KR20200024620A - Heat management apparatus of battery pack for electric vehicles and control method thereof - Google Patents

Abstract

The present invention relates to a heat management device of a battery pack for an electric vehicle and a controlling method thereof. The heat management device comprises: a compressed air supply line which supplies, to a battery pack, compressed dry air (hereinafter referred to as ′compressed air′), filled in an air tank supplying compressed air to a braking system as a driving source; a flow control valve which is installed on the compressed air supply line to control the flow of compressed air supplied to the battery pack; a pressure reducing valve which reduces the compressed air with a predetermined pressure; a cooling unit which cools the compressed air; a heating unit which heats the compressed air; and a control unit which controls the operation of each device based on the temperature of the compressed air and the battery pack. The present invention is able to perform heat management efficiently by receiving compressed air from the air tank for supplying compressed air to the braking system, and by cooling or heating the battery pack.

Description

Heat management device for electric vehicle battery pack and its control method {HEAT MANAGEMENT APPARATUS OF BATTERY PACK FOR ELECTRIC VEHICLES AND CONTROL METHOD THEREOF}

The present invention relates to a thermal management apparatus of a battery pack for an electric vehicle and a control method thereof, and more particularly, to a battery pack using compressed air stored in an air tank of a pneumatic braking system for forming a braking force using pneumatic pressure in an electric vehicle. The present invention relates to a thermal management apparatus of an electric vehicle battery pack for managing heat and a control method thereof.

An electric vehicle is a vehicle that obtains driving energy of an automobile from electric energy rather than combustion of fossil fuel like a conventional vehicle.

Therefore, electric vehicles have no exhaust gas and have a very small noise.

The electric car was manufactured before the gasoline car in 1873, but it was not practically used due to the heavy weight of the battery and the time required for charging.

That is, a technology for solving light weight, miniaturization and short charging time of a battery, which is an energy supply source of an electric vehicle, has been developed.

On the other hand, the thermal management technology of the battery pack applied to the electric vehicle is very important because it has a great effect on the output performance, running distance and durability of the battery.

In general, in the case of an electric passenger car, the inside of the battery is constructed by forming an air cooling method that separates the battery pack using air inside the vehicle and a separate cooling water circuit in connection with an air conditioning system (Heating, Ventilation and Air conditioning (HVAC)). It is divided into water cooling method to cool.

In the case of the water-cooling method, the efficiency is complicated, but the structure is complicated, and the weight of the battery pack, the development cost and material costs are increased, so that the air-cooled heat management system is applied to the expensive electric cars that produce some high power.

For example, Patent Documents 1 to 3 below disclose a battery pack thermal management technology of an electric vehicle according to the prior art.

Republic of Korea Patent Registration No. 10-1768136 (August 14, 2017 announcement) Republic of Korea Patent Registration No. 10-1360423 (announced February 13, 2014) Republic of Korea Patent Registration No. 10-1918917 (January 18, 2018 announcement)

However, in the case of applying an air-cooling method of cooling a battery pack using air in a cabin in a commercial vehicle according to the prior art, as the battery pack is exposed to the outside, watertight, dustproof, electrical insulation, cabin and separate duct ( Due to structural problems inherent to commercial vehicles such as ducts, different cooling methods are required.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems as described above, and a thermal management apparatus of a battery pack for an electric vehicle and a control method thereof for managing the heat of the battery pack using a compressed dry air that is the driving source of the electric vehicle conveying system To provide.

Another object of the present invention is to provide a thermal management apparatus for a battery pack for an electric vehicle and a control method thereof, which do not need to be connected to an air conditioning system of an electric vehicle and manage heat of the battery pack while maintaining an existing air conditioning system.

Another object of the present invention is to obtain the optimum efficiency by cooling the battery pack according to the condition and the outer conditions of the battery cell, the thermal management device of the battery pack for electric vehicles to increase the life of the battery by enhancing the durability against degradation And a control method thereof.

