JPH0486443A - Controller for air conditioner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a heat pump type air conditioner, and more specifically to an air conditioner that automatically changes the current value of a current release operation that controls input current during cooling/heating. This invention relates to a control device for a harmonizer.

[Conventional Example] Conventionally, this type of heat pump type air conditioner has a rectifier circuit 2 that rectifies an AC power source (commercial) 1 to direct current, and a rectifier circuit 2 that rectifies an AC power source (commercial) 1 to direct current, as shown in FIG. An inverter unit 3 that performs switching and converts into a rectangular wave voltage (three-phase AC), and a compressor motor 4 that is driven by this three-phase AC.
, a current detection device 5 that detects the input current from the AC power source 1, a four-way valve device 6 that changes the flow of refrigerant during cooling/heating operation, and a current release operation (controls the input current) based on the detected input current value. A microcomputer 7 is provided which performs control), switches the transistors of the inverter section 3, controls the compressor motor 4, and controls the four-way valve device 6.

The current detection device 5 also includes a current transformer (CT) 51 that detects an input current, a resistor circuit 5□ that converts this current into a voltage, five variable resistors for fine adjustment that divides this converted voltage, and A resistance circuit including a resistor 54 connected in series is provided. Furthermore, the four-way valve device 6 includes:
Four-way valve drive unit (buffer circuit, etc.) 61 and relay circuit 6
2, and a four-way valve 6. are provided.

Then, the voltage divided by the resistance circuit of the variable resistor 53 and the resistor 54 is outputted to the A/D conversion port of the microcomputer 7 as a detected input current value. The microcomputer 7 compares the input current value with a predetermined set value, and performs a current release operation based on the comparison result.

[Problems to be Solved by the Invention] Incidentally, the current release operation in the air conditioner is performed at a low value during cooling operation and at a high value during heating operation, but the current release operation is performed at a low value during cooling operation and at a high value during heating operation. )
will have the same value whether the input current is the same during cooling operation or heating operation. Therefore, it was necessary to switch the setting value (corresponding to the current release operation value) in the microcomputer 7 during the cooling operation and heating operation.

In addition, air conditioners include, for example, IOA, 15A, 2
Since there are rated ones such as 0A, it is necessary to use a microcomputer that memorizes the current value of the current release operation suitable for each and determines when to operate for cooling/heating.In other words, it is necessary to use a microcomputer to control the air conditioner. The microcomputers used were not compatible and had to be changed for each model.

This invention was made in view of the above problems, and its purpose is to provide an air conditioner that automatically switches the current value of the current release operation during cooling operation and heating operation, and allows it to be changed arbitrarily. The purpose is to provide a control device for the machine.

[Means for Solving the Problem] In order to achieve the above object, the present invention has a refrigeration cycle including a compressor, a heat exchanger, a four-way valve, etc.
During heating operation, the input current from the AC power supply is detected, this detected current is converted to voltage and divided into voltages, the input current value is detected using this divided voltage, and the current release operation ( In a control device for a heat pump type air conditioner, which controls the input current (input current control) and sets the current value of this current release operation to a different value during heating/cooling operation, a voltage dividing circuit that divides the converted voltage is used. , comprising a variable means for varying the partial pressure ratio according to a switching signal of the four-way valve, and automatically switching the current release operating current value to be larger during heating operation than during cooling operation, and including the variable means. The present invention is summarized in that the input current value is detected using the voltage obtained by the voltage dividing circuit, and is compared with the detected current value to keep the set value constant for performing the current release operation.

Further, the variable means includes a variable resistor connected in series to the resistor circuit of the voltage dividing circuit and connected in parallel to the variable resistor,
The transistor is turned on and off by the switching signal.

[Function] With the above configuration, the four-way valve switches during cooling/heating operation, and this switching signal changes the voltage division ratio of the voltage division circuit that detects the input current.

Moreover, the voltage (detection input current value) obtained from the voltage divider circuit
is set to a larger value during heating operation than during cooling operation, even if the input current is the same. Therefore, even if the set value of the current release operation is constant, the current value of the current release operation will be automatically switched during cooling operation/heating operation.In other words, the current value of the current release operation will be automatically switched during cooling operation/heating operation. This is the same as automatically switching the current control setting value.

Furthermore, when the rated power sources of the air conditioners are different, by arbitrarily varying the variable resistor, the voltage dividing ratio of the voltage dividing circuit including the variable means can be arbitrarily changed. That is, the current value of the current release operation can be easily changed, and can be used for current control of different types of air conditioners.

[Example] Hereinafter, an embodiment of the present invention will be described based on FIG.

In the figure, the same parts as in FIG. 2 are denoted by the same reference numerals, and redundant explanation will be omitted.

In the figure, the current detection device 5 of this heat pump type air conditioner includes a second variable resistor 5. and this second variable resistor 5. and an npn type transistor 56 connected in parallel to. Further, the npn type transistor 56 is turned on and off by a signal from the output port of the microcomputer 7 (switching signal of the four-way valve 63). In this case, if the output signal of the output port is at the 11H11 level, the four-way valve 63 is turned on (heating operation), and if it is at the II L I+ level, the four-way valve 63 is turned off (cooling operation). It is assumed that there is The npn type transistor 5. is that I
Assuming that it is turned on at the I HPI level and turned off at the "L" level, the npn transistor 56 is turned on during heating operation and turned off during cooling operation.
Even if the input current is the same, the detected input current value (divided voltage value) input to the A/D conversion port of the microcomputer 7 is larger during cooling operation.

