JPH0658605A - Control method of air-conditioner - Google Patents

Abstract

PURPOSE:To reduce the number of parts of a control system by a method wherein a microcomputer is employed in the control system of an indoor machine to control the ventilating fan of the indoor machine by the microcomputer. CONSTITUTION:The objective rotating number of a ventilating fan for an indoor machine is obtained in a microcomputer 12 and a signal for driving a transistor 3d is outputted while base signals for driving other transistors are outputted at the same time. In this case, the present rotating number of a DC brushless motor 1 is operated. When the present rotating number is smaller than the objective rotating number, the transistor 3d is put ON/OFF and rectified voltages are switched, however, the ON-duty ratio of a chopping signal for driving the transistor 3d is increased. When the present rotating number is larger than the objective rotating number, the duty ratio of the chopping signal for driving the transistor 3d is reduced down and the level of a voltage, supplied to a switching circuit 4, is reduced. According to this method, the rotating number of the DC brushless motor 1 is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling an air conditioner composed of an indoor unit and an outdoor unit, and more specifically, the indoor unit is controlled by a single microcomputer to reduce the number of control system parts. The present invention relates to a control method for an air conditioner that operates.

[0002]

[Prior art] Recently, as a fan motor for various home appliances,
Since a DC brushless motor has come to be used instead of an AC motor, and the DC brushless motor can be applied to various devices and can be easily used, a DC brushless motor control circuit for controlling the DC brushless motor has been developed. Various proposals have been made.

For example, as shown in FIG. 4, even in an indoor unit of an air conditioner, a DC brushless motor is used as a blower motor that blows out air obtained by an indoor heat exchanger that constitutes a refrigeration cycle into a room. There is.

In FIG. 4, this indoor unit switches a DC brushless motor 1 of a blower, a rectifying circuit 3a for rectifying and smoothing an input commercial power source 2 and a capacitor 3b, and switches the smoothed voltage. A first power supply circuit 3 including a transformer 3c, a transistor 3d, a diode 3e, a capacitor 3f (switching power supply), etc. for smoothing the smoothed output voltage, and a fixed DC brushless motor 1 with the smoothed DC voltage. A switching circuit 4 that supplies the child winding (coil), a position detection sensor (for example, a hall element) 5 that detects the position of the rotor of the DC brushless motor 1, and the above-described position information based on the position information from the position detection sensor 5. Signals for driving each transistor of the switching circuit 4 (for example, u, v, and Inverted signal and x the, y, z signal)
And a DC brushless motor for driving the transistor 3d of the first power supply circuit 3 based on rotation speed information (target rotation speed) of the blower obtained by setting operation of a remote controller or the like and room temperature. The control circuit 6, the drive circuit 7 for driving each transistor of the switching circuit 4 by a signal from the DC brushless motor control circuit 6, and at least the actuator of the indoor unit are controlled, and the rotation speed information is output. The air conditioner system control microcomputer (CPU) 8 having an input / output function necessary for controlling the indoor unit of the air conditioner, such as transmitting necessary control signals to the outdoor unit, and the input commercial power supply 2 for the air conditioner system. Transformer 9a for obtaining power supply for the control microcomputer 8 and power supply for actuators, rectification A second power supply circuit 9 by road 9b and the capacitor 9c and the like, and an output voltage according to the first power supply circuit 3 and a voltage control circuit 9d steps down the power supply voltage of the DC brushless motor control circuit 6.

When the DC brushless motor 1 is a three-phase DC brushless motor, the switching circuit 4 is composed of a pnp transistor 4a and an npn transistor 4b, for example, as shown in FIG.

In the rotation control of the DC brushless motor 1, the timing of the inverted signals of u, v, w and the x, y, z signals shown in FIGS. 6 (a) to 6 (f), that is, the DC brushless motor is used. 1 current switching timing is determined by the position detection signal from the position detection sensor 5, and the switching circuit 4 is determined by these signals.
The respective transistors 4a and 4b are turned on and off.

