JPH10246550A - Device for control of compressor of refrigerator and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable reduction of a rush current, which flows instantaneously upon starting a compressor motor for a refrigerator, by a method wherein an AC voltage is supplied intermittently to the compressor motor after a predetermined delay time has elapsed from the zero intersecting time point of the AC voltage. SOLUTION: An AC voltage, impressed on a compressor motor 20 for the driving thereof, is inspected whether the AC voltage is a first wave form or not and when the same is the first wave form, a SSR 16 is operated at a time when a delay time has elapsed from an AC voltage zero intersecting time, detected by a zero intersection detecting unit 10, to impress a power supply on the compressor motor 20. In the second wave form, third wave form and fourth wave form, the compressor motor 20 is driven at a time when a predetermined delay time has elapsed respectively after the zero intersecting time in the same manner. Then, the compressor motor is driven at the zero intersecting time after the fourth wave form. In this case, the delay time is decreased gradually for every half cycles of the AC voltage and, at last, the compressor motor 20 is driven at the zero intersecting point.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for controlling a compressor of a refrigerator, and more particularly to an apparatus and method for controlling an inrush current generated when a compressor motor is started.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 7, a refrigerator has a main body 1 forming an outer shape of the refrigerator, a freezing room 2 and a refrigerating room 4 formed in the main body 1, a freezing room and a refrigerating room 2.4. Doors 6 and 8 for opening and closing the freezer 2
Is provided with an F sensor 12 for temperature sensing. A compressor (not shown) for compressing the gaseous refrigerant from the evaporator and discharging it to a high-pressure refrigerant gas is provided on the rear surface of the refrigerating chamber 4, and the compressor sucks the gaseous refrigerant. It has a cylinder device for compressing and discharging, and a compressor motor for driving the cylinder device.

[0003] The compressor repeatedly operates and stops so that the freezing compartments and the refrigerating compartments 2 and 4 are maintained at a predetermined temperature or less, and thus the compressor motor repeats the driving and stopping states. However, when the compressor motor is started, an inrush current 60 is instantaneously generated as shown in FIG. The inrush current 60 is a phenomenon in which a relatively large current flows into the compressor motor for a short time when the compressor motor is started, and a current of about 8 A flows for approximately 0.1 seconds. However, in conventional refrigerators,
No control device for reducing the inrush current 60 was provided. Therefore, a fuse having an unnecessarily large value must be provided in preparation for the case where the inrush current 60 flows, and the inrush current 60 is generated every time the compressor motor is started, and a large current flows. There is a problem that the current consumption of the refrigerator increases.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention has been devised to solve the above-mentioned problems, and its object is to reduce an inrush current that flows instantaneously when a compressor motor of a refrigerator is started. It is to provide a compressor control device and method.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a compressor control device for a refrigerator having a compressor having a compressor motor according to the present invention, wherein a zero crossing of an AC voltage for driving the compressor motor is provided. A zero-crossing detecting unit for detecting a time point, and a predetermined delay from a zero-crossing time point of the AC voltage detected by the zero-crossing detecting unit at a plurality of half cycles of the AC voltage when the compressor motor is started. This is achieved by a compressor control device for a refrigerator, including a control unit that intermittently supplies the AC voltage to the compressor motor after a lapse of time.

Here, it is preferable that the delay time is gradually reduced during each half cycle, and the control unit includes a microcomputer and an SSR that operates under the control of the microcomputer by interrupting the AC voltage. Is desirable. The control unit may further include a temperature sensing sensor for sensing a temperature of the cooling chamber, wherein the control unit detects a result of the temperature sensing sensor,
When the temperature of the cooling chamber is equal to or higher than a predetermined temperature, it is desirable to start the compressor motor.

Further, according to the present invention, in a compressor control method for a refrigerator provided with a compressor having a compressor motor,
Detecting a zero-crossing point of the AC voltage for driving the compressor motor; and, when starting up the compressor motor, according to a detection result of the detection step, a plurality of half cycles of the detection step. A compressor control method is provided that includes a step of intermittently supplying the AC voltage to the compressor motor after a predetermined delay time has elapsed from the zero crossing point of the AC voltage according to a detection result. . The method may further include detecting a temperature of the cooling chamber, and activating the compressor motor when a temperature of the cooling chamber is equal to or higher than a predetermined temperature as a result of the detecting the temperature.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the attached drawings. As shown in FIG. 7, which relates to the related art, a refrigerator in which the present compressor control device and method are used includes a main body 1 forming an outer shape of the refrigerator, a freezing room 2 and a refrigerator room formed in the main body 1. 4 and freezer and refrigerator 2
4 is provided with doors 6 and 8 for opening and closing, and an F sensor (temperature sensing sensor) for sensing the temperature of the freezing room 2 in the freezing room 2
12 are provided.

FIG. 1 is a block diagram of a compressor control device according to the present invention in such a refrigerator. The block diagram includes a zero-crossing detection unit 10 for detecting a zero-crossing time point at which the instantaneous value of the AC voltage becomes 0, an F sensor 12 for sensing the temperature of the freezing compartment 2, and a signal from the F sensor 12. There is a microcomputer 14 for receiving and processing. The microcomputer 14 outputs a control signal to control the SSR (solid state relay) 16 and the relay 18, the SSR 16 interrupts an AC power supply applied for driving the compressor motor 20, and the relay 18 supplies a cold air supply. AC power applied to the circulation fan 22 is interrupted. At this time, the zero-crossing detector 10 and the SSR 16
The same AC power is applied to the relay 18 and the relay 18.

