Design parameter optimization method and system for electric vehicle motor insulation cover

Abstract

The present invention provides a method and system for optimizing the design parameters of an electric vehicle motor insulation cover, the method comprising the following steps: taking the ratio of the heat absorbed by the coolant from the motor heat generation to the active heat generation of the motor heat source as the goal, solving the design parameters of the motor insulation cover by an optimization algorithm; wherein, in the optimization algorithm solving process, the design parameters of the motor insulation cover are used to characterize the temperature data of the motor, coolant, air and the motor insulation cover; the temperature data of the motor, coolant, air and the motor insulation cover are used to characterize the heat absorbed by the coolant from the motor heat generation and the active heat generation of the motor heat source. The present invention effectively optimizes the structure of the electric vehicle motor insulation cover to maximize the heat absorbed by the coolant from the active heating process of the motor.

Description

Technical Field

[0001] The invention belongs to the technical field of electric vehicle design, and in particular relates to a design parameter optimization method and system for an electric vehicle motor thermal insulation cover. Background Art

[0002] The market share of new energy vehicles, especially pure electric vehicles, is increasing rapidly due to their huge advantages in energy saving, low carbon and environmental protection compared to traditional fuel vehicles and the increasing maturity of electric vehicle technology in recent years.

[0003] As the number of electric vehicles increases, various problems and user pain points are gradually exposed, among which the heat source problem of pure electric vehicles in extremely low temperature environments is particularly prominent.

[0004] Unlike traditional fuel vehicles, where engine waste heat can be used as the main heat source, the heat sources of pure electric vehicles mainly include air source heat pumps, electric heaters, and motor waste heat recovery. Air source heat pumps use the reverse Carnot cycle to make the heat exchange medium absorb heat from the environment by using the compressor to do work. Electric heaters need to be equipped with high-power electric heater parts and related cables, and arranged in the corresponding water circuit or installed in the air conditioning box. Motor waste heat recovery is to use the heat generated by the motor when it is running, and recover it through various technical means and convert it into a heat source for the thermal management system. Since the motor waste heat is the heat that must be generated during the normal operation of the vehicle, the adoption of this technology can effectively improve the energy efficiency of the entire vehicle. The active heating of the motor, including reduced efficiency heating during driving and heat generation during stalling at idling, is an emerging technology applied to electric vehicles in recent years. Based on the artificially set control strategy, this technology allows the motor to actively reduce the efficiency of converting electrical energy into kinetic energy, convert most of the electrical energy into thermal energy as an additional heat source for the system, and can provide considerable heat in the thermal management system. After reasonable design and optimization, this technology can replace the traditional electric heater in electric vehicles, thereby significantly reducing the cost of the thermal management system of the entire vehicle. Therefore, the ability of the coolant to absorb heat from the motor is crucial to the thermal management system that adopts motor de-efficiency heating.

[0005] Current research on inventions related to active heating of motors focuses more on improving the heat generation capacity inside the motor, but has not yet considered increasing the thermal insulation effect of the motor to prevent heat loss. One typical motor insulation measure is to tightly wrap a motor insulation cover around the outer surface of the motor.

[0006] Existing inventions and research on the evaluation of the active heating capacity of motors and the design of motor insulation cover structures mostly adopt three-dimensional CFD thermal simulation to obtain the overall temperature field distribution and then design the insulation structure. The advantage of CFD simulation is that the results are accurate and the physical field information is complete and comprehensive, but the disadvantage is that the solution resource requirements are large, the calculation efficiency is low, and it is difficult to combine the optimization algorithm to quickly optimize the design parameters. Therefore, the design of the motor insulation cover structure is mostly based on engineering experience, and lacks comprehensive optimization considerations of the heat transfer process of air, motor housing, internal heat source of the motor, and coolant. As a result, it is impossible to obtain the optimal or near-optimal design parameters of the motor insulation cover under certain design constraints, and it is difficult to maximize the heat absorbed by the coolant from the active heating process of the motor. Summary of the invention

[0007] The purpose of the present invention is to solve the deficiencies of the above-mentioned background technology and to provide a method and system for optimizing the design parameters of an electric vehicle motor insulation cover, so as to effectively optimize the structure of the electric vehicle motor insulation cover to improve the heat absorption capacity of the coolant.

