A control method and device of a proportional three-way valve of a pure electric vehicle thermal management system

Abstract

The application discloses a pure electric vehicle thermal management system proportional three-way valve control method and device, and belongs to the technical field of automobiles, wherein the implementation of the method comprises the following steps: combining a passenger cabin thermal management state and a battery thermal management state according to condition judgment in a driving process to obtain different driving modes; determining heating requirements of the passenger cabin and the battery according to the different driving modes, and then controlling a proportional three-way valve according to the heating requirements of the passenger cabin and the battery in different driving modes. The application guarantees the optimality of the battery temperature and the comfort of the passenger cabin in different modes.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of automobile technology, more specifically, relates to a pure electric vehicle thermal management system proportional three-way valve control method and device. BACKGROUND

[0002] Facing energy shortage and environmental pollution and many other challenges, the automobile industry is undergoing an "electrification" revolution. Pure electric vehicles with zero emission characteristics are popular in the market, and are also the focus of current new energy vehicle research. However, the large-scale promotion of pure electric vehicles is facing the difficult problem of short driving range, so reasonable use of electric vehicle energy can effectively extend the driving range. The current electric vehicle thermal management system is heated for the passenger cabin and battery pack through PTC or heat pump mode, and through the control of the proportional three-way valve, the heat source can be effectively utilized, the comfort can be improved, and the battery temperature can be prevented from being too low due to the heat source being provided to the passenger cabin, thereby reducing the performance; also, the heat source can be prevented from being provided to the battery pack, thereby reducing the comfort of the passenger cabin.

[0003] Referring to the patent application with publication number CN106739944A, a control method for a proportional three-way valve of an automobile air conditioner and an automobile air conditioner controller are disclosed. The application introduces a control method for a proportional three-way valve of an automobile air conditioner, which controls the proportional three-way valve according to the engine water temperature and the PTC heater water inlet temperature, thereby solving the problem of sudden temperature change at the air outlet during the engine start-stop process of a hybrid vehicle. However, the above control logic is relatively simple, and only controls the engine start-stop mode, and cannot be applied to the electric vehicle thermal management system. SUMMARY

[0004] In view of the above defects or improvement needs of the prior art, the present application provides a pure electric vehicle thermal management system proportional three-way valve control method and device, which guarantees the battery temperature optimality and the comfort of the passenger cabin in different modes.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present application, a pure electric vehicle thermal management system proportional three-way valve control method is provided, comprising:

[0006] determining the passenger cabin thermal management state and the battery thermal management state according to the conditions in the driving process to obtain different driving modes;

[0007] determining the heating requirements of the passenger cabin and the battery according to different driving modes, and then controlling the proportional three-way valve according to the heating requirements of the passenger cabin and the battery in different driving modes.

[0008] In some optional embodiments, determining the passenger cabin thermal management state comprises: no PTC heating and no compressor heat pump, PTC heating or compressor heat pump;

[0009] Determine the battery thermal management state output: PTC heating or compressor heat pump, no PTC heating and no compressor heat pump.

[0010] In some optional embodiments, the passenger cabin thermal management state and the battery thermal management state are combined according to the conditions in the driving process to obtain different driving modes, including:

[0011] The passenger cabin thermal management state and the battery thermal management state are combined to obtain four driving modes, including: state A: no PTC heating and no compressor heat pump for the passenger cabin, PTC heating or compressor heat pump for the battery; state B: PTC heating or compressor heat pump for the passenger cabin, PTC heating or compressor heat pump for the battery; state C: PTC heating or compressor heat pump for the passenger cabin, no PTC heating and no compressor heat pump for the battery; and state D: others.

[0012] In some optional embodiments, when entering state A, the passenger cabin has no heating demand, no PTC heating and no heat pump demand, and the battery has a heating demand, PTC heating or compressor heat pump. This state A is battery pack heating alone, and the 1 and 2 ports of the proportional three-way valve are fully open.

[0013] In some optional embodiments, when entering state B, the passenger cabin has a heating demand and the battery also has a heating demand, and the proportional three-way valve is adjusted according to the PTC water temperature, the warm air core inlet target water temperature, and the battery pack inlet target water temperature and the battery pack water temperature.