[0010] The operation of the compressor control device having such a configuration is as follows, as shown in the flow chart of FIG.
Measures the temperature of the freezer compartment 2 through the F sensor 12, and compares the measured temperature of the freezer compartment 2 with the initially set temperature (S30). As a result of the comparison, when the temperature of the freezing compartment 2 is lower than the set temperature, the supply of the cool air is unnecessary, so that the SSR 16 and the relay 18 are controlled to shut off the power supply to the compressor motor 20 and the circulation fan 22 to keep the off state ( S3
2) Subsequently, the temperature of the freezing room 2 is compared with the set temperature (S30).

When the temperature of the freezer 2 becomes higher than the set temperature,
In order to supply cold air, it is necessary to drive the compressor motor 20 and the circulation fan 22. In this case, first, the compressor motor 20
It is checked whether the AC voltage applied for driving the first waveform is the first waveform (S34). If the AC voltage is the first waveform, as shown in FIG. SSR at time when delay time TA has elapsed from voltage zero crossing time
16 is operated to apply power to the compressor motor 20 (S36).

In the same manner, in the case of the second waveform, the compressor motor 20 is driven at the time when the delay time TB has elapsed from the zero crossing time (S38, S40). The compressor motor 20 is driven at the time when the delay time TC has elapsed from the crossing time (S42, S44), and in the fourth waveform, the compressor motor 20 is driven at the time when the delay time TD has elapsed from the zero crossing time (S46). , S4
8). Then, after the fourth waveform, the compressor motor is driven at the zero crossing time (S50). Here, the delay times TA, TB, TC, and TD gradually decrease every half cycle of the AC voltage, and finally the compressor motor 20 at the zero crossing point.
Is driven, whereby the magnitude of the AC voltage supplied to the compressor motor 20 is gradually increased.

FIGS. 4A and 4B show waveforms of an AC voltage applied to the compressor motor 20 when the compressor motor 20 is driven through this process. Here, (A) shows the time when the compressor motor is in the ON state, and (B) shows the waveform of the AC voltage applied for driving the compressor motor 20 during this time. As can be seen from (B), the compressor motor 2
It can be seen that the AC voltage applied to 0 is applied from the beginning instead of the AC voltage having a constant magnitude, the AC voltage whose magnitude gradually increases from a small value.

FIG. 5 is a graph showing a waveform of a current flowing through the compressor motor when the compressor motor 20 is driven according to the above-described method. As the voltage applied to the compressor motor 20 has a waveform as shown in FIG.
The waveform of the current applied to 0 changes in a gradual shape, thus reducing the inrush current 50.

[0015]

As described above, the method of the present invention drives the compressor motor 20 by turning on / off the supply of AC power after a predetermined time has elapsed near the instantaneous value of the AC voltage becoming zero. It is a kind of zero cross system. By using such a compressor control device and method, not only can the inrush current generated at the time of starting the compressor motor be reduced, but also excessive voltage and switching noise can be suppressed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a compressor control device of the present invention.

FIG. 2 is a flowchart illustrating a compressor control method according to the present invention.

FIG. 3 is a diagram for explaining a time during which a compressor motor of the present invention is driven.

4A is a diagram showing a driving state of the compressor motor of the present invention, and FIG. 4B is a diagram showing a waveform of an AC voltage when the compressor motor is started.

FIG. 5 is a diagram showing a waveform of a current when the compressor motor of the present invention is started.

FIG. 6 is a diagram showing a current waveform when a conventional compressor motor is started.

FIG. 7 is a front view of the refrigerator.

[Explanation of symbols]

 Reference Signs List 10 Zero crossing detector 12 F sensor (temperature sensing sensor) 14 Microcomputer 16 SSR (solid state relay) 20 Compressor motor TA, TB, TC, TD delay time

Claims (6)

[Claims] 1. A compressor control device for a refrigerator having a compressor equipped with a compressor motor, comprising: a zero-crossing detecting unit for detecting a zero-crossing point of an AC voltage for driving the compressor motor; At the time of starting the compressor motor, the AC voltage is supplied to the compressor motor after a predetermined delay time has elapsed from the zero-crossing point of the AC voltage detected by the zero-crossing detecting unit in each of a plurality of half cycles of the AC voltage. A compressor control device for a refrigerator, comprising: a control unit for intermittently controlling the operation of the compressor. 2. The compressor control device according to claim 1, wherein the delay time is gradually reduced during each half cycle. 3. The compressor control device according to claim 1, wherein the control unit includes a microcomputer and an SSR that operates under the control of the microcomputer by interrupting the AC voltage. 4. The apparatus further comprises a temperature sensor for sensing a temperature of the cooling chamber, wherein the control unit controls the compressor motor when the temperature of the cooling chamber is higher than a predetermined temperature as a result of the temperature sensor. The compressor control device according to claim 1, wherein the compressor control device is started. 5. A method for controlling a compressor of a refrigerator having a compressor having a compressor motor, comprising: detecting a zero-crossing point of an AC voltage for driving the compressor motor; At a time, according to the detection result of the detection step, the AC voltage is changed to the compressor motor after a predetermined delay time has elapsed from the zero crossing point of the AC voltage during a plurality of half cycles according to the detection result of the detection step. A step of intermittently supplying the compressed air to the compressor. 6. The method according to claim 6, further comprising a step of sensing a temperature of the cooling chamber, and a step of activating the compressor motor when the temperature of the cooling chamber is higher than a predetermined temperature as a result of the temperature sensing step. The compressor control method according to claim 5, wherein