In order to achieve the above object, the thermal management apparatus of the battery pack for an electric vehicle according to the present invention is compressed dry air (hereinafter referred to as 'compressed air') filled in an air tank for supplying compressed air as a driving source to a braking system. ) Compressed air supply line for supplying a battery pack, a flow rate control valve installed on the compressed air supply line to regulate the flow rate of the compressed air supplied to the battery pack, a pressure reducing valve for reducing the compressed air to a predetermined pressure, Cooling unit for cooling the compressed air, a heating unit for heating the compressed air and a control unit for controlling the operation of each device based on the temperature of the battery pack and compressed air.

In addition, in order to achieve the object as described above, the control method of the thermal management apparatus of the battery pack for an electric vehicle according to the present invention (a) the pressure of the battery pack and the pressure inside the air tank to supply compressed air to the braking system in the control unit Receiving a temperature, (b) controlling the driving of the air compressor based on the pressure inside the air tank by the controller, and (c) compressed air filled in the air tank based on the temperature of the battery pack and the compressed air. It is characterized in that it comprises the step of reducing the pressure to a predetermined pressure or less and then heating or cooling the battery pack and (d) maintaining the temperature of the battery pack in a predetermined set temperature range.

As described above, according to the thermal management apparatus and control method of the battery pack for an electric vehicle according to the present invention, by receiving the compressed dry air from the air tank for supplying compressed air to the braking system to cool or heat the battery pack efficiently The effect of thermal management can be obtained.

Accordingly, according to the present invention, compared to the battery pack to which the water-cooling method of the prior art is applied, the effect that the internal structure of the battery pack can be simplified to minimize the development cost, material cost and weight.

In addition, according to the present invention, an effect of increasing the output and efficiency of the vehicle through thermal management of the battery pack and preventing degradation of the battery pack, thereby increasing durability.

In addition, according to the present invention, by utilizing the existing system of the electric vehicle to which the pneumatic braking system is applied as it is, the system configuration is easy, and the system for thermally managing the battery pack using the air in the room generally applied in the electric passenger vehicle structurally The effect that it can be applied to the electric commercial vehicle which is impossible is obtained.

In addition, according to the present invention, compared to the conventional method of attaching and cooling a fan to the front and rear of the battery pack, the effect of increasing the stability to the external environment such as moisture, dust is obtained.

1 is a block diagram of a thermal management apparatus and a braking system of an electric vehicle battery pack according to a preferred embodiment of the present invention;
2 is a diagram illustrating input and output factors of a control unit;
Figure 3 is a flow chart illustrating a step-by-step method of controlling the thermal management apparatus of the battery pack for an electric vehicle according to an embodiment of the present invention.

Hereinafter, a thermal management apparatus and a control method thereof of a battery pack for an electric vehicle according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a thermal management apparatus and a braking system of an electric vehicle battery pack according to a preferred embodiment of the present invention.

Thermal management apparatus 10 of an electric vehicle battery pack according to a preferred embodiment of the present invention is filled in the air tank 20 for supplying compressed air to a drive source for driving the braking system 21, as shown in FIG. The compressed air is heated or cooled and supplied to the battery pack 11 to manage heat of the battery pack 11.

In detail, the thermal management apparatus 10 of the battery pack for an electric vehicle according to the preferred embodiment of the present invention includes a compressed dry air (hereinafter referred to as “compressed air”) filled in the air tank 20. 11) flow control valve for adjusting the flow rate of the compressed air supplied to the compressed air supply line (hereinafter referred to as 'supply line') 30, the supply line 30 to be supplied to the battery pack 11 (31), a pressure reducing valve 32 for reducing the compressed air to a predetermined pressure, a cooling unit 40 for cooling the compressed air, a heating unit 50 for heating the compressed air, and a control unit for controlling the driving of each device ( 60).

The air tank 20 is connected to an air compressor 22 that compresses air introduced from the outside of the vehicle and fills the air tank 20.

Therefore, the air tank 20 may supply the compressed air filled therein to the braking system 21 as a driving source for performing a braking operation according to the control signal of the controller 60.

The controller 60 may control the driving of each device provided in the thermal management apparatus 10 of the battery pack and may control the driving of the air compressor 22 and the air tank 20.

