Electric vehicle battery charging auxiliary cooling system and control method

Abstract

The invention discloses an electric vehicle battery charging auxiliary cooling system and a control method. The charging auxiliary heat dissipation loop is connected to the whole vehicle battery refrigeration loop in series, the external battery cooling unit of the auxiliary heat dissipation loop can utilize an external power source to supply power for heat dissipation to conduct secondary cooling on the cooling water channel, heat management energy consumption during charging is reduced, the charging efficiency is improved, and accurate and efficient temperature control is achieved. When auxiliary heat dissipation is not needed, the cooling liquid only passes through the charging auxiliary heat dissipation loop, and the external battery cooling unit is not started. The design size and power consumption of an original vehicle cooling part are effectively reduced, and the charging rate is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery temperature management, and more specifically, to an electric vehicle battery charging auxiliary heat dissipation system and a control method. Background Art

[0002] With the development of electrification of commercial vehicles, the stability and safety performance of battery packs as core components are increasingly valued. In the actual use of commercial vehicles, the battery power is large and a lot of heat will be generated during fast charging, so battery cooling is a problem that must be solved during the charging process.

[0003] Existing technologies usually design corresponding large-capacity Chiller and compressor cooling circuits to charge and cool the battery according to the battery thermal management demand signal. By monitoring the battery temperature, cooling is turned on when the trigger threshold is reached and turned off when the target temperature value is reached. However, commercial vehicles have large requirements for the size of compressors and battery heat exchangers. At the same time, charging power is consumed during the charging process to maintain the cooling cycle, which has high requirements for design layout and low charging efficiency. Summary of the invention

[0004] The present invention overcomes the deficiency of the prior art that charging power is consumed to maintain a cooling cycle with low charging efficiency during charging, and provides an electric vehicle battery charging auxiliary heat dissipation system and control method, in the hope of solving the problems existing in the prior art.

[0005] In order to solve the above technical problems, one embodiment of the present invention adopts the following technical solution:

[0006] The present invention provides an electric vehicle battery charging auxiliary heat dissipation system comprising:

[0007] Battery cooling circuit, charging auxiliary heat dissipation circuit, battery pack, battery cooler;

[0008] The water outlet of the battery refrigeration circuit is connected to the water inlet of the charging auxiliary heat dissipation circuit, and the water inlet of the battery refrigeration circuit is connected to the water outlet of the charging auxiliary heat dissipation circuit;

[0009] The battery pack, battery cooler, battery refrigeration circuit, and charging auxiliary heat dissipation circuit are connected in series;

[0010] The charging auxiliary heat dissipation circuit includes an external battery cooling unit;

[0011] The external battery cooling unit is connected to an external power source, and the external battery cooling unit is connected in series to a charging auxiliary heat dissipation circuit.

[0012] The existing battery refrigeration circuit generally uses a compressor, condenser, and expansion valve in series to cool down. By connecting a charging auxiliary heat dissipation circuit in series with the vehicle battery refrigeration circuit, the external battery cooling unit of the auxiliary heat dissipation circuit can use an external power supply to dissipate heat and perform secondary cooling of the cooling water circuit, thereby reducing the energy consumption of thermal management during charging, improving charging efficiency, and achieving precise and efficient temperature control. When auxiliary heat dissipation is not required, the coolant only passes through the charging auxiliary heat dissipation circuit, and the external battery cooling unit is not started.

[0013] A further technical solution is that the charging auxiliary heat dissipation circuit also includes a battery cooling water pump;

[0014] The battery cooling water pump is connected in series to the charging auxiliary heat dissipation circuit.

[0015] A further technical solution is that the water outlet of the battery refrigeration circuit is connected to the water inlet of the charging auxiliary heat dissipation circuit through a battery cooler, and the water inlet of the battery refrigeration circuit is connected to the water outlet of the charging auxiliary heat dissipation circuit through a battery cooler.

