Electric vehicle thermal management system virtual calibration method and system

Abstract

The application provides a kind of electric vehicle thermal management system virtual calibration method and system, comprising the following steps: model establishing step: establishing thermal management system simulation model;Calibration step: running thermal management system simulation model for virtual calibration.The application uses modeling software to build physical modeling in thermal management system.Provide simulation process data input for model using actual driving data or simulation data containing relevant information, simulate the driving condition of vehicle in real environment.Using real-time data or data trend given by simulation system model, help calibration personnel to complete parameter calibration of air conditioning control system and three-electricity cooling system control model.The whole calibration process is realized in simulation software.The application realizes the process of simplifying calibration and shortening calibration time by loading software into the controller of development vehicle and using ring model laboratory for preliminary control parameter calibration in computer end.

Description

Technical Field

[0001] This invention relates to the technical field of virtual calibration, and more specifically, to a virtual calibration method and system for an electric vehicle thermal management system. Background Technology

[0002] Electric vehicles require heating and cooling management of their components during operation. This demand has spurred the development of the entire thermal management system industry, with needs stemming from various aspects such as electric vehicle safety, comfort, component lifespan, and charging power. While meeting these requirements, the thermal management system also consumes battery energy, thus reducing driving range. Therefore, calibrating the thermal management system of electric vehicles is essential to simultaneously meet the demands of thermal management and driving range.

[0003] The traditional calibration method for electric vehicle thermal management systems is as follows: developers complete the writing of thermal management control software, load the software into the controller of the vehicle being developed, then use an environmental simulation laboratory to perform preliminary control parameter calibration, and finally conduct road tests to verify the control effect of the control parameters in the actual environment, and finally obtain the calibration results.

[0004] Similarly, the development of automatic air conditioning systems largely depends on environmental simulation laboratory testing and field road testing to verify and calibrate control strategies. Figure 1 This document demonstrates the typical process and timeline for calibrating an automatic air conditioning system. After the automotive project commences and the general control software for the automatic air conditioning system is developed, initial calibration of the automatic air conditioning system begins on a prototype vehicle. First, the transfer functions of the relevant sensors are determined and verified. Then, the prototype vehicle undergoes calibration in an environmental simulation laboratory, a process that takes 2-3 weeks. After the environmental simulation calibration is completed, the automatic air conditioning performance essentially meets the requirements for road testing, entering the road test calibration phase. During road tests, the performance of the automatic air conditioning system under various operating conditions is examined by the OEM customer. If it does not meet the technical specifications, the calibration data is repeatedly revised to improve system performance, ultimately achieving customer acceptance. The road test phase also takes approximately 2-3 weeks. It is important to note that as the condition of the prototype vehicle improves, the vehicle suitability of the initial air conditioning system calibration may decrease, requiring repeated environmental simulation and road test calibration. Calibration is an ongoing process that continues until the vehicle enters production and is launched on the market. Sometimes, based on market feedback, the calibration process may require repeated revisions even after production and market launch before final completion. For a more detailed description of the automotive automatic air conditioning calibration process, please refer to [link to relevant documentation]. Figure 2 .

[0005] Chinese invention patent document CN102073278A discloses a system for automotive ECM calibration and verification. It uses an application to construct virtual vehicle components and virtual powertrain components, and uses these virtual components to construct a virtual vehicle platform and virtual powertrain. Then, a simulator is used as a bridge between the virtual and real worlds to achieve accurate and real-time interaction between the application and the ECM hardware. In this interaction process, ECM calibration and verification can be achieved.

[0006] Chinese utility model patent document with publication number CN208298966U discloses a calibration device for the thermal management system of an electric vehicle. The device includes: an environmental simulation chamber, in which the thermal management system is installed, and the environmental simulation chamber is used to simulate the target environment required for testing the thermal management system; and a host computer, which is connected to the thermal management system to simulate the temperature changes of the power battery pack by controlling the electric heating device or cooling device of the thermal management system.

[0007] Regarding the aforementioned technologies, the inventors believe that current calibration methods are cumbersome, time-consuming, require the participation of various engineering and management personnel, and are costly, thus increasing vehicle development time and costs. With shortening product cycles and increasing pricing pressure, suppliers and OEMs must find ways to reduce costs and shorten delivery times. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the purpose of this invention is to provide a virtual calibration method and system for an electric vehicle thermal management system.

[0009] A virtual calibration method for an electric vehicle thermal management system according to the present invention includes the following steps:

[0010] Model building steps: Build a simulation model of the thermal management system;

[0011] Calibration steps: Run the thermal management system simulation model for virtual calibration.

[0012] Preferably, the calibration step includes the following steps:

[0013] Operation steps: Run the thermal management system simulation model;

[0014] Judgment steps: Determine whether the running result meets expectations;

[0015] If the results meet expectations, the calibration process ends.

[0016] If the running results do not meet expectations, adjust the calibration parameters and continue running the thermal management system simulation model according to the adjusted calibration parameters until the running results meet expectations.