Of course, the present invention is not necessarily limited thereto, and the control unit 60 may be configured separately from a controller for controlling the driving of the air compressor 22 and the air tank 20, and may be changed to communicate with the controller. have.

On the other hand, between the air compressor 22 and the air tank 20 is an air dryer (not shown) for drying the air flowing from the outside and a filter (not shown) for filtering dust and foreign matter contained in the air, etc. Can be prepared.

As described above, the present invention fills the air tank with a clean dry air, which is free of moisture and dust, by using an air dryer and a filter. Thermal management by cooling or heating.

Accordingly, the present invention can increase the stability to the external environment, such as moisture and dust, compared to the prior art that attaches the cooling fan to the front and rear ends of the battery pack.

The battery pack 11 includes a plurality of battery cells, and both ends of the battery pack 11 perform heat exchange in the air inlet 12 and the battery pack 11 through which compressed air is injected into the battery pack 11. An air outlet 13 through which one air is discharged to the outside may be formed.

The air inlet 12 is formed in a manifold structure to uniformly distribute the compressed air and supply it to each battery cell, and the air outlet 13 is a structure in which air that has undergone heat exchange can be smoothly discharged, for example, an air inlet ( It may be formed in a larger diameter than the tip of 13, or a variety of structures, such as a manifold structure such as the air inlet (12).

Accordingly, the present invention can prevent the heat load from rising locally in the plurality of battery cells, and can uniformly adjust the temperature of each battery cell.

The battery pack 11 may be provided with a battery management system (BMS) for managing the battery pack 11.

The battery management system 14 monitors the battery's voltage, current, and temperature in real time to optimally manage the battery to increase energy efficiency and extend its lifespan, thereby preventing excessive charging or discharging and preventing battery safety. And it increases the reliability.

The flow rate control valve 31 may adjust the flow rate of the compressed air supplied from the air tank 20 to the battery pack 11 by controlling the opening and closing operation or opening amount according to the control signal of the control unit 60.

Here, the air compressed in the high pressure of about 7.8 bar or more is filled in the air tank 20.

When supplying such high-pressure compressed air to the battery pack 11 as it is, the internal structure of the battery pack 11 is damaged, the compressed air cooler 41 and the heating unit of the cooling unit 40 to be described below The time which can heat-exchange with the heater of 50 becomes short. In addition, as the air compressor 22 is frequently operated due to the excessive use of the compressed air filled in the air tank 20, it may adversely affect the energy efficiency or the braking performance of the braking system 21.

Therefore, in the present exemplary embodiment, the pressure reducing valve 32 is used to reduce the compressed air to a predetermined low pressure state, for example, about 2 bar or less, which can maintain a level of air flow required for cooling or heating the battery pack 11.

The cooling unit 40 may include a cooler 41 for cooling the compressed air and a cooling fan 42 for blowing outside air to the cooler 41 according to a control signal of the controller 60.

The heating unit 50 may include a PTC heater (hereinafter, referred to as a "heater") that heats the compressed air by generating heat according to a control signal of the controller 60.

On the other hand, the supply line 30 may be further provided with a temperature sensor 70 for detecting the temperature of the compressed air supplied to the battery pack (11).

In this embodiment, the temperature sensor 70 is provided between the cooling unit 40 and the heating unit 50 to detect the temperature of the compressed or uncooled compressed air according to whether the cooling unit 40 is driven, and the temperature detection The detection signal output from the sensor 70 is transmitted to the controller 60.

The control unit 60 is communicatively connected to the main control unit 23 and the battery management system 14 of the electric vehicle so as to share various information such as the state of the vehicle and the state of the battery pack. The driving of each device provided in the thermal management device 10 of the pack can be controlled.

For example, FIG. 2 illustrates an input / output factor of a controller.

As shown in FIG. 2, the controller 60 receives battery state information including a temperature, a state of charge (SoC), and the like of the battery cell and the battery pack 11 from the battery management system 14. Can be input.