[0008] The technical solution adopted by the present invention is: a method for optimizing the design parameters of an electric vehicle motor insulation cover, comprising the following steps:

[0009] The design parameters of the motor insulation cover are solved by an optimization algorithm with the goal of maximizing the ratio of the heat absorbed by the coolant from the motor heat generation to the active heat generation of the motor heat source.

[0010] Among them, the design parameters of the motor insulation cover are used in the optimization algorithm solution process to characterize the temperature data of the motor, coolant, air and motor insulation cover; the temperature data of the motor, coolant, air and motor insulation cover are used to characterize the heat absorbed by the coolant from the heat generated by the motor and the active heat generated by the motor heat source.

[0011] In the above technical solution, the constraints of the optimization algorithm solution process include:

[0012] The volume of the motor insulation cover does not exceed its upper limit;

[0013] The design parameters of the motor insulation cover do not exceed their corresponding upper limits;

[0014] The heat exchange between the motor, coolant, air and motor insulation cover follows the law of conservation of energy;

[0015] The convective heat transfer energy between the motor, coolant, air and motor insulation cover is equal to the product of the corresponding convective heat transfer coefficient, contact area and temperature difference;

[0016] The heat conduction energy between the motor housing, the internal heat source of the motor and the motor insulation cover is equal to the negative value of the product of the temperature change rate of the object undergoing heat conduction at the corresponding distance and the thermal conductivity multiplied by the heat exchange area.

[0017] In the above technical scheme, the process of using the design parameters of the motor insulation cover to characterize the temperature data of the motor, coolant, air and the motor insulation cover includes: constructing a linear equation group for characterizing the mathematical relationship between the design parameters of the motor insulation cover and the motor, coolant, air and the motor insulation cover temperature data based on the design parameters of the motor insulation cover, the initial assumed temperature of the motor housing and the heat transfer coefficients of the air and coolant; iteratively solving the linear equation group until the calculation accuracy requirements are met, and outputting the calculation results of the motor, coolant, air and motor insulation cover temperature data under the current design parameters of the motor insulation cover; the motor housing includes the outer shell of the motor, and the internal structure of the motor except the motor heat source; the motor housing is in contact with the motor heat source, coolant, air and the motor insulation cover and performs heat exchange.

[0018] In the above technical solution, the solution convergence criterion is defined as the relative deviation value of the motor housing temperature obtained from two iterations; when the relative deviation value meets the given iteration condition, it is considered that the calculation accuracy requirement is met, the iteration stops, and the calculation result is output.

[0019] In the above technical solution, the heat transfer coefficients of air and coolant are calculated according to the set boundary conditions; the boundary conditions include: air inlet flow rate and temperature, coolant inlet flow rate and temperature, and heat of the motor heat source.

[0020] In the above technical solution, the design parameters of the motor insulation cover are solved by genetic algorithm.

[0021] In the above technical solution, the design parameters of the motor insulation cover include: the coverage, average thickness and thermal conductivity of the motor insulation cover.

[0022] In the above technical solution, the temperature data of the motor, coolant, air and motor insulation cover include: motor heat source temperature, motor housing temperature, coolant outlet temperature, air outlet temperature and motor insulation cover surface temperature.

[0023] In the above technical solution, the expression of the linear equation group is:

[0024] ;

[0025] Among them, A represents the coefficient matrix, B represents the constant vector, and T represents the unknown quantity to be solved; q motor Indicates the active heat generated by the motor heat source, T motor Indicates the temperature of the motor heat source, T f-ave Indicates the average temperature of the coolant, T f-out Indicates the outlet temperature of the coolant, T air-ave represents the average temperature of the air, q air Indicates the heat of air, T air-outIndicates the air outlet temperature, T w Indicates the temperature of the motor housing, T cover Indicates the temperature of the motor insulation cover, q air-cover Indicates the heat exchanged between air and motor insulation cover; q air-uncover Indicates the heat exchanged between the air and the part of the motor not covered by the motor insulation cover.

