JPH06165589A - Control method for air-conditioner - Google Patents

Abstract

PURPOSE:To allow rotational control of induction motors for compressor and outdoor fan by feeding the induction motors with AC power having predetermined voltage and frequency. CONSTITUTION:Voltage of an AC power supply 2 is converted through a power supply circuit 3 into a predetermined DC voltage which is fed, as input power supply voltage, to first and second drive circuits 4, 11. A microcomputor 12 for controlling an outdoor unit turns a plurality of switching elements in the first and second drive circuits 4, 11 ON/OFF according to a predetermined sequence in order to rotate the first and second induction motors 1, 10 at predetermined r.p.m. and feeds the first and second induction motors with AC power having predetermined voltage and frequency thus controlling rotation of the first and second induction motors.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner including an indoor unit and an outdoor unit, and a method of controlling an air conditioner for controlling an induction motor for a compressor of an outdoor unit and an induction motor for an outdoor blower. It is about.

[0002]

2. Description of the Related Art Conventionally, an outdoor unit of this type of air conditioner has a configuration shown in FIG. 5, for example, and a first induction motor (three-phase induction motor) 1 of a compressor that constitutes a refrigeration cycle and a commercial AC. A power supply circuit 3 including a rectifier circuit 3a, a voltage doubler circuit 3b, a smoothing capacitor 3c, and the like for inputting a power supply 2 through a reactor and obtaining a driving DC voltage (for example, 280V) for the first induction motor 1. And six transistors U1, V1, which are a plurality of three-phase bridge-connected switching elements for converting a DC voltage output from the power supply circuit 3 into a three-phase AC and supplying the three-phase AC to the first induction motor 1.
A drive circuit 4 composed of W1, X1, Y1, and Z1, a second induction motor (single-phase induction motor; capacitor motor) 5 of the blower of the outdoor unit (outdoor blower), and a single-phase by the AC power source 2. In order to supply alternating current to the predetermined winding of the second induction motor 5, the winding switching circuit 6 that switches the winding that supplies the same single-phase alternating current, and input the necessary control signal from the indoor unit Various input / outputs required for controlling the machine, controlling the outdoor unit, outputting a drive signal for controlling rotation of the first induction motor 1, and controlling the second induction motor 5 at a variable speed. A microcomputer 7 for outputting a switching signal of the winding switching circuit 6 and a drive circuit 8 for turning on / off each transistor of the driving circuit 4 by a driving signal from the microcomputer 7.
It has and.

When the rotation of the first induction motor 1 is controlled, the microcomputer 7 operates as shown in FIG.
For each half period Tf of the modulated wave shown in (a), this modulated wave is compared with the fundamental waves U1, V1, W1 to find the intersections of this modulated wave and the fundamental waves U1, V1, W1. Based on the intersections thus obtained, the times Tu1, Tv1, Tw1 to the intersections shown in (b), (d) and (f) of FIG.
Based on these Tu1, Tv1, Tw1, PWM signals (drive signals) U1, X1, V1, Y1, W1, Z1 (X1,
Y1 and Z1 are generated by outputting signals obtained by inverting U1, V1 and W1) (shown in (b) to (g) of the same figure), and driven by these drive signals U1, X1, V1, Y1, W1 and Z1. U1, X1, V1, of the drive circuit 4 via the circuit 8
The Y1, W1, and Z1 transistors are turned on and off. When each transistor of the drive circuit 4 is on / off controlled by the drive signal, the input DC voltage of the drive circuit 4 is converted into three-phase AC U1, V1, W1 to generate the three-phase of the first induction motor 1. It is supplied to the windings U1, V1 and W1 (shown in (h) of the figure).

