WO2018131768A1

WO2018131768A1 - Phase control apparatus and phase control method using same

Info

Publication number: WO2018131768A1
Application number: PCT/KR2017/009423
Authority: WO
Inventors: 임금성
Original assignee: 주식회사 모스트파워; 임금성
Priority date: 2017-01-11
Filing date: 2017-08-29
Publication date: 2018-07-19
Also published as: KR101793698B1

Abstract

The present invention relates to a phase control apparatus and a phase control method using the same. The phase control apparatus comprises: a voltage distribution unit connected to a load for distributing a voltage across the load during phase control; a switching unit for performing ON control or OFF control; a discharge circuit unit for discharging energy generated by counter electromotive force during the OFF control; and a control unit for controlling operations of the switching unit, the voltage distribution unit, and the discharge circuit unit. Thus, the present invention has an effect of being capable of performing more efficient phase control by eliminating, through a single circuit, impulse noise that may occur during the ON control and inductive kickback that may occur during the OFF control, and also has an effect of being capable of performing power saving control by sequentially performing the ON control and the OFF control within one period.

Description

Phase control device and phase control method using the same

The present invention relates to a phase control method, and more particularly, to a phase control apparatus and a phase control method using the same so that no impulse noise and inductive kickback occur.

Current that changes in magnitude and direction periodically with time is called alternating current, and voltage that changes in magnitude and direction periodically with time is called alternating current voltage.

An AC power source having a sinusoidal wave shape may have various frequencies, but generally, an AC power source having a frequency of 50 Hz or 60 Hz is used. In the case of 60Hz, which is mainly used at present, the half cycle time is 8.33ms and the phase angle corresponds to 0 ° ~ 180 °.

In general, phase control refers to controlling only a part of all sinusoidal inputs to be output based on a half cycle with respect to an AC voltage. Such phase control methods include a phase on control method and a phase off control method.

The phase on control method does not output a voltage (or current) signal for a predetermined time from the zero crossing time point, and then controls to output a voltage (or current) when a specific time point is reached. That is, since there is no output signal for a predetermined time from the zero crossing time point and output starts at a specific time point, this is called phase-on control.

On the other hand, the phase-off control method outputs a voltage (or current) signal for a predetermined time from the time of zero crossing, and then controls not to output the voltage (or current) when the specific time is reached. That is, since the signal is continuously output from the time of zero crossing and the output is cut off at a specific time, this is called phase-off control.

1 shows an example of a signal waveform according to phase on control.

Referring to FIG. 1, the AC voltage is cut off from the first zero crossing point T11 to the on control point T12. On the other hand, the AC voltage signal starts to be output as soon as the on-control time point T12 is reached, and the output of the AC voltage is continued until the second zero crossing point (phase angle 180 °) T13. Then, the output of the AC voltage is cut off from the second zero crossing time point (phase angle 180 °) T13. The AC voltage is output again from the moment when the on-control time point T14 is reached, and the output of the AC voltage continues until the third zero crossing time point T15 (phase angle 360 °).

The phase on control method as described above has the following problems.

Phase on control is to perform the switching on operation at a certain time point with respect to the alternating AC voltage. Therefore, when a sudden switching on operation is performed at a high voltage, impulse noise and overcurrent occur.

Such impulse noise and overcurrent not only can seriously damage the load device but also generate EMI.

Therefore, the phase-on control method according to the prior art has a problem that is used only in limited fields, such as illumination illumination control or temperature controller.

2 shows an example of a signal waveform according to phase off control.

Referring to FIG. 2, an AC voltage is output from the first zero crossing point T21 to the off control point T22. Then, the AC voltage starts to be cut off from the OFF control point T22, and the AC voltage is cut off until the second zero crossing point (phase angle 180 °) T23. Then, the AC voltage output starts from the second zero crossing time T23 and continues until the off control time T24. The output of the AC voltage is cut off from the off control point T24 to the instant (phase angle 360 °) of the third zero crossing point T25.

The phase off control method as described above has the following problems.

The most serious problem of the phase off control method is the inductive kickback phenomenon. Inductive kickback is a phenomenon in which counter electromotive force occurs when a voltage signal is input to an inductive load and then suddenly switched off.

3 shows an example of a waveform of an inductive kickback.

As shown in FIG. 3, when the

inductive kickbacks

31, 32, and 33 occur during the off-control operation T31, T32, and T33, a large hit may be applied to the load by suddenly generated counter electromotive force. . Therefore, due to the inductive kickback phenomenon as described above, the phase off control method is generally not used.

An object of the present invention is to enable efficient on and off control by eliminating impulsive noise and inductive kickback, which are a problem in on and off control. It is also an object of the present invention to be able to freely perform on control and off control within a period.

According to an aspect of the present invention, there is provided a phase control apparatus including a voltage divider connected to a load so as to distribute a voltage applied to a load during phase control, a switching unit for performing on or off control, and an off control. And a control unit for controlling the operation of the switching unit, the voltage distribution unit, and the discharge circuit unit to discharge energy generated by the counter electromotive force at the time.

