JPH06101896A - Air conditioner control method - Google Patents

Abstract

PURPOSE:To reduce heat generation from an electronic part and the like by reducing an input current to an inverter device, while making heat discharge from a heat exchanger increase through making an outside fan rotate with high speed, in the case wherein a periphery outside temperature of an outside unit is high. CONSTITUTION:Self heat generation quantity from an electronic part in an inverter device is made to reduce by reducing an input current 14 into the inverter device through making an operation frequency decrease in number of an inverter executing a feed to a compressor motor 4 which is made not to exceed a specified maximum value with respect to an input current fed to an outside machine, while changing-over an outside fan motor 6 for air- cooling at a point where an outside temperature exceeds a specified one. Besides, according to increase in fan air quantity, not only a heat radiation effect of a heat exchanger is raised, but also heat radiation from the electronic part is promoted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method for an air conditioner equipped with an inverter device for controlling the rotation speed of a compressor motor.

[0002]

2. Description of the Related Art Conventionally, in an outdoor unit of an air conditioner,
An outdoor fan motor is used to dissipate heat from the heat exchanger.
The fan speed is changed according to the operation mode. In addition, in an inverter device that has many parts that generate heat, such as a power transistor, a method is used in which the secondary air generated by the fan is used to allow the outside air to pass through the inside of the inverter device to radiate heat from each part. Was there. Therefore, when the ambient temperature of the outdoor unit is high, the amount of heat radiation decreases. Therefore, in order to prevent the electronic components themselves from exceeding the maximum operating temperature even when the outside air temperature is high,
Designing to specifications with a margin and, for example, it was necessary to use parts of high grade, which was a factor of cost increase.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and when the temperature of outside air around the outdoor unit is high, the outdoor fan is rotated at a high speed to increase the heat radiation of the heat exchanger. At the same time, it is an object of the present invention to provide a control method for reducing heat generation of an electronic component or the like by reducing the input current to the inverter device based on the condition that the maximum current supplied does not exceed a predetermined value.

[0004]

In order to achieve the above object, current detection means for detecting the total amount of current supplied,
It comprises a refrigerant compression means for the refrigeration cycle, a heat radiation means provided with an air cooling fan or the like for heat radiation of the heat-generating components, a temperature detection means for detecting the outside air temperature, and a control means for controlling each part.

[0005]

When the outside air temperature exceeds the preset temperature, the outdoor fan motor for air cooling is switched to high-speed operation, and the input current supplied to the outdoor unit is prevented from exceeding a predetermined maximum value while the compressor motor is being operated. By reducing the operating frequency of the inverter supplied to the inverter device, the input current of the inverter device is reduced, and the self-heating amount of the electronic components of the inverter device is reduced. Further, not only the heat radiation effect of the heat exchanger is improved by increasing the fan air flow, but also the heat radiation of the electronic components of the inverter device is promoted.

[0006]

The air conditioner according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of essential parts of an air conditioner according to the present invention. An input current detector 1 detects the total amount of the input current 13 supplied from a power source such as AC 100V. Reference numeral 2 is a rectifying / smoothing unit for rectifying and smoothing an AC current shunted from the input current 13 to obtain an inverter input current 14. An inverter control unit 3 obtains an alternating current in a predetermined frequency range based on the inverter control signal 12 from the direct current (inverter input current 14) output from the rectifying / smoothing unit 2. Reference numeral 4 is a compressor motor that compresses the refrigerant of the refrigeration cycle. Reference numeral 5 denotes a fan drive unit having a speed switching function for controlling the outdoor fan motor 6 based on a fan drive control signal 11 output from the microcomputer 8.
Reference numeral 6 is an outdoor fan motor that promotes heat dissipation from the heat exchanger and electronic components. An outside air temperature detector 7 measures the outside air temperature. 8 stores the set value of the outside air temperature in advance,
The signal from the outside air temperature detector 7 is input, the input current detection signal 10 output from the input current detector 1 is input, and the inverter control unit 3 and the fan drive unit 5 are controlled based on the input signal. It consists of a controlling microcomputer.

FIG. 2 is a diagram showing the state of the maximum value of each input current with respect to the set value of the outside air temperature in the air conditioner according to the present invention. The vertical axis shows the current and the horizontal axis shows the temperature, and the set value of the outside air temperature is set on the horizontal axis. 20 represents the maximum value (e) of the input current 13. Reference numeral 21 represents the maximum value of the inverter input current 14 input to the inverter controller 3 for driving the compressor motor. Reference numeral 22 represents the maximum value of the fan motor drive input current 15 that is input to the fan drive unit 4 that controls the rotation of the outdoor fan motor 6 that promotes heat dissipation of the heat exchanger and the like. Reference numeral 23 represents a set value for switching the rotation speed of the fan motor, which is stored in advance in the memory of the microcomputer. Further, the maximum value 21 of the inverter input current takes a value indicated by a on the low temperature side and a value c on the high temperature side with the set value 23 as a boundary. Furthermore, the maximum value of the fan motor drive input current is 2
2 has a value indicated by b on the low temperature side and a value of d on the high temperature side with the set value 23 as a boundary. In addition, the input current 13 is the maximum value (e)
From the condition of not exceeding To control the relationship.

The operation will be described. FIG. 3 is a flowchart showing the operation of operating the air conditioner according to the present invention. When the cooling operation or the like is started, the signal of the outside air temperature detector 7 is input to the microcomputer 8 at a predetermined cycle, the outside air temperature is checked, and compared with the set value 23 of the outside air temperature stored in the memory, and the outside air temperature is checked. Temperature exceeds the set value 23 (N at STP1
In the case of O), in order to increase the rotation speed of the fan by the fan drive control signal 11, the fan motor drive input current is increased to d, which is the maximum value, to rotate the fan at high speed (ST
P2). The microcomputer 8 fetches the input current detection signal 10 of the input current detector 1 in a predetermined cycle, judges whether the maximum value e is input within a preset range, and exceeds the maximum value e based on the judgment. Input current 13 is supplied (ST
In the case of NO in P3), the inverter control signal 12 is supplied to the compressor motor 4 while lowering the AC frequency so as not to exceed the maximum value c of the inverter input current (STP4). Check the input current 13 again (S
Return to TP3). The outside air temperature is lower than the set value 23 (ST
If YES in P1, the maximum value 22 of the fan motor drive input current is the value of b, and the maximum value 2 of the inverter input current is 2
1 operates normally within the range of the value of a (STP
7). When the maximum input current value 20 is less than the maximum input current value e (YES in STP3),
It returns to monitoring the outside air temperature again (STP1).

[0009]

As described above, according to the present invention, when the temperature of the outside air around the outdoor unit is high, the outdoor fan is rotated at a high speed to increase the heat radiation of the heat exchanger and the heat radiation of the components of the inverter device. , And based on the condition that the supplied current must not exceed a predetermined maximum value,
Provided is a control method for reducing the supply current to an inverter device and reducing the heat generation of components. Therefore, an air conditioner that is inexpensive and has excellent cooling efficiency can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram of a main part of an air conditioner according to the present invention.

FIG. 2 is a diagram showing a state of a maximum value of each input current with respect to a set value of an outside air temperature in the air conditioner according to the present invention.

FIG. 3 is a flowchart showing the operation of operating the air conditioner according to the present invention.

[Explanation of symbols]

 1 Input Current Detector 2 Rectification / Smoothing Section 3 Inverter Control Section 4 Compressor Motor 5 Fan Drive Section 6 Outdoor Fan Motor 7 Outdoor Air Temperature Detector 8 Microcomputer 10 Input Current Detection Signal 11 Fan Drive Control Signal 12 Inverter Control Signal 13 Input Current 14 Inverter input current 15 Fan motor drive input current 20 Maximum input current 21 Maximum inverter input current 22 Maximum fan motor drive input current 23 Set value

Claims (1)

[Claims] 1. A current detecting means for detecting a total amount of supplied current, a temperature detecting means for detecting an outside air temperature, a signal input from the current detecting means and the temperature detecting means, and a compressor motor and a heat radiating unit for a refrigeration cycle. Therefore, in an outdoor unit of an air conditioner that includes a control unit that controls a fan motor that drives a fan, if the outside air temperature is detected by the temperature detecting means and the temperature is above a predetermined set temperature, the fan motor of the outdoor unit While rotating at a high speed, the total amount of current supplied by the current detection means is detected, and when the total amount of current is equal to or greater than a predetermined maximum value, the rotation speed of the compressor motor is controlled so as to be equal to or less than the maximum value. Air conditioner control method.