In this way, the first induction motor 1
The DC voltage from the power supply circuit 3 is the three-phase AC U1, V
1, W1 is converted and supplied, but at this time, in the microcomputer 7, the first induction motor 1 has a predetermined rotation speed, so that the fundamental wave has a predetermined peak value in accordance with the predetermined rotation speed. , A predetermined frequency, the intersection of the modulated wave and the fundamental wave is varied, and the values of Tu1, Tv1, and Tw1 are varied, and the pulse width (on / off timing) of the PWM signal is varied by this variation. As a result, the three-phase alternating current supplied from the drive circuit 4 to the first induction motor 1 has a predetermined voltage and a predetermined frequency, and the first induction motor 1 is rotationally controlled at a predetermined rotation speed.

Further, as shown in FIG. 5, the second induction motor 5 of the outdoor blower is a single-phase induction motor having a main winding, an auxiliary winding and two reduction windings, and the main winding has the above-mentioned structure. The single-phase alternating current is supplied from the alternating-current power supply 2, and the single-phase alternating current is supplied to the auxiliary winding through the capacitor 5a.
The induction motor 5 rotates. Regarding the variable speed of the second induction motor 5, the connection between the AC power source 2 and the lead wires a, b, c of each winding is switched by a winding switching circuit 6 including switching means such as a relay. This switching is controlled by the microcomputer 7. For example, when the second induction motor 5 is rotated at high speed, the AC power supply 2 is connected to the lead wire a, and when it is rotated at medium speed, the AC power supply 2 is drawn out. In the case of the low speed rotation, the AC power supply 2 is connected to the lead wire c.

In this way, the second induction motor 5
To the AC power supply 2 and any one of the lead wires a, b, and c to supply the single-phase AC,
The induction motor 5 is rotated, and variable speed control in three stages is possible.

[0007]

However, in the above air conditioner control method, the commercial AC power supply 2 is used as the power supply for driving the second induction motor 5 of the outdoor blower. The number of revolutions of the induction motor 5 of No. 2 depends on the voltage and frequency of the AC power supply 2, and the maximum number of revolutions is determined by the AC power supply 2. This limits the range of the number of revolutions at which variable speed is possible, and for example, 100V. , 50Hz commercial power supply to the air conditioner, 100V, 6
There is a problem that the rotation speed of the second induction motor 5 is different from the case where a commercial power supply of 0 Hz is used for the air conditioner.

Further, in order to improve the performance of the air conditioner, reduce the noise of the outdoor unit, and improve the performance of the air conditioner by power-saving operation, the controllability of the induction motor of the outdoor blower is improved,
In other words, the rotational speed needs to be controlled in a wide range from high speed to low speed and in multiple stages (steplessly), while the second induction motor 5 described above can perform only three stages of speed change and the same induction. The controllability of the electric motor is poor, and the performance of the air conditioner cannot be improved.

In addition, the second induction motor requires two reduction windings and two lead wires in order to carry out three stages of variable speed, which increases the cost of the induction motor, deteriorates productivity, and increases the size of the induction motor. Is becoming a factor. Further, in order to improve the performance of the air conditioner, an induction motor capable of variable speed in multiple stages may be used. For that purpose, more reduction windings and more reduction windings than those of the induction motor of the three-stage shifting are used. Since more lead wires are required and the cost of the induction motor is further increased, the productivity is deteriorated, and the size of the induction motor is increased, it is not realistic and has been an obstacle to improving the performance of the air conditioner.

Further, when the commercial AC power source 2 used in the air conditioner is 200 V, it is necessary to double the winding (conducting wire) of the second induction motor 5, which is much more effective than the induction motor. Cost, productivity, and size.

The present invention has been made in view of the above problems, and an object thereof is to improve the cost increase, productivity deterioration and size increase of an induction motor, and further, to restrict the rotation speed of the induction motor to an input commercial power source. It is therefore an object of the present invention to provide a control method for an air conditioner, which enables wider and stepless variable speed control without fail, and which improves the controllability of the induction motor and improves the performance of the air conditioner.

