KR20120062412A - Method for controlling electric compressor of air conditioner for vehicle - Google Patents

Abstract

PURPOSE: A method for controlling an electronic compressor of an air-conditioner for vehicles is provided to improve the fuel efficiency, and reducing the power consumption by departmentalizing the limit number of rotation of the electronic compressor. CONSTITUTION: A method for controlling an electronic compressor of an air-conditioner for vehicles comprises next steps. A car speed, the outside air temperature, and RPM are detected(S200). Whether the vehicles are in an idle state or not is determined(S300). Whether the vehicles are in an EV mode or not is determined(S400). If the vehicles are in the EV mode and idle state, the limit number of rotation of the electronic compressor is calculated according to a blower level(S500). The number of rotation of the electronic compressor is controlled less than the calculated limit number of the rotation(S600). If the vehicles are in the idle state but not the EV mode, the limit number of the rotation of the electronic compressor is calculated according to the outside air temperature, and the blower level.

Description

Method for controlling electric compressor of vehicle air conditioner {Method for controlling electric compressor of air conditioner for vehicle}

The present invention relates to a method of controlling an electric compressor of a vehicle air conditioner, and more particularly, to a method of controlling an electric compressor of a vehicle air conditioner which can reduce vehicle power consumption and improve fuel efficiency.

Recently, development of a hybrid vehicle using an engine and an electric motor simultaneously as a driving source continues. In a hybrid vehicle, the engine is used as a driving source of a vehicle when starting or when a large driving force is required, and an electric motor is used as a driving source when a large driving force is not required, such as when driving on a flat surface or when stopping.

In such a hybrid vehicle, an electric compressor is used. Electric compressor does not have a big difference in configuration or operation principle with a general compressor, but discharges the refrigerant by receiving the rotational force of the electric motor driven by the power supplied to the battery as the driving force. Since the electric compressor is driven by using the power charged in the battery, it can exhibit a constant performance regardless of the vehicle speed or the engine speed of the vehicle.

However, when the electric compressor operates at the same output speed as in the high-speed driving state even in a vehicle idle state with low vehicle speed and engine speed, the battery power consumption is large, which not only adversely affects the power supply required for driving the vehicle, but also the battery. Since the engine needs to be driven more or powered from the outside for charging, there is a problem that hinders the fuel economy of the vehicle.

In order to solve this problem, conventionally, the vehicle idling state and the driving state are divided, and the electric compressor is controlled so that the rotation speed of the electric compressor is smaller than the vehicle driving state when the vehicle is in the idling state.

However, when controlling the electric compressor by dividing the vehicle idling state and the driving state as in the prior art, the operation noise of the electric compressor is significantly higher than the vehicle driving in the vehicle idling / EV mode in which the vehicle engine is not operated and the electric motor is operated only. This may cause an inconvenience to the driver's operation.

Summary of the Invention An object of the present invention is to solve the problems of the prior art, and an object of the present invention is to control the electric compressor of a vehicle air conditioner which can reduce the vehicle power consumption and improve fuel efficiency by varying the condition for calculating the limited rotation speed of the electric compressor. To provide a way.

The present invention for achieving the above object in the control of the electric compressor of the vehicle air conditioner, (A) detecting the vehicle speed, outside air temperature and engine speed; (B) determining whether the vehicle is in an idle state; (C) determining whether the vehicle is in an EV mode; (D) calculating a limit rotation speed of the electric compressor according to the number of blowers when the vehicle is in an idle state and in the EV mode; (E) adjusting the rotational speed of the electric compressor to be calculated below the limited rotational speed.

In addition, in the step (d), when the vehicle is in an idle state but not in the EV mode, the limited rotation speed of the electric compressor is calculated according to the outside temperature and the blower stage.

In the step (b), when the vehicle is not in an idle state, it is further determined whether the vehicle speed is 40 KPH or less.

When the vehicle speed is 40KPH or less from above, it is characterized by further determining whether the outside air temperature is 40 ℃ or less.

When the vehicle speed is 40KPH or less and the outside temperature is 40 ℃ or less from the above, it is characterized by calculating the limit rotation speed of the electric compressor according to the vehicle speed.

If the vehicle speed is not less than 40KPH and the vehicle speed is less than 40KPH, but the outside temperature is not less than 40 ℃, it characterized in that the limit of the rotational speed of the electric compressor according to the outside temperature and the number of blowers.

According to the electric compressor control method of the vehicle air conditioner according to the present invention it is possible to obtain the following effects.