[0026] In the above technical solution, the coefficient matrix A is formed by arranging the coefficients on the left side of the following formula:

[0027] ;

[0028] Among them, x 1 Represents the coverage rate of the motor insulation cover; x 2 Represents the average thickness of the motor insulation cover; average thickness x 3 Represents the thermal conductivity of the motor insulation cover; h f Identifies the convective heat transfer coefficient of the coolant, A f Indicates the contact area of ​​the coolant, T f-ave represents the average temperature of the coolant, q fluid represents the heat of the coolant, c p-fluid represents the specific heat capacity of the coolant, q m-fluid represents the mass flow rate of the coolant, T f-in Indicates the inlet temperature of the coolant, h air represents the convective heat transfer coefficient of air, A motor Represents the surface area of ​​the motor housing, T air-in represents the air inlet temperature, c p-air represents the specific heat capacity of air, q m-air represents the mass flow rate of air, δ motor Indicates the average distance between the motor heat source and the motor housing, k motor Indicates the thermal conductivity of the motor.

[0029] The present invention provides a design parameter optimization system for an electric vehicle motor insulation cover, which is used to implement the design parameter optimization method for the electric vehicle motor insulation cover described in the above technical solution; the system comprises a design parameter optimization module, which is used to solve the design parameters of the motor insulation cover by an optimization algorithm with the goal of maximizing the ratio of the heat absorbed by the coolant from the motor heat generation to the active heat generation of the motor heat source;

[0030] Among them, the design parameters of the motor insulation cover are used in the optimization algorithm solution process to characterize the temperature data of the motor, coolant, air and motor insulation cover; the temperature data of the motor, coolant, air and motor insulation cover are used to characterize the heat absorbed by the coolant from the heat generated by the motor and the active heat generated by the motor heat source.

[0031] The above technical solution also includes a constraint input module, which is used to receive external input constraint parameters; the constraint parameters include: the upper limit of the volume of the motor insulation cover; and the upper limit of the design parameters of the motor insulation cover.

[0032] The above technical solution also includes a boundary condition input module, which is used to receive boundary condition parameters input from the outside; the boundary condition parameters include: air inlet flow rate and temperature, coolant inlet flow rate and temperature, heat of the motor heat source and the initial assumed temperature of the motor housing.

[0033] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the method for optimizing the design parameters of the electric vehicle motor insulation cover described in the above technical solution is implemented.

[0034] The present invention also provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the design parameter optimization method of the electric vehicle motor insulation cover as described in the above technical solution by executing the computer instructions.

[0035] The beneficial effects of the present invention are as follows: the present invention aims to maximize the ratio of the heat absorbed by the coolant from the heat generated by the motor to the active heat generated by the motor heat source, solves the design parameters of the motor insulation cover through an optimization algorithm, and can optimize the design parameters of the motor insulation cover based on the goal of maximizing the performance of the coolant absorbing the active heat of the motor, thereby effectively improving the heat absorption capacity of the coolant. At the same time, the method of the present invention is simple and easy to implement, applicable to various types of motors and coolants, and has wide applicability and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the heat transfer process principle of the present invention;

[0037] Figure 2 It is a flow chart of the temperature solving algorithm of the present invention;

[0038] Figure 3 It is a typical genetic algorithm flow chart;

[0039] Figure 4 It is a schematic diagram of the system module of the present invention. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments to facilitate a clear understanding of the present invention, but they do not constitute a limitation on the present invention.

[0041] Example 1

[0042] The present invention provides a method for optimizing design parameters of an electric vehicle motor insulation cover, comprising the following steps:

[0043] The design parameters of the motor insulation cover are solved by an optimization algorithm with the goal of maximizing the ratio of the heat absorbed by the coolant from the motor heat generation to the active heat generation of the motor heat source.

[0044] Among them, the design parameters of the motor insulation cover are used in the optimization algorithm solution process to characterize the temperature data of the motor, coolant, air and motor insulation cover; the temperature data of the motor, coolant, air and motor insulation cover are used to characterize the heat absorbed by the coolant from the heat generated by the motor and the active heat generated by the motor heat source.

[0045] The present invention establishes a fast solution model for evaluating the heat absorption capacity of motor coolant. The model is based on parameters such as motor heating power, coolant inlet flow, coolant inlet temperature, ambient temperature and wind speed, combined with fluid mechanics and heat transfer principles, and based on the lumped parameter method, it simplifies and establishes mathematical relationships, and uses matrices to quickly solve the temperature rise of the coolant after absorbing the heat of the motor. The heat transfer process diagram of the solution model is as follows: Figure 1 As shown, the motor heat source is in direct contact with the motor housing, and heat is transferred in the form of heat conduction; the motor housing is respectively in contact with the motor heat source, the coolant, the motor insulation cover coated on the outside of the motor housing, and the air flowing through the area not coated with the motor insulation cover, and the heat exchange between the motor housing and the coolant is convection heat exchange, and the heat exchange between the motor housing and the motor insulation cover is heat conduction; the air in the environment is respectively in direct contact with the motor housing area not coated by the motor insulation cover and the outer surface of the motor insulation cover for convection heat exchange.

[0046] based on Figure 1 The fast solution model, the cooling liquid heat absorption rate γ used in the present invention f The definition is as follows:

[0047] ;

[0048] Among them, q fluid It represents the heat absorbed by the coolant from the heat generated by the motor, in W. The heat absorbed can be calculated based on the temperature difference between the coolant inlet and outlet using the following formula; q motor Indicates the active heat generated by the motor heat source, unit: W.

[0049] ;

[0050] Among them, c p-fluid Represents the specific heat capacity of the coolant, in J / (kg K), q m-fluid Represents the mass flow rate of the coolant, in kg / s, T f-out and T f-inRepresents the coolant outlet and inlet temperatures respectively, unit K.

[0051] like Figure 1 As shown, the convective heat transfer coefficient between the air and the motor, and the convective heat transfer coefficient between the coolant and the motor can be approximately calculated by using the Nusselt number calculated using empirical formulas.

[0052] Specifically, the constraints of the optimization algorithm solution process include:

[0053] The volume of the motor insulation cover does not exceed its upper limit;

[0054] The design parameters of the motor insulation cover do not exceed their corresponding upper limits;

[0055] The heat exchange between the motor, coolant, air and motor insulation cover follows the law of conservation of energy;

[0056] The convective heat transfer energy between the motor, coolant, air and motor insulation cover is equal to the product of the corresponding convective heat transfer coefficient, contact area and temperature difference;

[0057] The heat conduction energy between the motor housing, the internal heat source of the motor and the motor insulation cover is equal to the negative value of the product of the temperature change rate of the object undergoing heat conduction at the corresponding distance and the thermal conductivity multiplied by the heat exchange area.

[0058] Preferably, the optimization problem can be described as follows (including design parameters, objective function and constraints):

[0059] ;

[0060] In the above formula, x 1 、x 2 、x 3 Respectively represent the coverage, average thickness and thermal conductivity of the motor insulation cover, and are all set with corresponding upper and lower limits (this parameter is optimized in this specific embodiment, and other parameters can be optimized in actual applications. When using this method, the number and type of variables can be increased or reduced in combination with the complexity and focus of the actual problem). V cover Represents the volume of the motor insulation cover, V max Represents the upper limit of the volume of the motor insulation cover. Considering the assembly requirements, material properties and cost, the overall volume of the motor insulation cover needs to be given an upper limit constraint. cover is the area of ​​the motor insulation cover, depth cover is the thickness of the motor insulation cover, Σq represents the overall energy conservation, q conv represents the convective heat transfer, h represents the convective heat transfer coefficient, A represents the contact area, △T represents the temperature difference; q cond represents the heat conduction energy, k represents the thermal conductivity, It indicates the rate of temperature change of two heat conducting objects along a certain direction. Figure 1 In the f-w Indicates the temperature difference between the coolant and the motor housing; △T u-a Indicates the temperature difference between the part of the motor not covered by the motor insulation cover and the air; △T c-a Indicates the temperature difference between the motor insulation cover and the air.

