JPS6361862A - Operation controller for refrigerator, etc. - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an operation control device for a refrigerator or the like that controls a compressor by switching between a commercial power source and an inverter device to vary its capacity.

BACKGROUND OF THE INVENTION In recent years, in refrigeration equipment such as refrigerators, it has become possible to start and operate the compressor using commercial power and switch to an inverter when necessary to change its cooling capacity. ing.

However, switching between conventional commercial power supply and inverter equipment is
The connection was simply switched by a relay, and no consideration was given to the voltage phase or current phase of the commercial power supply and the inverter device, or to the switching timing of the relay. Furthermore, the compressor had a configuration including a switching means for turning the compressor on and off using a commercial power source, and the relay.

Problems to be Solved by the Invention However, in the conventional method described above, in order to switch the relay even when current is flowing, a high voltage is induced at both ends of the motor, that is, at the relay contacts, by the inductance of the motor, and the relay contacts This has the disadvantage that it adversely affects the lifespan, destroys the elements of the inverter device, and generates noise. Furthermore, because of the configuration including the switching means for turning off the compressor and the relay, the configuration of the high current circuit through which the compressor current flows is complicated.

Means for Solving the Problems In order to solve the above problems, the operation control device for a refrigerator, etc. of the present invention includes a switching means for switching the compressor to be driven by either a commercial power supply or an inverter device; When the compressor is turned off, the control circuit switches the switching means to the inverter side and brings the inverter into a stopped state.

Effect of the Invention With the above-described configuration, the present invention can smoothly switch the operation between the commercial power source of the compressor and the inverter device, and furthermore, can realize the compressor operation switch with only a switching means and a minimum configuration. can.

Embodiment Hereinafter, an operation control device for a refrigerator or the like according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a circuit block diagram of an operation control device for a refrigerator or the like in one embodiment of the present invention. The refrigeration cycle part has been omitted to simplify the explanation. In FIG. 1, 1 is a commercial power source. 2
04 is an inverter connected to the other terminal of the switching means 3.06 is a refrigerator. A temperature detector detects the temperature inside the refrigerator, and a comparator 6 compares the temperature with a set temperature and sends a signal.

7 is a switch which is operated when it is desired to rapidly cool down the inside of a refrigerator or the like. 8 is a zero cross detection circuit,
The point where the voltage of the commercial power supply 1 becomes zero volts is detected and a signal is sent out. 9 is a control circuit, which is a comparator 6 for internal temperature.
It is connected to the inverter device 4 and the switching means 3 so as to receive the outputs of the rapid cooling switch 7 and the zero-cross detection circuit 8 as inputs, and output a control signal to the inverter device 4 and the switching means 3.

The operation of the operation control device for a refrigerator or the like configured as described above will be described below with reference to FIGS. 1 and 2.

FIG. 2 shows a timing diagram when switching from the commercial power supply 1 to the inverter device 4 output in the configuration of FIG. 1. In FIG. 1, when the compressor 2 of a refrigerator or the like is started up or in normal operation, a signal is sent from the control circuit 9 to the switching means 3 and connected to the commercial power source 1 to operate the compressor 2 with the commercial power source 1. . When the inside of the refrigerator is cooled down to below the set temperature, a signal is sent from the comparator 6 to the control circuit 9, and the control circuit 9 sends a stop signal to the inverter device 4 to stop the inverter device 4 and switch the switching means 3 to the inverter device. By switching to the 4 side, the compressor 2 is stopped. Next, when the temperature inside the refrigerator rises, the operation returns to the normal operation described above, and normally the compressor 2 is operated at 0N10FF using the commercial power supply 1 and the switching means 3 to maintain the temperature inside the refrigerator at a constant temperature. If the temperature rises abnormally, an abnormal temperature rise signal is sent to the control circuit 9 when the comparator 6 exceeds a predetermined upper limit temperature setting value. Upon receiving this temperature rise signal, the control circuit 9 first detects the zero cross point of the output of the zero cross detection circuit 8 shown in FIG. Drive with frequency and phase. Next, the control circuit 9 operates the switching means 3 at the zero-crossing point of the zero-crossing detection circuit 8 as shown in the opening of FIG. As a result, as shown in FIG. 2, the voltage applied to the compressor 2 is switched by the switching means 3 at zero volts of the commercial power supply 1, and the switching waveform of the inverter device 4 is continuously supplied. After switching to the inverter device 4, the inverter device 4 is operated at a high frequency to operate the compressor 2 at high speed, thereby rapidly cooling the inside of the refrigerator.