According to the present invention, in calculating the limited rotational speed of the electric compressor, the conditions were diversified into vehicle idle state, blower number, outside air temperature and vehicle speed. The value of the limiting speed of the electric compressor calculated based on the above diversified conditions is subdivided. Therefore, the vehicle power consumption is reduced and the fuel economy is improved.

1 is a block diagram schematically showing the configuration of an air conditioning apparatus and an electric compressor driving source of a general hybrid vehicle.
Figure 2 is a flow chart showing a step-by-step method of controlling the electric compressor of the vehicle air conditioner according to the present invention.

The electric compressor control method of the vehicle air conditioner according to the present invention will be described in detail with reference to the drawings.

As shown in FIG. 1, an air conditioner of a typical hybrid vehicle includes an electric compressor 11 for compressing a refrigerant and changing a rotation speed according to a cooling demand, a condenser 12 for condensing the refrigerant discharged from the electric compressor 11, and The expansion of the refrigerant liquefied through the condenser 12 to make a gas and liquid mixed state and the expansion valve 13 and the refrigerant is changed in the opening degree according to the refrigerant discharge amount of the electric compressor (11) The indoor and outdoor temperatures input from the evaporator 14 for cooling the ambient air by using latent heat of evaporation and returning the refrigerant to the electric compressor 11 and various sensors respectively installed inside and outside the vehicle. The controller 20 controls the number of rotations of the electric compressor 11 according to the air conditioning environment and the air conditioning condition input by the user.

Herein, the control unit 20 controls the rotation speed of the electric compressor 11,

First, the control unit 20 calculates the target rotational speed by using the current evaporator temperature, the current rotational speed and the target evaporator temperature measured by the evaporator temperature sensor as variables in order to calculate the target rotational speed of the electric compressor 11. .

Here, the target evaporator temperature is determined corresponding to the target indoor temperature set by the driver. In addition, other variables in the exterior and interior of the vehicle may be additionally considered.

The controller 20 controls the electric compressor 11 at the target rotational speed calculated as above. Then, the process of calculating the target rotation speed by measuring the evaporator temperature is repeated.

On the other hand, the power provided to the electric compressor 11, first, the rotational force by the engine 10, the wheel drive motor 21, etc. is converted into electrical energy in the generator 31, the electricity is converted in the generator 31 Energy is generated by storing chemical energy in the battery 32.

In addition, the inverter 33 receives the DC power from the battery 32 and converts the AC power into a frequency variable.

In addition, the energy stored in the battery 32 is transferred to the electric motor 34 via the inverter 33 is converted into physical energy, which is transferred to the electric compressor 11 again to drive the electric compressor 11. Let's do it. That is, the driving force of the electric compressor 11 is supplied from the battery 32 through the inverter 33 and the electric motor 34.

When operating the air conditioning device configured as described above, the control unit 20 is an air conditioning condition, such as indoor temperature and outdoor temperature transmitted from various sensors, and the air conditioning conditions, such as selecting the vehicle indoor set temperature, heating or cooling set by the user As a result, the rotation speed of the electric compressor 11 is changed.

The refrigerant discharged from the electric compressor 11 is condensed and liquefied while passing through the condenser 12, and gas and liquid are mixed while passing through the expansion valve 13. In this case, the opening degree of the expansion valve 13 is changed according to the amount of refrigerant discharged from the electric compressor 11.

Thereafter, the refrigerant introduced into the evaporator 14 is vaporized to cool the surrounding air through heat exchange with the surrounding air. That is, since the latent heat of evaporation required to evaporate the refrigerant from the ambient air, the temperature of the ambient air of the evaporator 14 is lowered.

The vaporized refrigerant is introduced into the electric compressor 11 again, and the air cooled through heat exchange is supplied to the room to cool the room. At this time, the temperature sensor 21 for detecting the temperature of the air is installed on the outlet side of the evaporator 14, the controller 20 is the inverter from the battery 32 if the temperature of the evaporator outlet side is below a certain temperature By stopping the rotation of the electric motor 34 through 33 to stop the operation of the electric compressor (11). This is to prevent the water vapor contained in the air frozen in the condensed state in the evaporator 14 to inhibit the heat exchange.

When the electric motor 34 is off and the operation of the electric compressor 11 is stopped, the circulation of the refrigerant is stopped. Since the heat exchange between the evaporator 14 and the ambient air does not occur when the circulation of the refrigerant is stopped, the evaporator outlet temperature gradually increases, and when the evaporator outlet temperature rises above the threshold temperature, the inverter 33 again returns the electric motor ( 34. The electric compressor 11 is operated by resuming power supply. Of course, since the temperature of the evaporator outlet is lowered when the compressor 11 is operated again, the above process may be repeated.