The first power supply circuit 3 is also based on the rotation speed information from the air conditioner system control microcomputer 8.
Since the ON duty ratio of the transistor 3d is varied, the output DC voltage level of the first power supply circuit 3 is varied, and this level-varied DC voltage is supplied to the switching circuit 4. As a result, the input DC voltage of the switching circuit 4 is supplied to the predetermined stator winding of the DC brushless motor 1 at a predetermined timing, so that the DC brushless motor 1 is rotationally controlled and the DC brushless motor 1 is rotated as described above. It will be rotated according to the numerical information.

[0008]

However, in the above air conditioner, at least the DC brushless motor control circuit 6 and the air conditioner system control microcomputer 8 are provided.
Since there is a need for types, the number of parts is increased correspondingly, and the number of revolutions is constant for each target number of revolutions, so that the number of revolutions also fluctuates due to changes in load.

The present invention has been made in view of the above problems, and an object thereof is to use a microcomputer for a control system of the indoor unit and control the indoor unit blower by the microcomputer to reduce the number of parts of the control system. An object of the present invention is to provide an air conditioner control method that can reduce the number of costs, reduce the cost, and keep the rotation speed constant even when the load changes.

[0010]

In order to achieve the above object, the present invention comprises at least an indoor unit and an outdoor unit,
A DC brushless motor for an indoor unit blower that blows out the air obtained by the indoor heat exchanger that constitutes a refrigeration cycle into the room, a switching circuit that drives this DC brushless motor, and an input commercial power source, and a variable DC voltage is input by switching. And a position detecting means for detecting the position of the rotor of the DC brushless motor, the position detecting means for detecting the position of the rotor of the DC brushless motor. Then, each switching element of the switching circuit is turned on and off at a predetermined timing, and the duty ratio of switching in the power supply circuit is changed based on the rotation speed information of the indoor unit blower so that the DC brushless motor has a target rotation speed. Voltage to control and supply to the switching circuit An air conditioner for controlling the number of revolutions of the same DC brushless motor by varying a bell, which outputs a signal for driving each of the switching elements based on position information by the position detection means, and outputs the signal according to the position information. Calculate the rotation speed of the DC brushless motor,
And at the time of controlling the air conditioner at least the rotation speed information of the indoor unit blower is obtained, and the duty ratio of the switching in the power supply circuit according to the comparison between the rotation speed information obtained by the position information and the rotation speed information. A variable chopping signal is output, the voltage level supplied to the switching circuit is varied to control the rotation speed of the DC brushless motor, and at least an input / output function necessary for controlling the indoor unit is provided, The gist of the present invention is that a microcomputer for controlling the indoor unit is provided, and the indoor unit can be controlled by one microcomputer.

[0011]

With the above structure, the microcomputer has the functions of the DC brushless motor control circuit for controlling the indoor unit blower and the air conditioner system control microcomputer for controlling all other units in the indoor unit. Since the DC brushless motor control circuit is omitted and the control system of the indoor unit is one system, the number of parts of the control system of the indoor unit is reduced accordingly.

Further, since the rotation speed of the DC brushless motor is detected and controlled so as to reach the target rotation speed, the rotation speed is kept constant at the target rotation speed even if the load changes. be able to.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the figure, the same parts as those in FIG.

In FIG. 1, this air conditioner compares an output signal of a position detection sensor 5 for detecting the position of a rotor of a DC brushless motor (three-phase DC brushless motor) 1 of an indoor unit blower with a reference value. The circuit 10, the amplifier circuit 11 that amplifies the signals of these comparison results, and the rotation speed information (target rotation speed) of the indoor unit blower are obtained, and the transistor 3d of the first power supply circuit 3 is set based on the rotation speed information. It is turned on and off, and each transistor 4a, 4b of the switching circuit 4 is turned on and off at a predetermined timing based on the position information obtained by the signal of the comparison result, and a predetermined stator winding of the DC brushless motor 1 is predetermined. A voltage is supplied, the current rotation speed of the DC brushless motor 1 is calculated from the position information, and the calculated rotation speed is compared with the rotation speed information. Flip the duty ratio of the drive signal (chopping signal) of the first transistor 3d of the power supply circuit 3 and variable, and a microcomputer 12 for adjusting the output voltage level of the first power supply circuit 3.

The microcomputer 12 is
The voltage from the second power supply circuit 9 is used as a power supply voltage, and the function of the air conditioner system control microcomputer 8 having the input / output function necessary for controlling the DC brushless motor control circuit 6 of the conventional example and the indoor unit of the air conditioner is provided. Therefore, in addition to controlling the indoor unit blower, it controls the entire indoor unit, such as an actuator.

Further, as shown in FIG. 2, the detection signal obtained by the position detection sensor 5 is input to the input port (for position detection sensor) of the microcomputer 12, that is, the input port as an external interrupt. From the output port (for switching element) of the microcomputer 12, that is, the output port as a large current output, base signals (inverted signals of u, v, w and x, y, which drive the respective transistors 4a, 4b of the switching circuit 4). z signal) is output, and a signal for driving the transistor 3d is output from an output port (for voltage adjustment) of the microcomputer 12, that is, an output port as a timer output.

The operation of the indoor unit of the air conditioner having the above structure will be described with reference to the flowchart of FIG. 3. First, the indoor unit and the outdoor unit of the air conditioner are operated according to the setting operation by the remote controller or the like. I shall. At this time, the microcomputer 12 performs input / output required to control the indoor unit of the air conditioner, and controls the indoor unit.

Then, in the microcomputer 12, similar to the air conditioner system control microcomputer 8 of the conventional example, the target rotation speed of the indoor unit blower is obtained according to the temperature detected by the room temperature sensor and the set temperature by the remote controller. A signal for driving the transistor 3d is output, and a base signal (for example, for driving each transistor 4a, 4b of the switching circuit 4 based on the position information of the rotor of the DC brushless motor 1 input through the input port) is output. U shown in FIGS. 6A to 6F,
Inverted signals of v, w and x, y, z signals) are output via the output port (step ST1).

As a result, the above DC brushless motor 1
Is rotationally driven. At this time, the current rotation speed of the DC brushless motor 1 is calculated based on the position information by the position detection sensor 5 (step ST2), and this calculated rotation speed is compared with the target rotation speed ( Step ST3, ST
5).

When the current rotation speed is lower than the target rotation speed, the transistor 3d of the first power supply circuit 3 is turned on / off according to a predetermined frequency, and the first power supply circuit 3 is turned on.
Although the voltage rectified by the rectifier circuit 3a is switched, the ON duty ratio of the chopping signal that drives the transistor 3d of the first power supply circuit 3 is increased (step ST4). Therefore, the voltage obtained by the first power supply circuit 3, that is, the voltage level supplied to the switching circuit 4 is increased, and the rotation speed of the DC brushless motor 1 is thereby increased.

On the other hand, when the current speed is higher than the target speed (step ST5), the transistor 3d is used.
The duty ratio of the chopping signal for driving the DC brushless motor 1 is reduced (step ST6), and the voltage obtained by the first power supply circuit 3, that is, the voltage level supplied to the switching circuit 4 is lowered. The rotation speed can be reduced.

By repeating the steps ST1 to ST6, the rotation speed of the DC brushless motor 1 is variably controlled as in the conventional case to approach the target rotation speed, and the DC brushless motor 1 is driven at the target rotation speed.

As described above, in the indoor unit, since the functions of the DC brushless motor control circuit 6 and the air-conditioning system control microcomputer 8 of the conventional example are realized by one Mycorro computer 12, the indoor unit is controlled. It is possible to reduce the number of parts of the voltage control circuit 9d used in one of the systems and the control system, and consequently reduce the cost of the air conditioner. Further, since the rotation speed of the DC brushless motor 1 is detected and controlled so as to reach the target rotation speed, the rotation speed can be kept constant at the target rotation speed even if the load changes.

