JP3535073B2 - Control device for inverter equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for inverter equipment. In particular, it relates to a configuration of connection between a control circuit and an inverter circuit in an inverter device and reduction of standby power.

[0002]

2. Description of the Related Art A conventional inverter control device mounted on a washing machine will be described as an example with reference to FIG.
The power switch 8 is a push switch having a NO contact that is closed when pressed and is opened when not pressed, and an NC contact that is closed when not pressed and opened when pressed. The power switch 8 is usually arranged on an operation panel provided on the upper part of the washing machine body.

First, when the power switch 8 is pressed, the NO contact of the power switch 8 is closed, and the AC power supply 1 and the rectifying diode 9 are connected. As a result, an AC voltage is supplied from the AC power supply 1 to the rectifier diode 9. This AC voltage becomes a DC voltage half-wave rectified by the rectifying diode 9, and is further smoothed by the capacitor 10. The smoothed DC voltage is stepped down and stabilized by the power supply circuit 11 and supplied to the control circuit 13.

The control circuit 13 starts its operation by the voltage supply from the power supply circuit 11, and closes the contact of the power supply relay 7 via the power supply relay means 14. The closed state of the power supply relay 7 is self-maintained until a signal for turning off the power supply relay 7 is output from the control circuit 13 to the power supply relay 7 via the power supply relay means 14.

Therefore, once the power supply relay 7 is closed, the voltage is supplied from the AC power supply 1 to the control circuit 13 via the contact of the power supply relay 7 even if the pressing of the power supply switch 8 is released thereafter. The operation of the control circuit 13 can be continued.

On the other hand, when the power switch 8 is pressed, the rectifier circuit 3 in which the four diodes 3a to 3d are bridge-connected
Is also connected to the AC power supply 1. As a result, the AC voltage is also supplied from the AC power supply 1 to the rectifier circuit 3. Even if the pressing of the power switch 8 is released, the contact of the power relay 7 is in the closed state as described above, so that the supply of the AC voltage is continued via the contact of the power relay 7.

This AC voltage becomes a DC voltage rectified by the rectifying circuit 3, and is further smoothed by the capacitor 4.
The inverter motor drive circuit 5 drives the motor 6 based on the control signal from the control circuit 13 using the smoothed DC voltage as an input voltage. The control circuit 13 includes a memory 13A that stores an operation program in advance, and the inverter motor drive circuit 5 is based on the operation program.
Send a control signal to. Since the control signal output from the control circuit 13 has a different reference potential (negative potential) from the control circuit 13 and the inverter motor drive circuit 5, the photo coupler circuit 17 converts the voltage level to drive the inverter motor. Sent to the circuit 5. Photo coupler circuit 1
7 is formed by arranging the light emitting diode 15 and the phototransistor 16 close to each other.

In this way, the motor 6 is controlled by the control circuit 13
It is driven according to the operation program stored in advance in the memory 13A provided in the. Similarly, the water supply valve and the drain valve (not shown) are also opened / closed according to the operation program stored in advance in the memory 13A provided in the control circuit 13. As a result, the washing machine performs a series of operations including washing, rinsing, and dehydration.

When the series of operations of washing, rinsing, and dehydration are completed, the control circuit 13 opens the contacts of the power supply relay 7 via the power supply relay control means 14. As a result, the control circuit 13 and the inverter motor drive circuit 5 are cut off from the AC power supply 1, respectively, and power consumption during non-operation in each circuit, that is, standby power does not occur.

The power supply filter circuit 2 is a low-pass filter circuit that prevents noise (several to several tens of kHz) generated by switching of the transistors forming the inverter motor drive circuit 5 from entering the AC power supply 1.

[0011]

In the above conventional circuit configuration, the photocoupler circuit 17 is required because the reference potential (negative side potential) of the control circuit 13 and the inverter drive circuit 5 are different. Therefore, the circuit configuration is complicated and the cost is high.

Since the power supply filter circuit 2 is provided between the AC power supply 1 and the contact of the power supply relay 7, even if the contact of the power supply relay 7 is in the open state, the power supply filter circuit 2 has the AC power supply 1 Was still connected, consuming a small amount of power. Therefore, the standby power could not be reduced to zero.

In view of the above problems, it is an object of the present invention to provide a control device for an inverter device, which has a simple and inexpensive circuit structure and reduces standby power to zero.