[0014] In some optional embodiments, the proportional three-way valve is adjusted according to the PTC water temperature, the warm air core inlet target water temperature, and the battery pack inlet target water temperature and the battery pack water temperature, including:

[0015] When entering state B, the proportional three-way valve stops at the initial position. When the PTC outlet water temperature is greater than or equal to the warm air core inlet target water temperature + a first preset temperature value, if the battery pack inlet water temperature is less than the warm air core inlet target water temperature - a second preset temperature value, the proportional three-way valve opening degree is controlled to decrease at a preset duty ratio rate according to a preset period; if the battery pack inlet water temperature is between the warm air core inlet target water temperature - the second preset temperature value and the target warm air core inlet water temperature + the second preset value, the proportional three-way valve is controlled to keep the current duty ratio unchanged; if the battery pack inlet water temperature is greater than the warm air core inlet target water temperature + the second preset temperature value, the proportional three-way valve is controlled to increase at a preset duty ratio rate according to a preset period;

[0016] When the PTC outlet water temperature is less than the warm air core inlet target water temperature + the first preset temperature value, the proportional three-way valve is controlled to keep the current opening degree unchanged.

[0017] In some alternative embodiments, when entering state C, the passenger cabin has heating demand, the battery has no demand, the control proportional three-way valve is fixed opening, and the 2 and 3 ports of the proportional three-way valve are full open.

[0018] In some alternative embodiments, when entering state D, the passenger cabin and the battery have no heating demand, the control three-way valve opening is fixed, and the duty cycle is the first preset duty cycle.

[0019] According to another aspect of the present application, a pure electric vehicle thermal management system proportional three-way valve control device is provided, comprising:

[0020] A mode determination module is configured to determine different driving modes by combining the passenger cabin thermal management state and the battery thermal management state according to the conditions in the driving process.

[0021] A control module is configured to determine the heating demand of the passenger cabin and the battery according to the different driving modes, and to control the proportional three-way valve according to the heating demand of the passenger cabin and the battery in the different driving modes.

[0022] According to another aspect of the present application, a computer readable storage medium is provided, which stores a computer program, and the computer program is executed by a processor to implement the steps of the method according to any one of the above aspects.

[0023] Overall, the above technical solutions conceived by the present application can achieve the following beneficial effects compared with the prior art:

[0024] The present application controls the opening of the proportional three-way valve to meet the comfort of the passenger cabin and keep the battery at the optimal temperature under the heating demand of the passenger cabin and the battery, so as to achieve the highest efficiency and ensure the optimal battery temperature and the comfort of the passenger cabin in different modes. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a flowchart of a pure electric vehicle thermal management system proportional three-way valve control method provided by an embodiment of the present application;

[0026] Figure 2 is a schematic connection diagram of a pure electric vehicle thermal management system proportional three-way valve provided by an embodiment of the present application;

[0027] Figure 3 is a structural schematic diagram of a pure electric vehicle thermal management system proportional three-way valve control device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not used to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0029] In the examples of the present application, "first", "second", and the like are used to distinguish different objects, rather than to describe a specific order or sequence.

[0030] As shown in Figure 1 , a control method of a proportional three-way valve of a pure electric vehicle thermal management system, comprising:

[0031] S101: According to the condition judgment in the driving process, the passenger cabin thermal management state and the battery thermal management state are combined to obtain different driving modes;

[0032] S102: Determine the heating demand of the passenger cabin and the battery according to the different driving modes, and then control the proportional three-way valve according to the heating demand of the passenger cabin and the battery in different driving modes.

[0033] In the embodiments of the present application, step S101 can be realized by the following way:

[0034] According to the condition judgment in the driving process, the passenger cabin thermal management state includes: no PTC heating and no compressor heat pump, PTC heating or compressor heat pump; The battery thermal management state output: PTC heating or compressor heat pump, no PTC heating and no compressor heat pump; The combination of the passenger cabin thermal management state and the battery thermal management state: 1, the passenger cabin has no PTC heating and no compressor heat pump, the battery has PTC heating or compressor heat pump, which is state A; 2, the passenger cabin has PTC heating or compressor heat pump, the battery has PTC heating or compressor heat pump, which is state B; 3, the passenger cabin has PTC heating or compressor heat pump, the battery has no PTC heating and no compressor heat pump, which is state C; 4, others are state D.