[0016] A further technical solution is that the electric vehicle battery charging auxiliary heat dissipation system also includes a battery pack inlet temperature sensor, a battery management system, and a vehicle thermal management controller;

[0017] The battery pack inlet temperature sensor is arranged on the battery pack water inlet circuit;

[0018] The battery management system is connected to the vehicle thermal management controller and the battery pack;

[0019] The vehicle thermal management controller is connected to the battery pack inlet temperature sensor, the battery refrigeration circuit, and the external battery cooling unit.

[0020] The thermal management controller can select the time to intervene in the work according to the collected signal values ​​such as ambient temperature, battery cell temperature, battery pack inlet temperature, etc., and control the working power of the battery refrigeration circuit and charging auxiliary heat dissipation circuit.

[0021] The present invention also provides a method for controlling auxiliary heat dissipation of an electric vehicle battery during charging;

[0022] A method for controlling the auxiliary heat dissipation of an electric vehicle battery during charging, comprising the following steps:

[0023] S1: The battery management system confirms that the battery is in a charging state and the ambient temperature signal is greater than the set temperature;

[0024] S2: The power supply of the external battery cooling unit is turned on;

[0025] S3: The vehicle thermal management controller controls the external battery cooling unit of the charging auxiliary heat dissipation loop to start auxiliary heat dissipation.

[0026] A further technical solution is that S3 comprises the following steps:

[0027] The battery pack inlet temperature sensor transmits the temperature at the battery pack inlet to the vehicle thermal management controller;

[0028] When the difference between the battery pack inlet temperature and the target temperature is lower than the set value, the external battery cooling unit shuts down;

[0029] When the difference between the battery pack inlet temperature and the target temperature is higher than the set value but lower than the dangerous value, the cooling equipment of the battery refrigeration circuit will reduce power and operate until it shuts down, and the external battery cooling unit will maintain the set temperature difference;

[0030] When the inlet temperature of the battery pack is higher than the dangerous value, the external battery cooling unit operates at full power, and the cooling equipment of the battery refrigeration circuit adjusts the power operation according to the temperature difference;

[0031] When the temperature difference becomes larger, increase the operating power of the cooling equipment;

[0032] When the temperature difference becomes smaller, reduce the operating power of the cooling equipment.

[0033] When actually controlling the charging and cooling system, it is necessary to take into account both the cooling effect and the cooling power output by the charging pile. Therefore, when the temperature is within an acceptable range, the external battery cooling unit is shut down. When the temperature gradually rises, it is necessary to make the external battery cooling unit bear more cooling power and try to control the working power of the cooling equipment of the battery refrigeration circuit, because the cooling equipment of the battery refrigeration circuit is powered by the charging pile. When the external battery cooling unit is already running at full power, the operating power of the cooling equipment of the battery refrigeration circuit can only be increased.

[0034] Compared with the prior art, the present invention has at least the following beneficial effects: the present invention connects a charging auxiliary heat dissipation circuit in series with the battery refrigeration circuit of the whole vehicle, and the external battery cooling unit of the auxiliary heat dissipation circuit can use the external power supply to dissipate heat and perform secondary cooling of the cooling water circuit, thereby reducing the energy consumption of thermal management during charging, improving the charging efficiency, and achieving precise and efficient temperature control. When auxiliary heat dissipation is not required, the coolant only passes through the charging auxiliary heat dissipation circuit, and the external battery cooling unit is not started. The design size and power consumption of the original vehicle cooling components are effectively reduced, and the charging rate is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0036] Figure 2 This is a schematic diagram of the process of the second embodiment of the present invention.

[0037] In the figure, 1-electric compressor, 2-cooling fan, 3-condenser, 4-high pressure sensor, 5-electronic expansion valve, 6-battery cooler, 7-battery kettle, 8-external battery cooling unit, 9-battery cooling water pump, 10-battery pack, 11-refrigerant temperature and pressure sensor. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0039] Embodiment 1

[0040] An electric vehicle battery charging auxiliary heat dissipation system, comprising:

[0041] Battery cooling circuit, charging auxiliary heat dissipation circuit, battery pack 10, battery cooler 6, battery pack 10 inlet temperature sensor, battery management system, vehicle thermal management controller;

