JP2002022247A - Method for controlling air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a compressor and an outdoor fan at the optimum number of revolution, in particular, to maintain the outdoor fan at the high number of revolution. SOLUTION: The number of revolution of the compressor and the outdoor fan is brought to a target value in the method for controlling the air conditioner. In a condition where a target number of revolution Rct of the compressor is higher than a current number of revolution Re and a PWM duty ratio Da is at a maximum value, or where a target number of revolution Rft of the outdoor fan is higher than a current number of revolution Rf and a PWM duty ratio Df is at a maximum value, process is forwarded from a step ST1 to a step ST2 to raise the output voltage (PAM voltage) of a booster means. On the other hand, in a condition where at least the revolution Rct of the compressor is lower than the revolution Rc and the ratio Df is smaller than the maximum value, or where the revolution Rft is lower than the revolution Rf and the ratio Dc is smaller than the maximum value, process is forwarded from a step ST3 to a step ST4 to reduce the output voltage (PAM voltage) of a booster circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PAM control technique for controlling a compressor motor and an outdoor fan motor of an air conditioner by PWM while increasing the voltage of the motor by using an active filter or the like. The present invention relates to a method for controlling an air conditioner that appropriately controls these motors when the boosted voltage is used as a power supply voltage of a compressor motor of an outdoor unit and a power supply voltage of a fan motor of an outdoor unit, thereby enabling comfortable operation. It is.

[0002]

2. Description of the Related Art As shown in FIG. 3, for example, an air conditioner comprises an indoor unit 1 having a refrigeration cycle and an outdoor unit 2. Power is supplied from the commercial power supply 3 to the indoor unit 1 and also to the outdoor unit 2 via the indoor unit 1. The indoor unit 1 and the outdoor unit 2 perform transmission and reception of control signals between their respective control circuits (microcomputers) 4 and control circuits (microcomputers) 5 to perform room temperature control for maintaining the room temperature at the set temperature of the remote controller. I do.

For example, the control circuit 4 of the indoor unit 1 controls the rotation of the indoor fan in response to a setting operation from a remote controller, and transmits information on the setting operation (instruction for cooling / heating operation) to the outdoor unit. 2 and a command for heating / cooling operation such as the operating frequency of the compressor motor 6 of the outdoor unit 2 according to the difference between the room temperature and the set temperature is transmitted to the outdoor unit 2.

The outdoor unit 2 converts a commercial power supply 3 input through the indoor unit 1 into a direct current by a rectifier circuit (died bridge circuit; full-wave rectifier circuit) 7, and boosts the full-wave rectified DC voltage. A predetermined voltage (PAM voltage) is applied by a booster circuit (active filter or the like) 8. Then, this predetermined voltage is used as a power supply voltage of the compressor drive circuit 9 and the fan drive circuit 10,
The rotation of the compressor motor 6 and the outdoor fan motor 11 is controlled by PWM control.

The reason why the booster circuit 8 is provided is to perform PAM control in which the compressor motor 6 and the outdoor fan motor 11 are rotated as quickly as possible in order to quickly set the room temperature to the set value. In addition, the necessity is increasing from the viewpoint of improving the efficiency of the refrigeration cycle and saving energy.

In this PAM control, the control circuit 5 controls the booster circuit 8, and initially lowers the output voltage of the booster circuit 8. When the target rotational speed of the compressor is higher than the current rotational speed, the control circuit 5 controls the booster circuit 8. Is subjected to PWM control. In this case, even if the PWM duty ratio reaches the maximum (100%), if the rotation speed does not reach the target rotation speed, the output voltage of the booster circuit 8 is controlled, that is, the PAM voltage is boosted.

When the target rotation speed of the compressor is lower than the current rotation speed, the output voltage of the booster circuit 8 is reduced, and the output voltage is reduced until the rotation speed reaches the target rotation speed.
In this case, even if the output voltage of the booster circuit 8 is reduced to the minimum,
If the rotation speed does not decrease to the target rotation speed, P
The WM duty ratio is reduced to set the compressor at the target rotation speed.

