speed of the coolant pump, so that the coolant pump operates at a relatively high speed, thereby avoiding insufficient heat dissipation capacity.

[0026] In the present invention, the smaller of the temperature of the motor and the temperature of the coolant can be taken into consideration when setting the speed of the coolant pump, so that the coolant pump operates at a relatively low speed, thereby ensuring sufficient heat dissipation capacity while reducing the energy consumption of the coolant pump as much as possible.

[0027] In the present invention, by using the first, second and third mapping diagrams, a specific method of determining the speed of the coolant pump according to the speed and torque of the motor and the temperature of the motor and / or the temperature of the coolant is proposed. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other details and advantages of the present invention will become apparent from the detailed description provided below. It should be understood that the following drawings are merely schematic and not drawn to scale, and thus cannot be regarded as limiting the present application. The following will be described in detail with reference to the drawings, wherein:

[0029] Figure 1 A flow chart of a method for setting a rotation speed of a coolant pump of an electric motor according to a first specific embodiment of the present invention is schematically shown.

[0030] Figure 2The process of searching the first mapping result corresponding to the rotation speed of the motor and the torque of the motor in the first mapping relationship diagram is schematically shown.

[0031] Figure 3 The process of searching the second mapping result corresponding to the first mapping result and the temperature of the motor in the second mapping relationship diagram is schematically shown.

[0032] Figure 4 The process of searching the third mapping result corresponding to the first mapping result and the temperature of the coolant in the third mapping relationship diagram is schematically shown.

[0033] Figure 5 A flow chart of a method for setting a rotation speed of a coolant pump of an electric motor according to a second specific embodiment of the present invention is schematically shown.

[0034] Figure 6 A flow chart of a method for setting a rotation speed of a coolant pump of an electric motor according to a third specific embodiment of the present invention is schematically shown.

[0035] Figure 7 A flow chart of a method for setting a rotation speed of a coolant pump of an electric motor according to a fourth specific embodiment of the present invention is schematically shown.

[0036] Figure 8 A flow chart of a method for setting a rotation speed of a coolant pump of an electric motor according to a fifth specific embodiment of the present invention is schematically shown. DETAILED DESCRIPTION

[0037] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, many specific details are set forth so that those skilled in the art can more fully understand and implement the present invention. However, it is obvious to those skilled in the art that the present invention may be implemented without some of these specific details. In addition, it should be understood that the present invention is not limited to the specific embodiments described. On the contrary, any combination of the features and elements described below may be considered to implement the present invention, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments and advantages are for illustrative purposes only and should not be regarded as elements or limitations of the claims unless clearly stated in the claims.

[0038] Now refer to Figure 1 , schematically shows a flow chart of a method for setting the rotation speed of a coolant pump according to a first specific embodiment of the present invention. The coolant pump is used to deliver coolant to a coolant flow path of an electric drive system of a vehicle to cool the electric drive system. The method can be executed by any suitable electronic device, for example, by a motor controller of the electric drive system. Figure 1 As shown, the method includes:

[0039] Step S101, determining whether the electric drive system is in a safe state.

[0040] The safety state of the electric drive system can be any possible safety state, and these variations do not exceed the protection scope of the present invention. For example, the safety state is an ASC (Active Short Circuit) state or a Free Wheeling (coasting) state.

[0041] Step S102, when the electric drive system is in a safe state, the speed of the coolant pump is set to a predetermined speed corresponding to the safe state; when the electric drive system is not in a safe state, the speed of the coolant pump is set to a speed determined according to the following conditions: the speed of the motor, the torque of the motor, and the temperature of the motor and / or the temperature of the coolant.

[0042] The specific value of the predetermined rotation speed corresponding to the safe state can be set according to the actual situation of the electric drive system, and these variations do not exceed the protection scope of the present invention.

[0043] During the normal operation of the electric drive system, the speed of the motor, the torque of the motor, the temperature of the motor and the temperature of the coolant are closely related to the heat dissipation requirements of the electric drive system. Generally speaking, the greater the speed of the motor, the greater the torque of the motor, the higher the temperature of the motor and the higher the temperature of the coolant, the greater the heat generated by the electric drive system and the higher the corresponding heat dissipation requirements. Therefore, in the present invention, when setting the speed of the coolant pump, the influence of the above factors on the heat dissipation requirements of the electric drive system is comprehensively considered so that the speed of the coolant pump is adapted to the heat dissipation requirements of the electric drive system.