[0012]

To achieve the above object, at least a compressor that constitutes a refrigeration cycle and circulates a refrigerant, an outdoor blower that performs heat exchange of the refrigerant in a heat exchanger, and an outdoor unit are provided. A method for controlling an air conditioner comprising an indoor unit and an outdoor unit, comprising: a microcomputer having an input / output function required for control and controlling the outdoor unit; A first induction motor, and a second induction motor that drives the outdoor blower,
A power supply circuit which inputs an AC power supply and outputs a predetermined DC voltage, and a first drive which inputs the output DC voltage of the power supply circuit and bridge-connects a plurality of switching elements for driving the first induction motor. A second drive circuit in which a plurality of switching elements for inputting the output DC voltage of the power supply circuit to drive the second induction motor are bridge-connected, and the microcomputer includes: A plurality of switching elements of the first drive circuit are controlled to be turned on and off in a predetermined manner to convert a direct current voltage input to the first drive circuit into a predetermined voltage and an alternating current having a predetermined frequency,
The first drive signal to be supplied to the first induction motor is output, and a plurality of switching elements of the second drive circuit are controlled to be turned on and off in a predetermined manner and are input to the second drive circuit. The direct current voltage is converted into an alternating current having a predetermined voltage and a predetermined frequency, and a second drive signal for supplying the second induction motor is output, and the microcomputer outputs at least the first induction motor and the second induction signal. The gist is that rotation control of the induction motor and control of the outdoor unit are performed.

[0013]

With the above structure, the one microcomputer controls the rotation of the first induction motor for the compressor and the second induction motor for the outdoor blower, and controls the entire outdoor unit. Be seen.

In controlling the rotation of the first induction motor for the compressor, a plurality of switching elements forming the first drive circuit are turned on in a predetermined manner by a first drive signal output from the microcomputer. The DC voltage output from the power supply circuit, which is controlled to be turned off, is converted into an alternating current having a predetermined voltage and a predetermined frequency by the first drive circuit and supplied to the first induction motor. The induction motor is rotationally controlled at a predetermined rotation speed.

When controlling the rotation of the second induction motor for the outdoor blower, the same control as the rotation control of the first induction motor is performed by the microcomputer.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An air conditioner control method according to the present invention controls an outdoor unit by a microcomputer having an input / output function necessary for controlling the outdoor unit, and a first induction motor for a compressor. The rotation control is performed and the second induction motor for the outdoor blower is also rotation controlled. In addition, for example, when the second induction motor is a three-phase induction motor, the three-phase alternating current supplied to the three-phase winding has a predetermined voltage and a predetermined frequency, or the second induction motor is a single-phase induction motor. In this case, the single-phase alternating current supplied to the main winding and the auxiliary winding is set to a predetermined voltage and a predetermined frequency to control the rotation of the second induction motor at a predetermined rotation speed.

Next, an embodiment of a control method for an air conditioner according to the present invention will be described with reference to FIGS. 1 to 4. In addition,
5, those parts which are the same as or corresponding to those in FIG. 5 are designated by the same reference numerals, and a duplicate description will be omitted.

In FIG. 1, an outdoor unit of this air conditioner converts a DC voltage output from a second induction motor (three-phase induction motor) 10 for an outdoor blower and a power supply circuit 3 into a three-phase AC. The three-phase winding U2 of the second induction motor 10
Six transistors U2, V which are a plurality of switching elements connected in three-phase bridge for supplying to V2, W2
In addition to the function of the second drive circuit 11 composed of 2, W2, X2, Y2 and Z2 and the microcomputer 7 shown in FIG. 5, a drive signal for controlling the rotation of the second induction motor 10 is output. A microcomputer 12 and a second drive circuit 13 for turning on and off each transistor of the second drive circuit 11 by a drive signal from the microcomputer 12 are provided. The rest of the air conditioner has the same configuration as that of FIG. 5, and the drive circuit 4 shown in FIG. 5 is the first drive circuit 4 and the drive circuit 8 is the first drive circuit 8.