In order to achieve the above object, a control device for an inverter device according to the present invention comprises rectifying means for rectifying an AC voltage supplied from an AC power source,
A capacitor for smoothing the rectified voltage supplied from the means,
Stabilizes the DC voltage output from the capacitor
The power supply means and the voltage supplied from the power supply means are the power supply voltage
And a control means for supplying the load to the load
The reference potential is common with the inverter means whose voltage is controlled.
Are connected so that they are closed when pressed and not pressed.
A push switch with a first contact that opens
The control means is provided between the AC power supply and the rectifying means.
Relay contacts controlled by the push switch
With a semiconductor switching element that opens and closes according to the open / close state of
In addition to providing the switch means consisting of the parallel circuit of
When the push switch is pressed, the semiconductor switch
The switching element is closed and the control means controls the relay
The contact of the
Upon completion, the control means opens the relay contacts.
I am trying to

[0015] With this configuration, since the reference potential of the control unit and the inverter unit is identical, the photocoupler circuit is no longer required, cost reduction for the voltage level conversion
Can be achieved. In addition, the adjustment supplied from the rectification means
Since the capacitor that smoothes the flow voltage has a large capacity,
When charging, a large charging current flows, but in such a configuration
By switching the large charging current to semiconductor switching
The capacitor can be supplied through the element. Obey
The push switch with a relatively inexpensive switch with a small current capacity.
Can be This will reduce costs
Be done. Also, the current flowing through the push switch is small.
Therefore, the contact life of the push switch is extended.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment of the present invention will be described with reference to FIG. In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals.

The power switch 8 has an NO contact which is closed when pressed and opened when not pressed. When the power switch 8 is pressed, the AC power supply 1 is connected to the rectifier circuit 3 via the NO contact. As a result, the AC voltage is supplied from the AC power supply 1 to the rectifier circuit 3.

The rectifying circuit 3 rectifies the AC voltage to convert it into a DC voltage, and then supplies it to the capacitor 4. The capacitor 4 smoothes the rectified voltage and supplies it to the power supply circuit 11. The rectifier circuit 3 and the capacitor 4 form a full-wave rectifier circuit, but the present invention is not limited to this embodiment. For example, when the voltage supplied to the motor 6 is increased, a double voltage rectifier circuit is used. Good.

The power supply circuit 11 steps down and stabilizes the smoothed DC voltage supplied from the capacitor 4, and then supplies it to the control circuit 13. The power supply circuit 11 is a continuous control type DC voltage stabilizing power supply circuit as shown in FIG. In this circuit, the output voltage is stabilized by utilizing the voltage drop between the collector and the emitter of the transistor 20. The output voltage supplied to the control circuit 13 is the Zener diode 22.
It is determined by the breakdown voltage (Zener voltage) and the resistors R1 and R2. Reference numeral 23 is an input-side + terminal, 24 is an output-side + terminal, and 25 is a-terminal common to input and output.

In the present embodiment, the power supply circuit 11
Although the power supply circuit is a continuous control type power supply circuit, a switching control type power supply circuit may be used. Since the power supply circuit of the switching control system can stabilize the output voltage by the switching operation of the transistor, the power loss becomes significantly smaller than that of the continuous control system. Further, the switching control type power supply circuit can be integrated.

The control circuit 13 receives the DC voltage that has been stepped down and stabilized by the power supply circuit 11, and starts its operation. The control circuit 13 closes the contacts of the power supply relay 7 via the power supply relay control means 14 with the start of the operation. The closed state of the power supply relay 7 is self-maintained until a signal for turning off the power supply relay 7 is output from the control circuit 13 to the power supply relay 7 via the power supply relay means 14.

Therefore, once the power supply relay 7 is closed, the voltage is continuously supplied from the AC power supply 1 to the control circuit 13 via the contact of the power supply relay 7 even if the pressing of the power supply switch 8 is released thereafter. The operation of the control circuit 13 can be continued.

The control circuit 13 is provided with a memory 13A in which an operation program is stored in advance. Based on this operation program, the control signal S is sent to the inverter motor drive circuit 5.
Send 1. The inverter motor drive circuit 5 drives the motor 6 based on the control signal S1. Similarly, the water supply valve and the drain valve (not shown) are also opened / closed according to the operation program stored in advance in the memory 13A provided in the control circuit 13. As a result, the washing machine performs a series of operations including washing, rinsing, and dehydration.

When the series of operations of washing, rinsing and dehydration are completed, the control circuit 13 opens the contact of the power supply relay 7 via the power supply relay control means 14 to cut off the AC power supply 1. Since the reference potential of the control circuit 13 and the inverter drive circuit 5 is common to the negative potential of the capacitor 4, it is not necessary to convert the voltage level of the control signal S1 sent from the control circuit 13 to the inverter drive circuit 5.