[0017] Preferably, in the model building step, the established thermal management system simulation model includes simulation data, an air conditioning control model, a cooling system control model, and a thermal air conditioning system simulation model;

[0018] The established simulation model of the thermal air conditioning system includes a cabin thermal response model, a refrigeration heat pump system model, and a cooling system model;

[0019] The operation steps include the following steps:

[0020] Simulation data input steps: Configure simulation data;

[0021] Air conditioning control steps: The air conditioning control model obtains air conditioning control data based on the simulation data and the cabin response data output by the cabin thermal response model;

[0022] Cooling control steps: The cooling system control model obtains cooling system control data based on simulation data, air conditioning control data, and cooling system response data output by the cooling system model;

[0023] Thermal simulation steps: The thermal air conditioning system simulation model obtains the output data of the refrigeration and heat pump system model based on the cooling system control data; the cabin response data and cooling system response data are obtained based on the simulation data, air conditioning control data, cooling system control data, and the output data of the refrigeration and heat pump system model.

[0024] Preferably, in the simulation data input step, the initial conditions and boundary conditions of the simulation process are loaded using the data loading function of the simulation software;

[0025] The initial conditions include the initial state data of the thermal system and control system at the start of the simulation;

[0026] The boundary conditions include environmental parameters during operation, vehicle state parameters, and set requirements for the thermal system.

[0027] Preferably, in the air conditioning control step, the inputs to the air conditioning control model include: ambient temperature, sunlight intensity, vehicle interior temperature, user-set temperature, relevant setting parameters, and sensor parameters;

[0028] The interior temperature is provided by a cabin thermal response model in a simulated manner;

[0029] The output of the air conditioning control model is air conditioning control data, which includes target values ​​for outlet air temperature, target air volume of the air conditioning system, target blower voltage, or target control data for air conditioning outlet mode.

[0030] Preferably, in the model building step, the established cooling system control model includes a three-electric cooling system control model, and the established cooling system model includes a three-electric cooling system model.

[0031] In the cooling control step, the inputs to the three-electric cooling system control model include: the output of the air conditioning control model and the response data of the three-electric cooling system model;

[0032] The response data of the three-electric cooling system model includes the temperature parameters of the components of the three-electric cooling system;

[0033] The output of the three-electric cooling system control model is cooling system control data, which includes compressor speed, electronic expansion valve opening, shut-off valve opening status, condenser fan speed, water pump switch, and water pump speed.

[0034] Preferably, in the model building step, the established thermal management system simulation model includes simulation data, an air conditioning control model, and a thermal air conditioning system simulation model;

[0035] The established simulation model of the thermal air conditioning system includes a cabin thermal response model.

[0036] Preferably, in the model building step, the established thermal management system simulation model includes simulation data, a cooling system control model, and a thermal air conditioning system simulation model;

[0037] The established simulation model of the thermal air conditioning system includes a refrigeration heat pump system model and a cooling system model.

[0038] A virtual calibration system for an electric vehicle thermal management system according to the present invention includes the following modules:

[0039] Model building module: Builds a simulation model of the thermal management system;

[0040] Calibration module: Runs the thermal management system simulation model for virtual calibration.

[0041] Preferably, the calibration module includes the following modules:

[0042] Run module: Runs the thermal management system simulation model;

[0043] Judgment module: Determines whether the running result meets expectations;

[0044] If the results meet expectations, the calibration process ends.

[0045] If the running results do not meet expectations, adjust the calibration parameters and continue running the thermal management system simulation model according to the adjusted calibration parameters until the running results meet expectations.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. This invention utilizes modeling software to build a physical model of a thermal management system. Actual driving data or simulation data containing relevant information is used as input to the model to simulate the vehicle's driving conditions in a real environment. The control models of the air conditioning control system and the three-electric cooling system to be calibrated are combined with the physical model of the thermal air conditioning system and the simulation data input to form a simulation system model. Real-time data or data trends provided by the simulation system model help calibration personnel complete the parameter calibration of the air conditioning control system and the three-electric cooling system control models. The entire calibration process is implemented entirely within the simulation software. This solution simplifies the calibration process and shortens the calibration time by implementing "loading the software into the vehicle's controller and performing preliminary control parameter calibration in a simulation laboratory" on the computer.

[0048] 2. This invention proposes to establish a virtual laboratory based on the physical model of the electric vehicle thermal management system to conduct virtual experiments and road tests, and to carry out basic calibration work;

[0049] 3. In view of the high level of development of computer capabilities today, the calibration method provided by this invention is not only simple and fast, but also extremely economical, which can significantly reduce the development cycle and cost of automobiles. Attached Figure Description

[0050] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0051] Figure 1 This is a typical diagram illustrating the calibration process of a vehicle's automatic air conditioning system.

[0052] Figure 2 A comparison diagram of the virtual calibration process and the typical calibration process for automotive automatic air conditioning;

[0053] Figure 3 This is a schematic diagram of the virtual calibration system model structure and data flow;

[0054] Figure 4 This is a flowchart of the calibration process for this invention;

[0055] Figure 5 This is a schematic diagram of a thermal air conditioning system architecture;

[0056] Figure 6 This is a thermodynamic cycle diagram of refrigeration vapor compression;

[0057] Figure 7 This is a cabin energy balance diagram;

[0058] Figure 8 The system diagram is a graphical representation of a refrigeration and heat pump system in MATLAB / Simscape.

[0059] Figure 9 Programming model diagram for a MATLAB / Simulink graphical air conditioning control system (including refrigeration and heat pump control);

[0060] Figure 10 This is a baseline diagram of the automotive air conditioning system control performance.