Further, since a DC voltage (for example, 280 V) obtained by the power supply circuit 3 for inputting the commercial AC power supply 2 through the reactor is supplied to the first and second drive circuits 4 and 11, it is necessary for the compressor. A first induction motor (three-phase induction motor) 1 having a rated voltage of 280 V is used, and a second induction motor 10 for an outdoor blower is a high-voltage type (for example, a rated voltage 280 V). High voltage type transistors (eg rated voltage 280)
V) is used.

The microcomputer 12 controls the outdoor unit and, like the conventional example, the six transistors U1, which are a plurality of switching elements of the first drive circuit 4 via the first drive circuit 8. X1, V1, Y
1, W1 and Z1 are turned on and off, the DC voltage input to the first drive circuit 4 is converted into a three-phase alternating current U1, V1 and W1 having a predetermined voltage and a predetermined frequency, and the first induction is performed. A first drive signal (PWM signal) U1, X1, V1, Y1 for supplying the three-phase windings U1, V1, W1 of the electric motor 1 to control the rotation of the first induction motor 1 at a predetermined rotational speed. , W1,
While Z1 is output, six transistors U2, X2, which are a plurality of switching elements of the second drive circuit 11 via the second drive circuit 13, as in the control method of the first induction motor 1. V2, Y2, W2. Turn on Z2,
The DC voltage input to the second drive circuit 11 is turned off and the three-phase alternating current U2, V2 having a predetermined voltage and a predetermined frequency is used.
Converted to W2, the three-phase winding U of the second induction motor 10
2, V2, W2, and a second drive signal (PW) for controlling the rotation of the second induction motor 10 at a predetermined rotation speed.
M signal) U2, X2, V2, Y2, W2, Z2 are output.

In this way, the second induction motor 1 described above is used.
The direct current voltage from the power supply circuit 3 is converted into a three-phase alternating current and supplied to 0. At this time, the microcomputer 1
In 2, the intersection of the modulated wave and the fundamental waves U2, V2, W2 is obtained for each half cycle Tf of the modulated wave by the same method as in the case of controlling the rotation of the first induction motor 1, and based on this intersection. Times Tu2, Tv2, Tw2 to each intersection are obtained,
PWM signals (drive signals) U2, X2, V2, Y2, W2 and Z2 are generated and output based on the Tu2, Tv2 and Tw2. Further, at this time, since the outdoor blower is set to a predetermined rotation speed, the fundamental waves U2, V2 and W2 are set to predetermined peak values and predetermined frequencies according to the predetermined rotation speed,
As a result, the intersection of the modulated wave and the fundamental wave is changed, Tu2, Tv2, Tw2 are changed by this change, and the pulse widths of the output PWM signals U2, X2, V2, Y2, W2, Z2 are changed. As a result, the second drive circuit 1
The three-phase alternating current U2, V2, W2 supplied from 1 to the second induction motor 10 has a predetermined voltage and a predetermined frequency,
The rotation of the second induction motor 10 is controlled at a predetermined rotation speed.

Here, the microcomputer 12
2 has an outdoor unit control means 12a of the air conditioner having an input / output function necessary for controlling the outdoor unit of the air conditioner, as shown in the example of FIG. 2, and controls the outdoor unit by the control means 12a. A first and a second control circuit for controlling the transistors of the first and second drive circuits 4 and 11 for controlling the rotation of the first and second induction motors 1 and 10 It has a drive signal generating means 12b (PWM signal generating means) for generating a second drive signal (PWM signal).