When the inside of the refrigerator is cooled and reaches the set temperature, the control circuit 9 receives the change in the output of the comparator 6, stops the inverter device 4, and
Compressor 2 is stopped.

Next, when the rapid cooling switch 7 is turned on during normal operation, the procedure for switching from the commercial power source 1 to the drive by the inverter device 4 is the same as when the temperature inside the refrigerator increases. If this switch is turned on while the compressor 2 is stopped, the control circuit 9 switches the switching means 3 to the commercial power supply 1 side and after starting the compressor 2, the switching means 3 is switched to the commercial power supply 1 side by the control circuit 9. After that, the compressor 2 is operated at high speed to rapidly cool the inside of the refrigerator. After a predetermined period of time has elapsed, the inverter device 4 is stopped by a signal from the control circuit 9, the compressor 2 is stopped, and the rapid cooling operation in the refrigerator is completed.

Note that the zero-cross detection circuit 8 is not limited to the above-mentioned embodiment, and is assumed to detect the current in one line of the commercial power supply 1, detect the point where the value becomes zero, send out a signal, and control in the same procedure as in the above-mentioned embodiment. It's okay.

Furthermore, regarding switching from the inverter device 4 to the commercial power source 1, it is easily possible in the above embodiment to synchronize the operating frequency and phase of the inverter device 4 with the commercial power source 1 and switch the switching means 3.

As described above, according to this embodiment, the compressor 2 is connected to the commercial power supply
and an inverter device 4, and a control circuit that switches the switching means 3 to the inverter device 4 side and brings the inverter device 4 to a stopped state when the compressor 2 is stopped. 9, switching from the commercial power supply 1 to the inverter device 4 can be performed without inducing high voltage due to the motor inductance of the compressor 2 in the switching means 3 and the elements (not shown) of the inverter device 4. Therefore, switching can be performed without damaging the elements of the inverter device 4 and the switching means 3. Also, from the operation by the inverter device 4 to the commercial power supply 1
Switching to can also be done smoothly in the same way. Furthermore, since no high voltage is generated, noise generation during switching can be reduced. Furthermore, the configuration of the switching part of the large current circuit through which the current of the compressor 2 flows is changed to the minimum configuration of only the switching means 3 to switch between the commercial power source 1 and the inverter device 4 while the compressor 2 is operating, and 0N10FF
And high-low speed operation by the inverter device 4 becomes possible.

Effects of the Invention As described above, the present invention provides a switching means for switching the compressor to be driven by either a commercial power supply or an inverter, and a switching means for switching the switching means to the inverter when the compressor is turned off. By providing a control circuit for stopping the apparatus, desired control of the switching portion of the large current circuit through which the current of the compressor flows can be realized with a minimum configuration of only the switching means.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram of an operation control device for a refrigerator or the like according to an embodiment of the present invention, and FIG. 2 is a timing diagram for the configuration of FIG. 1. 1...Commercial power supply, 2...Compressor, 3.
...Switching means, 4...Inverter device, 8.
...Zero cross detection circuit, 9...Control circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
figure

Claims (1)

[Claims] an inverter device that converts the frequency of the commercial power source; a switching device that switches the compressor to be driven by either the inverter device or the commercial power source; and a switching device that switches the switching device to the inverter device side when the compressor is off, and An operation control device for a refrigerator, etc., which is equipped with a control circuit that stops the device.