[0008]

However, in the method for controlling the air conditioner, since the drive power of the compressor motor 6 and the outdoor fan motor 11 is shared, the compressor and the outdoor fan are optimized. May not be maintained. In particular, when the output voltage of the booster circuit 8 is reduced,
Naturally, there is a drawback that the power supply voltage of the fan drive circuit 10 drops and the rotation speed of the outdoor fan motor 11 drops, so that control at a high rotation speed becomes impossible.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to maintain the rotational speeds of a compressor and an outdoor fan in an optimum state, and particularly to reduce the rotational speed of the outdoor fan even when the rotational speed of the compressor is reduced. It is an object of the present invention to provide a control method of an air conditioner capable of operating at a high rotation speed.

[0010]

In order to achieve the above object, the present invention comprises an indoor unit and an outdoor unit having a refrigeration cycle, and performs room temperature control for maintaining at least the room temperature at a set temperature of a remote controller. The compressor and the outdoor fan constituting the refrigeration cycle are PWM-controlled, the DC voltage is set to a predetermined voltage (PAM voltage) by a booster, and the PAM voltage is shared by the compressor drive and the fan drive. In an air conditioner control method in which a compressor and an outdoor fan are controlled to a target rotation speed by controlling a compressor drive unit and a fan drive unit, the booster is controlled to control the compressor or the outdoor fan to a target rotation speed. When the output voltage (PAM voltage) rises or falls, the PWM duty ratio can be controlled. If, it is characterized in that so as to control the boost means.

In the control method of the air conditioner of the present invention, when the target rotational speed Rct of the compressor is higher than the current rotational speed Rc and the PWM duty ratio Dc is maximum, When the rotation speed Rft is higher than the current rotation speed Rf and the PWM duty ratio Df is the maximum, the output voltage of the booster is increased.

In the method for controlling an air conditioner according to the present invention, the target rotational speed Rct of the compressor is lower than the current rotational speed Rc, and at least the PWM duty ratio D of the outdoor fan is adjusted.
When f is smaller than the maximum, or when the target rotation speed Rft of the outdoor fan is lower than the current rotation speed Rf and the PWM duty ratio Dc of the compressor is smaller than the maximum, the output voltage of the booster is decreased. It is characterized by doing so.

[0013]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described in detail with reference to FIG. In FIG. 2,
The same parts as those in FIG. 3 are denoted by the same reference numerals, and redundant description will be omitted.

In FIG. 2, an outdoor unit 20 to which the air conditioner control method of the present invention is applied controls to increase or decrease the output voltage (PAM voltage) of the booster circuit 8 according to the processing shown in FIG. Circuit (microcomputer)
21. The control circuit 21 has the function of the control circuit 5 shown in FIG.

In FIG. 1, the condition for increasing the PAM voltage is that the target rotation speed Rct of the compressor is larger than the current rotation speed Rc and the duty ratio Dc of the PWM control of the compressor is set.
Is the maximum (100%), or the target rotation speed Rft of the outdoor fan is larger than the current rotation speed Rf, and the duty ratio Df of the PWM control of the outdoor fan is the maximum (1
00%).

The condition for decreasing the PAM voltage is that the target rotation speed Rct of the compressor is smaller than the current rotation speed Rc, the duty ratio Df of the PWM control of the outdoor fan is smaller than the maximum, or the target rotation speed of the outdoor fan is smaller. This is the case where Rft is smaller than the current rotational speed Rf and the duty ratio Dc of the PWM control of the compressor is smaller than the maximum.

Next, the operation of the control device having the above configuration will be described. First, a signal for performing room temperature control is transmitted and received between the control circuit 4 of the indoor unit 1 and the control circuit 21 of the outdoor unit 2 according to the setting operation of the remote controller. At this time, the control circuit 21 The routine shown in FIG. 1 is executed while the rotation speed of the compressor or the outdoor fan is set as the target rotation speed.