[0061] Figure 11 Control performance diagrams for baseline calibration of new automotive air conditioning systems;

[0062] Figure 12 Performance diagram of the new automotive automatic air conditioning system after virtual calibration optimization. Detailed Implementation

[0063] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0064] This invention discloses a virtual calibration method for an electric vehicle thermal management system, such as... Figure 3 and Figure 4 As shown, it includes the following steps:

[0065] Model building steps: Establish a thermal management system simulation model. This model includes simulation data, an air conditioning control model, a cooling system control model, and a thermal air conditioning system simulation model. The thermal air conditioning system simulation model includes a cabin thermal response model, a refrigeration / heat pump system model, and a cooling system model. The cooling system control model includes the three-electric cooling system control model, and the overall cooling system model includes the three-electric cooling system model.

[0066] Calibration steps: Run the thermal management system simulation model for virtual calibration.

[0067] The calibration process includes the following steps:

[0068] Operation steps: Run the thermal management system simulation model. The operation steps include the following:

[0069] Simulation data input steps: Configure initial and boundary conditions for the simulation. Utilize the simulation software's data loading function to load the initial and boundary conditions for the simulation process. Initial conditions include the initial state data of the thermal and control systems at the start of the simulation; boundary conditions include environmental parameters during operation, the vehicle's own state parameters, and the set requirements for the thermal system, including the automatic air conditioning cabin temperature setting and the operating temperature settings of the three-electric systems. The automatic air conditioning set temperature and the battery and electric drive control set operating temperature are the control target data. The boundary conditions of the simulation data include control target data (such as battery temperature).

[0070] Air Conditioning Control Steps: The air conditioning control model obtains air conditioning control data based on simulation data and cabin response data output from the cabin thermal response model. Inputs to the air conditioning control model include: ambient temperature, sunlight intensity, interior temperature, user-set temperature, relevant setting parameters, and sensor parameters. The interior temperature is provided by the cabin thermal response model in a simulated manner. The output of the air conditioning control model is the air conditioning control data, which includes target values ​​for outlet air temperature, target airflow for the air conditioning system, target blower voltage, or target airflow mode control data.

[0071] Cooling control steps: The cooling system control model obtains cooling system control data based on simulation data, air conditioning control data, and the cooling system response data output by the cooling system model. The inputs to the three-electric cooling system control model include: simulation data, the output of the air conditioning control model, and the response data of the three-electric cooling system model.

[0072] The response data of the three-electric cooling system model includes the temperature parameters of the components of the three-electric cooling system.

[0073] The output of the three-electric cooling system control model is cooling system control data, which includes target parameter values ​​such as compressor speed, electronic expansion valve opening, shut-off valve opening status, condenser fan speed, water pump switch and water pump speed, thereby providing cooling water flow rate and temperature values.

[0074] Thermal simulation steps: The thermal air conditioning system simulation model obtains the output data of the refrigeration and heat pump system model based on the cooling system control data; the cabin response data and cooling system response data are obtained based on the simulation data, air conditioning control data, cooling system control data, and the output data of the refrigeration and heat pump system model.

[0075] Based on the output data of the refrigeration and heat pump system model and the output of the air conditioning control model, including exhaust temperature, exhaust volume and exhaust mode, the cabin thermal response model calculates the cabin response data. Based on the cooling water flow rate and temperature provided by the three-electric cooling system control model, the three-electric cooling system model calculates the cooling system response data.

[0076] Judgment steps: Determine whether the running result meets expectations.

[0077] If the results meet expectations, the calibration process ends.

[0078] If the running results do not meet expectations, adjust the calibration parameters and continue running the thermal management system simulation model according to the adjusted calibration parameters until the running results meet expectations.

[0079] Embodiment 1 of the present invention also discloses a virtual calibration system for an electric vehicle thermal management system, comprising the following modules:

[0080] Model building module: Builds a simulation model of the thermal management system.

[0081] The calibration module includes the following modules:

[0082] Run module: Runs the thermal management system simulation model.

[0083] Judgment module: Determines whether the running result meets expectations.

[0084] If the results meet expectations, the calibration process ends.

[0085] If the running results do not meet expectations, adjust the calibration parameters and continue running the thermal management system simulation model according to the adjusted calibration parameters until the running results meet expectations.

[0086] Calibration module: Runs the thermal management system simulation model for virtual calibration.

[0087] Embodiment 2 of the present invention also discloses a virtual calibration method for an electric vehicle thermal management system, such as... Figure 3 and Figure 4 As shown, a thermal management system simulation model is established. This model includes simulation data, an air conditioning control model, a three-electric cooling system control model, and a thermal air conditioning system simulation model. The simulation software used in this invention is Matlab's Simulink, but other similar simulation platform software can also be used. This invention uses the thermal management system simulation model to simulate and predict the control performance of the automotive automatic air conditioning system on the vehicle's interior temperature. During the simulation process, the intrinsic parameters in the automatic air conditioning model are adjusted and calibrated to improve the automatic air conditioning performance, optimizing the calibration parameters to meet the performance requirements of a real-world vehicle automatic air conditioning system. Similarly, this invention uses the thermal management system simulation model to simulate and predict the control performance of the three-electric cooling control system on the temperature of the drive battery, drive motor, and high-voltage electronic control components. During the simulation process, the intrinsic parameters in the three-electric cooling control system model are adjusted and calibrated to improve the performance of the three-electric cooling control system, optimizing the calibration parameters to meet the performance requirements of a real-world vehicle automatic air conditioning system.

[0088] Construction and provision of simulation data: Using the data loading function of simulation software, some necessary initial conditions and boundary conditions are loaded during the simulation process.