In addition, the controller 60 may receive state information of various vehicles together with the temperature of the compressed air detected by the temperature sensor 70, the pressure in the air tank 20, and the atmospheric temperature.

The controller 60 receiving these factors controls the driving of the air compressor 22 according to the pressure in the air tank 20, and controls the flow rate of the compressed air supplied to the battery pack 11. The driving of 31 can be controlled.

In addition, the controller 60 may control driving of a motor driving the cooling fan 42 provided in the cooling unit 40 and a heater provided in the heating unit 50 according to the temperature of the compressed air and the atmospheric temperature.

For example, the controller 60 controls the cooling unit 40 to supply the cooled compressed air to the battery pack 11 by cooling as the air temperature rises in the summer, and the heating unit 50 in the winter. ) May be controlled to supply heated compressed air to the battery pack 11 to heat it.

As described above, the present invention can efficiently manage the heat of the battery pack by using the compressed air filled in the air tank, regardless of the change in conditions such as the external temperature.

Next, with reference to Figure 3 will be described in detail a control method of the thermal management device of the battery pack for an electric vehicle according to an embodiment of the present invention.

3 is a flowchart illustrating a step-by-step method of controlling a thermal management apparatus of an electric vehicle battery pack according to an exemplary embodiment of the present invention.

When the ignition key or the start button (not shown) of the vehicle is operated in step S10 of FIG. 3, the power charged in the battery pack 11 controls each device provided in the electric vehicle and the thermal management device 10 of the battery pack. It is supplied to the control part 60.

Thus, the controller 60 initializes each device provided in the thermal management apparatus 10 of the battery pack, and prepares to perform the thermal management operation of the battery pack according to the state of the vehicle and the state of the battery pack 11.

In step S12, the control unit 60 receives and receives state information of the vehicle and the battery pack 11 through communication with the main control unit 23 and the battery management system 14 of the vehicle.

That is, the controller receives and receives the battery state information including the temperature of the battery cell and the battery pack 11, the state of charge (SoC), etc. from the battery management system 14, the temperature sensor 70 The state information of the various vehicles can be input together with the temperature of the compressed air detected in the air, the pressure inside the air tank 20, and the air temperature.

In step S14, the control unit 60 checks whether the pressure inside the air tank 20 is lower than a predetermined reference pressure, for example, about 7.8 bar.

If the pressure in the air tank 20 is lower than the reference pressure as a result of the check in step S14, the control unit 60 controls the driving of the air compressor 22 to increase the pressure by further filling the compressed air into the air tank. (S16).

Subsequently, the controller 60 checks whether the pressure inside the air tank 20 changed due to the operation of the air compressor 22 is a predetermined threshold pressure, for example, about 8.8 bar or more (S18).

If, as a result of the check in step S18, if the pressure in the air tank 20 is lower than the limit pressure, the control unit 60 performs steps S16 to S18 until the pressure in the air tank 20 reaches the limit pressure. Repeat it.

On the other hand, if the pressure in the air tank 20, the result of step S18 is greater than the threshold pressure, the control unit 60 proceeds to step S40 below.

On the other hand, when the result of the inspection in step S14 the pressure in the air tank 20 is equal to or more than the reference pressure, the control unit 60 checks whether the temperature of the battery pack 11 is within a predetermined set temperature range (S20).

If the result of the check in step S20 is that the temperature of the battery pack 11 is within the set temperature range, since the thermal management operation of the battery pack is unnecessary, the control unit 60 proceeds to step S40 below.

The set temperature range may be set by an experimental value to cool the battery pack 11 in the summer using the thermal management apparatus 10 of the battery pack and to effectively heat the battery pack 11 in the winter.

For example, the set temperature range may be set to a range between a lower temperature of about 10 ° C and an upper limit temperature of about 35 ° C.

Of course, since the condition that requires thermal management of the battery pack is different depending on the application of the vehicle, the set temperature range may be changed according to various conditions such as the specification of the vehicle, the specification of the battery pack.