[0035] In the embodiments of the present application, as shown in Figure 2 , step S102 can be realized by the following way:

[0036] When entering state A, the passenger cabin has no heating demand, no PTC heating and no heat pump demand, the battery has heating demand, PTC heating or compressor heat pump, this state is battery pack heating alone, then the 1 and 2 ends of the three-way valve are full open;

[0037] When entering state B, the passenger cabin has heating demand and the battery also has heating demand, i.e. heating at the same time, so the proportional three-way valve is adjusted according to the PTC water temperature, the warm air core inlet target water temperature, the battery pack inlet target water temperature and the battery pack water temperature, and the specific adjustment process is as follows:

[0038] When entering state B, the proportional three-way valve stops at the initial position, wherein the initial position can be calibrated, and is temporarily set as 15%;

[0039] When the PTC outlet water temperature is greater than or equal to the warm air core inlet target water temperature + a first preset temperature value (such as 3 degrees Celsius), the following strategy is adopted for adjustment:

[0040] When the battery pack inlet water temperature is less than the warm air core inlet target water temperature - a second preset temperature value (such as 1 degree Celsius), the proportional three-way valve opening degree is reduced at a preset duty ratio (such as 5%, which can be calibrated) per preset period (such as 20s, which can be calibrated); when the battery pack inlet water temperature is between the warm air core inlet target water temperature - the second preset temperature value (such as 1 degree Celsius) and the warm air core inlet target water temperature + the second preset temperature value (such as 1 degree Celsius), the three-way valve maintains the current duty ratio unchanged; when the battery pack inlet water temperature is greater than the warm air core inlet target water temperature + the second preset temperature value (such as 1 degree Celsius), the proportional three-way valve is increased at a preset duty ratio (5%, which can be calibrated) per preset period (20s, which can be calibrated);

[0041] When the PTC outlet water temperature is less than the warm air core inlet target water temperature + a first preset temperature value (such as 3 degrees Celsius), the proportional three-way valve maintains the current opening degree unchanged;

[0042] When entering state C, the passenger cabin has heating demand and the battery has no demand, at this time the three-way valve has a fixed opening degree, and the 2 and 3 ports are fully open, wherein the fixed opening degree is a calibrated value, and in the embodiment of the application, for example, it can be taken as 0;

[0043] When entering state D, the passenger cabin and the battery have no heating demand, and the three-way valve opening degree is a fixed opening degree, and the duty ratio is a first preset duty ratio (such as 50%, which can be calibrated).

[0044] As shown in FIG. Figure 3 A proportional three-way valve control device of a pure electric vehicle thermal management system, comprising:

[0045] A mode determination module 301 is configured to determine different driving modes by combining the passenger cabin thermal management state and the battery thermal management state according to the conditions in the driving process;

[0046] A control module 302 is configured to determine the heating demand of the passenger cabin and the battery according to different driving modes, and to control the proportional three-way valve according to the heating demand of the passenger cabin and the battery in different driving modes.

[0047] The specific implementation of each module can refer to the description of the above method embodiments, and the embodiments of the present application will not be repeated.

[0048] It should be noted that, according to the needs of implementation, each step / component described in the present application can be split into more steps / components, or two or more steps / components or part of the operation of the steps / components can be combined into a new step / component, to achieve the purpose of the present application.

[0049] Those skilled in the art can easily understand that the above only describes the preferred embodiments of the present application and is not intended to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for controlling a proportional three-way valve in a thermal management system for a pure electric vehicle, characterized in that, include: Based on the conditions during driving, the thermal management status of the passenger compartment and the thermal management status of the battery are combined to obtain different driving modes; The heating requirements of the passenger compartment and battery are determined according to different driving modes, and then the proportional three-way valve is controlled according to the heating requirements of the passenger compartment and battery in different driving modes. The thermal management status of the crew cabin is determined as follows: no PTC heating and no compressor heat pump, or with PTC heating or compressor heat pump. Determine the battery thermal management status output: with PTC heating or with compressor heat pump, without PTC heating or without compressor heat pump; Based on the conditions during driving, the system combines the passenger compartment thermal management status and the battery thermal management status to obtain different driving modes, including: Combining the passenger compartment thermal management status with the battery thermal management status, four driving modes are obtained, including: Status A: Passenger compartment without PTC heating and without compressor heat pump, battery with PTC heating or compressor heat pump; Status B: Passenger compartment with PTC heating or compressor heat pump, battery with PTC heating or compressor heat pump; Status C: Passenger compartment with PTC heating or compressor heat pump, battery without PTC heating and compressor heat pump; Status D: Other; When entering state B, both the passenger compartment and the battery require heating. In state B, the proportional three-way valve remains in its initial position. When the PTC outlet water temperature is greater than or equal to the target inlet water temperature of the heater core plus a first preset temperature, if the battery pack inlet water temperature is less than the target inlet water temperature of the heater core minus a second preset temperature, the proportional three-way valve opening decreases at a rate corresponding to a preset duty cycle. If the battery pack inlet water temperature is between the target inlet water temperature of the heater core minus a second preset temperature and the target inlet water temperature of the heater core plus a second preset temperature, the proportional three-way valve maintains its current duty cycle. If the battery pack inlet water temperature is greater than the target inlet water temperature of the heater core plus a second preset temperature, the proportional three-way valve increases at a rate corresponding to a preset duty cycle. When the PTC outlet water temperature is less than the target inlet water temperature of the heater core plus a first preset temperature, the proportional three-way valve maintains its current opening.

2. The method according to claim 1, characterized in that, When entering state A, the crew cabin has no heating requirement, no PTC heating and no heat pump requirement, but the battery has a heating requirement, either PTC heating or compressor heat pump. In this state A, the battery pack is heated separately, so ports 1 and 2 of the proportional three-way valve are fully open.

3. The method according to claim 1, characterized in that, When entering state C, the crew cabin requires heating, but the battery does not. The proportional three-way valve is controlled at a fixed opening, and ports 2 and 3 of the proportional three-way valve are fully open.

4. The method according to claim 1, characterized in that, When entering state D, neither the crew compartment nor the battery requires heating, so the three-way valve opening is fixed and the duty cycle is the first preset duty cycle.

5. A proportional three-way valve control device for a thermal management system of a pure electric vehicle, characterized in that, include: The mode determination module is used to determine the conditions during driving, combine the thermal management status of the passenger compartment and the thermal management status of the battery, and obtain different driving modes. The control module is used to determine the heating requirements of the passenger compartment and battery according to different driving modes, and then control the proportional three-way valve according to the heating requirements of the passenger compartment and battery in different driving modes. The thermal management status of the crew cabin is determined as follows: no PTC heating and no compressor heat pump, or with PTC heating or compressor heat pump. Determine the battery thermal management status output: with PTC heating or with compressor heat pump, without PTC heating or without compressor heat pump; Based on the conditions during driving, the system combines the passenger compartment thermal management status and the battery thermal management status to obtain different driving modes, including: Combining the passenger compartment thermal management status with the battery thermal management status, four driving modes are obtained, including: Status A: Passenger compartment without PTC heating and without compressor heat pump, battery with PTC heating or compressor heat pump; Status B: Passenger compartment with PTC heating or compressor heat pump, battery with PTC heating or compressor heat pump; Status C: Passenger compartment with PTC heating or compressor heat pump, battery without PTC heating and compressor heat pump; Status D: Other; When entering state B, both the passenger compartment and the battery require heating. In state B, the proportional three-way valve remains in its initial position. When the PTC outlet water temperature is greater than or equal to the target inlet water temperature of the heater core plus a first preset temperature, if the battery pack inlet water temperature is less than the target inlet water temperature of the heater core minus a second preset temperature, the proportional three-way valve opening decreases at a rate corresponding to a preset duty cycle. If the battery pack inlet water temperature is between the target inlet water temperature of the heater core minus a second preset temperature and the target inlet water temperature of the heater core plus a second preset temperature, the proportional three-way valve maintains its current duty cycle. If the battery pack inlet water temperature is greater than the target inlet water temperature of the heater core plus a second preset temperature, the proportional three-way valve increases at a rate corresponding to a preset duty cycle. When the PTC outlet water temperature is less than the target inlet water temperature of the heater core plus a first preset temperature, the proportional three-way valve maintains its current opening.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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