[0044] Specifically, when the electric drive system is not in a safe state, the speed of the coolant pump can be set in one of the following ways:

[0045] 1). Set the speed of the coolant pump to a speed determined according to the speed of the motor, the torque of the motor and the temperature of the motor;

[0046] 2). Set the speed of the coolant pump to a speed determined according to the motor speed, motor torque and coolant temperature;

[0047] 3). The speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor, and one selected from the temperature of the motor and the temperature of the coolant according to the set rules. It will be appreciated by those skilled in the art that one of the temperature of the motor and the temperature of the coolant can be selected according to any suitable rule, and these variations do not exceed the scope of protection of the present invention. For example, the larger one of the temperature of the motor and the temperature of the coolant can be selected, or the smaller one of the temperature of the motor and the temperature of the coolant can be selected. Accordingly, if the temperature of the motor is selected from the temperature of the motor and the temperature of the coolant according to the set rules, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor, and the temperature of the motor; if the temperature of the coolant is selected from the temperature of the motor and the temperature of the coolant according to the set rules, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor, and the temperature of the coolant.

[0048] Those skilled in the art will appreciate that the speed of the coolant pump may be set in any suitable manner according to the speed of the motor, the torque of the motor, the temperature of the motor and / or the temperature of the coolant, and these variations do not exceed the scope of protection of the present invention. For example, the speed of the coolant pump may be determined by a mapping diagram.

[0049] Specifically, the correspondence between the motor speed and the motor torque and the first mapping result can be recorded in the first mapping relationship diagram; the correspondence between the first mapping result and the motor temperature and the second mapping result can be recorded in the second mapping relationship diagram; and the correspondence between the first mapping result and the coolant temperature and the third mapping result can be recorded in the third mapping relationship diagram.

[0050] Specifically, the process of setting the speed of the coolant pump to a speed determined according to the speed of the motor, the torque of the motor, and the temperature of the motor by using a mapping relationship diagram may include: first, searching the first mapping result corresponding to the speed of the motor and the torque of the motor in the first mapping relationship diagram; then, searching the second mapping result corresponding to the first mapping result and the temperature of the motor in the second mapping relationship diagram, and the second mapping result is the determined speed. The process of setting the speed of the coolant pump to a speed determined according to the speed of the motor, the torque of the motor, and the temperature of the coolant by using a mapping relationship diagram may include: first, searching the first mapping result corresponding to the speed of the motor and the torque of the motor in the first mapping relationship diagram; then, searching the third mapping result corresponding to the first mapping result and the temperature of the motor in the third mapping relationship diagram, and the third mapping result is the determined speed.

[0051] The specific forms of the first, second and third mapping relationship diagrams can be set according to actual conditions, and these variations do not exceed the protection scope of the present invention. Figure 2The process of searching the first mapping result corresponding to the rotation speed of the motor and the torque of the motor in the first mapping relationship diagram is schematically shown. Figure 3 The process of searching the second mapping result corresponding to the first mapping result and the temperature of the motor in the second mapping relationship diagram is schematically shown. Figure 4 The process of searching the third mapping result corresponding to the first mapping result and the temperature of the coolant in the third mapping relationship diagram is schematically shown. Those skilled in the art can understand that the specific numerical mapping relationships in the first, second and third mapping relationship diagrams can be set according to the actual situation of the electric drive system, and these variations do not exceed the protection scope of the present invention.

[0052] Based on the principle of the method for setting the rotation speed of a coolant pump of a motor according to the first specific embodiment of the present invention, Figure 5 A flow chart of a method for setting the speed of a coolant pump of a motor according to a second specific embodiment of the present invention is schematically shown. In the second specific embodiment, when the electric drive system is not in a safe state, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor, and the temperature of the motor.

[0053] like Figure 5 As shown, first, determine whether the electric drive system is in the ASC state or the FreeWheeling state. If the judgment result is yes, the speed of the coolant pump is set to the predetermined speed corresponding to the ASC state or the FreeWheeling state. If the judgment result is no, the motor controller continues to obtain the speed, torque and temperature of the motor. In the first mapping relationship diagram, the first mapping result corresponding to the speed of the motor and the torque of the motor is searched, and the second mapping result corresponding to the first mapping result and the temperature of the motor is searched in the second mapping relationship diagram. The second mapping result is the determined speed of the coolant pump. The motor controller can send the speed determined in real time to the coolant pump, so that the coolant pump runs at this speed to pump coolant, thereby cooling the electric drive system.

[0054] Based on the principle of the method for setting the rotation speed of a coolant pump of a motor according to the first specific embodiment of the present invention, Figure 6 A flow chart of a method for setting the speed of a coolant pump of a motor according to a third specific embodiment of the present invention is schematically shown. In the third specific embodiment, when the electric drive system is not in a safe state, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor, and the temperature of the coolant.

[0055] like Figure 6As shown, first, determine whether the electric drive system is in the ASC state or the FreeWheeling state. If the judgment result is yes, the speed of the coolant pump is set to the predetermined speed corresponding to the ASC state or the FreeWheeling state. If the judgment result is no, the motor controller continues to obtain the speed, torque and coolant temperature of the motor. In the first mapping relationship diagram, the first mapping result corresponding to the speed of the motor and the torque of the motor is searched, and in the third mapping relationship diagram, the third mapping result corresponding to the first mapping result and the temperature of the coolant is searched, and the third mapping result is the determined speed of the coolant pump. The motor controller can send the speed determined in real time to the coolant pump, so that the coolant pump runs at the speed to pump coolant, thereby cooling the electric drive system.

[0056] Based on the principle of the method for setting the rotation speed of a coolant pump of a motor according to the first specific embodiment of the present invention, Figure 7 A flowchart of a method for setting the speed of a coolant pump of a motor according to a fourth specific embodiment of the present invention is schematically shown. In the fourth specific embodiment, when the electric drive system is not in a safe state, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor, and the larger of the temperature of the motor and the temperature of the coolant.

[0057] like Figure 7 As shown, first, determine whether the electric drive system is in the ASC state or the FreeWheeling state. If the judgment result is yes, the speed of the coolant pump is set to the predetermined speed corresponding to the ASC state or the FreeWheeling state. If the judgment result is no, the motor controller continuously obtains the speed, torque and temperature of the motor and the temperature of the coolant. Select the larger of the temperature of the motor and the temperature of the coolant. In the first mapping relationship diagram, find the first mapping result corresponding to the speed of the motor and the torque of the motor, and in the second or third mapping relationship diagram, find the second or third mapping result corresponding to the larger of the first mapping result and the selected temperature of the motor and the temperature of the coolant, and the second or third mapping result is the determined speed of the coolant pump. The motor controller can send the speed determined in real time to the coolant pump so that the coolant pump runs at the speed to pump coolant, thereby cooling the electric drive system.

[0058] Based on the principle of the method for setting the rotation speed of a coolant pump of a motor according to the first specific embodiment of the present invention, Figure 8A flowchart of a method for setting the speed of a coolant pump of a motor according to a fifth specific embodiment of the present invention is schematically shown. In the fifth specific embodiment, when the electric drive system is not in a safe state, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor, and the smaller of the temperature of the motor and the temperature of the coolant.

[0059] like Figure 8 As shown, first, determine whether the electric drive system is in the ASC state or the FreeWheeling state. If the judgment result is yes, the speed of the coolant pump is set to the predetermined speed corresponding to the ASC state or the FreeWheeling state. If the judgment result is no, the motor controller continuously obtains the speed, torque and temperature of the motor and the temperature of the coolant. Select the smaller of the temperature of the motor and the temperature of the coolant. In the first mapping relationship diagram, find the first mapping result corresponding to the speed of the motor and the torque of the motor, and in the second or third mapping relationship diagram, find the second or third mapping result corresponding to the smaller of the first mapping result and the selected temperature of the motor and the temperature of the coolant, and the second or third mapping result is the determined speed of the coolant pump. The motor controller can send the speed determined in real time to the coolant pump so that the coolant pump runs at this speed to pump coolant, thereby cooling the electric drive system.

[0060] Compared with the prior art, the method for setting the rotation speed of the coolant pump according to the embodiment of the present invention has at least the following advantages:

[0061] In the present invention, when the electric drive system is not in a safe state, various factors that may affect the heat dissipation requirements of the electric drive system (i.e., the speed of the motor, the torque, and the temperature of the motor and / or the temperature of the coolant) are taken into consideration when setting the speed of the coolant pump, and the speed of the coolant pump is set based on these factors so that the speed of the coolant pump is adapted to the heat dissipation requirements of the electric drive system, thereby saving energy consumption of the coolant pump and the energy consumption of the entire vehicle.

[0062] In the present invention, when the electric drive system is in a safe state, the speed of the coolant pump is set to a predetermined speed corresponding to the safe state, so that the speed of the coolant pump is adapted to the heat dissipation requirement of the electric drive system in the safe state, thereby saving the energy consumption of the coolant pump and the energy consumption of the entire vehicle.

[0063] In the present invention, the larger one of the temperature of the motor and the temperature of the coolant can be taken into consideration when setting the speed of the coolant pump, so that the coolant pump operates at a relatively high speed, thereby avoiding insufficient heat dissipation capacity.

[0064] In the present invention, the smaller of the temperature of the motor and the temperature of the coolant can be taken into consideration when setting the speed of the coolant pump, so that the coolant pump operates at a relatively low speed, thereby ensuring sufficient heat dissipation capacity while reducing the energy consumption of the coolant pump as much as possible.

[0065] In the present invention, by using the first, second and third mapping diagrams, a specific method of determining the speed of the coolant pump according to the speed and torque of the motor and the temperature of the motor and / or the temperature of the coolant is proposed.

[0066] It should be noted that the above description is only for example and not for limitation of the present invention. In other embodiments of the present invention, the method may have more, fewer or different steps, and the order, inclusion and function of each step may be different from that described and illustrated. For example, generally multiple steps can be combined into a single step, and a single step can also be divided into multiple steps. For those of ordinary skill in the art, without paying creative work, the sequential changes of each step are also within the scope of protection of the present invention.

[0067] The technical solution of the present invention, in essence or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor or a microcontroller to perform all or part of the steps of the method described in each embodiment of the present invention.

[0068] Those skilled in the art can understand that all or part of the steps of implementing the above-mentioned method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, the steps of the above-mentioned method embodiments are executed; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk and other media that can store program codes.

[0069] Although the present invention has been disclosed as above with preferred embodiments, the present invention is not limited thereto. Any changes and modifications made by any person skilled in the art without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention, and therefore the protection scope of the present invention should be subject to the scope defined by the claims.

Claims

1. A method for setting the rotation speed of a coolant pump, wherein the coolant pump is used to deliver coolant to a coolant flow path of an electric drive system of a vehicle to cool the electric drive system, wherein the electric drive system includes a motor, characterized in that: The method comprises: When the electric drive system is in a safe state, setting the rotation speed of the coolant pump to a predetermined rotation speed corresponding to the safe state; and When the electric drive system is not in the safe state, the rotation speed of the coolant pump is set to a rotation speed determined according to the following conditions: the rotation speed of the motor, the torque of the motor, and the temperature of the motor and / or the temperature of the coolant.

2. The method according to claim 1, wherein: The security state is the ASC state or the FreeWheeling state.

3. The method according to claim 1, wherein: When the electric drive system is not in the safe state, the rotation speed of the coolant pump is set to a rotation speed determined according to the rotation speed of the motor, the torque of the motor, and the temperature of the motor.

4. The method according to claim 1, wherein: When the electric drive system is not in the safe state, the rotation speed of the coolant pump is set to a rotation speed determined according to the rotation speed of the motor, the torque of the motor, and the temperature of the coolant.

5. The method according to claim 1, wherein: When the electric drive system is not in the safe state, the rotation speed of the coolant pump is set to a rotation speed determined according to the rotation speed of the motor, the torque of the motor, and one selected from the temperature of the motor and the temperature of the coolant according to a set rule.

6. The method according to claim 5, wherein: The rules set are: Selecting the greater of the temperature of the motor and the temperature of the coolant, or The smaller one of the temperature of the motor and the temperature of the coolant is selected.

7. The method according to claim 6, wherein: If the temperature of the motor is selected from the temperature of the motor and the temperature of the coolant according to a set rule, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor and the temperature of the motor.

8. The method according to claim 6, wherein: If the coolant temperature is selected from the temperature of the motor and the temperature of the coolant according to a set rule, the speed of the coolant pump is set to a speed determined according to the speed of the motor, the torque of the motor and the temperature of the coolant.

9. The method according to claim 3 or 7, wherein: Setting the rotation speed of the coolant pump to a rotation speed determined according to the rotation speed of the motor, the torque of the motor, and the temperature of the motor includes: Searching for a first mapping result corresponding to the rotation speed of the motor and the torque of the motor in a first mapping relationship diagram; A second mapping result corresponding to the first mapping result and the temperature of the motor is searched in the second mapping relationship diagram, where the second mapping result is the determined rotation speed.

10. The method according to claim 4 or 8, wherein: Setting the rotation speed of the coolant pump to a rotation speed determined according to the rotation speed of the motor, the torque of the motor and the temperature of the coolant comprises: Searching the first mapping result corresponding to the rotation speed of the motor and the torque of the motor in the first mapping relationship diagram, A third mapping result corresponding to the first mapping result and the temperature of the coolant is searched in a third mapping relationship diagram, where the third mapping result is the determined rotation speed.

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