In the case of this example, the drive signal generating means 12b outputs the PWM signals which are the first and second drive signals in order to control the rotation of the three-phase induction motor which is the first and second induction motors. A total of 12 each, 6 for each. The method of generating these twelve signals is based on the half cycle Tf of the modulated wave shown in FIG.
, The fundamental waves U1, V1, W1 for generating the modulated wave and the first drive signal (see (a) in the same figure) and the second wave
Of the fundamental waves U2, V2, W2 for generating the drive signal of each of them, and the intersections thereof are obtained, and based on the intersections, the times Tu1, Tv1, T
w1 (see (b), (d), (f) in the figure), and T
u2, Tv2, Tw2 are obtained, and the half cycle Tf of the modulated wave is obtained.
Is set in the memory 12c and the obtained Tu1,
Tv1 and Tw1 are stored in the memories 12d, 12e and 12f, and the obtained Tu2, Tv2 and Tw2 are stored in the memories 12g and 1
Set to 2h, 12i.

Then, the timer counter 12j is reset and started, and at the same time, the six U1, V1 and W1 output from the comparing means 12k ((b), (d) in FIG.
(See (f)), and U2, V2, and W2 signals are set to L level. Then, the count value of the timer counter 12j and the memories 12d to 12 are compared by the comparing means 12k.
i values Tu1, Tv1, Tw1, and Tu2, Tv
2, Tw2 are compared with each other, and if they match, the output signal corresponding to each is inverted. After that, when the count value of the timer counter 12j matches the half cycle Tf of the modulated wave which is the value of the memory 12c, the comparing means 12k.
Resets the timer counter 12j. During this period, the microcomputer 12 receives the modulated wave in the next half cycle of the modulated wave and the fundamental waves U1, V1, W1, and U.
2, V2, W2, and the new intersections Tu1, Tv1, Tw1, and Tu2, Tv2, Tw.
2 is obtained, and Tu1, Tv1, Tw1, and Tu2, Tv2, Tw2 newly obtained at the same time when the timer counter 12j is reset are stored in the memories 12d, 12e, 12.
f and 12g, 12h, 12i are set again, and the timer counter 12j is restarted.

The above process is repeated in the same manner, and the count value of the timer counter 12j is the value Tu1, Tv1, Tw1, and Tu2 of the memories 12d to 12f and 12g to 12i for each half cycle Tf of the modulated wave. T
When v2 and Tw2 match, the corresponding signals are inverted, and when the count value matches the half cycle Tf of the modulated wave of the memory 12c, the timer counter 12j is reset, and the next half of the modulated wave is reset during this period. Tu1, Tv1, Tw1, and Tu2, Tv2, T in the cycle Tf
w2 is newly calculated by the method described above, and the memory 12
d to 12i, the timer counter 12j is started, and the six PWM signals U1, V1, W1 (see (b), (d) and (f) in the figure) and U2, V2, W
2 is output.

The six output signals U1, V1, W1 and U2, V2, W2 (PWM signals) from the comparison means 12k are inverted by the inversion means 121, 12m, 12n and 12.
X1, Y inverted by o, 12p, 12q respectively
1, Z1, and X2, Y2, Z2 signals, and these inverted signals X1, Y1, Z1, and X2, Y
2, Z2 and non-inverted signals U1, V1, W1, and U
Twelve signals of 2, V2 and W2 are input to the dead time generating means 12r. This dead time generating means 12r
Is a delay means, and includes first and second drive circuits 4 and 11
Two in-phase transistors (U1 and X1, V1 and Y)
1, W1 and Z1, U2 and X2, V2 and Y2, W2
And Z2) are turned on at the same time to prevent the power supply from being short-circuited, the 12 input drive signals U1, V1, W1,
The rising edges of X1, Y1, Z1 (see (b) to (g) in the figure) and U2, V2, W2, X2, Y2, Z2 are delayed so that the two transistors in the same phase of each drive circuit are simultaneously at the H level (ON. ) Is to prevent.