The method of controlling the electric compressor of the vehicle air conditioner having the above configuration starts with checking whether the air conditioner is on or off as shown in FIG. 2 (S100). In this case, the on / off of the air conditioner means the on / off of the vehicle cooling function of the air conditioner.

If the air conditioner is turned on in step 100 (S100), the control unit 20 receives the current vehicle speed, outside air temperature and engine speed (RPM) information of the vehicle (S200). At this time, the controller 20 is connected to each sensor so as to receive the vehicle speed, outside temperature and engine speed information of the vehicle.

When the controller 20 receives the vehicle speed, the outside temperature, and the engine speed information in step 200, the controller 20 uses the vehicle speed and the engine speed information to determine whether the vehicle is in an idle state. Determine (S300).

At this time, the vehicle is in the idle state, which means that the vehicle is low speed and the load on the engine is small. When the vehicle speed is less than or equal to the preset speed and the engine speed is less than or equal to the preset speed, the vehicle is in the idle state. You can judge. At this time, each of the set speed and the rotation speed is preselected to an appropriate number capable of determining the state of the vehicle.

If it is determined in step S300 that the vehicle is in the idle state, the controller 20 determines whether the vehicle is in the EV mode state (S400). The EV mode is also referred to as an electric driving mode, in which a motor is driven by a pure motor only when the engine is turned off.

If it is determined in step 400 (S400) that the vehicle is in the EV mode state, the control unit 20 calculates the limited number of revolutions according to the blower stage of the air conditioning apparatus currently operated by the driver (S500). In this case, the control unit 20 previously stores a first table (Table 1) for calculating the limit rotation speed according to the number of blowers. The first table (Table 1) will be described later.

Finally, the control unit 20 controls the rotation speed of the electric compressor 11, the rotation speed of the electric compressor 11 or more than the minimum rotation speed previously stored in the control unit 20, step 500 It should have a value less than the limit number of revolutions calculated in (S600).

The series of steps 200 to 600 is repeatedly performed until the air conditioner is turned off (S700).

On the other hand, if it is determined in step 400 (S400) that the vehicle is not in the EV mode state, the controller 20 calculates the limit rotation speed according to the outside temperature and the number of blowers (S450). In other words, the electric compressor is controlled in consideration of the external air temperature as well as the number of blowers. In this case, the limit rotation speed according to the outside air temperature and the number of blowers may be stored in advance in the control unit 20 in the form of a second table (Table 2).

When the limited rotation speed is calculated in operation 450, operations 600 and 700 are performed in common.

On the other hand, if it is determined in step 300 that the vehicle is not in the idle state, the controller 20 determines whether the vehicle speed is less than 40KPH (S320). Next, when it is confirmed that the vehicle speed is 40 KPH or less, the controller 20 again determines whether the outside temperature is 40 ° C. or less (S330). At this time, if the outside temperature is 40 ° C or less, the control unit 20 calculates the limit rotation speed according to the vehicle speed (S340). Of course, other limited revolution speeds in the vehicle speed may be stored in advance in the control unit 20 in the form of a third table (Table 3). Next, step 600 and step 700 are performed in common.

On the other hand, if the vehicle speed is not less than 40KPH in step 320, the control unit 20 calculates the limit rotation speed according to the outside temperature and the number of blowers (S350). In addition, even if it is determined in step 330 that the outside air temperature is not 40 ° C. or less, the controller 20 calculates the limit rotation speed according to the outside air temperature and the blower stage (S350). In this case, the relationship between the outside temperature, the number of blowers, and the limit rotation speed may be previously stored in the controller 20 in the form of a fourth table (Table 4). After steps 340 and 350, steps 600 and 700 described above are commonly performed.

The first to fourth tables are shown in Tables 1 to 4, respectively. For reference, A to G shown in Tables 1 to 4 display the value of the limiting speed instead of a number, and the value increases from A to G.

1st table Vehicle idle status In EV mode Blower Singular Speed limit 3 steps or less B 4-5 steps D 6 or more steps D

2nd table If the vehicle is idle When not in EV mode Blower singular air temperature -40 0 5 10 15 20 25 30 35 40 50 60
3 steps or less A A A A A B B C D D D D
4-5 steps A A A C C C D D D D D D
6 or more steps A A A C C C D D D E E E

3rd table If the vehicle is not idle Vehicle speed is below 40KPH and outside temperature is below 40 ℃ Vehicle speed (KPH) Speed limit 0 C 10 C 20 D 30 E 40 G

4th table If the vehicle is not idle If the vehicle speed is not below 40KPH
If the vehicle speed is 40KPH and the outside air temperature is not below 40 ℃ Blower singular air temperature -40 0 5 10 15 20 25 30 35 40 50 60
3 steps or less
D D D D D D D E G G G G 4 or more steps
D D D E E E F G G G G G

The present invention differs from the prior art by simply dividing the vehicle state into whether it is idle / driving to have a constant speed limit value for each state.