[0089] Initial conditions refer to the initial state data of the thermal and control systems that are necessary for the simulation system to begin. This data can include the initial temperature of the car's passenger compartment, defined as the instantaneous temperature reading transmitted by the in-vehicle temperature sensor when the car's ignition switch is turned on; it can also include the initial temperature inside the electric vehicle's battery, i.e., the battery temperature when the electric vehicle is restarted after a period of time since it was parked. These initial conditions establish the initial state of the simulation system, upon which the simulation of the state parameters of each subsystem at all subsequent time points can begin.

[0090] Boundary conditions are the environmental parameters necessary for the simulation system to operate. These include external environmental parameters such as instantaneous ambient temperature and humidity, solar radiation intensity, and road condition parameters, as well as the state parameters of the vehicle itself as a component of the simulation system, such as vehicle speed and direction of travel. Boundary conditions also include setting parameters for the thermal system, such as the set temperature for automatic air conditioning control and the set temperatures for components in the electric drive system. The basic equations of the thermal management system simulation model require boundary conditions as basic inputs, combined with the initial conditions at the start of the simulation, to simulate the temperatures of relevant components and other parameters at subsequent times.

[0091] Boundary conditions and initial conditions can be established through analysis methods based on national standards and domestic automotive testing standards, or they can be provided directly from experimental data recorded during the development of relevant automobiles.

[0092] Simulation data input sampling time: The sampling time of the simulation data input needs to be consistent with or compatible with the sampling time of the simulation system.

[0093] Air Conditioning Control Model: The air conditioning control model refers to the MATHLAB / Simulink model of the automotive automatic air conditioning control system. This model is compiled into machine code and written into the automotive automatic air conditioning controller to achieve automatic control of the air conditioning and reach the optimal comfortable temperature inside the vehicle. The automotive automatic air conditioning controller is a standard component in mass-produced vehicles; in electric vehicles, the functionality of this controller is often integrated into a domain controller. The air conditioning control model only needs to include all control logic, algorithms, and calibration parameters; it is an application-level model and does not need to include models at the basic input / output (BIOS) level related to automotive hardware.

[0094] The main inputs to the air conditioning control model include: ambient temperature, sunlight intensity, vehicle interior temperature, user-set temperature, and other relevant setting parameters and sensor parameters. In this invention, the cabin simulation model within the thermal air conditioning system simulation model provides the vehicle interior temperature through simulation.

[0095] The main outputs of the air conditioning control model include: target air outlet temperature, air volume data or blower voltage data of the air conditioning system, air outlet mode and other air conditioning-related control data.

[0096] Input / output sampling time of the air conditioning control model: The sampling time needs to be consistent with or compatible with the sampling time of the simulation system.

[0097] The three-electric system cooling system control model is an algorithmic model used to manage the flow and temperature of coolant inputs to the motor, battery, and electronic control (three-electric) system, aiming to maintain the optimal operating temperature of the three-electric system. This model takes the temperature parameters of the three-electric system components as input (in this invention, the temperature parameters are given as response data by the three-electric cooling system model in the thermodynamic system simulation model), and takes the optimal operating temperature of the three-electric components as the control target. Through logical operations, the control model determines how to obtain a coolant supply with a suitable temperature and outputs control parameters to control water circuit (coolant circuit) valves, reorganize the coolant circuit flow, control the front-end cooling fan speed, or control the refrigerant circuit compressor power, etc., to achieve the required coolant temperature; and delivers different coolant flow rates to the three-electric components by controlling the power of each circuit's water pump. The model also includes the output of the air conditioning control model as input; its basic function is to integrate the control outputs of the two systems and avoid control signal conflicts. This model, after being compiled into machine code, can be directly used in mass-produced automotive thermal management controllers or related domain controllers. The model needs to include all control logic, algorithms, and calibration parameters; basic software related to vehicle hardware is not mandatory.

[0098] The main inputs to the three-electric cooling system control model include the outputs of the air conditioning control model and the response data provided by the thermal system simulation model. The main outputs of the three-electric cooling system control model include control data for the thermal air conditioning system, such as compressor speed, electronic expansion valve opening, shut-off valve opening status, condenser fan speed, water pump on / off status, and speed.

[0099] Input / output sampling time of the three-electric cooling system control model: The sampling time needs to be consistent with or compatible with the sampling time of the simulation system.

[0100] The thermal air conditioning system simulation model mainly includes three subsystems: the passenger cabin temperature response system model, the refrigeration heat pump system model, and the three-electric cooling system model. Its main function is to accurately simulate the performance parameters of each subsystem under given input.

[0101] like Figure 5 and Figure 6 As shown, Figure 5 The overall design of a typical refrigeration and heat pump system model is shown. Its purpose is to implement... Figure 6The vapor compression cycle is shown. The refrigeration system consists of four main components: a compressor, a condenser, a throttle valve, and an evaporator. These components perform four processes in the vapor compression cycle: low-temperature refrigerant vapor is compressed by the compressor to form high-temperature, high-pressure vapor; the high-temperature, high-pressure vapor is condensed into high-pressure liquid by the condenser; the condensed liquid expands isenthalpically through the throttle valve to become low-temperature, low-pressure, high-liquid-ratio vapor; finally, the liquid refrigerant in the evaporator evaporates, while simultaneously cooling the air flowing outside the evaporator. The cooled air is mixed with a suitable amount of hot air in the air conditioning unit to reach the required temperature and then enters the passenger cabin for temperature control.