[0042] The water outlet of the battery refrigeration circuit is connected to the water inlet of the charging auxiliary heat dissipation circuit, and the water inlet of the battery refrigeration circuit is connected to the water outlet of the charging auxiliary heat dissipation circuit;

[0043] It should be noted that the battery refrigeration circuit can be designed according to the needs, and any existing refrigeration equipment on the market can be used. In this embodiment, the battery refrigeration circuit is connected in series with: an electric compressor 1, a condenser 3, a high-pressure sensor 4, an electronic expansion valve 5, a battery cooler 6, and a refrigerant temperature and pressure sensor 11; a cooling fan 2 is provided outside the condenser 3.

[0044] The heat dissipation method of the battery refrigeration circuit is the same as that of the air conditioner, so it will not be repeated here.

[0045] The battery pack 10 and the battery cooler 6 are connected in series with the battery refrigeration circuit and the charging auxiliary heat dissipation circuit;

[0046] In a further preferred embodiment, the water outlet of the battery refrigeration circuit is connected to the water inlet of the charging auxiliary heat dissipation circuit through the battery cooler 6, and the water inlet of the battery refrigeration circuit is connected to the water outlet of the charging auxiliary heat dissipation circuit through the battery cooler 6.

[0047] The charging auxiliary heat dissipation circuit includes an external battery cooling unit 8 and a battery cooling water pump 9;

[0048] The external battery cooling unit 8 is connected to an external power source, and the external battery cooling unit 8 and the battery cooling water pump 9 are connected in series to the charging auxiliary heat dissipation circuit.

[0049] In this embodiment, the battery pack 10 is disposed after the battery cooling water pump 9 and the external battery cooling unit 8 .

[0050] In a further preferred embodiment, the charging auxiliary heat dissipation circuit further includes a battery kettle 7, and the battery kettle 7 is connected in series to the charging auxiliary heat dissipation circuit.

[0051] The battery pack 10 inlet temperature sensor is arranged on the water inlet circuit of the battery pack 10;

[0052] The battery management system is connected to the vehicle thermal management controller and the battery pack 10;

[0053] The vehicle thermal management controller is connected to the inlet temperature sensor of the battery pack 10 , the battery refrigeration circuit, and the external battery cooling unit 8 .

[0054] When auxiliary heat dissipation is not needed, the coolant only passes through the charging auxiliary heat dissipation circuit, and the external battery cooling unit 8 is not started.

[0055] When auxiliary heat dissipation is needed, the external battery cooling unit 8 of the charging auxiliary heat dissipation circuit is started, and the refrigerant cooled by the battery refrigeration circuit is cooled by the external battery cooling unit 8 for secondary cooling, and then the battery pack 10 is cooled.

[0056] Embodiment 2

[0057] A method for controlling the auxiliary heat dissipation of an electric vehicle battery charging, see Figure 2 , including the following steps:

[0058] S1: The battery management system confirms that the battery is in a charging state and the ambient temperature signal is greater than the set temperature;

[0059] S2: The power supply of the external battery cooling unit is turned on;

[0060] S3: The vehicle thermal management controller controls the external battery cooling unit of the charging auxiliary heat dissipation loop to start auxiliary heat dissipation.

[0061] The S3 comprises the following steps:

[0062] S31: The battery pack inlet temperature sensor transmits the temperature at the battery pack inlet to the vehicle thermal management controller, where the inlet temperature minus the target temperature = △t;

[0063] S32: When the difference between the battery pack inlet temperature and the target temperature is lower than the set value z (△t<z), the external battery cooling unit shuts down;

[0064] S33: When the difference between the battery pack inlet temperature and the target temperature is higher than the set value z but lower than the dangerous value y (z<△t<y), the cooling equipment of the battery refrigeration circuit reduces power and operates until it shuts down, and the external battery cooling unit maintains the set temperature difference;

[0065] S34: When the battery pack inlet temperature is higher than the dangerous value y (△t>y), the external battery cooling unit operates at full power, and the cooling equipment of the battery refrigeration circuit adjusts the power operation according to the temperature difference;

[0066] When the temperature difference becomes larger, increase the operating power of the cooling equipment;

[0067] When the temperature difference becomes smaller, reduce the operating power of the cooling equipment.