In the above embodiment, the comparison circuit 10 and the amplification circuit 11 for comparing the position detection signal from the position detection sensor 5 with the reference value and outputting the position information signal.
May be incorporated in the microcomputer 12.

[0025]

As described above, according to the air conditioner of the present invention, the input commercial power source is input, the variable DC voltage is obtained by switching, and the variable DC voltage drives the DC brushless motor of the blower. A first power supply circuit including a switching power supply for supplying to the switching circuit;
When controlling the air conditioner, the rotation speed information (target rotation speed) of the indoor blower is obtained, and each transistor of the switching circuit for driving the DC brushless motor is predetermined based on the position information by the position detecting means of the DC brushless motor. It is turned on and off at a timing, and the current rotation speed of the DC brushless motor is obtained from the position information.
The switching duty ratio of the power supply circuit is variably controlled based on the comparison between the rotation speed information and the current rotation speed to change the voltage level supplied to the switching circuit, and at least other control of the indoor unit is performed. And a microcomputer having an input / output function necessary for controlling the indoor unit of the air conditioner for controlling the indoor unit blower and all the other indoor units can be controlled by one microcomputer. Since the DC brushless motor control circuit that controls the DC brushless motor of the blower can be omitted, the number of parts of the indoor unit can be reduced accordingly, which in turn can reduce the cost of the air conditioner, and the rotation speed of the DC brushless motor. Is detected and controlled to reach the target speed, even if the load fluctuates In can be constant.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an indoor unit of an air conditioner showing an embodiment of the present invention.

FIG. 2 is a schematic partial block diagram of a control system used in the indoor unit shown in FIG.

FIG. 3 is a schematic flowchart illustrating a method for controlling the air conditioner shown in FIG.

FIG. 4 is a schematic block diagram of an indoor unit of a conventional air conditioner.

5 is a schematic circuit diagram of a switching circuit used in the indoor unit shown in FIG.

FIG. 6 is a time chart for explaining the operation of the DC brushless motor of the blower of the indoor unit shown in FIG.

[Explanation of symbols]

 1 DC brushless motor (of indoor unit blower) 2 Commercial power supply 3 First power supply circuit 3a, 9b Rectifier circuit 3c, 9a Transformer 3d Transistor 3e Diode 3b, 3f, 9c Capacitor (for smoothing) 4 Switching circuit 4a pnp Transistor 4b npn Transistor 5 Position detection sensor (position detection means; Hall element) 7 Drive circuit 9 Second power supply circuit 10 Comparison circuit 11 Amplification circuit 12 Microcomputer

Claims (1)

[Claims] 1. At least an indoor unit and an outdoor unit,
A DC brushless motor for an indoor unit blower that blows out air obtained by an indoor heat exchanger that constitutes a refrigeration cycle into a room, a switching circuit that drives the DC brushless motor, and an input commercial power source, and a variable DC voltage is input by switching. And a power supply circuit comprising a switching power supply for supplying the variable DC voltage to the switching circuit,
Position detecting means for detecting the position of the rotor of the DC brushless motor, and turning ON / OFF each switching element of the switching circuit at a predetermined timing based on the position information by the position detecting means. The DC brushless motor rotation speed is controlled by variably controlling the switching duty ratio in the power supply circuit based on the rotation speed information of the indoor unit blower so as to reach a target rotation speed, and changing the voltage level supplied to the switching circuit. An air conditioner for controlling, while outputting a signal for driving each of the switching elements based on position information by the position detection means, calculating the number of rotations of the DC brushless motor by the position information, and At the time of controlling the air conditioner, at least the rotational speed information of the indoor unit blower And a chopping signal for varying the duty ratio of switching in the power supply circuit according to the comparison between the rotation speed obtained by the position information and the rotation speed information is output, and the voltage level supplied to the switching circuit is changed. Variablely controlling the number of revolutions of the DC brushless motor, and having at least an input / output function necessary for controlling the indoor unit, a microcomputer for controlling the indoor unit is provided, and the microcomputer is controlled by one microcomputer. A method for controlling an air conditioner, which is capable of controlling an indoor unit.