As shown in the routine of FIG.
1 is that the target rotation speed Rct of the compressor is larger than the current rotation speed Rc and the duty ratio Dc of the PWM control is the maximum, or the target rotation speed Rft of the outdoor fan is larger than the current rotation speed Rf, and Then, it is determined whether or not the duty ratio Dc of the PWM control of the outdoor fan is the maximum (step ST1).

For example, when the operating frequency (target rotational speed Rct) of the compressor transmitted from the indoor unit 1 is higher than the current rotational speed Rc and the duty ratio Dc of the PWM control has reached the maximum, the process proceeds from step ST1 to ST2. Then, the output voltage of the booster circuit 8 is increased, and the rotation speed Rc of the compressor is controlled to the target rotation speed Rct. In this case, when the output voltage of the booster circuit 8 is increased, the rotation speed Rf of the outdoor fan also increases. However, if the duty ratio Df is reduced in accordance with the increase, the rotation speed Rf is reduced to the target rotation speed Rft. It can be.

When the duty ratio Dc has not reached the maximum, the duty ratio Dc is increased to increase the rotational speed Rc of the compressor. Also, the duty ratio Dc does not reach the maximum, and the current rotational speed R of the compressor is obtained.
When c reaches the target rotation speed Rct, the current state is maintained. In this case, even if the duty ratio Dc reaches the maximum, if the rotation speed Rc of the compressor does not reach the target rotation speed Rct, the condition of step ST1 is satisfied.
The processing described above is executed.

On the other hand, the target rotation speed Rft of the outdoor fan is higher than the current rotation speed Rf, and the duty ratio D of the PWM control is higher.
When f has reached the maximum, even if the steps ST1 to S
Proceeding to T2, the output voltage of the booster circuit 8 is increased to control the outdoor fan speed Rf to the target speed Rft. In this case, when the output voltage of the booster circuit 8 is increased, the rotation speed Rc of the compressor increases. However, if the duty ratio Dc is reduced in accordance with the increase, the rotation speed Rc is reduced to the target rotation speed Rc.
t.

When the duty ratio Df has not reached the maximum, the duty ratio Df is increased to increase the rotation speed Rf of the outdoor fan. Further, the duty ratio Df does not reach the maximum and the current rotational speed R
When f reaches the target rotation speed Rft, the current state is maintained. In this case, even if the duty ratio Df reaches the maximum, when the rotation speed Rf of the outdoor fan does not reach the target rotation speed Rft, the condition of step ST1 is satisfied, and thus the above-described processing is executed.

Subsequently, when the condition of step ST1 is not satisfied, it is determined whether the target rotation speed Rct of the compressor is smaller than the current rotation speed Rc and the duty ratio Df of the PWM control of the outdoor fan is smaller than the maximum. Alternatively, the target rotation speed Rft of the outdoor fan is smaller than the current rotation speed Rf,
Further, it is determined whether or not the duty ratio Dc of the PWM control of the compressor is smaller than the maximum (step ST3).

For example, when the operating frequency (target rotation speed Rct) of the compressor transmitted from the indoor unit 1 is lower than the current rotation speed Rc and the duty ratio Df of the PWM control of the outdoor fan is smaller than the maximum, the operation proceeds from step ST3. Proceeding to ST4, the output voltage of the booster circuit 8 is decreased, and the rotation speed R of the compressor is reduced.
c is controlled to the target rotation speed Rct. In this case, the rotation speed Rf of the outdoor fan decreases, but if the duty ratio Df is increased in accordance with the decrease, the rotation speed Rf of the outdoor fan is increased.
Can be set as the target rotation speed Rft.