[0068] The vehicle thermal management controller serves as the control terminal of the entire thermal management system. It collects temperature signals from various sensors and batteries in real time for processing logic. When it determines that the ambient temperature signal is greater than the set temperature, the battery management system is in charging status, and the external battery cooling unit is powered on, it means that the battery pack is being charged and the ambient temperature requires heat dissipation for the rechargeable battery pack.

[0069] Although the present invention is described herein with reference to the illustrative embodiments of the present invention, it should be understood that those skilled in the art can design many other modifications and implementations, which will fall within the scope and spirit of the principles disclosed in the present application. More specifically, within the scope disclosed in the present application, multiple variations and improvements can be made to the components and / or layout of the subject combination layout. In addition to the variations and improvements made to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. An electric vehicle battery charging auxiliary heat dissipation system, characterized in that: include: Battery cooling circuit, charging auxiliary heat dissipation circuit, battery pack, battery cooler; The water outlet of the battery refrigeration circuit is connected to the water inlet of the charging auxiliary heat dissipation circuit, and the water inlet of the battery refrigeration circuit is connected to the water outlet of the charging auxiliary heat dissipation circuit; The battery pack, battery cooler, battery refrigeration circuit, and charging auxiliary heat dissipation circuit are connected in series; The charging auxiliary heat dissipation circuit includes an external battery cooling unit; The external battery cooling unit is connected to an external power source, and the external battery cooling unit is connected in series to a charging auxiliary heat dissipation circuit.

2. An electric vehicle battery charging auxiliary heat dissipation system as claimed in claim 1, characterized in that: The charging auxiliary heat dissipation circuit also includes a battery cooling water pump; The battery cooling water pump is connected in series to the charging auxiliary heat dissipation circuit.

3. The electric vehicle battery charging auxiliary heat dissipation system according to claim 1, characterized in that: The battery refrigeration circuit water outlet is connected to the charging auxiliary heat dissipation circuit water inlet through the battery cooler, and the battery refrigeration circuit water inlet is connected to the charging auxiliary heat dissipation circuit water outlet through the battery cooler.

4. The electric vehicle battery charging auxiliary heat dissipation system according to claim 1, characterized in that: It also includes the battery pack inlet temperature sensor, battery management system, and vehicle thermal management controller; The battery pack inlet temperature sensor is arranged on the battery pack water inlet circuit; The battery management system is connected to the vehicle thermal management controller and the battery pack; The vehicle thermal management controller is connected to the battery pack inlet temperature sensor, the battery refrigeration circuit, and the external battery cooling unit.

5. A method for controlling the auxiliary heat dissipation of an electric vehicle battery during charging, characterized in that: The following steps are involved: S1: The battery management system confirms that the battery is in a charging state and the ambient temperature signal is greater than the set temperature; S2: The power supply of the external battery cooling unit is turned on; S3: The vehicle thermal management controller controls the external battery cooling unit of the charging auxiliary heat dissipation loop to start auxiliary heat dissipation.

6. The electric vehicle battery charging auxiliary heat dissipation control method as claimed in claim 5, characterized in that: The S3 comprises the following steps: The battery pack inlet temperature sensor transmits the temperature at the battery pack inlet to the vehicle thermal management controller; When the difference between the battery pack inlet temperature and the target temperature is lower than the set value, the external battery cooling unit shuts down; When the difference between the battery pack inlet temperature and the target temperature is higher than the set value but lower than the dangerous value, the cooling equipment of the battery refrigeration circuit will reduce power and operate until it shuts down, and the external battery cooling unit will maintain the set temperature difference; When the inlet temperature of the battery pack is higher than the dangerous value, the external battery cooling unit operates at full power, and the cooling equipment of the battery refrigeration circuit adjusts the power operation according to the temperature difference; When the temperature difference becomes larger, increase the operating power of the cooling equipment; When the temperature difference becomes smaller, reduce the operating power of the cooling equipment.

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