KR102097020B1 - Method for controlling electric compressor of air conditioner for vehicle - Google Patents

Abstract

The present invention relates to a method for controlling an electric compressor of a vehicle air conditioner, according to an embodiment of the present invention, by changing the rate of rpm increase according to whether or not slugging conditions are applied, sludge generated at the initial stage of compressor operation by forming a liquid refrigerant A method of controlling an electric compressor of an air conditioning system for a vehicle capable of reducing ging noise is provided.

Description

Method for controlling electric compressor of air conditioner for vehicle

The present invention relates to a method for controlling a compressor, and more particularly, to a method for controlling an electric compressor of a vehicle air conditioner capable of reducing slugging noise generated by the formation of a liquid refrigerant.

In general, a vehicle air conditioner, as shown in Figure 1, a compressor 11 for compressing the refrigerant, a condenser 12 for condensing the compressed refrigerant, an expansion valve 13 for throttling the condensed refrigerant, and a refrigerant It is equipped with an air conditioner system (10) consisting of an evaporator (14) to cool the air using latent heat according to evaporation of the. Such an air conditioner performs cooling by allowing air blown by a blower (not shown) to pass through the evaporator 14 and then introducing cooled air into the room.

On the other hand, in recent automobiles, even if the user does not directly control the air conditioning system, automatic temperature control so that the temperature can be adjusted to the optimized specifications according to the use environment, that is, the air conditioning conditions according to the user input and environmental conditions such as outside temperature and air temperature An air conditioner equipped with a device (FATC; Full Automatic Temperature Controller, 20) is widely used.

At this time, the automatic temperature control device (FATC), the air conditioning conditions set by the user operation button 25, the air temperature detected by the air temperature sensor 22, the air temperature detected by the air temperature sensor 23, and The target rpm (target rpm) of the compressor 11 is calculated using environmental data such as solar radiation detected by the solar radiation sensor 24, and the air conditioning device is optimized according to the air conditioning conditions and environmental conditions. Control.

Here, the compressor 11 of the air conditioner system 10 is operated by an engine (not shown), and when the engine is not operated, since the compressor 11 is also not operated, cooling is not possible because the refrigerant is not compressed.

Accordingly, in the case of a hybrid vehicle using both an engine and an electric motor as a driving source, an electric compressor is used so that the compressor can be operated even if the engine is not operated. That is, by using an electric compressor provided on one side of a motor driven by a battery, it is possible to compress the refrigerant regardless of whether the engine is operating.

In the air conditioning apparatus of such a hybrid compressor, since the refrigerant is compressed by the electric compressor, it is possible to provide air conditioning when the engine is stopped as well as when using an electric motor other than the engine.

2 is a flow chart showing a conventional method for controlling an electric compressor when the air conditioning apparatus is operated, and FIG. 3 is a graph showing a change in rpm of the electric compressor by the control method of FIG. 2.

2 and 3, in the prior art, when the electric compressor is driven (ON), receives the target rpm (Target RPM) calculated by the thermostat, and the maximum rpm increase rate to reach the target rpm as soon as possible The compressor rpm was raised to (r_max).

However, when the vehicle is left stationary for a long time in winter, the refrigerant is converted from gas to liquid due to cold outside air, and a liquid refrigerant is formed in the air conditioning system.

At this time, the liquid refrigerant on the suction side generally accumulates in the compressor, but when the air conditioner is operated immediately after the vehicle engine starts, slugging noise caused by liquid refrigerant in the compressor is generated, resulting in user complaints. It is becoming a factor that causes.

KR 10-2003-0006298 A (2003.01.23 open) KR 10-2008-0040093 A (2008.05.08 open)

The present invention is to solve the problems as described above, an embodiment of the present invention, when driving the electric compressor of the vehicle air conditioning apparatus, the rate of increase in rpm is determined according to whether the slugging conditions are applicable It is aimed at providing.

According to a preferred embodiment of the present invention, (a) calculating the target rpm of the compressor by a thermostat (FATC); (b) determining whether a slugging occurrence condition is applicable; (c) determining an rpm increase rate according to the determination result of step (b); And (d) raising the rpm of the compressor according to the rpm increase rate determined in step (c).

Here, the step (b), (b-1) measuring the temperature (T) of the compressor and (b-2) slugging by comparing the measured compressor temperature (T) with a preset reference temperature (T_ref) And determining whether the occurrence condition is applicable.

In this case, the step (b-1) is characterized in that the temperature of the inverter is measured by a temperature sensor provided on one side of the inverter of the compressor.

In addition, in step (b-2), when the measurement temperature T is equal to or lower than the reference temperature T_ref, it is characterized in that it is determined as a slugging occurrence condition.

In addition, the step (c), (c-1) when the determination result of step (b) is a slugging condition, the step of setting the rate of increase in rpm to the minimum rate of increase in rpm (r_min).

In addition, the step (c), (c-2) when the determination result of the step (b) is not a slugging occurrence condition, the step of setting the rpm increase rate to the maximum rpm increase rate (r_max).

At this time, it is determined whether or not the reference time (Δt) has elapsed when the step (c-1) is performed, and the rpm increase rate when the reference time (Δt) elapses is set as the maximum rpm increase rate (r_max).

According to a method for controlling an electric compressor of a vehicle air conditioner according to an exemplary embodiment of the present invention, when the slugging condition is satisfied, the initial rpm increase rate of the compressor is formed to be small, thereby preventing slugging damage occurring instantaneously. Can be reduced.

In addition, when the slugging occurrence condition is exceeded after a certain period of time has elapsed, the speed increase can be increased by bringing the rpm increase rate back to the maximum value.

1 is a block diagram of a general vehicle air conditioning system.
Figure 2 is a flow chart showing a conventional electric compressor control method step by step.
Figure 3 is a graph showing the rpm change of the electric compressor by the control method of Figure 2;
4 is a cross-sectional view of an electric compressor according to an embodiment of the present invention.
5 is a flowchart illustrating a method for controlling an electric compressor of an air conditioning system for a vehicle according to an embodiment of the present invention.
Figure 6 is a graph showing the rpm change of the electric compressor according to the slugging conditions.

Hereinafter, with reference to the accompanying drawings, with reference to the accompanying drawings, a preferred embodiment of the present invention will be described with reference to the method of controlling the electric compressor of the vehicle air conditioning apparatus. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience.

In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or practice. Therefore, definitions of these terms should be made based on the contents throughout this specification.

In addition, the following embodiments are not intended to limit the scope of the present invention, but are merely illustrative of the components presented in the claims of the present invention, and are included in the technical idea throughout the specification of the present invention and constitute the claims. Embodiments that include a substitutable component as an equivalent in the elements can be included in the scope of the present invention.

Example

4 is a cross-sectional view of an electric compressor according to an embodiment of the present invention.

As shown in Figure 4, the electric compressor (hereinafter referred to as 'compressor') 100 according to an embodiment of the present invention is a housing 200 formed in a substantially hollow cylindrical shape, and the inner side of the housing 200 The driving unit 300 is mounted to generate driving force, the compressor unit 400 is mounted on one side of the driving unit 300 to compress refrigerant, and is mounted on the other side of the driving unit 300 to control the operation of the driving unit 300 It includes a control unit 500.

Here, the housing 200 is to form the overall appearance of the compressor 100 according to an embodiment of the present invention, the driving unit housing 210, the driving unit 300 is mounted therein, and one side of the driving unit housing 210 Combined and the head housing 220 is provided with an inverter for controlling the operation of the drive unit 300, and the cover housing 230 coupled to the rear of the drive unit housing 210 and the compression mechanism 400 is mounted therein. It includes.

At this time, although not shown, a suction port is formed on one side of the outer circumferential surface of the driving unit housing 210 to suck the refrigerant into the inside suction chamber 210a, and one side of the outer circumferential surface of the cover housing 230 is provided for supplying refrigerant to the outside. A discharge port is formed.

At this time, the shape of the driving unit housing 210, the head housing 220, and the cover housing 230 may be variously modified, and the entire housing 200 may also be formed in various configurations.

For example, the driving unit housing 210 may be composed of two parts, the front housing 211 and the rear housing 212, which are coupled to each other as shown in FIG. 4, and the front housing 211 and the rear housing 212 ) May be integrally formed, or the compressor mechanism 400 may be mounted in the driving unit housing 210. In addition, it is also possible that the driving unit housing 210 and the head housing 220, or the driving unit housing 210 and the cover housing 230 are integrally formed.

A space part forming the suction chamber 210a is formed inside the drive part housing 210, and the drive part 300 is mounted on one side of the space part.

Here, the driving unit 300 is composed of a driving motor including a stator 310 and a rotor 320.

The stator 310 is a cylindrical shape through which the center is mounted, and is mounted inside the driving unit housing 210, and a plurality of coil 311 bundles are wound along the circumference of the stator 310.

The rotor 320 is mounted coaxially on the inside of the stator 310 to be rotationally driven, and is rotatably inserted into a central through hole of the stator 310, and a rotating shaft 321 disposed long along the central axis, And a permanent magnet 322 attached to the outer circumferential surface of the rotating shaft 321.

At this time, when a current flows through the winding coil 311 of the stator 310, a magnetic field is formed around the stator 310 and rotates by interaction between the stator 310 and the permanent magnet 322 according to the driving principle of the motor. The shaft 321 is driven to rotate.

Meanwhile, a first bearing receiving portion 214 in which the first bearing 213 is fixedly installed is protruded on the bottom surface of the front housing 211, and a second bearing 215 is provided on the bottom surface of the rear housing 212. The second bearing accommodating portion 216 which is fixedly installed is protruded.

At this time, the front end of the rotating shaft 321 is rotatably supported by the first bearing 213, and the rear end is rotatably supported by the second bearing 215.

A suction port is formed on one side of the outer circumferential surface of the driving unit housing 210 to suck refrigerant, and the refrigerant sucked into the suction chamber 210a in the driving unit housing 210 through the suction port is compressed in the compression chamber 430 to be described later. After being compressed at high pressure and discharged to the discharge chamber 231, it is supplied to the outside through a discharge port formed spaced apart from the suction port.

A cover housing 230 is coupled to the rear of the driving unit housing 210, and a compressor mechanism 400 for compressing refrigerant is mounted in the cover housing.

Here, the compressor mechanism 400 according to an embodiment of the present invention includes a fixed scroll 410 and a turning scroll 420 installed to face each other. However, the present invention is not limited to this, and the compression mechanism 400 of the present invention receives all the rotational driving force through the rotating shaft 321 and compresses all forms of compressing the refrigerant by reducing the volume of the compression chamber 430 It goes without saying that the mechanism part is applicable.

The fixed scroll 410 includes a fixed end plate 411 in the form of a disk, and a fixed wrap 412 protruding in a vortex shape so as to converge toward the center from one surface of the fixed end plate 411. In addition, the orbiting scroll 420 is a circular orbiting end plate 421 and an orbiting wrap 422 that protrudes in a vortex shape so as to converge toward the center opposite to the fixed wrap 412 on one surface of the orbiting end plate 421. It includes.

At this time, the orbiting scroll 420 is eccentrically coupled to one end of the rotating shaft 321 by an eccentric bush 323, and the fixed scroll 410 is fixed to one side of the driving unit 300 so as to face the orbiting scroll 420. Is installed. Therefore, when the rotating shaft 321 is rotated, the orbiting scroll 420 rotates with respect to the fixed scroll 410.

When the orbiting scroll 420 is rotated relative to the fixed scroll 410, the fixed wrap 412 and the orbiting wrap 422 come into contact with each other at a plurality of points, at this time between the fixed wrap 412 and the orbiting wrap 422. The space is divided into a plurality of compression chambers 430.

That is, when the orbiting scroll 420 orbits, the fixed scroll 410 and the orbiting scroll 420 are matched with each other, and by the relative rotation of the fixed wrap 412 and the rotating wrap 422, the fixed wrap 412 and The refrigerant sucked into the outer periphery of the orbiting wrap 422 is compressed into the central portion thereof, and is discharged through the discharge port 413 formed through the center of the fixed scroll 410. The high-pressure refrigerant discharged to the discharge chamber 231 through the discharge port 413 is supplied to the outside through the discharge port.

The head housing 220 is coupled to the front of the driving unit housing 210, and a control unit 500 including a PCB 221 and various driving circuits and devices mounted on the PCB 221 is provided inside.

The control unit 500 includes an inverter (not shown) that converts DC power into AC power, and a temperature sensor (not shown) is installed on one side of the inverter. At this time, the control unit 500 is electrically connected to the driving motor to control the amount of compression of the refrigerant by controlling the rpm (revolution speed) of the compressor 100, and serves to keep the vehicle interior constant at a desired temperature.

According to an embodiment of the present invention, the target rpm (Target rpm) calculated by the Full Automatic Temperature Controller (FATC) 20 (see FIG. 1) when the compressor 100 is initially driven is the controller 500. The control unit 500 controls the operation of the driving motor so that the rpm of the compressor 100 reaches the target rpm.

At this time, it is determined whether or not the environmental conditions inside and outside the compressor 100 correspond to the slugging occurrence condition, and if it does not correspond to the slugging occurrence condition, the compressor 100 rpm is maximized to the target rpm in order to improve the fast-acting effect. To reach quickly, the rpm up rate is set to the maximum rpm increase rate (r_max).

On the other hand, in order to reduce the slugging damage (slugging damage) that occurs instantaneously when the slugging occurs, the rpm increase rate is set to the minimum rpm increase rate (r_min).

Whether the slugging generation condition is applicable can be determined by examining whether the temperature of the compressor 100 corresponds to the slugging generation temperature (liquid temperature of the gas refrigerant).

According to an embodiment of the present invention, the temperature T measured by the temperature sensor installed on one side of the inverter is compared with the reference temperature T_ref to determine whether the slugging occurrence condition is applicable.

As an example, if the reference temperature is set to -10 ° C and the inverter temperature measured from the temperature sensor is higher than -10 ° C, it is determined that the slugging occurrence condition is not met, and the rpm increase rate is the maximum rpm increase rate (r_max). It is set to 1400 rpm / s, thereby rapidly raising the compressor 100 rpm to the target rpm.

On the other hand, if the inverter temperature measured from the temperature sensor is below -10 ° C, it is determined that the slugging occurs according to the formation of liquid refrigerant, and the rpm increase rate is set to 300 rpm / s, which is the minimum rpm increase rate (r_min). , Thereby raising the compressor 100 rpm.

At this time, after a predetermined period of time after the compressor 100 is driven, the internal temperature of the compressor 100 rises and goes out of the slugging temperature range. Therefore, even when the minimum rpm increase rate (r_min) is applied to the slugging occurrence condition during initial driving, the maximum rpm increase rate (r_max) is applied after the reference time (Δt, for example, 5 seconds) to apply the compressor 100 rpm. It is desirable to raise it rapidly to the target rpm.

Here, the maximum rpm increase rate (r_max), the minimum rpm increase rate (r_min), the reference temperature (T_ref), and the reference time (Δt) may be appropriately selected according to the environmental conditions such as the capacity of the compressor 100 and the outside temperature.

On the other hand, according to an embodiment of the present invention, the determination of whether the slugging occurrence condition is applicable and whether the reference time (Δt) has elapsed is performed by the control unit 500 of the compressor 100. However, this determination may be performed in advance in the automatic temperature control device (FATC), it is of course also possible to be performed by a separate compressor control unit (not shown) installed between the automatic temperature control device and the compressor 100.

Hereinafter, a method of controlling an electric compressor of an air conditioning apparatus for a vehicle according to an embodiment of the present invention will be described step by step with reference to FIG. 5.

5 is a flowchart illustrating a method for controlling an electric compressor of an air conditioning apparatus for a vehicle according to an embodiment of the present invention.

Compressor driving stage ( S10 ):

First, based on the air conditioning conditions according to the user input and environmental conditions such as outside temperature and inside temperature, the automatic temperature control device (FATC) 20 (refer to FIG. 1) starts the operation of the compressor 100 (ON). .

goal rpm  Pick-up phase ( S10 ):

At this time, the automatic temperature controller (FATC) calculates the target rpm (Target rpm) of the compressor 100 using the air conditioning conditions set by the user operation button, and environmental data such as air temperature, air temperature, and solar radiation. The control unit 500 of the (100) receives the target rpm calculated from the thermostat.

Slugging  Step to determine whether the occurrence condition is applicable ( S30 ):

The inverter temperature is measured by a temperature sensor installed on one side of the inverter of the compressor 100 (S31). Thereafter, the measured temperature (T) value is compared with the reference temperature (T_ref) value to determine whether a slugging occurrence condition is applied (S32).

At this time, if the measured temperature (T) value is lower than the reference temperature (T_ref) value, it is judged as a slugging condition due to the formation of liquid refrigerant, and if the measured temperature (T) value is higher than the reference temperature (T_ref) value, slugging does not occur Judging by the condition that does not

rpm  Determination of growth rate ( S40 ):

As a result of comparing the measured temperature (T) value with the reference temperature (T_ref), if it is determined that slugging does not occur because the measured temperature (T) is higher than the reference temperature (T_ref), the rpm up rate value is the maximum. The rpm increase rate (r_max) is set to a value (S41), and accordingly, the compressor 100 rapidly increases the rpm to the target rpm.

On the other hand, if the measurement temperature T is determined to be a slugging condition due to the reference temperature T_ref or lower, the rpm increase rate value is set to the minimum rpm increase rate (r_min) value (S42), and accordingly the compressor 100 rpm is set. Slowly increase to minimize slugging damage.

At this time, if the time at which the compressor 100 increases the rpm by applying the minimum rpm increase rate (r_min) value exceeds the reference time (Δt) (S43), it is determined that the slugging occurs, and the maximum rpm increase rate (r_max) The value is applied to rapidly increase the compressor 100 rpm to the target rpm.

goal rpm  Reach step ( S50 ):

In the previous step (S40), when the rpm increase rate value is set to the maximum rpm increase rate (r_max) value, the compressor 100 rpm rapidly reaches the target rpm according to the maximum rpm increase rate (r_max).

On the other hand, if the rpm increase rate value is set to the minimum rpm increase rate (r_min) in the previous step (S40), initially, the compressor 100 rpm slowly rises according to the minimum rpm increase rate (r_min), and the reference time (Δt) elapses After the maximum rpm increase rate (r_max), the compressor 100 rpm rapidly rises to the target rpm.

Figure 6 is a graph showing the rpm change of the electric compressor according to the slugging conditions.

According to an embodiment of the present invention, as shown by a dotted line in FIG. 6, when the compressor 100 is driven, when it does not correspond to a slugging condition (non-slugging condition), the compressor 100 rpm is the maximum rpm It rapidly increases to a target rpm (target rpm) of 7000 rpm at an increase rate (r_max) of 1400 rpm / s.

On the other hand, when it corresponds to the slugging occurrence condition, initially, the compressor 100 rpm slowly rises to 300 rpm / s, which is the minimum rpm increase rate (r_min), minimizing slugging damage, and the reference time (Δt) is 5 seconds. After passing through, it rapidly rises to 7000 rpm, the target rpm, at the maximum rpm increase rate of 1350 rpm / s.

That is, according to the control method of the electric compressor of the vehicle air conditioning apparatus according to an embodiment of the present invention, when the compressor 100 is driven, the slugging damage is caused by setting the rate of increase of the rpm of the compressor 100 to be small. Can be minimized.

At this time, when a predetermined time elapses after driving the compressor 100 to escape the slugging condition, the speed of the air conditioner system is guaranteed by raising the compressor 100 rpm to the target rpm as quickly as possible.

100: electric compressor
200: housing
300: drive unit
400: compression mechanism
500: control unit

Claims (7)

(a) calculating a target rpm of the compressor 100 by an automatic temperature controller (FATC);
(b) determining whether a slugging occurrence condition is applicable;
(c) determining an rpm increase rate according to the determination result of step (b); And
(d) increasing the rpm of the compressor 100 according to the rpm increase rate determined in step (c),
In step (d), the rpm continues to rise without a section where the rpm is kept constant in all sections until the target rpm is reached,
Step (b) is,
(b-1) measuring the temperature T of the compressor 100,
(b-2) comparing the measured compressor (100) temperature (T) with a preset reference temperature (T_ref) to determine whether a slugging condition is applicable, and controlling the electric compressor of the vehicle air conditioning apparatus. Way.
delete The method according to claim 1, wherein the step (b-1),
Method for controlling an electric compressor of a vehicle air conditioner, characterized in that the temperature of the inverter is measured by a temperature sensor provided on one side of the inverter of the compressor (100).
The method according to claim 1, wherein the step (b-2),
When the measurement temperature (T) is less than the reference temperature (T_ref), the control method of the electric compressor of the vehicle air conditioning apparatus, characterized in that it is determined as a slugging occurrence condition.
The method according to claim 1, wherein the step (c),
(c-1) In the case of the slugging condition as a result of the determination in step (b), a method of controlling an electric compressor for an air conditioning apparatus for a vehicle, comprising setting the rpm increase rate to the minimum rpm increase rate (r_min).
The method according to claim 5, step (c) is,
(c-2) If the result of the determination in step (b) is not a slugging occurrence condition, a method of controlling an electric compressor for an air conditioning apparatus for a vehicle, comprising setting the rpm increase rate to the maximum rpm increase rate (r_max).
The method according to claim 5,
When performing the step (c-1), it is determined whether the reference time (Δt) has elapsed, and when the reference time (Δt) elapses, the rpm increase rate is set to the maximum rpm increase rate (r_max). Way.

Images