Next, the inverter motor drive circuit 5 will be described with reference to FIG. The inverter motor drive circuit 5 includes an inverter 30, a drive circuit 31, and a microcomputer 32. Terminal 33 is + of capacitor 4
The terminal 34 is connected to the negative side of the capacitor 4. The reference potential (negative potential) of the inverter 30, the drive circuit 31, and the microcomputer 32 is common to the reference potential (negative potential) of the control circuit 13 connected via the terminal 34.

The inverter 30 has six NPN type transistors 26a to 26c and 27a to 2 as switching means.
7c has a three-phase full-wave bridge configuration. Then, the six transistors 26a to 26c and 27a to 27c
In parallel with diodes 28a-28c, 29a-
29c is connected. Transistors 26a-26c
And the connection points a, b, and c of the transistors 27a to 27c are connected to the respective phases (U phase, V
Phase, W-phase) stator coil. Also,
The bases of the transistors 26a to 26c and 27a to 27c are connected to the drive circuit 31.

The microcomputer 32 is a control circuit 13
Drive signals P1 to P based on the control signal S1 output from
6 is output to the drive circuit 31. The drive circuit 31 PWM-chops and amplifies the drive signals P1 to P6 at several to several tens of kHz and amplifies them by the transistors 26a.
To 26c and 27a to 27c. As a result, the transistors 26a to 26c and 27a to 27c are switched, and a sinusoidal voltage having an arbitrary frequency can be supplied to the motor 6.

The power switch 8 also has an NC contact which is closed when not pressed and opened when pressed. Therefore, when the power switch 8 is pressed while the inverter device is in operation, the NC contact is opened and the signal sent from the NC contact to the control circuit 13 via the switch detection means 12 is cut off. The control circuit 13 detects the interruption of this signal, stops the operation of the inverter device, and then opens the contact of the power supply relay 7 via the power supply relay means 14.
As a result, the control circuit 13 and the inverter motor drive circuit 5 are disconnected from the AC power supply 1. Further, unlike the above-described conventional inverter device control device, since the contact of the power supply relay 7 is provided between the AC power supply 1 and the power supply filter circuit 2, in the inverter device control device of the present embodiment, the power supply filter circuit is provided. 2 is also cut off from the AC power supply 1 during standby. As a result, the power consumption during non-operation, so-called standby power, becomes zero.

The power supply filter circuit 2 is a low-pass filter circuit that prevents noise (several to several tens of kHz) generated by switching of the transistors constituting the inverter motor drive circuit 5 from entering the AC power supply 1. As shown in FIG. 6, it is composed of a capacitor 36 and a reactor 37. The terminal 38 is connected to the AC power supply 1 side, and the terminal 39 is connected to the rectifier circuit 3 side. The power supply filter circuit 2
Is not limited to this configuration, and may be any filter circuit that prevents noise generated in the inverter motor drive circuit 5 from entering the AC power supply 1.

Next, a second embodiment of the control device for the inverter equipment according to the present invention will be described with reference to FIG. In FIG. 3, the same parts as those in FIG. 2 are designated by the same reference numerals.

First, when the power switch 8 is first pressed, the NO contact is closed. Power switch 8 NO
When the contact is closed, a trigger signal is sent from the gate trigger circuit 19 to the gate of the triac 18, and the triac 18 becomes conductive. Through the triac 18, the capacitor 4 is initially charged. When the pressing of the power switch 8 is released, the NO contact is opened, and the gate trigger circuit 19 is accordingly closed by the triac 1.
Triac 1 stops sending trigger signal to gate 8
8 is no longer conducting. Other configurations and operations are the same as those in the first embodiment, and therefore description thereof will be omitted.

Since the capacitor 4 has a large capacity, a large charging current flows when the power is turned on. With such a structure, the large charging current can be supplied to the capacitor 4 via the triac 18. Therefore, the power switch 8 only controls the gate of the triac 18, and only a small current flows. This allows the power switch 8
Can be a relatively inexpensive switch with a small current capacity. Also, since the current flowing through the power switch 8 is small,
The life of the contacts of the power switch 8 is also improved.

The above description is for the case where the control device for an inverter device according to the present invention is applied to a washing machine, but the present invention is not limited to this embodiment, and other inverters having an inverter are provided. It can also be applied to electrical equipment.

[0034]

According to the present invention, the reference potential is common between the control means which uses the voltage supplied from the power supply means as the power supply voltage and the inverter means which controls the voltage supplied to the load by the control means. Connected to the inverter means, it is not necessary to convert the voltage level of the control signal sent from the control means to the inverter means. As a result, a photocoupler circuit for converting the voltage level of the control signal is not needed, and the cost can be reduced. Furthermore, an AC power source and a rectifying means
Between the relay contacts and the push switch open / closed state
Is it a parallel circuit with a semiconductor switching element that opens and closes according to
Switch means consisting of
When the switch is pressed, the semiconductor switching element is closed.
And the control means closes the relay contacts,
When the memorized operation is completed, the control means
Since the contacts are opened, the adjustment supplied from the rectifying means
Since the capacitor that smoothes the flow voltage has a large capacity,
A large charging current flows when the power is turned on, but the large charging current
Supply the current to the capacitor via the semiconductor switching element
can do. Therefore, push switch
It can be an inexpensive switch with a small current capacity. this
As a result, cost reduction can be achieved. Also push switch
Because the current that flows in the
The life is also improved.

[0035]

[0036]

[0037]

Further, according to the present invention, since the semiconductor switching element is a triac, the signal sent to the gate functions as a trigger regardless of whether the signal is positive or negative. As a result, the gate trigger circuit provided between the push switch and the gate of the semiconductor switching element can be simplified and the cost can be reduced.

Further, according to the present invention, since the filter circuit is provided between the switch means and the rectifier circuit, it is possible to prevent noise generated in the inverter means from entering the AC power supply. Further, since the switch means is provided closer to the AC power supply side than the filter circuit, it is possible to eliminate power consumption in the filter circuit when not operating.
As a result, even when the filter circuit is provided, the power consumption during non-operation, so-called standby power, can be reduced to zero, and energy saving can be achieved.

Further, according to the present invention, the push switch is in the closed state when not pressed and in the open state when pressed.
When the push switch is pressed while the inverter device is operating, the control means stops the operation of the inverter device and then opens the contact of the relay, so that one push switch can be used to power the inverter device. It can be turned on and off. This improves the operability of the inverter device.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a conventional control device for an inverter device.

FIG. 2 is a diagram showing a configuration of a control device for an inverter device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a control device for an inverter device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a power supply circuit in FIG.

5 is a diagram showing a configuration of an inverter motor drive circuit in FIG.

FIG. 6 is a diagram showing a configuration of a power supply filter circuit in FIG.

[Explanation of symbols]

1 AC power supply 2 Power supply filter circuit 3 rectifier circuit 3a-3d diode 4 capacitors 5 Inverter motor drive circuit 6 motor 7 power relay 8 power switch 9 Rectifier diode 10 capacitors 11 power supply circuit 12 Power switch detection means 13 Control circuit 14 Power relay control means 15 Light emitting diode 16 phototransistor 17 Photocoupler circuit 18 TRIAC 19 Gate trigger circuit 20 transistors 21 transistor 22 Zener diode 23 terminals 24 terminals 25 terminals 26a-26c transistors 27a to 27c transistors 28a-28c diode 29a-29c diode 30 inverter 31 Drive circuit 32 microcomputer 33 terminals 34 terminals 35a to 35c terminals 36 capacitors 37 reactor 38 terminals 39 terminals P1 to P6 drive signals R1 to R4 resistance S1 control signal

Claims (4)

(57) [Claims] 1. A capacitor for rectifying an AC voltage supplied from an AC power supply, a capacitor for smoothing the rectified voltage supplied from the rectification unit, and a power supply for stepping down and stabilizing a DC voltage output from the capacitor. The means, the control means that uses the voltage supplied from the power supply means as the power supply voltage, and the inverter means that controls the voltage supplied to the load by the control means are connected so that the reference potential is common, and the pressing means is connected. Sometimes closed and open when not pressed
A push switch having a contact, between the AC power source and the rectifying means,
Controlled relay contacts and opening / closing of the push switch
Parallel with semiconductor switching element that opens and closes according to the state
A switch means including a circuit is provided, and when the push switch is pressed , the semiconductor switch is pressed.
The pendulum element is closed and the control means
When the relay contacts are closed and the driving operation stored in advance is completed, the control means
A control device for an inverter device, wherein a contact of the relay is opened . 2. The semiconductor switching device is a triad.
Control device for an inverter device according to claim 1, characterized in that the click. 3. Between the switch means and the rectifying means
In addition, noise generated in the inverter means is caused by the AC power supply.
That a filter means is installed to prevent
The control device for an inverter device according to claim 1 or 2, which is characterized . 4. The push switch is in a closed state when not pressed.
And has a second contact that is in the open state when pressed.
By the way, while the inverter device is operating, the push switch
When pressed, the control means energizes the second contact.
Of the inverter device is detected,
After stopping the rotation, open the contact of the relay.
The control device for an inverter device according to any one of claims 1 to 3, wherein: