JP2001248884A - Controller for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent total stoppage of an air conditioner even at the time of overcurrent or overheat of a fan motor 4. SOLUTION: The controller for air conditioner comprises a compressor, an air supply fan rotary driven through a fan motor, an outdoor heat exchanger exchanging heat with outdoor air supplied from the air supply fan, and an outdoor controller for controlling operation of the compressor and the fan motor disposed in the body, a sensor for detecting the r.p.m., a motor control section for controlling the r.p.m., and a section for drive controlling the motor with a control signal from the motor control section disposed in the fan motor. A current sensor for detecting the current value of the motor drive section and an overcurrent detecting part are provided in the fan motor and when overcurrent is detected, the motor control section stops the fan motor or decreases the r.p.m. thereof and delivers an overcurrent detection signal to the outdoor controller. Furthermore, a temperature sensor for detecting the temperature of the fan motor and an overheat detecting section are provided in the fan motor and when overheat is detected, the motor control section stops the fan motor or decreases the r.p.m. thereof and delivers an overheat detection signal to the outdoor controller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outdoor unit of an air conditioner, and more particularly to a rotation control of a fan motor for blowing air to an outdoor heat exchanger.

[0002]

2. Description of the Related Art Conventionally, feedback control is performed by detecting the rotation of a blower fan provided in an outdoor unit of an air conditioner.
PWM that reduces the difference between the set number of revolutions and the actual number of revolutions by a motor control circuit or motor drive provided in the outdoor control device
Although control such as pulse width modulation has been performed, a fan motor having a built-in motor control circuit or motor drive circuit has recently been used due to the need for cost reduction and power saving.

[0003]

However, such a conventional fan motor has a unique safety device provided in the motor when the current value of the winding is excessively increased due to overload operation or the winding is overheated. Since the fan motor was stopped during this period, the outdoor control device could only obtain information on the number of revolutions of the fan motor. Therefore, the outdoor control device could simply know that the fan motor was abnormal (the motor was stopped). It is not possible to determine whether the safety device is operating due to overcurrent or overheating, or other serious failures,
The problem is that the air conditioner is completely stopped even though the safety device was only activated by the overload operation, which caused the indoor environment to deteriorate or caused a misunderstanding that the air conditioner failed due to the complete stop. was there.

[0004]

The present invention focuses on this point and solves the above-mentioned drawbacks. To solve the above-mentioned drawbacks, a compressor, a blower fan driven to rotate by a fan motor, and outside air blown by the blower fan are provided. An outdoor heat exchanger for exchanging heat, an outdoor control device for controlling operation of the compressor, the fan motor, and the like, a rotation speed detection sensor for detecting a rotation speed in the fan motor, and a motor for controlling the rotation speed A control unit;
In a control device for an air conditioner provided with a motor drive unit for driving and controlling a motor according to a control signal from the motor control unit, a current sensor for detecting a current value of the motor drive unit and an overcurrent detection unit are provided with a fan motor. When the overcurrent is detected, the motor control unit stops the fan motor or reduces the rotation speed, and sends an overcurrent detection signal to the outdoor control device. Further, a temperature sensor for detecting the temperature of the fan motor and an overheat detection unit are provided in the fan motor, and when the overheat is detected, the motor control unit stops the fan motor or decreases the rotation speed and sends an overheat detection signal to the outdoor control device. Is sent.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.
A blower fan 5 having a suction port 2 on the back and one side and a blowout port 3 on the front, and rotationally driven by a fan motor 4 inside.
And a heat exchanger 6 for exchanging heat with the outside air blown by the blower fan 5. The outdoor unit main body 1 is connected to an indoor unit 7 by a refrigerant pipe 8, and communicates with a compressor 11 and the heat exchanger 6 via an indoor heat exchanger 9 and an expansion device 10 to form a refrigeration circuit.

In the indoor unit 7, an indoor blower fan 12 for blowing indoor air to the indoor heat exchanger 9 to cool and heat the room is provided.
And an indoor fan motor 13 for rotating the blower fan 12
And an indoor control device 14 for controlling the indoor unit 7. The fan unit 4 and the compressor 1
An outdoor control device 15 for controlling the entire outdoor unit such as the drive 1 is provided, and the blower fan 5 and the compressor 11 are operated according to a command or temperature from the indoor unit.

A motor winding 16 is provided in the fan motor 4.
Not only that, but also a control withstand voltage IC 17 and other sensors and peripheral circuits are provided. The pressure-resistant IC 17 is an IC dedicated to motor control, and has a motor control unit 18 that controls the rotation of the motor in accordance with a set rotation speed command from the outdoor control device 15 and an input from the motor control unit 18. The motor drive unit 19 outputs three-phase DC power corresponding to the PWM modulation signal to the motor winding 16.

In the fan motor 4, a current sensor 20 for detecting a current value of the motor drive unit 19, the motor winding 16, etc., a temperature sensor 21 for detecting the temperature in the motor 4 by a thermistor or the like, a Hall IC, For example, a rotation speed detection sensor 22 for detecting the rotation speed of the motor is provided.

Reference numeral 23 denotes an overheat detecting section provided in the pressure-resistant IC 17, and an overheat state (about 100 in this embodiment) in the motor.
℃ or more, but depends on the position of the temperature sensor 21 and the heat-resistant temperature of each part) based on the signal from the temperature sensor 21 and sends an overheat signal to the motor control unit 18, which lowers the rotation speed. The motor winding 16 and other components are prevented from being destroyed by heat due to overheating such as operation or temporary stop.

At this time, not only the actual rotation speed of the fan motor 4 but also the motor rotation speed reduction or stop is controlled by the signal from the temperature sensor 21 when the inside of the motor is overheated. The outdoor controller 15 receives this signal and transmits
It is also possible to perform special control such as reducing the rotation speed, restarting the engine after a certain period of time after stopping, or operating the system for a certain time after decreasing the rotation speed, and then increasing the rotation speed.

Reference numeral 24 denotes an overcurrent detection unit provided in the withstand voltage IC 17. The overcurrent detection unit detects that the current value from the current sensor 20 has become an overcurrent (in this embodiment, about 0.9 A or more, Position, and the performance of the motor winding 16 and other components), and sends an overcurrent signal to the motor control unit 18. The motor winding 16 and other parts are prevented from being broken.

At this time, not only the actual number of revolutions of the fan motor 4 but also the current value of the motor drive unit 19 and the like increases due to the overload operation as in the above-described overheat detection from the motor control unit 18 to the outdoor control unit 15. In response to the signal from the current sensor 20, the fact that the motor rotation speed reduction or stop control is being performed is transmitted, and the outdoor controller 15 receives this signal and also reduces the rotation speed of the compressor 11, stops, or stops. It is possible to perform a special control such that the engine is operated for a certain period of time after the rotation speed is decreased and then the rotation speed is increased thereafter.

In this embodiment, the overheat detecting section 23 and the overcurrent detecting section 24 are separately provided. However, the overheating detecting section 23 is not specially provided. The voltage signal can also be processed together so that the overcurrent detection unit 24 can also output an overheat signal to the motor control unit 18.

The operation will be described with reference to the flowchart of FIG. 5. In S1, the motor control unit 18 reads a preset number of revolutions from the outdoor control device 15 in accordance with operating conditions and room temperature in S1. Next, in S2, the actual rotational speed from the rotational speed detection sensor 22 is read, and in S3, the current value of the current sensor 20 is read in S4.
Read the temperature of the temperature sensor 21 respectively. Then, in S5, PWM control is performed using the rotation speed data read in S1 and S2.

Next, in S6, it is determined whether or not the current value A of the current sensor 20 read in S3 is 0.9 amperes or more. If the current value A is 0.9 amperes or more, the motor rotation speed is decreased in S8. Or the control for lowering the current value such as stop is performed. If the current value A is smaller than 0.9 amp, the process proceeds to S7. In S7, it is determined whether or not the temperature T read by the temperature sensor 21 in S4 is equal to or higher than 100 ° C. If the temperature T is equal to or higher than 100 ° C., the motor speed is reduced or stopped in S8 as in S6. Is performed, and if the temperature T is lower than 100 ° C., the process returns to S1 to continue the PWM control of the rotation speed while monitoring the current value A and the temperature T.

Next, at S9, a signal is output from the motor controller 18 to the outdoor controller 15 for controlling the reduction or stop of the motor speed due to the occurrence of an overcurrent or overheating state in the motor. Then, in step S10, the outdoor control device 15 does not merely output a signal of stopping the air conditioner completely due to the failure of the fan motor 4, but the compressor 11 according to the state of the fan motor 4.
Operating at a reduced number of rotations, re-operating after a certain time after a temporary stop, or operating for a certain time after a reduction in the number of rotations,
Thereafter, special control such as increasing the rotation speed can be performed.

As described above, even when the motor control unit 18 is provided in the fan motor 4, it is necessary to simply stop the air conditioner completely even if an overcurrent or an overheated state of the fan motor 4 occurs. As a result, the indoor environment is not deteriorated due to the complete stoppage of the air conditioner, and a misunderstanding that the air conditioner has failed can be prevented.

[0018]

As described above, according to the present invention, it is not necessary to simply stop the air conditioner completely even if an overcurrent or overheat condition occurs in the fan motor 4, and the air conditioner is completely stopped. By doing so, the indoor environment is not degraded, and misunderstanding that the air conditioner has failed can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view of one embodiment of the present invention.

FIG. 2 is a sectional view of the same plane.

FIG. 3 is a schematic diagram of the refrigeration circuit.

FIG. 4 is the same block diagram.

FIG. 5 is a flowchart of the same.

[Explanation of symbols]

 Reference Signs List 4 fan motor 5 blower fan 6 outdoor heat exchanger 18 motor drive unit 19 motor control unit 20 current sensor 21 temperature sensor 22 rotation speed detection sensor 23 overheat detection unit 24 overcurrent detection unit

Continued on the front page (72) Inventor Mizuki Nagano 7-7 Higashi Shinbo, Sanjo City, Niigata Prefecture Inside (72) Inventor Tatsuya Mano 7-7 Higashi Shinbo, Sanjo City, Niigata Prefecture Corona Co., Ltd. ) 3L060 AA05 CC01 CC10 CC19 DD02 EE02 EE05 3L061 BA04 BE02 BF01 BF08

Claims (2)

[Claims] 1. A compressor in a main body, a blower fan rotationally driven by a fan motor, an outdoor heat exchanger for exchanging heat with outside air blown by the blower fan, and operation control of the compressor, a fan motor, and the like. A rotation control sensor for detecting a rotation speed in the fan motor, a motor control unit for controlling the rotation speed, and a motor for driving and controlling the motor based on a control signal from the motor control unit. In a control device for an air conditioner provided with a drive unit, a current sensor for detecting a current value of the motor drive unit and an overcurrent detection unit are provided in a fan motor. A control device for an air conditioner, wherein the motor is stopped or the number of revolutions is reduced and an overcurrent detection signal is sent to the outdoor control device. 2. A compressor in the main body, a blower fan rotated by a fan motor, an outdoor heat exchanger for exchanging heat with the outside air blown by the blower fan, and operation control of the compressor, the fan motor and the like. A rotation control sensor for detecting a rotation speed in the fan motor, a motor control unit for controlling the rotation speed, and a motor for driving and controlling the motor based on a control signal from the motor control unit. In an air conditioner control device provided with a drive unit, a temperature sensor for detecting the temperature of the fan motor and an overheat detection unit are provided in the fan motor, and when the overheat is detected, the motor control unit stops or controls the fan motor. A control device for an air conditioner, wherein a rotation speed is reduced and an overheat detection signal is sent to the outdoor control device.