On the other hand, when the test result of the step S20 the temperature of the battery pack 11 is out of the set temperature range, the control unit 60 to supply the compressed air filled in the air tank 22 to the battery pack 11, The flow control valve 31 is controlled to open.

Then, the compressed air is supplied from the flow control valve 31 to the pressure reducing valve 32 along the compressed air supply line 30, and the pressure is reduced by a pressure reducing valve 32 to a predetermined low pressure state, for example, 2 bar or less.

In step S24, the control unit 60 checks whether the temperature of the battery pack 11 and the compressed air corresponds to a preset cooling condition.

For example, the cooling condition is that the temperature of the battery pack 11 is the upper limit temperature, that is, 35 ℃ or more, the temperature of the battery pack 11 is higher than the temperature of the compressed air, and the temperature of the battery pack 11 and the compressed air The temperature difference may be set to a state in which the temperature difference is a preset reference temperature difference, for example, 10 ° C. or less.

If the test result of step S24 corresponds to the cooling condition, the control unit 60 drives the cooling fan 42 of the cooling unit 40 to cool the compressed air supplied to the cooler 41. Control of driving of the motor provided in (S26).

Accordingly, the battery pack 11 is cooled by receiving compressed air cooled by the cooling unit 40.

As such, when the temperature of the battery pack is higher than the upper limit temperature and the compressed air is 10 ° C. or more lower than the battery pack temperature, the present invention naturally cools the compressed air in the cooler without operating the cooling fan.

Therefore, the present invention can reduce the power consumption due to the driving of the motor of the cooling fan, increase the cooling capacity by operating the cooling fan only when the compressed air does not have a large difference within the temperature of the battery pack within 10 ℃.

In step S28, the controller 60 checks whether the temperature of the cooled battery pack 11 is lower than the upper limit temperature, and repeats steps S26 to S28 until the temperature of the battery pack 11 becomes lower than the upper limit temperature. .

If the test result of step S28 is lower than the temperature of the battery pack 11, the control unit 60 proceeds to step S40.

On the other hand, when the test result in step S24 does not correspond to the cooling condition, the control unit 60 checks whether the temperature of the battery pack 11 is below the lower limit temperature (S30).

If the temperature of the battery pack 11 is less than the lower limit temperature as a result of the check in step S30, the controller 60 controls to drive the heater of the heating unit 50 to heat the compressed air (S32).

Accordingly, the battery pack 11 is heated by receiving compressed air heated by the heating unit 60.

As described above, the present invention can operate the heater in winter when the temperature of the battery pack is lower than the lower limit temperature to inject heated compressed air into the battery pack to maintain the temperature of the battery pack above the lower limit temperature.

In step S34, the control unit 60 checks whether the temperature of the heated battery pack 11 is higher than the lower limit temperature, and repeats steps S32 to S34 until the temperature of the battery pack 11 becomes higher than the lower limit temperature. .

If the test result of step S34 is higher than the lower limit temperature of the battery pack 11, the control unit 60 proceeds to step S40 below.

In step S40, the control unit 60 checks whether the ignition key or the start button is turned off to stop the power supply, and controls to repeat steps S12 to S40 until the power supply is stopped.

On the other hand, when the power supply is stopped as a result of the check in step S40, the control unit 60 stops driving of each device, and ends.

Through the above process, the present invention can be thermally managed by cooling or heating the battery pack by receiving compressed dry air from an air tank for supplying compressed air to the braking system.

Accordingly, the present invention can minimize the development cost, material cost and weight by simplifying the internal structure of the battery pack, compared to the battery pack to which the water-cooling method of the prior art is applied.

And the present invention can increase the output and efficiency of the vehicle through the thermal management of the battery pack, and can prevent the deterioration of the battery pack, it is possible to increase the durability.

In addition, the present invention by utilizing the existing system of the electric vehicle with the pneumatic braking system as it is, the system configuration is easy, and the system that thermally manages the battery pack using the air in the room generally applied in the electric vehicle structurally impossible electric It can be applied to commercial vehicles.

In addition, the present invention can increase the stability to the external environment, such as moisture, dust, compared to the conventional method of attaching and cooling the fan to the front and rear of the battery pack.

As mentioned above, although the invention made by the present inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

The present invention is applied to a thermal management apparatus of a battery pack for an electric vehicle and a control method thereof for receiving thermal compressed air from an air tank for supplying compressed air to a braking system to cool or heat the battery pack.

10: thermal management device of an electric vehicle battery pack
11: battery pack 12: air inlet
13: air outlet 14: battery management system
20: air tank 21: braking system
22: air compressor 23: main control unit
30: compressed air supply line 31: flow control valve
32: pressure reducing valve
40: cooling part 41: cooler
42: cooling fan 50: heating part
60: control unit 70: temperature sensor

Claims (5)

In the thermal management device of a battery pack for an electric vehicle to which a pneumatic braking system is applied,
Compressed air supply line for supplying compressed dry air (hereinafter referred to as 'compressed air') filled in an air tank that supplies compressed air as a driving source to a braking system as a battery pack,
A flow control valve installed on the compressed air supply line to control the flow rate of the compressed air supplied to the battery pack;
Pressure reducing valve for reducing the compressed air to a predetermined pressure,
Cooling unit for cooling the compressed air,
A heating unit for heating the compressed air;
And a control unit for controlling the driving of each device based on the temperature of the battery pack and the compressed air. The method of claim 1,
Further comprising a temperature sensor for sensing the temperature of the compressed air supplied to the battery pack,
The control unit receives and receives battery state information including battery cell and battery pack temperature and charge state information from a battery management system provided in the battery pack.
Receive the state information of the vehicle including the temperature of the compressed air detected by the temperature sensor, the pressure in the air tank, the atmospheric temperature,
Battery pack for an electric vehicle, characterized in that for controlling the cooling or heating of the battery pack by driving a motor provided for driving the cooling fan provided in the cooling unit and the heater provided in the cooling unit according to the temperature of the compressed air and the air temperature. Thermal management device. The method of claim 2,
Both ends of the battery pack and the air inlet for injecting the compressed air
An air outlet for discharging the air heat-exchanged inside the battery pack to the outside is formed,
The air inlet is a manifold structure for uniformly distributing the compressed air and supplying each battery cell to prevent a local heat load rise and to uniformly control the temperature of each battery cell provided in the battery pack. Formed into
An air dryer for drying the compressed air between the air compressor and the air tank filling the air tank with compressed air;
A filter for filtering the dust and foreign matter contained in the compressed air is installed,
The control unit is a thermal management device of a battery pack for an electric vehicle, characterized in that for controlling the driving of the air compressor based on the pressure inside the air tank. In the control method of the thermal management apparatus of a battery pack for an electric vehicle to which the pneumatic braking system according to any one of claims 1 to 3 is applied,
(A) receiving the pressure in the air tank and the temperature of the battery pack to supply the compressed air to the braking system in the control unit,
(b) controlling the driving of the air compressor based on the pressure inside the air tank in the control unit;
(c) reducing the compressed air filled in the air tank to a predetermined pressure or less based on the temperature of the battery pack and the compressed air and then supplying the battery pack by heating or cooling it;
and (d) maintaining the temperature of the battery pack in a preset set temperature range. The method of claim 4, wherein step (c)
(c1) if the temperature of the battery pack and the compressed air corresponds to a preset cooling condition in the controller, driving the cooling fan of the cooling unit to cool the compressed air and supply the compressed air to the battery pack;
(c2) stopping the driving of the cooling fan when it is out of the cooling condition, and supplying the battery pack by naturally cooling the compressed air;
(c3) if the temperature of the battery pack is lower than or equal to the lower limit temperature of the set temperature range, driving the heater of the heating unit to heat the compressed air and supply the battery pack to the battery pack,
The cooling condition may be set such that the temperature of the battery pack is higher than the upper limit temperature of the set temperature range, the temperature of the battery pack is higher than the temperature of the compressed air, and the temperature difference between the battery pack and the compressed air is equal to or less than a preset reference temperature difference. Control method of the thermal management device of an electric vehicle battery pack.

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