That is, according to the present invention, in calculating the limited rotational speed of the electric compressor, the conditions were diversified into vehicle idle / EV status, blower number, outside air temperature, and vehicle speed. The value of the limiting speed of the electric compressor calculated based on the above diversified conditions is subdivided.

Particularly in the vehicle idle / EV mode, that is, when the driver is sensitive to noise in the vehicle because the engine is off, the value of the limited speed of the electric compressor is subdivided by the number of blowers (Table 1). If not, the value of the limiting speed was subdivided based on the number of blowers and the outside air temperature (Table 2).

In the case where the vehicle speed is 40KPH or less, that is, when the engine is on but the vehicle speed is slow and the driver can feel the noise in the vehicle, the value of the limiting speed is subdivided according to the vehicle speed (Table 3).

On the other hand, when the vehicle speed is not more than 40KPH, that is, when the driver is difficult to detect the noise in the vehicle by the sound of the engine, the value of the limit rotation speed is subdivided based on the number of blowers and the outside air temperature (Table 4).

The present invention will be described again on the basis of the limit speed value, in which the motor speed can not cover the operation noise (that is, low cooling load) is to adjust the limit speed value down, and cover the operating noise of the motor compressor In a possible situation (ie, high cooling load), the limiting speed value is increased to focus on performance.

Herein, a situation in which the electric compressor operating noise cannot be covered (that is, a low cooling load) may be referred to as, for example, vehicle idle state and EV mode in the present invention. It can be seen that the value of is set variously. That is, as shown in Table 1, it can be seen that when the number of blower stages is three stages or less, the limit speed is relatively lower than when the stage of blower stages is four or more stages.

In addition, the situation (that is, high cooling load) that can cover the operation noise of the electric compressor is referred to in the present invention is not the vehicle idle state, but the vehicle speed is 40KPH or more, for example, the noise in the vehicle by the engine sound Since the output of the electric compressor can be increased because it is difficult to detect, it is set to have a value of the limit rotational speed more than D as shown in Table 4.

The rights of the present invention are not limited to the embodiments described above, but are defined by the claims, and those skilled in the art can make various modifications and adaptations within the scope of the claims. It is self-evident.

10: engine 11: electric compressor
12: condenser 13: expansion valve
14: evaporator 20: control unit
31: generator 32: battery
33: Inverter 34: Electric Motor

Claims (6)

In the electric compressor control of the vehicle air conditioner,
(A) detecting vehicle speed, outside air temperature and engine speed;
(B) determining whether the vehicle is in an idle state;
(C) determining whether the vehicle is in an EV mode;
(D) calculating a limit rotation speed of the electric compressor according to the number of blowers when the vehicle is in an idle state and in the EV mode;
(E) controlling the electric compressor of the vehicle air conditioner, characterized in that the step of adjusting the rotational speed of the electric compressor to less than the calculated limit. The method of claim 1,
In the step (d), if the vehicle is in an idle state but not in the EV mode, the electric compressor control method of the air conditioner for a vehicle, characterized in that for calculating the limited rotational speed of the electric compressor according to the outside temperature and the number of blowers. The method of claim 1,
And (b) if the vehicle is not in an idle state, further determining whether or not the vehicle speed is 40 KPH or less. The method of claim 3, wherein
If the vehicle speed is 40KPH or less, the electric compressor control method of the vehicle air conditioner, characterized in that further determining whether the outside air temperature is 40 ℃ or less. The method of claim 4, wherein
If the vehicle speed is 40KPH or less and the outside air temperature is 40 ℃ or less, the electric compressor control method of the air conditioner for a vehicle, characterized in that for calculating the limited rotational speed of the electric compressor according to the vehicle speed. The method according to claim 3 or 4,
If the vehicle speed is not less than 40KPH and if the vehicle speed is less than 40KPH, but the outside temperature is not less than 40 ℃, the electric compressor control method of the air conditioner for a vehicle, characterized in that for calculating the limited rotational speed of the electric compressor according to the outside temperature and the number of blowers.

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