[0102] In a heat pump heating cycle, the evaporator function is performed by an external heat exchanger, while the condenser function is performed by a condenser built into the air conditioning unit. The evaporator absorbs heat from the outside air and releases it to the airflow in the air conditioning unit via the built-in condenser, forming hot air, which is then delivered into the passenger compartment for heating in winter.

[0103] Modeling refrigeration and heat pump systems involves establishing mathematical models and related parameters for each component within the system. In isomorphic systems, component and system performance can be altered by calibrating relevant parameters. However, replacing components with the same function but different operating principles, such as reciprocating compressors and scroll compressors, requires updating the mathematical models and related parameters.

[0104] The main input parameters of a refrigeration heat pump system include compressor speed, air flow rate and temperature flowing into the external heat exchanger, air flow rate and temperature flowing into the internal condenser, air flow rate and temperature flowing into the evaporator, position parameters of each controllable valve in the system, water flow rate and inlet temperature of the liquid cooler, etc. These input parameters are provided directly or indirectly by the cooling system control model.

[0105] The main output parameters of the refrigeration and heat pump system include the outlet air temperature of the external heat exchanger, the outlet air temperature of the internal condenser, the outlet air temperature of the evaporator, and the outlet water temperature of the liquid cooler. The output temperature of the external heat exchanger is used as input for the water tank model of the three-electric cooling system; the outlet air temperature of the internal condenser is used as a heat source for calculating the air temperature of the vehicle's air conditioning system; the outlet air temperature of the evaporator is used as a cold source for calculating the air temperature of the vehicle's air conditioning system; and the outlet water temperature of the liquid cooler is used as the input parameter for the cooling water of the three-electric cooling system.

[0106] like Figure 7As shown, the cabin model is a mathematical model based on the conservation of thermal energy. It can be programmed using computer programming languages ​​(such as MatLab / Simulink) to predict the cabin air temperature and output it as a parameter. As a virtual cabin, it can interface with the automatic air conditioning system, converting the output signals of the automatic air conditioning module into the airflow, temperature, and mode for cooling or heating the air conditioning unit. The air conditioning energy is balanced with the cabin heat load, including sunlight and ambient air heating, as well as transient heat capacity load, to achieve cabin temperature prediction. The predicted temperature, as an output, can be fed back to the automatic air conditioning system, compared with the passenger's set temperature, and used to calculate further control outputs.

[0107] Cabin Model Initialization and Operation: The cabin model includes a set of calibrable parameters used to fine-tune the model based on actual vehicle characteristics. These calibrable parameters can be determined through testing in a ring model laboratory or by using existing data from similar commercially available vehicles. The model can be initialized upon vehicle startup using temperature input from non-breathing sensors (thermometers). After initialization, the cabin model calculates the cabin temperature in real time based on the air conditioning gas flow rate, temperature, and mode entering the cabin, as well as information such as the external ambient temperature, solar radiation intensity, and vehicle speed.

[0108] The three-electric cooling system model mainly refers to the physical mechanism model of the heat generation and cooling of each subsystem of battery, motor, and electronic control. Each component model is established based on the principle of conservation of thermophysical energy, balancing energy terms such as heat generation of components, heat dissipation of coolant, and internal energy contained in the mass of components. At the same time, the three-electric cooling system model also includes a model of the coolant support system.

[0109] Initialization and Operation of the Three-Electric Cooling System Model: The three-electric cooling system model includes a set of calibrable parameters used to fine-tune the model based on actual vehicle characteristics. These calibrable parameters can be determined through testing in a ring model laboratory or by using existing data from similar commercially available vehicles. The model can be initialized upon vehicle startup using recorded temperatures of components such as the motor and battery when stationary, or other temperature assessments, as initial conditions. After initialization, the three-electric cooling system model predicts subsequent temperature changes based on energy conservation equations related to heat generation from components, heat dissipation from coolant, and the internal energy contained in the mass of components, and feeds the temperature signal back to the control system.

[0110] Figure 5The diagram illustrates the design architecture of the battery and motor cooling subsystems, as well as the refrigeration heat pump system architecture. While the electronic control cooling system is not included, its basic design architecture is the same as the motor cooling subsystem. It can be seen that the three-electric cooling system uses cryogenic coolant prepared by the air conditioning system to maintain its optimal operating temperature. More complex three-electric cooling system architectures also include cooling with coolant regulated by a cryogenic water tank from ambient air, or directly diverting cryogenic refrigerant from the air conditioning system into the heat-generating subsystem for efficient cooling.

[0111] The main inputs to the three-electric cooling system model include the inlet flow rate and temperature of the water channels for the components, the electrical power input (motor, electronic control) and output (drive battery) of the components, etc.

[0112] The main outputs of the three-electric cooling system model include the individual temperatures of each component and the water outlet temperatures. As a whole system, the main inputs of the thermal air conditioning system simulation model include: the outputs of the three-electric cooling system control model and the air conditioning control model, as well as related configuration option data. Specifically, it is a comprehensive set of input signals required by the various subsystems of the refrigeration / heat pump system, cabin model, and three-electric cooling system model. This includes the main input parameters of the refrigeration / heat pump system: compressor speed, airflow and temperature flowing into the external heat exchanger, airflow and temperature flowing into the internal condenser, airflow and temperature flowing into the evaporator, and the position parameters of each controllable valve in the system, liquid cooler water flow and inlet temperature, etc.; the cabin model input—air conditioning unit output—airflow, temperature, and mode, provided by the air conditioning unit under the control of the air conditioning control model; and the three-electric cooling system model inputs: component water inlet flow and temperature, component electrical power input (motor, electronic control) and output (drive battery), etc.

[0113] The main outputs of the thermal air conditioning system simulation model include: cabin thermal response data, such as interior temperature; refrigeration and heat pump system response data, such as the operating status parameters (temperature, pressure, flow rate) of various components in the refrigerant circuit. These parameters directly or indirectly determine the temperature parameters of the fluid flowing out of each heat exchanger to support the calculation of the cabin thermal response model and the three-electric cooling system model. The system also includes response signals from the three-electric cooling system, such as the temperature in the water circuit and the internal operating temperatures of each subsystem of the three-electric system, as well as other system status parameters.

[0114] Input / output sampling time of the thermal air conditioning system simulation model: The sampling time needs to be consistent with or compatible with the sampling time of the simulation system.

[0115] Model Interconnections: The simulation system model consists of the four main parts mentioned above, with corresponding input and output ports connected. The connection relationships can be found in [reference needed]. Figure 3 A schematic diagram of the data flow.

[0116] Air conditioning control system and three-electric cooling control system calibration steps:

[0117] Step 1: Using simulation software, configure a set of initial and boundary condition input parameters for the simulation.

[0118] Step 2: Based on the successful representation of the automotive-related systems by the thermal air conditioning system simulation model, starting with calibration data of a control system (air conditioning control system and three-electric cooling control system) that requires improvement, run the entire simulation system model. During this simulation, the air conditioning control system and the three-electric cooling control system integrate and output a set of control signals for relevant system components based on the preliminary calibration data, initial and boundary conditions, and the simulation output of the thermal air conditioning system simulation model to the physical system, according to the control objectives set by the physical system. The thermal air conditioning system simulation model operates under the obtained control parameters, outputting the state parameters of each subsystem during the simulation.

[0119] Since the control system operates with an imperfect initial calibration, it is expected that the simulated data output of the thermal air conditioning system may not meet the set requirements. For example, the interior temperature may not reach the set temperature (e.g., 24 degrees Celsius), or the drive battery operating temperature may be too high (e.g., exceeding the maximum temperature limit of 40 degrees Celsius). Therefore, the control quality may not meet the standard. Compare the system response with the expected control results. If the control results are unsatisfactory, optimize the calibration parameters in the air conditioning control model and the three-electric cooling control model, and perform the next round of simulation. Repeat steps 1 and 2 until the system output meets the expectations or satisfies the set conditions.

[0120] The above calibration steps are repeated under various sets of simulation input data representing different road conditions and operating conditions until the calibration parameters meet the expected control quality for all road conditions and operating conditions. Only then can the calibration parameters be frozen, ending the calibration process. The calibration parameters can then be embedded into the control model or developed into software, allowing for further development tasks. The calibration process can be referenced below. Figure 4 conduct.

[0121] Figure 3 The integrated simulation model of air conditioning control, electric motor cooling control, and thermal control system shown has been successfully modeled using the MATLAB / Simulink / Simscape graphical programming platform, and virtual calibration has been performed on representative automotive air conditioning and electric motor cooling systems under development.

[0122] As part of the integrated simulation calibration system Figure 8A representative example is the Simscape graphical programming refrigeration system model. The main components of the refrigeration system, including the compressor, condenser (or gas cooler), regenerator, expansion valve, and multiple evaporators, are all graphically programmed and connected through relevant piping models to form a complete refrigeration system loop. During simulation, numerical solutions satisfying system capacity and mass conservation are determined. The entire refrigeration system provides each evaporator with a low-temperature refrigerant at the desired temperature, and absorbs energy from the flowing air outside the evaporators through evaporation, thereby providing cool air for the air conditioning unit and ultimately entering the car cabin to ensure passenger comfort.

[0123] Figure 9 This presentation showcases a representative graphical programming control model of an air conditioning control system (including a refrigeration and heat pump) using MATLAB / Simulink. The control system demonstrates the control modules for the air conditioning unit's blower, exhaust mode, exhaust temperature, and corresponding compressor. Driven by valid input data, it can control the air conditioning unit, compressor, and other controllable components, providing control signal outputs.

[0124] Figure 8 , Figure 9 Other subsystems not shown here are integrated on the MATLAB / Simulink / Simscape platform, either through Simscape graphical programming or Simulink graphical programming, to form a complete integrated simulation and calibration system, realizing the simulation and calibration of the overall system.

[0125] The virtual calibration system described in this invention has been successfully applied to the air conditioning calibration and optimization process in automotive modification design. The new automotive design is based on a baseline model, and therefore the air conditioning control system is also optimized and calibrated based on the baseline vehicle's air conditioning control system. The new vehicle has significant changes in its passenger compartment design, and the expected passenger compartment heat load will also change accordingly. Assuming the heating and cooling system remains unchanged, and the automatic air conditioning system architecture remains unchanged, the virtual automatic air conditioning calibration and optimization only needs to consider the changes in calibration parameters caused by the change in passenger compartment heat load.

[0126] As a baseline vehicle (such as the automatic air conditioning system in a commercially available car), its automatic air conditioning control and simulation model were simulated on the MATLAB / Simulink / Simscape platform under the following boundary conditions and design parameters: 1) The sunroof area of ​​the car is 0.833m². 2 The front left side window has an area of ​​0.1225m². 2 The front right-side window has an area of ​​0.1225m². 2 The total area of ​​the rear side windows is 0.588m². 2 ;2) Ambient temperature 29-38℃;3) Sunlight 200-1000W / m 2;4) Vehicle speed 0-80kph;5) Set temperature: 24℃.

[0127] Figure 10 This demonstrates the performance of the car's automatic air conditioning system in controlling the head temperature inside the vehicle. Under given speed and ambient temperature conditions, the head temperature in the left and right front passenger areas fluctuates around 24°C (the passenger's set temperature), with fluctuations of less than 1°C, meeting typical requirements for automatic air conditioning performance.

[0128] The newly developed vehicle (hypothetically) is a design modification based on the baseline vehicle. The modified vehicle completely eliminates windows and adopts a fully enclosed design with four-wall television screens. The cabin thermal response simulation model is run under the new design parameters: 1) The sunroof area is 0 m². 2 The front left side window area is 0m² 2 The front right-side window area is 0m² 2 The total area of ​​the rear side windows is 0m². 2 The automotive automatic air conditioning calibration will not be updated; that is, the baseline automotive calibration parameters will still be used for simulation on the MATLAB / Simulink / Simscape platform. Other operating conditions remain unchanged: 2) Ambient temperature 29-38℃; 3) Sunlight 200-1000W / m². 2 ;4) Vehicle speed 0-80kph;5) Set temperature: 24℃.

[0129] Figure 11 The display shows that the temperature in the front left compartment approached or fell below 20°C between 2700 and 3500 seconds, indicating that the air conditioning was activated. This change in automatic air conditioning control performance is entirely consistent with the expected reduction in heat load in a windowless, fully enclosed cabin design. Simultaneously, it can be observed that the temperature difference between the left and right head compartments widened, exceeding the automatic air conditioning control requirements. Therefore, to improve the automatic air conditioning control performance of new vehicles, the calibration parameters of the automatic air conditioning system must be optimized and adjusted.

[0130] Figure 12 The results show that after virtual calibration optimization of the baseline control calibration for the new car cabin design, the temperature control performance of the new car's automatic air conditioning system has been significantly improved. Under the same road conditions, ambient temperature, and solar radiation settings, the temperature control in the left and right front passenger areas is more uniform than before. Figure 11 The displayed temperatures have improved: the front left zone is operating at the set temperature of 24°C, while the right zone head temperature is operating stably at 25°C, meeting the design requirements of the new car's automatic air conditioning.

[0131] The electric vehicle's three-electric cooling system model includes physical models of the motor, electronic control system, and battery, as well as related heat exchangers, water pumps, valves, and other components, comprehensively representing the heat dissipation and cooling performance of the motor, electronic control system, and battery. Equipped with national or international standard experimental procedures, the physical model of the three-electric cooling system can accurately simulate the heat dissipation data and operating temperature of the motor, electronic control system, and battery under various operating conditions. The three-electric cooling control system is a set of functional modules managed by CPU software based on the operating status of the motor, electronic control system, and battery, controlling the opening and closing of the water pump, front-end fan, and coolant circuit valves. Its control quality largely depends on the calibration quality. Traditionally, the calibration of this system is determined through laboratory experiments and real-world road tests. This solution proposes to use the electric vehicle thermal management system physical model as a basis to create a virtual laboratory for virtual experiments and road tests, conducting basic calibration work. Given the current high level of computing power, this solution provides an unprecedented calibration method that is not only simple and fast but also extremely cost-effective, significantly reducing the vehicle development cycle and cost.

[0132] The physical model of an electric vehicle's refrigeration and heat pump system includes mathematical models of all refrigeration and air conditioning components, such as the compressor, external heat exchanger (OHX), receiver-dryer, electronic expansion valve, thermal expansion valve, evaporator, built-in condenser, front-end fan, and air conditioning unit. This forms a complete air conditioning and heat pump heating system, which can be modeled using MATLAB / Simulink / Simscape and accurately simulates and predicts the system's operating conditions and cooling / heating capacity under various working conditions. Meanwhile, the automotive cabin thermal response model can accurately predict changes and stability of the cabin temperature under different environmental conditions (outside temperature and sunlight intensity) and the influence of air conditioning airflow. The automotive automatic air conditioning system is an automatic system that calculates and determines the correct exhaust temperature, airflow, and mode of the air conditioning unit based on data provided by external sensors (temperature and sunlight) and internal sensors (head temperature and vent temperature). It operates primarily on a calibrable software module running in a dedicated automotive controller and directly controls the air conditioning unit driver and blower to refrigerate the cabin. This is a standard feature in modern automobiles. As mentioned above, the calibration of this system is extremely complex, time-consuming, and expensive. This solution proposes using a physical model of an electric vehicle's air conditioning heat pump system as a basis to create a virtual laboratory for virtual experiments and road tests, conducting basic calibration work. Given the advanced computing capabilities of today, this solution provides an unprecedented calibration method that is not only simple and fast but also extremely cost-effective, significantly reducing vehicle development cycles and costs. Since the simulation model contains vehicle state information, different models or configuration parameters are required in different development stages to ensure data accuracy. This invention, by establishing a simulation system model in modeling software and using the simulation model to complete the initial calibration of the air conditioning system, can effectively save development time and costs for air conditioning software developers.

[0133] Embodiment 3 of the present invention also discloses a virtual calibration method for an electric vehicle thermal management system. The difference from Embodiment 1 is that the established thermal management system simulation model includes simulation data, an air conditioning control model, and a thermal air conditioning system simulation model; the established thermal air conditioning system simulation model includes a cabin thermal response model. Alternatively, the established thermal management system simulation model includes simulation data, a cooling system control model, and a thermal air conditioning system simulation model; the established thermal air conditioning system simulation model includes a refrigeration heat pump system model and a cooling system model.

[0134] Specifically, the simplified model of the simulation system model: Different automotive projects have different calibration requirements. Some projects may only involve the parameter calibration of the air conditioning control model. In this case, the aforementioned model can be simplified into a simulation model consisting of simulation data input, the air conditioning control model, and the cabin thermal response model in the thermal air conditioning system simulation model. If only the parameter calibration of the thermal (three-electric) system model is involved, it can be simplified into a simulation model consisting only of the refrigeration heat pump subsystem model and the three-electric cooling subsystem model in the thermal air conditioning system simulation model.

[0135] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0136] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A virtual calibration method for an electric vehicle thermal management system, characterized in that, Includes the following steps: Model building steps: Build a simulation model of the thermal management system; Calibration steps: Run the thermal management system simulation model for virtual calibration; In the model building step, the established thermal management system simulation model includes simulation data, an air conditioning control model, a cooling system control model, and a thermal air conditioning system simulation model. The established simulation model of the thermal air conditioning system includes a cabin thermal response model, a refrigeration heat pump system model, and a cooling system model; The calibration process includes the following steps: Operation steps: Run the thermal management system simulation model; The operation steps include the following steps: Simulation data input steps: Configure simulation data; Air conditioning control steps: The air conditioning control model obtains air conditioning control data based on the simulation data and the cabin response data output by the cabin thermal response model; Cooling control steps: The cooling system control model obtains cooling system control data based on simulation data, air conditioning control data, and cooling system response data output by the cooling system model; Thermal simulation steps: The thermal air conditioning system simulation model obtains the output data of the refrigeration and heat pump system model based on the cooling system control data; based on the simulation data, air conditioning control data, cooling system control data, and the output data of the refrigeration and heat pump system model, the cabin response data and cooling system response data are obtained. Based on the output data of the refrigeration and heat pump system model and the output of the air conditioning control model, including exhaust air temperature, exhaust air volume, and exhaust mode, the cabin thermal response model calculates the cabin response data. Based on the cooling water flow rate and temperature provided by the three-electric cooling system control model, the three-electric cooling system model calculates the cooling system response data. The calibration steps also include the following steps: Judgment steps: Determine whether the running result meets expectations; If the results meet expectations, the calibration process ends. If the running results do not meet expectations, adjust the calibration parameters and continue running the thermal management system simulation model according to the adjusted calibration parameters until the running results meet expectations. In the simulation data input step, the initial conditions and boundary conditions of the simulation process are loaded using the data loading function of the simulation software. The initial conditions include the initial state data of the thermal system and control system at the start of the simulation; the initial state data includes the initial temperature of the car cabin and the initial temperature inside the electric vehicle battery; these initial conditions establish the initial state of the simulation system, on which the simulation of the state parameters of each subsystem at all subsequent time points can begin. The boundary conditions include environmental parameters during operation, vehicle state parameters, and set requirements for the thermal system. The basic equations of the thermal management system simulation model require boundary conditions as basic inputs, combined with the initial conditions at the start of the simulation, to simulate the temperature of relevant components and other parameters at subsequent times.

2. The virtual calibration method for an electric vehicle thermal management system according to claim 1, characterized in that, In the air conditioning control step, the inputs to the air conditioning control model include: ambient temperature, sunlight intensity, vehicle interior temperature, user-set temperature, relevant setting parameters, and sensor parameters. The interior temperature is provided by a cabin thermal response model in a simulated manner; The output of the air conditioning control model is air conditioning control data, which includes target values ​​for outlet air temperature, target air volume of the air conditioning system, target blower voltage, or target control data for air conditioning outlet mode.

3. The virtual calibration method for the electric vehicle thermal management system according to claim 1, characterized in that, In the model building step, the established cooling system control model includes a three-electric cooling system control model, and the established cooling system model includes a three-electric cooling system model. In the cooling control step, the inputs to the three-electric cooling system control model include: the output of the air conditioning control model and the response data of the three-electric cooling system model; The response data of the three-electric cooling system model includes the temperature parameters of the components of the three-electric cooling system; The output of the three-electric cooling system control model is cooling system control data, which includes compressor speed, electronic expansion valve opening, shut-off valve opening status, condenser fan speed, water pump switch, and water pump speed.

4. The virtual calibration method for an electric vehicle thermal management system according to claim 1, characterized in that, In the model building step, the established thermal management system simulation model includes simulation data, an air conditioning control model, and a thermal air conditioning system simulation model. The established simulation model of the thermal air conditioning system includes a cabin thermal response model.

5. A virtual calibration system for an electric vehicle thermal management system, characterized in that, The virtual calibration method for the electric vehicle thermal management system according to claim 1 includes the following modules: Model building module: Builds a simulation model of the thermal management system; Calibration module: Runs the thermal management system simulation model for virtual calibration.

6. The virtual calibration system for the electric vehicle thermal management system according to claim 5, characterized in that, The calibration module includes the following modules: Run module: Runs the thermal management system simulation model; Judgment module: Determines whether the running result meets expectations; If the results meet expectations, the calibration process ends. If the running results do not meet expectations, adjust the calibration parameters and continue running the thermal management system simulation model according to the adjusted calibration parameters until the running results meet expectations.

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