On the other hand, when the target rotation speed Rft of the outdoor fan is lower than the current rotation speed Rf and the duty ratio Dc of the PWM control of the compressor is smaller than the maximum, the process proceeds from step ST3 to ST4, and the output voltage of the booster circuit 8 is increased. And the rotation speed Rf of the outdoor fan is controlled to the target rotation speed Rft. In this case, the rotation speed Rc of the compressor decreases, but if the duty ratio Dc is increased according to the decrease, the rotation speed Rc of the compressor can be set to the target rotation speed Rct.

When the duty ratio Dc of the PWM control of the compressor has reached the maximum, the above-described processing cannot be performed. Therefore, in controlling the number of rotations of the compressor, P
It is preferable to provide a margin so that the duty ratio Dc of the WM control is not maximized as much as possible.

As described above, when the power supply voltage of the compressor and the outdoor fan is shared, even if the output voltage of the booster circuit 8 is increased, the rotation speed of the compressor and the outdoor fan is set to the target rotation speed by the PWM duty ratio. Is controlled, the booster circuit 8 is controlled. Also, even if the output voltage of the booster circuit 8 decreases,
When those rotation speeds can be set to the target rotation speed by the PWM duty ratio, the booster circuit 8 is controlled.

Therefore, even when one of the rotation speeds is controlled, the other rotation speed is not affected, and the rotation speeds of the compressor and the outdoor fan can be maintained in the optimum state. In particular, even if the output voltage (PAM voltage) of the booster circuit 8 drops when the target rotation speed of the compressor is lower than the current rotation speed, not only can the rotation speed of the outdoor fan be maintained at the target rotation speed, but also that The rotation speed can be set to a high rotation speed, so that the performance of the air conditioner can be improved and the comfort can be improved.

[0029]

According to the present invention described above, the following effects can be obtained. According to the present invention, a compressor and an outdoor fan are PWM-controlled, a DC voltage is set to a predetermined voltage (PAM voltage) by a booster circuit, and the PAM voltage is shared by a compressor drive circuit and a fan drive circuit. In an air conditioner control method in which a drive circuit and a fan drive circuit are controlled to set a compressor and an outdoor fan to a target rotation speed, the booster is controlled to control the compressor or the outdoor fan to a target rotation speed. When the output voltage (PAM voltage) rises or falls, the PW
When the M duty ratio is in a controllable state, since the boosting means is controlled, even when the rotation speed of the compressor is set to the target rotation speed, the rotation speed of the outdoor fan is maintained at the target rotation speed. Also, even when the rotation speed of the outdoor fan is set to the target rotation speed, the rotation speed of the compressor can be maintained at the target rotation speed. Therefore, it is possible to maintain the rotational speeds of the compressor and the outdoor fan in an optimal state, and to improve the performance of the air conditioner.

The control method of the air conditioner according to the present invention is applied when the target rotation speed Rct of the compressor is higher than the current rotation speed Rc and the PWM duty ratio Dc is the maximum, or when the target rotation speed of the outdoor fan is increased. When Rft is higher than the current rotational speed Rf and the PWM duty ratio Df is the maximum, the output voltage of the booster circuit is increased. Therefore, when the rotational speed Rc of the compressor is increased,
When the PWM duty ratio Df of the outdoor fan is reduced to maintain the rotation speed Rf of the outdoor fan at the target rotation speed Rft and the rotation speed Rf of the outdoor fan is increased, the compressor P
By reducing the WM duty ratio Dc, the rotational speed R of the compressor is reduced.
c can be maintained at the target rotation speed Rct, and the same effect as described above can be obtained.