[0061] The constraint conditions set by the present invention can ensure that the results of optimizing parameters meet the actual needs of electric vehicle design, while ensuring the stability of practical applications.

[0062] Specifically, Figure 2 As shown, in the process of running the optimization algorithm, the temperature data of the motor, coolant, air and motor insulation cover are calculated based on the solution model, and the process of using the design parameters of the motor insulation cover to characterize the temperature data of the motor, coolant, air and motor insulation cover includes: based on the design parameters of the motor insulation cover, the initial assumed temperature of the motor housing and the heat transfer coefficient of air and coolant, a linear equation group for characterizing the mathematical relationship between the design parameters of the motor insulation cover and the temperature data of the motor, coolant, air and motor insulation cover is constructed; iteratively solve the linear equation group until the calculation accuracy requirements are met, and output the calculation results of the temperature data of the motor, coolant, air and motor insulation cover under the design parameters of the current motor insulation cover; the motor housing includes the outer shell of the motor, and the internal structure of the motor except the heat source of the motor; the motor housing is in contact with the coolant, air and motor insulation cover and performs heat exchange. When the present invention calculates the average temperature data of each region corresponding to the design parameters of each round in the optimization process, the calculation accuracy of the temperature data can be effectively guaranteed by making initial assumptions and iterative calculations on key physical quantities such as the motor housing temperature until the solution convergence standard is reached, thereby ensuring the calculation accuracy of the objective function, thereby improving the accuracy of the result of parameter optimization.

[0063] Preferably, the solution convergence standard is defined as the relative deviation value of the motor housing temperature (i.e., Tw-old and Tw) obtained from two iterations; when the relative deviation value meets the given iteration condition, it is deemed that the calculation accuracy requirement is met, the iteration stops, and the calculation result is output. The convergence set by the present invention is based on the relative deviation value of the motor housing temperature, mainly considering that the motor housing exchanges heat with the internal heat source of the motor, air, motor insulation cover and coolant, respectively, which is a more critical physical quantity in the physical process concerned by the present invention. By tracking its convergence iteration accuracy, the calculation accuracy of temperature data in other regions can be effectively guaranteed, and the performance of the coolant in absorbing heat from the heat generated by the motor can be effectively reflected, so as to improve the accuracy and optimization effect of parameter optimization design.

[0064] Preferably, the air and coolant heat exchange coefficients are calculated according to the set boundary conditions; the boundary conditions include: air inlet flow rate and temperature, coolant inlet flow rate and temperature, and heat of the motor heat source. The initial assumed temperature of the motor housing is also set by assumption. The present invention can set a given working condition through the set boundary conditions to meet the actual design requirements of the motor insulation cover.

[0065] Preferably, the air and coolant heat transfer coefficients are calculated under given working conditions (i.e., input boundary conditions), and combined with the input motor insulation cover design parameters: insulation coverage (defined as the ratio of the area of ​​the motor outer surface blocked by the motor insulation cover to the area of ​​the complete outer surface of the motor), the average thickness of the motor insulation cover, and the physical parameters (such as the thermal conductivity of the motor) to obtain the corresponding linear equations. The motor surface temperature is defined as the change in the iterative solution process, and the solution convergence standard is defined as the relative deviation of the motor surface temperature obtained between the previous and next two iterations; when the relative deviation meets the given iteration conditions, it can be regarded as meeting the calculation accuracy requirements, the iteration stops, and the calculation results under the current design are output: including the motor center temperature, motor surface temperature, coolant outlet temperature, air outlet temperature, and motor insulation cover surface temperature, etc.