In this way, the twelve PWM signals (U1, V1, W1, X1, Y1, Z1, and U2), which are the first and second drive signals for the first and second drive circuits 4 and 11, are provided. , V2, W2, X2, Y2, Z2) are output from the dead time generating means 12r and output from the microcomputer 12, while the first and second induction motors are controlled to rotate at a predetermined rotation speed. The microcomputer 12 changes the fundamental waves U1, V1, W1, and U2, V2, W2 to a predetermined crest value and a predetermined frequency, respectively, thereby changing the intersection of the modulated wave and each fundamental wave. That is, the value Tu set in the memories 12d to 12i is changed by changing the intersection.
1, Tv1, Tw1, and Tu2, Tv2, Tw2 are varied, so that the on / off timing (pulse width) of the output drive signal (PWM signal) is varied and output. In this way, the first and second induction motors 1, 1
The three-phase alternating current supplied to 0 has a predetermined voltage and a predetermined frequency, and the microcomputer 12 controls the rotation of the first and second induction motors at predetermined rotation speeds. In the microcomputer 12 of this embodiment, in order to supply the three-phase alternating current of the predetermined voltage and the predetermined frequency to the second induction motors 1 and 10, the respective fundamental waves U1 of the respective three-phase alternating currents are supplied. The first and second drive signals are generated on the basis of V1, W1 and U2, V2, W2 and one modulation wave of a predetermined cycle (half cycle Tf), that is, one modulation wave of each is generated. The fundamental wave is shared. The period of the modulated wave (half period Tf of the modulated wave) may be changed as necessary.

Thus, the first induction motor 1 of the compressor
Also, when the power source of the second induction motor 10 of the outdoor blower is a power source in which direct current is converted into alternating current, and when this alternating current power is supplied to the first and second induction motors 1 and 10, the outdoor unit is controlled. By the microcomputer 12
By changing the AC voltage and frequency of the power source to a predetermined value,
Since the rotation of the second induction motors 1 and 10 is controlled, for example, when a commercial power supply of 100V, 50Hz is used for the air conditioner, and when a commercial AC power supply of 100V, 60Hz is used for the air conditioner. The rotation speed of the second induction motor 10 does not differ from that when it is used, that is, it does not depend on the AC power supply 2, and the maximum rotation speed and the rotation speed width capable of variable speed control are set freely. Therefore, the controllability of the induction motor can be improved.

Also, the second induction motor 10 of the outdoor blower.
Since the number of rotations of the air conditioner can be controlled in a wider range from high speed to low speed and in multiple stages (steplessly), it is possible to improve the capacity of the air conditioner, reduce the noise of the outdoor unit, and save energy. Therefore, the performance of the air conditioner can be improved. Further, the second induction motor 1
No. 0, the number of windings and lead wires is small, so the controllability of the induction motor is improved and the performance of the air conditioner is improved without any problems such as increase in the cost of the induction motor, deterioration of productivity and increase in size. Can be planned. Further, the rotation control of the compressor and the outdoor blower required for the outdoor unit of the air conditioner can be freely performed by the microcomputer 12 that also controls the outdoor unit required for the outdoor unit of the air conditioner. In
The first and second drive signals can be generated with one modulated wave.

FIG. 3 is a block diagram showing a modified embodiment of the microcomputer 12 used in the control method of the air conditioner of the present invention. In the figure, the same parts as those in FIG.

In the figure, this microcomputer 1
The second drive signal generating means 12b controls ON / OFF of each transistor of the first drive circuit 4 in order to control the rotation of the first induction motor 1, and the first drive signal (PWM signal).
And a memory 12c1 for setting a half cycle Tf1 of the first modulated wave, and a timer counter 12j1 for generating
A timer counter 12j2 and a second modulated wave for generating a second drive signal (PWM signal) for turning on and off each transistor of the second drive circuit 11 for controlling the rotation of the second induction motor 10 It separately has a memory 12c2 for setting the half cycle Tf2 of. As a result, modulated waves for generating the first and second drive signals (PWM signals) of the respective transistors of the first and second drive circuits 4 and 11 of the first and second induction motors 1 and 10 are generated. The first modulated wave and the second modulated wave are respectively set, and the periods of the modulated waves 1 and 2 are separately set to the half period Tf.
1 and Tf2 can be set in the memories 12c1 and 12c2, so that the microcomputer 12 can optimally control the first and second induction motors 1 and 10 when rotating the first induction motor 1 and the second induction motor 10, respectively. Drive signal (PWM signal) can be generated and output.