In addition, the phase control method according to the present invention for solving the above technical problem, in the phase control apparatus, comprising the step of turning on the voltage divider, the step of turning on the switching unit and the step of turning off the voltage divider. It is done by

The present invention has an effect of performing phase control more efficiently by removing impulse noise and inductive kickback generated during on control and off control.

In addition, the present invention has the effect of performing an effective phase control by sequentially performing the on control and off control in one period.

1 shows an example of a signal waveform according to phase on control.

2 shows an example of a signal waveform according to phase off control.

3 shows an example of a waveform of an inductive kickback.

Figure 4 shows an embodiment of a phase on control device according to the present invention.

5 illustrates an embodiment of a voltage divider.

FIG. 6 illustrates signal waveforms according to the operation of the phase on controller of FIG. 4.

7 shows an embodiment of a phase control apparatus according to the present invention.

8 illustrates an embodiment of a voltage divider.

9 shows an embodiment of a discharge circuit portion.

FIG. 10 illustrates signal waveforms according to the operation of the phase control apparatus when the phase off control is performed using the phase control apparatus of FIG. 7.

11 shows signal waveforms according to the operation of the phase controller when the phase off control is performed at a voltage higher than the reference voltage.

12 illustrates a signal waveform according to the operation of the phase controller when the phase off control is performed at a voltage lower than the reference voltage.

13 shows signal waveforms according to the operation of the phase controller when the phase off control is performed at a voltage higher than the reference voltage.

The phase control apparatus according to the present invention includes a voltage divider connected to the load so that the voltage applied to the load is distributed during phase control, a switching unit for performing on or off control, and energy generated by back EMF during off control. And a control unit for controlling the operation of the discharge circuit unit for discharging the switching unit, the voltage distribution unit, and the discharge circuit unit.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 4, an embodiment of the phase-on control device 40 according to the present invention includes a zero crossing detection unit 41, a switching unit 42, a voltage distribution unit 43, and a control unit 44. Is done.

In FIG. 4, a single phase has been described as an embodiment, but the present invention can be applied to a single phase as well as a single phase.

5 illustrates an embodiment of the voltage divider 43.

As shown in FIG. 5, the voltage divider 43 includes a resistive element 431 and a switching element 432. In this case, the resistance value of the resistive element 431 is preferably very large compared to the resistance value of the load 46.

6 illustrates an output signal waveform according to the operation of the phase on controller 40 of FIG. 4.

Hereinafter, with reference to FIG. 6, the operation of the phase on control device 40 according to FIG.

The switching unit 42 is controlled to be in a switching off state from the first zero crossing time point T41 to the on control time point T42. That is, the controller 44 detects the first zero crossing point T41 through the zero crossing detection unit 41, and controls the switching unit 42 to perform a switching off operation at the first zero crossing point T41. do.

On the other hand, the switching element 432 of the voltage divider 43 performs a switching-on operation at the first zero crossing point T41 under the control of the controller 44 and is closed until the on control point T12. Therefore, the voltage signal supplied from the input terminal is caught by the resistive element 431 and the load 46 of the voltage divider 43. At this time, when the resistance value of the resistive element 431 is much larger than the resistance value of the load 46, most of the voltage is applied to the resistive element 431 of the voltage divider 43 according to the law of voltage division. .

When the controller 44 turns on the switching unit 42 at the on-control time point T42, the voltage signal supplied from the input terminal is input toward the load 46.

The switching element 432 of the voltage distribution unit 43 performs a switching off operation at the time of switching on operation of the switching unit.

In this case, the point in time at which the switching element 432 of the voltage divider 43 performs the switching off operation may be performed simultaneously with the switching on operation of the switching unit 42, or immediately before the switching on operation of the switching unit 42. Can be.

However, in order to prevent impulse noise caused by the switching-on operation of the switching unit 42, the switching element 432 of the voltage distribution unit 43 is turned on for a while even after the switching unit 42 performs the switching-on operation. It is preferable to control to maintain the state and to perform the switching off operation when a certain time point. That is, the switching off operation of the switching element 432 is preferably performed immediately after the switching on operation of the switching unit 42.

The switching element 432 of the voltage divider 43 maintains a switching off state and performs a switching on operation when the second zero crossing point T43 is reached.

That is, when the controller 44 detects the second zero crossing point T43 through the zero crossing detection unit 41, the control unit 44 controls the switching element 432 of the voltage distribution unit 43 to perform a switching on operation. .

Meanwhile, the switching unit 42 maintains the switching on state from the on control time point T42, and performs a switching off operation at the second zero crossing time point T13. That is, when the controller 42 detects the second zero crossing point T43 through the zero crossing detection unit 41, the control unit 42 controls the switching unit 42 to perform a switching off operation.

Referring to FIG. 7, one embodiment of the phase control device 70 according to the present invention includes a zero crossing detection unit 71, a switching unit 72, a control unit 74, a voltage divider 73, and a discharge circuit unit ( 75).

In FIG. 7, a single phase has been described as an embodiment, but the present invention can be applied to a single phase as well as a single phase.