[0066] Specifically, the design parameters of the motor insulation cover are solved by genetic algorithm. In practical applications, a suitable optimization algorithm can be selected to find a set of optimal design variables to obtain the optimal objective function value under the premise of satisfying the constraint function. A recommended optimization algorithm in this embodiment is a genetic algorithm, which has the characteristics of strong flexibility and versatility, can be applied to various optimization problems, whether discrete or continuous, and has strong global search capabilities. The algorithm flow is as follows Figure 3 shown.

[0067] Specifically, the design parameters of the motor insulation cover include: the coverage, average thickness and thermal conductivity of the motor insulation cover. The temperature data of the motor, coolant, air and motor insulation cover include: motor heat source temperature, motor housing temperature, coolant outlet temperature, air outlet temperature and motor insulation cover surface temperature. It should be pointed out that the above three design variables are only given as examples. When using this method, the number and type of variables can be increased or decreased in combination with the complexity and focus of the actual problem.

[0068] When the design parameters of the motor insulation cover are the coverage, average thickness and thermal conductivity of the motor insulation cover, based on the three design variables [x 1 x 2 x 3 ] T An example of solving equations is as follows:

[0069] The coefficient matrix A is formed by arranging the coefficients on the left side of the following equation, which is a 11*11 matrix in this embodiment:

[0070] ;

[0071] The constant term on the right side of the above equation is reorganized into a constant vector B, where the unknown quantity is defined as T, where B and T are defined as follows:

[0072] ;

[0073] Among them, x 1 、x 2 、x 3 Respectively represent the coverage, average thickness and thermal conductivity of the motor insulation cover; h f Identifies the convective heat transfer coefficient of the coolant, A f Indicates the contact area of ​​the coolant, T f-ave represents the average temperature of the coolant, q fluid represents the heat of the coolant, c p-fluid represents the specific heat capacity of the coolant, q m-fluid represents the mass flow rate of the coolant, T f-in Indicates the inlet temperature of the coolant, h air represents the convective heat transfer coefficient of air, A motor Represents the surface area of ​​the motor housing, T air-in represents the air inlet temperature, c p-air represents the specific heat capacity of air, q m-air represents the mass flow rate of air, δ motor Indicates the average distance between the motor heat source and the motor housing, k motor represents the thermal conductivity of the motor; where A represents the coefficient matrix, B represents the constant vector, and T represents the unknown quantity to be solved; q motor Indicates the active heat generated by the motor heat source, T motor Indicates the temperature of the motor heat source, T f-ave Indicates the average temperature of the coolant, T f-out Indicates the outlet temperature of the coolant, T air-ave represents the average temperature of the air, q air Indicates the heat of air, T air-out Indicates the air outlet temperature, T w Indicates the temperature of the motor housing, T cover Indicates the temperature of the motor insulation cover, q air-cover Indicates the heat exchanged between air and motor insulation cover; q air-uncover Indicates the heat exchanged between the air and the part of the motor not covered by the motor insulation cover.

[0074] The linear equations constructed by the present invention are a reasonable simplification of complex physical models based on the lumped parameter method. The constructed equations can fully describe the convective heat transfer process and the heat conduction process between the internal heat source of the motor, the motor, the coolant, the air and the motor insulation cover. Since the physical quantities of interest are mainly the average temperature and the heat transfer capacity, the complex and time-consuming solution process of obtaining physical field results based on traditional CFD simulation can be effectively avoided, and the influence of the design parameters of the motor insulation cover on the heat absorption capacity of the coolant inside the motor can be quickly and accurately reflected, and the optimization algorithm can be adopted to obtain the optimal solution of the design parameters.

[0075] Example 2

[0076] The present invention provides a design parameter optimization system for an electric vehicle motor insulation cover, which is used to implement the design parameter optimization method for the electric vehicle motor insulation cover described in the above technical solution; the system comprises a design parameter optimization module, which is used to solve the design parameters of the motor insulation cover by an optimization algorithm with the goal of maximizing the ratio of the heat absorbed by the coolant from the motor heat generation to the active heat generation of the motor heat source;

[0077] Among them, the design parameters of the motor insulation cover are used in the optimization algorithm solution process to characterize the temperature data of the motor, coolant, air and motor insulation cover; the temperature data of the motor, coolant, air and motor insulation cover are used to characterize the heat absorbed by the coolant from the heat generated by the motor and the active heat generated by the motor heat source.

[0078] Specifically, it also includes a constraint input module, which is used to receive external input constraint parameters; the constraint parameters include: the upper limit of the volume of the motor insulation cover; and the upper limit of the design parameters of the motor insulation cover.

[0079] Specifically, it also includes a boundary condition input module, which is used to receive boundary condition parameters input from the outside; the boundary condition parameters include: air inlet flow rate and temperature, coolant inlet flow rate and temperature, heat of the motor heat source and the initial assumed temperature of the motor housing.

[0080] Example 3

[0081] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the method for optimizing the design parameters of the electric vehicle motor insulation cover described in the above technical solution is implemented.

[0082] Example 4

[0083] The present invention also provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the design parameter optimization method of the electric vehicle motor insulation cover as described in the above technical solution by executing the computer instructions.

[0084] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0085] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0086] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0087] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0088] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

[0089] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field.

Claims

1. A method for optimizing design parameters of an electric vehicle motor insulation cover, characterized in that: The following steps are involved: The design parameters of the motor insulation cover are solved by an optimization algorithm with the goal of maximizing the ratio of the heat absorbed by the coolant from the motor heat generation to the active heat generation of the motor heat source. Among them, the design parameters of the motor insulation cover are used in the optimization algorithm solution process to characterize the temperature data of the motor, coolant, air and motor insulation cover; the temperature data of the motor, coolant, air and motor insulation cover are used to characterize the heat absorbed by the coolant from the heat generated by the motor and the active heat generated by the motor heat source; The process of using the design parameters of the motor insulation cover to characterize the temperature data of the motor, coolant, air and the motor insulation cover includes: constructing a linear equation group for characterizing the mathematical relationship between the design parameters of the motor insulation cover and the motor, coolant, air and the motor insulation cover temperature data based on the design parameters of the motor insulation cover, the initial assumed temperature of the motor housing and the heat transfer coefficients of the air and coolant; iteratively solving the linear equation group until the calculation accuracy requirements are met, and outputting the calculation results of the motor, coolant, air and the motor insulation cover temperature data under the current design parameters of the motor insulation cover; the motor housing includes the outer shell of the motor, and the internal structure of the motor except the motor heat source; the motor housing is in contact with the motor heat source, coolant, air and the motor insulation cover and performs heat exchange.

2. The design parameter optimization method of the electric vehicle motor insulation cover according to claim 1 is characterized in that: The constraints of the optimization algorithm solution process include: The volume of the motor insulation cover does not exceed its upper limit; The design parameters of the motor insulation cover do not exceed their corresponding upper limits; The heat exchange between the motor, coolant, air and motor insulation cover follows the law of conservation of energy; The convective heat transfer energy between the motor, coolant, air and motor insulation cover is equal to the product of the corresponding convective heat transfer coefficient, contact area and temperature difference; The heat conduction energy between the motor housing, the internal heat source of the motor and the motor insulation cover is equal to the negative value of the product of the temperature change rate of the object undergoing heat conduction at the corresponding distance and the thermal conductivity multiplied by the heat exchange area.

3. The design parameter optimization method of the electric vehicle motor insulation cover according to claim 1 is characterized in that: The solution convergence criterion is defined as the relative deviation value of the motor housing temperature obtained from two iterations. When the relative deviation value meets the given iteration condition, the calculation accuracy requirement is considered to be met, the iteration stops, and the calculation result is output.

4. The design parameter optimization method of the electric vehicle motor insulation cover according to claim 1 is characterized in that: The air and coolant heat exchange coefficients are calculated according to the set boundary conditions; the boundary conditions include: air inlet flow rate and temperature, coolant inlet flow rate and temperature, and heat of the motor heat source.

5. The design parameter optimization method of the electric vehicle motor insulation cover according to claim 1 is characterized in that: The design parameters of the motor insulation cover are solved by genetic algorithm.