The control method of the air conditioner according to the present invention is applied when the target rotational speed Rct of the compressor is lower than the current rotational speed Rc and at least the PWM duty ratio Df of the outdoor fan is smaller than the maximum, or Target rotation speed Rf
When t is lower than the current rotational speed Rf and the PWM duty ratio Dc of the compressor is smaller than the maximum, the output voltage of the booster circuit is decreased. Therefore, when the rotational speed Rc of the compressor is decreased. Is to increase the PWM duty ratio Df of the outdoor fan to increase the PWM duty ratio Dc of the compressor when the rotation speed Rf of the outdoor fan is maintained at the target rotation speed Rft by decreasing the rotation speed Rf of the outdoor fan. As a result, the rotation speed Rc of the compressor can be maintained at the target rotation speed Rct, and the same effects as described above can be obtained. In particular,
The rotation speed R of the outdoor fan is determined by the output voltage drop of the booster circuit.
There is a great effect that f can be maintained at a high target rotation speed Rft without decreasing f.

[Brief description of the drawings]

FIG. 1 is a schematic flowchart illustrating a method of controlling an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a schematic block diagram illustrating a control device of the air conditioner for executing the flowchart shown in FIG. 1;

FIG. 3 is a schematic block diagram of a conventional control device for an air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Indoor unit 2, 20 Outdoor unit 5, 21 Control circuit (microcomputer) 6 Compressor motor 8 Boost circuit 9 Compressor drive circuit 10 Fan drive circuit 11 Outdoor fan motor Dc Duty ratio (PWM of compressor) Df Duty ratio ( Outdoor fan PWM) Rc Current speed (of compressor) Rct Target speed (of compressor) Rf Current speed (of outdoor fan) Rft Target speed (of outdoor fan)

Claims (3)

[Claims] An indoor unit and an outdoor unit having a refrigerating cycle are provided, and while performing room temperature control for maintaining at least a room temperature at a set temperature of a remote controller, a compressor and an outdoor fan constituting the refrigerating cycle are PWM-controlled. The DC voltage is set to a predetermined voltage (PAM voltage) by a booster, and the PAM voltage is shared by the compressor drive and the fan drive. The compressor, the outdoor fan and the compressor are controlled by controlling the booster, the compressor drive and the fan drive. In the control method of the air conditioner having the target rotation speed, when the booster is controlled to increase or decrease the output voltage (PAM voltage) in order to set the compressor or the outdoor fan to the target rotation speed, When the PWM duty ratio can be controlled, the boosting means is controlled. Air conditioner control method. 2. An indoor unit and an outdoor unit having a refrigeration cycle are provided, and while performing room temperature control for maintaining at least a room temperature at a set temperature of a remote controller, PWM control is performed on a compressor and an outdoor fan constituting the refrigeration cycle, The DC voltage is set to a predetermined voltage (PAM voltage) by a booster, and the PAM voltage is shared by the compressor drive and the fan drive. The compressor, the outdoor fan and the compressor are controlled by controlling the booster, the compressor drive and the fan drive. In the control method of the air conditioner having the target rotation speed, the target rotation speed Rct of the compressor is higher than the current rotation speed Rc and the PWM duty ratio Dc is the maximum, or the target of the outdoor fan When the rotation speed Rft is higher than the current rotation speed Rf and the PWM duty ratio Df is the maximum, A method for controlling an air conditioner, wherein the output voltage of the boosting means is increased. 3. An indoor unit and an outdoor unit having a refrigeration cycle are provided, and while performing room temperature control for maintaining at least a room temperature at a set temperature of a remote controller, a compressor and an outdoor fan constituting the refrigeration cycle are PWM-controlled. The DC voltage is set to a predetermined voltage (PAM voltage) by a booster, and the PAM voltage is shared by the compressor drive and the fan drive. The compressor, the outdoor fan and the compressor are controlled by controlling the booster, the compressor drive and the fan drive. Is the target rotation speed, the target rotation speed Rct of the compressor is lower than the current rotation speed Rc, and at least the PWM duty ratio D of the outdoor fan
When f is smaller than the maximum, or when the target rotation speed Rft of the outdoor fan is lower than the current rotation speed Rf and the PWM duty ratio Dc of the compressor is smaller than the maximum, the output voltage of the booster is decreased. A method for controlling an air conditioner, characterized in that: