JPH09113035A - Driving control device for compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a rapid increasing of a load to be applied to an inverter compressor by a method wherein when a driving of a compressor having a rated capability is started during driving of a compressor having a variable capability, a driving frequency of the compressor having the variable capability is decreased down to a minimum frequency, thereafter a driving of the compressor having the rated capability is started to operate. SOLUTION: When a driving of a compressor 3 having a rated capability is started during driving of an inverter type compressor 10, a controller 20 for the inverter type compressor 10 decreases a driving frequency of a transistor module 21 down to a minimum frequency of 20Hz. With such an arrangement as above, a pressure difference in a refrigerant circuit inside an outdoor machine is reduced and a load applied to the transistor module 21 is reduced. Next, when the driving frequency reaches a minimum frequency of 20Hz, the driving of the compressor 3 having the rated capability is started. With such an arrangement as above, a load of the transistor module 21 which an inverter driving IC is reduced to prevent its damage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a compressor, and more particularly to a drive control device for a compressor installed in an outdoor unit of an air conditioner.

[0002]

2. Description of the Related Art Currently, an inverter air conditioner of variable compression capacity is used as an air conditioner. An inverter compressor as a variable compression capacity compressor is used in the outdoor unit of the inverter air conditioner. As the inverter compressor, for example, a compressor of 6 horsepower is used, and the compression capacity can be changed in the range of 0.5 to 6 horsepower by inverter control. However, when it is desired to obtain a capacity of 6 horsepower or more, a rated capacity compressor (for example, 4 horsepower) having a constant compression capacity is arranged together with the 6 horsepower inverter compressor. By thus combining the inverter compressor and the rated capacity compressor, it is possible to obtain a variable capacity inverter air conditioner having a maximum capacity of 10 horsepower.

[0003]

In an inverter air conditioner provided with both the inverter compressor and the rated capacity compressor, the inverter compressor is driven at the maximum frequency (for example, 75 Hz) in order to achieve the maximum capacity (6 horsepower). If the rated capacity compressor is started to be driven in order to obtain a capacity of more than 6 horsepower, the load applied to the inverter compressor sharply increases, and the drive current to the inverter compressor sharply increases. In such a state, a load is applied to the inverter driving transistor module IC (hybrid IC) that supplies a driving current to the inverter compressor, and the inverter driving IC may be damaged.

An object of the present invention is to provide a compressor drive control device capable of preventing the inverter driving IC from being damaged when the rated capacity compressor is driven while the variable capacity compressor is being driven. Especially.

[0005]

According to a first aspect of the present invention, there is provided a compressor including a rated capacity compressor and a variable capacity compressor connected in parallel, and a control circuit for driving and controlling the both compressors. In the drive control device, the control circuit lowers the drive frequency of the variable capacity compressor to the minimum frequency when starting the drive of the rated capacity compressor during driving of the variable capacity compressor, It is configured to start driving.

According to the present invention, when the drive of the rated capacity compressor is started while the variable capacity compressor is being driven, the drive frequency of the variable capacity compressor is lowered to the minimum frequency to reduce the pressure difference inside the outdoor unit (refrigerant circuit). After reducing the load on the variable capacity compressor by reducing it, driving of the rated capacity compressor is started. This reduces the load on the inverter driving IC (reduces the driving current) and prevents damage to the inverter driving IC.

According to a second aspect of the present invention, there is provided a compressor drive control device including a rated capacity compressor and a variable capacity compressor connected in parallel, and a control circuit for driving and controlling the both compressors. The control circuit lowers the drive frequency of the variable capacity compressor to the lowest frequency when starting the drive of the rated capacity compressor while driving the variable capacity compressor, and then starts the drive of the rated capacity compressor The drive frequency of the variable capacity compressor is configured to be changed from the lowest frequency to a desired frequency after the drive of the capacity compressor is started.

According to the present invention, in addition to the invention described in claim 2, after the drive of the rated capacity compressor is started, the drive frequency of the variable capacity compressor is changed from the minimum frequency to a desired frequency, and the rated capacity compressor and With both variable capacity compressors,
The desired outdoor function is obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described with reference to the drawings.

1 and 2 show a state in which a rear panel and the like of the outdoor unit 1 of the air conditioner are removed. FIG.
Shows a state in which the inner panel is further removed.

As shown in FIGS. 1 and 2, an outdoor unit 1 of an air conditioner includes a rated capacity rated compressor (first compressor) 3 and a variable capacity inverter compressor in a housing 2. (Second compressor) 10, accumulator 4, receiver tank (not shown) and the like are stored. An electrical box 8 is housed in the upper part of the housing 2. In addition, a heat exchanger is arranged on the back side of the outdoor unit 1, and the pair of fans 5a and 5b allows the air to flow from the side air suction port 11 to ventilate the heat exchanger. .

The housing 2 is divided into devices having a large amount of heat generation and devices having a low heat generation amount, and the devices having a relatively large heat generation amount are arranged on the left side in the figure. The device is arranged at the position of the first space (one side below the electrical equipment box 8) 6 and the device having a relatively small amount of heat generation is arranged in the second space 7 on the right side (the other side below the electrical equipment box 8).

In the first space 6, the rated compressor 3 and the inverter compressor 10 which generate a large amount of heat in the equipment of the refrigerant circuit and the equipment attached thereto are arranged.

The electrical equipment box 8 is equipped with an inverter drive circuit for driving the compressor and other devices and control circuits in the indoor unit.

3 and 4 show an example of an electric circuit block of a drive control device for a compressor according to a preferred embodiment of the present invention.

In FIGS. 3 and 4, AC power from the three-phase power source 12 is supplied to the inverter drive circuit in the electrical equipment box 8 via the terminal board 13. The terminal board 13 is connected to the noise filter 14.

The noise filter 14 is a noise filter for removing noise N1 (impulse noise or the like) that enters the converter section 22 of the circuit from the three-phase power supply 12, and for example, an LC integral type filter or the like is used. The output of the noise filter 14 is given to the bridge diode 16 via the magnet switch 15.

The bridge diode 16 is a full-wave rectifier circuit connected in a bridge and rectifies the three-phase AC power into DC power. The DC output of the bridge diode 16 is smoothed by a smoothing circuit including the noise filter 17, the reactor 18, and the capacitor 19 to obtain the transistor module 2
1 (inverter driving IC).

The noise filter 17 is a high frequency switching noise N2 generated from the transistor module 21.
Are prevented from entering the converter section 22.

The transistor module 21 is an inverter driving IC composed of a hybrid IC,
Under the control of the controller 20, the supplied DC power drives the inverter compressor 10 of the second compressor by variable frequency control by, for example, PWM (pulse width modulation) control.
Reference numeral 23 indicates an inverter unit.

Further, the AC power from the three-phase power source 12 is supplied to the rated compressor 3 via another terminal board 27 and the magnet switch 26, and by the current of a constant frequency,
The rated capacity compressor 3 operates. Reference numeral 25 indicates a module for other mounted components.

Next, FIG. 5 is a flowchart showing an example of the control procedure of the drive control device for the compressor according to the preferred embodiment of the present invention.

In FIG. 5, when the inverter compressor 10 is operating, control of the rated capacity compressor 3 is started in step 100, and the rated capacity compressor 3 is turned off in step 102.
It is determined whether or not N is requested. N at step 102
If it is O, the routine proceeds to step 104 and moves to the next control, but if YES at step 102, it proceeds to step 106 and determines whether or not the inverter compressor 10 is operating at the minimum frequency of 20 Hz. To determine. If NO in step 106, the process proceeds to step 108 to reduce the drive frequency of the inverter compressor 10 to the minimum frequency of 20 Hz by applying a control signal to the transistor module 21, and to step 110 via step 106. Then, the rated capacity compressor 3 is turned on.

As described above, when the drive of the rated capacity compressor 3 is started during the drive of the inverter compressor 10, the drive frequency of the inverter compressor 10, that is, the transistor module 21 is lowered to the minimum frequency (20 Hz), After the pressure difference inside the outdoor unit (refrigerant circuit) is reduced to reduce the load applied to the transistor module 21, the driving of the rated capacity compressor 3 is started. This allows
Transistor module 2 which is an inverter driving IC
Lighten the load of 1 (that is, reduce the drive current),
The transistor module 21 is prevented from being damaged.

When the result of step 106 is YES (the inverter compressor 10 has the lowest frequency of 20H).
(when operating on z) go directly to step 110,
The rated capacity compressor 3 is immediately turned on.

Next, FIG. 6 shows the operation of the flowchart of FIG. In addition, (A), (B), (C), respectively,
The horsepower of the inverter compressor 10 and the horsepower of the rated capacity compressor 3 are the total horsepower of both compressors.

In FIG. 6, from time t1 to t2, the frequency of the inverter compressor 10 increases from the minimum frequency of 20 Hz, and a drive start command for the inverter compressor 10 is issued. Since the frequency of 10 is not the lowest frequency (20 Hz), the drive of the rated capacity compressor 3 is not started, and the inverter compressor 10
Frequency begins to drop. At time t3, when the frequency of the inverter compressor 10 reaches the minimum frequency (20 Hz) (it becomes 0.5 horsepower at this time), the rated capacity compressor 3
Starts driving, and at time t4, the rated capacity compressor 3
Reaches four horsepower. After that, at time t5, the inverter compressor 10 increases from 0.5 horsepower as the frequency increases, and reaches 6 horsepower at time t6. At this time t, the total horsepower of both compressors becomes 10 horsepower.

Next, in the refrigerant circuit of FIG. 7, the rated capacity compressor 3 and the inverter compressor 10 are connected in parallel, and both compressors 3 and 10 receive the refrigerant gas from the SUC (suction side). The gas is compressed and then supplied to DIS (exhaust side). The SUC (suction side) and the DIS (discharge side) are connected by a SAVE valve 28, and the save valve 28
Has a function of releasing the high pressure on the discharge side to the suction side.

The compressor of FIG. 7 can obtain a total of 10 horsepower. In this case, if the rated capacity compressor 3 is 4 horsepower and the inverter compressor 10 is 6 horsepower, Although sufficient, it is preferable to use the rated capacity compressor 3 having 5 horsepower and the inverter compressor 10 having 6 horsepower because a total horsepower of the compressor has a margin.

Next, FIG. 8 shows a change in total horsepower when both the rated capacity compressor 3 and the inverter compressor 10 are used.

In the graph of FIG. 8, from time t1 to t2, the inverter compressor 10 increases its horsepower from 0.5 horsepower to 6 horsepower as the frequency increases. In addition, period T
At 1, the save valve 28 (see FIG. 7) is on. When there is a drive start command for the rated capacity compressor 3 at time t2, the inverter compressor 10 reduces its horsepower from 6 horsepower to 1 horsepower as the frequency decreases from time t2 to time t3. At this time t2 to t3 (period T2), the save valve 2
8 (see FIG. 7) is off. From time t3, the rated capacity compressor 3 is driven and the inverter compressor 10
Increases its horsepower with increasing frequency.

[0032]

As described above, according to the present invention,
When the drive of the rated capacity compressor is started during the drive of the inverter compressor, the drive frequency of the inverter compressor is lowered to the lowest frequency, and then the drive of the rated capacity compressor is started. In this way, when starting the drive of the rated capacity compressor while the inverter compressor is being driven, the drive frequency of the inverter compressor is lowered to the minimum frequency to reduce the pressure difference inside the outdoor unit (refrigerant circuit) and to perform the inverter compression. Since the drive of the rated capacity compressor is started after reducing the load applied to the machine, the load of the inverter driving IC can be lightened and its damage can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the inside of an outdoor unit of an air conditioner.

FIG. 2 is a front view showing the inside of the outdoor unit of the air conditioner.

FIG. 3 is a block circuit diagram showing an electric circuit of a drive control device for a compressor according to a preferred embodiment of the present invention.

FIG. 4 is a block circuit diagram showing an electric circuit of a drive control device for a compressor according to a preferred embodiment of the invention.

FIG. 5 is a flowchart showing the control of the drive control device for the compressor according to the preferred embodiment of the present invention.

FIG. 6 is a graph showing the operation of the flowchart of FIG. 5, where (A), (B), and (C) are the horsepower of the inverter compressor, the horsepower of the rated capacity compressor, and the total horsepower of both compressors, respectively. Indicates.

FIG. 7 is a circuit diagram showing a refrigerant circuit for a rated capacity compressor and an inverter compressor.

FIG. 8 is a graph showing a change in total horsepower when both a rated capacity compressor and an inverter compressor are used.

[Explanation of symbols]

 1 Outdoor Unit 2 Case 3 Rated Capacity Compressor 4 Accumulator 5a 5b Fan 6 First Space 7 Second Space 8 Electrical Box 10 Inverter Compressor 11 Air Suction Port 12 3-Phase Power Supply 13 Terminal Plate 14 Noise Filter 15 Magnet Switch 16 Bridge Diode 17 Noise filter 18 Reactor 19 Capacitor 20 Controller 21 Transistor module 22 Converter section 23 Inverter section 24 Centralized control panel 25 Other mounting parts 26 Magnet switch 27 Terminal board

Claims (2)

[Claims] 1. A drive control apparatus for a compressor, comprising: a rated capacity compressor and a variable capacity compressor connected in parallel; and a control circuit for driving and controlling the both compressors, wherein the control circuit is a variable capacity compressor. Drive the rated capacity compressor after lowering the drive frequency of the variable capacity compressor to the minimum frequency when starting the drive of the rated capacity compressor while the compressor is being driven. Control device. 2. A drive control device for a compressor, comprising: a rated capacity compressor and a variable capacity compressor connected in parallel; and a control circuit for driving and controlling the both compressors, wherein the control circuit is a variable capacity compressor. After the drive frequency of the variable capacity compressor is lowered to the lowest frequency when the drive of the rated capacity compressor is started during the operation of the machine, the drive of the rated capacity compressor is started and after the drive of the rated capacity compressor is started. A drive control device for a compressor, wherein the drive frequency of the variable capacity compressor is changed from a minimum frequency to a desired frequency.