6. The design parameter optimization method of the electric vehicle motor insulation cover according to claim 1 is characterized in that: The design parameters of the motor heat preservation cover include: the coverage rate, average thickness and thermal conductivity of the motor heat preservation cover.

7. The design parameter optimization method of the electric vehicle motor insulation cover according to claim 6 is characterized in that: The temperature data of the motor, coolant, air and motor insulation cover include: motor heat source temperature, motor housing temperature, coolant outlet temperature, air outlet temperature and motor insulation cover surface temperature.

8. The method for optimizing design parameters of an electric vehicle motor insulation cover according to claim 1, characterized in that: The expression of the linear equation system is: ； Among them, A represents the coefficient matrix, B represents the constant vector, and T represents the unknown quantity to be solved; q motor Indicates the active heat generated by the motor heat source, T motor Indicates the temperature of the motor heat source, T f-ave Indicates the average temperature of the coolant, T f-out Indicates the outlet temperature of the coolant, T air-ave represents the average temperature of the air, q air Indicates the heat of air, T air-out Indicates the air outlet temperature, T w Indicates the temperature of the motor housing, T cover Indicates the temperature of the motor insulation cover, q air-cover Indicates the heat exchanged between air and motor insulation cover; q air-uncover Indicates the heat exchanged between the air and the part of the motor not covered by the motor insulation cover.

9. The design parameter optimization method of the electric vehicle motor insulation cover according to claim 8, characterized in that: The coefficient matrix A is formed by rearranging the coefficients on the left side of the following equation: ； Where x1 represents the coverage of the motor insulation cover; x2 represents the average thickness of the motor insulation cover; the average thickness x3 represents the thermal conductivity of the motor insulation cover; h f Identifies the convective heat transfer coefficient of the coolant, A f Indicates the contact area of ​​the coolant, T f-ave represents the average temperature of the coolant, q fluid represents the heat of the coolant, c p-fluid represents the specific heat capacity of the coolant, q m-fluid represents the mass flow rate of the coolant, T f-in Indicates the inlet temperature of the coolant, h air represents the convective heat transfer coefficient of air, A motor Represents the surface area of ​​the motor housing, T air-in represents the air inlet temperature, c p-air represents the specific heat capacity of air, q m-air represents the mass flow rate of air, δ motor Indicates the average distance between the motor heat source and the motor housing, k motor Indicates the thermal conductivity of the motor.

10. A design parameter optimization system for an electric vehicle motor insulation cover, characterized in that: A method for optimizing the design parameters of an electric vehicle motor insulation cover according to any one of claims 1 to 9; It includes a design parameter optimization module, which is used to maximize the ratio of the heat absorbed by the coolant from the heat generated by the motor to the active heat generated by the motor heat source, and solve the design parameters of the motor insulation cover through an optimization algorithm; Among them, the design parameters of the motor insulation cover are used in the optimization algorithm solution process to characterize the temperature data of the motor, coolant, air and motor insulation cover; the temperature data of the motor, coolant, air and motor insulation cover are used to characterize the heat absorbed by the coolant from the heat generated by the motor and the total active heating value of the motor.

11. The design parameter optimization system for the electric vehicle motor insulation cover according to claim 10, characterized in that: It also includes a constraint condition input module, the constraint condition input module is used to receive external input constraint condition parameters; The constraint condition parameters include: the upper limit of the volume of the motor insulation cover; Upper limit of design parameters for motor insulation cover.

12. The design parameter optimization system for the electric vehicle motor insulation cover according to claim 10, characterized in that: It also includes a boundary condition input module, which is used to receive boundary condition parameters input from the outside; the boundary condition parameters include: air inlet flow rate and temperature, coolant inlet flow rate and temperature, heat of the motor heat source and the initial assumed temperature of the motor housing.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the design parameter optimization method of the electric vehicle motor insulation cover according to any one of claims 1 to 9 is implemented.

14. An electronic device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the design parameter optimization method for the electric vehicle motor insulation cover as described in any one of claims 1 to 9 by executing the computer instructions.

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