FIG. 7 is a schematic block diagram showing another embodiment of the control circuit of the outdoor unit to which the control method of the air conditioner of the present invention is applied. In the figure, the same parts as those in FIG.

In the figure, the outdoor unit of this air conditioner uses a single-phase induction motor (capacitor motor) as the second induction motor 14 as in the conventional example, and the second induction motor 14 is shown in FIG. Similarly to the second induction motor 10 shown in FIG. 1, rotation control is performed by the PWM signal which is the second drive signal output from the microcomputer 16. Therefore, the second induction motor 14 does not have a reduction winding, but has only the main winding and the auxiliary winding, and the microcomputer 16 controls the DC voltage from the power supply circuit 3 to the predetermined value by the second drive circuit 15. The voltage is converted into a single-phase alternating current of a predetermined frequency and supplied to the main winding, and the single-phase alternating current is supplied to the auxiliary winding through the capacitor 14a. Therefore, the second drive circuit 15 is composed of a plurality of switching elements. It has a structure in which four transistors are bridge-connected, and four drive signals (PWM signals) for controlling ON / OFF of the four transistors are output from the microcomputer 16 as a second drive signal, The induction motor 14 is controlled in rotation.

The outdoor unit of this air conditioner has, in addition to the function of the microcomputer 7 shown in FIG. 5, each transistor of the second drive circuit 15 for controlling the rotation of the second induction motor 14. Microcomputer 1 that outputs a second drive signal (PWM signal) for on / off control
6 and a second drive circuit 17 for turning on and off each transistor of the second drive circuit 15 by a second drive signal (PWM signal) output from the microcomputer 16. The other parts of this embodiment are the same as those of the previous embodiment, and the rotation control method of the second induction motor 14 is also the same as that of the previous embodiment, so the description thereof is omitted.

As described above, this embodiment has the same effects as the previous embodiment, and the problems of the conventional example can be solved.

[0036]

As described above, according to the air conditioner control method of the present invention, when controlling the compressor and the outdoor blower required for the outdoor unit of the air conditioner, the first compressor is used.
Of the induction motor and the second induction motor for the outdoor blower do not use an input commercial AC power supply as a power supply, and convert the input commercial AC power supply into a DC voltage to control the outdoor unit of the air conditioner. The computer converts this direct current voltage into an alternating current having a predetermined voltage and a predetermined frequency in the first and second drive circuits and supplies the alternating current to the first and second induction motors to rotate the first and second induction motors. Since the control is performed, the rotation speeds of the first and second induction motors do not depend on the voltage and frequency of the input commercial AC power supply, and the maximum rotation speed and the minimum rotation speed are freely set, and The number of revolutions can be controlled in a wide and stepless manner, which improves the controllability of the electric motor that drives the compressor and the outdoor blower, which is necessary for the outdoor unit of the air conditioner. It is possible to improve the performance of the air conditioner, such as improving the capacity of the air conditioner, reducing the noise of the outdoor unit, and power-saving operation. Also, since the deceleration winding is not required as the induction motor, the winding and drawing The number of wires is small, the productivity of the induction motor can be improved, the cost can be reduced and the size can be reduced, and the two motors of the compressor and the outdoor blower, which are necessary for the outdoor unit of the air conditioner, can be operated by the same air. Since the microcomputer for controlling the outdoor unit required for the outdoor unit of the harmony machine controls the rotation, there is a useful effect that the above effect can be realized without complicating and increasing the size of the control circuit of the outdoor unit.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of an outdoor unit control circuit to which an air conditioner control method according to an embodiment of the present invention is applied.

FIG. 2 is a schematic block diagram of a microcomputer used in the outdoor unit shown in FIG.

FIG. 3 is a schematic block diagram showing a modified example of a microcomputer used in the outdoor unit shown in FIG.

FIG. 4 is a schematic block diagram of a control circuit of an outdoor unit to which another embodiment of the present invention is applied and to which a method for controlling an air conditioner is applied.

FIG. 5 is a schematic block diagram of a control circuit of an outdoor unit of a conventional air conditioner.

FIG. 6 is a time chart diagram illustrating a method of controlling the first induction motor of the compressor of the outdoor unit shown in FIG.

[Explanation of symbols]

1 First Induction Motor (Three-Phase Induction Motor; For Compressor) 2 Commercial AC Power Supply 3 Power Supply Circuit 4 First Driving Circuit 8 First Drive Circuit 10 Second Induction Motor (Three-Phase Induction Motor; Outdoor Blower) ) 11,15 second drive circuit 13,17 second drive circuit 12,16 microcomputer 14 second induction motor (single-phase induction motor; outdoor blower) 12a air conditioner outdoor unit control means 12b drive signal Generator (PWM signal generator)

Claims (4)

[Claims] 1. A compressor that constitutes at least a refrigeration cycle, circulates a refrigerant, an outdoor blower that exchanges heat of the refrigerant in a heat exchanger, and an input / output function necessary for controlling the outdoor unit. A method for controlling an air conditioner, comprising: a microcomputer for controlling an outdoor unit, the indoor unit and the outdoor unit, wherein a first induction motor for driving the compressor and the outdoor blower are provided. A second induction motor to be driven, a power supply circuit for inputting an AC power supply to output a predetermined DC voltage, and a plurality of switchings for inputting the output DC voltage of the power supply circuit to drive the first induction motor. First bridge connection of elements
And a second drive circuit in which a plurality of switching elements for inputting the output DC voltage of the power supply circuit to drive the second induction motor are bridge-connected, Controls a plurality of switching elements of the first drive circuit to turn on and off in a predetermined manner to convert a direct current voltage input to the first drive circuit into a predetermined voltage and an alternating current having a predetermined frequency, Output a first drive signal to be supplied to the induction motor, and turn on a plurality of switching elements of the second drive circuit in a predetermined manner,
OFF control is performed to convert the DC voltage input to the second drive circuit into a predetermined voltage and an AC having a predetermined frequency, and a second drive signal for supplying to the second induction motor is output,
The control method for an air conditioner, wherein the microcomputer controls at least the rotation of the first induction motor and the second induction motor and the control of the outdoor unit. 2. The microcomputer comprises the first
And a drive signal generating means for generating at least the first and second drive signals as a function for controlling the rotation of the second induction motor, and the drive signal generating means includes the first and second drive signals. A plurality of PWM signals are generated as first and second drive signals for controlling ON / OFF of a plurality of switching elements of the drive circuit in a predetermined manner, and the plurality of P signals are generated.
2. The control method for an air conditioner according to claim 1, which is PWM signal generation means for generating ON / OFF timing of the WM signal by a timer means. 3. The microcomputer comprises the first
And a timing at which a plurality of switching elements of the first and second drive circuits are turned on and off based on respective fundamental waves of alternating currents supplied to the second induction motor and one modulated wave of a predetermined cycle. The air conditioner control method according to claim 1 or 2, wherein the drive signal generating means generates the first and second drive signals. 4. The microcomputer includes the first
And the plurality of switching elements of the first and second drive circuits are turned on based on the respective fundamental wave of each alternating current supplied to the second induction motor and each modulated wave of a predetermined cycle with respect to the fundamental wave. , Turning off timing is determined, and the first and second driving signal generating means are provided.
The method for controlling an air conditioner according to claim 1 or 2, wherein the drive signal is generated.