Next, to explain the operation of the air conditioner control device in more detail, when the air conditioner is in heating operation, an “H” level signal is output from the output port of the microcomputer 7, and the four-way valve 63 is turned on. , npn transistor 5
G is turned on. Then, the voltage dividing circuit becomes a form in which the first variable resistor 53 and the resistor 54 are connected in series,
The voltage division ratio of the input voltage (detected input current value) is determined by the first variable resistor 5. and resistance 54.

On the other hand, during cooling operation of the air conditioner, a signal of level 1 (L17) is output from the output port of the microcomputer 7, the four-way valve 63 is turned off, and the npn type transistor 56 is turned off. Then, the voltage dividing circuit includes the first variable resistor 53 resistor 54 and the second variable resistor 55.
are connected in series, and the voltage division ratio of the input voltage (detected input current value) is determined by the first variable resistor 53, the resistor 54, and the second variable resistor 55.

Therefore, the voltage division ratio in the above voltage dividing circuit is larger during heating operation than during cooling operation, so even if the input current is the same during cooling/heating operation, the voltage will be divided during cooling operation. The resulting voltage will be higher than the voltage divided during heating operation.

That is, when the input currents are the same, the detected current value input to the A/D conversion board of the microcomputer 7 is
It is low during heating operation and high during cooling operation.

In this way, on the microcomputer 7 side, even if the input current is the same, the input A is different during cooling operation and heating operation.
Since the /D-converted value changes automatically, there is no need to switch the current value for the current release operation (current control setting value).In other words, the current value for the current release operation is small during cooling operation, and smaller during heating operation. Since the value becomes larger, the setting value for the current release operation within the microcomputer 7 may be kept constant.

Further, the second variable resistor 5. By varying the voltage, the voltage dividing ratio of the voltage dividing circuit 5 can be easily changed. Therefore, the current value of the current release operation during cooling operation and heating operation can be freely changed, and the current value of the current control operation can be changed easily. Accuracy can be increased.

Furthermore, rated power supply 1 such as IOA, 15A, 20A
Even in the case of an air conditioner such as the above, if the second variable resistor 5° is varied, current release operation (current control) according to the rating is possible, so the microcomputer 7
can be applied to any type of air conditioner, which has the effect of providing compatibility.

[Effects of the Invention] As explained above, according to the present invention, there are a current sensor (current transformer) that detects input current from an AC power source, a resistor circuit that converts this detected current into voltage, and a voltage divider that divides this converted voltage. In a control device for a heat pump type air conditioner that is equipped with a current detection device consisting of a voltage dividing circuit and performs a current release operation (current control) based on a detected input current value from the voltage dividing circuit, the four-way valve of the air conditioner is We have installed a variable circuit that automatically changes the voltage division ratio of the voltage dividing circuit in response to a switching signal so that the above current release operating current value is larger during heating operation than during cooling operation, so it is possible to switch between cooling operation and heating operation. Since the voltage division ratio of the converted voltage (detected input current value) is automatically switched in synchronization with
There is no need to switch between cooling and heating, which means that the set value can be kept constant, and the voltage dividing ratio of the voltage dividing circuit can be changed arbitrarily, making it suitable for current control of various air conditioners with different rated power sources. The effect is that it can be applied.

[Brief explanation of drawings]

FIG. 1 is a schematic partial block diagram of a control device for a heat pump type air conditioner showing an embodiment of the present invention, and FIG. 2 is a schematic block diagram of a conventional control device for an air conditioner. In the figure, 1 is an AC power supply, 2 is a rectifier circuit, 3 is an inverter section, 4 is a compressor, 5 is a current detection device, and 51 is a current sensor (
current transformer), 5□, 54 is a resistor, 5 is a first variable resistor, 5. is a second variable resistor, 56 is an npn type transistor, 6 is a four-way valve device, 61 is a four-way valve drive unit (buffer circuit), 6□ is a relay circuit, 63 is a four-way valve, and 7 is a microcomputer. Patent applicant: Fujitsu General Co., Ltd. Agent, patent attorney: Takuya Ohara

Claims (2)

[Claims] (1) It has a refrigeration cycle with a compressor, a heat exchanger, a four-way valve, etc., and detects the input current from the AC power supply during cooling/heating operation, converts the detected current to voltage and divides the voltage, and then divides the voltage. The input current value is detected by voltage, and a current release operation (input current control) is performed according to the detected value, and the current value of the current release operation is set to a different value during the heating operation/cooling operation. In a control device for a heat pump type air conditioner, the voltage dividing circuit that divides the converted voltage has a voltage dividing ratio that is varied by a switching signal of the four-way valve, and the current release operating current value is set to the cooling voltage. It is equipped with a variable means that automatically switches to be larger during heating operation than during operation, and detects the input current value using the voltage obtained by a voltage dividing circuit including the variable means, and compares it with the detected current value. ,
A control device for an air conditioner, characterized in that a set value for performing the current release operation is constant. (2) The air conditioner according to claim 1, wherein the variable means is a variable resistor connected in series to the resistance circuit of the voltage dividing circuit and a transistor connected in parallel to the variable resistor and turned on and off by the switching signal. control device.