8 illustrates an embodiment of the voltage divider 73.

As shown in FIG. 8, the voltage divider 73 includes a resistive element 731 and a switching element 732. At this time, the resistance value of the resistive element 731 is preferably very large compared to the resistance value of the load 46.

9 shows an embodiment of the discharge circuit unit 75.

As shown in FIG. 9, the discharge circuit unit 75 includes a discharge element 751 and a switching element 752. At this time, the discharge element 751 is a resistive element, and the resistance value of the discharge element 751 preferably has a value that is very small compared to the resistance value of the load 76.

FIG. 10 illustrates signal waveforms according to the operation of the phase controller when the phase off control is performed by using the phase controller 70 of FIG. 7. In particular, FIG. 10 shows the output signal waveform when the phase off control is performed at a voltage lower than a predetermined reference voltage.

Hereinafter, the operation of the phase control apparatus according to FIG. 7 will be described with reference to FIG. 10.

The switching unit 72 is controlled to be in a switching on state from the first zero crossing time point T51 to the off control time point T52. That is, the controller 74 detects the first zero crossing point T51 through the zero crossing detection unit 71, and controls the switching unit 72 to perform a switching-on operation at the first zero crossing point T21. do.

Under the control of the controller 74, when the switching unit 72 performs the switching off operation at the off control time point T52, the voltage signal supplied to the load 76 from the input terminal is cut off.

In order to prevent inductive kickback caused by the switching off operation of the switching unit 72, the controller 74 controls the switching element 752 of the discharge circuit unit 75 to perform the switching on operation. When the switching unit 72 performs the switching on operation, the counter electromotive force energy generated by the switching off operation of the switching unit 72 is dissipated through the discharge element 751 of the discharge circuit unit 75.

The controller 74 may control the switching element 752 to perform the switching on operation at the time T52 at which the switching unit 72 performs the switching off operation, or immediately before or after the switching off operation. However, it is preferable that the time of performing the switching off operation of the switching element 752 is immediately after the switching off operation of the switching unit 72.

The switching element 752 of the discharge circuit unit 75 maintains the switching on state immediately after the off control time point T52, and performs a switching off operation at the second zero crossing time point T53.

That is, when the controller 74 detects the second zero crossing point T53 through the zero crossing detection unit 71, the control unit 752 of the discharge circuit unit 75 performs a switching off operation at that point. do.

As in the case of FIG. 10, when the phase-off control is performed at a voltage lower than a predetermined reference voltage, the controller 74 controls the switching element 732 of the voltage divider 73 to be always open.

FIG. 11 performs phase off control using the phase control device 70 shown in FIG. 7, but when the phase off control is performed at a voltage higher than a predetermined reference voltage, the phase control device 70 shown in FIG. ) Shows the output signal waveform according to the operation of.

Hereinafter, the operation of the phase control apparatus 70 according to FIG. 7 will be described with reference to FIG. 11.

The switching unit 72 is controlled to be in a switched on state from the first zero crossing time point T61 to the off control time point T62. That is, the controller 74 detects the first zero crossing point T61 through the zero crossing detection unit 71, and controls the switching unit 72 to perform a switching-on operation at the first zero crossing point T61. do.

As shown in FIG. 11, the input voltage at the off control time point T62 is higher than the reference voltage. In this situation, when the switching unit 72 performs the off operation, there is a problem in that only the discharge circuit unit 75 cannot remove all the counter electromotive force energy generated by the high voltage. Therefore, it is necessary to drop the voltage applied to the discharge circuit portion 75 by using the voltage divider 73.

Therefore, the control unit 74 controls the switching element 732 of the voltage distribution unit 73 to perform the switching-on operation immediately before the off control time point T62, so that the voltage applied to the discharge circuit unit 75 is below the reference voltage. Lower

When the switching unit 72 performs the switching off operation at the off control time point T62, the voltage signal supplied to the load 76 from the input terminal is cut off.

When the switching-off operation by the switching unit 72 is performed, in order to prevent the inductive kickback caused by this, the control unit 74 controls the switching element 752 of the discharge circuit unit 75 to perform the switching on operation. . Therefore, when the switching unit 72 performs the switching off operation, the counter electromotive force energy generated by the switching off operation of the switching unit 72 is dissipated through the discharge element 751 of the discharge circuit unit 75.

The controller 74 preferably controls the switching element 752 of the discharge circuit unit 75 to perform the switching on operation immediately after the switching off operation time T62 of the switching unit 72.

The control unit 74 controls the switching element 732 of the voltage distribution unit 73 to perform the switching off operation immediately after the switching element 752 of the discharge circuit unit 75 performs the switching on operation. desirable.

On the other hand, the switching element 752 of the discharge circuit unit 75 maintains the switching on state immediately after the off control time point T22, and performs a switching off operation at the second zero crossing time point T63.

That is, when the controller 74 detects the second zero crossing point T63 through the zero crossing detection unit 71, the control unit 752 of the discharge circuit unit 75 performs a switching off operation at that point. do.

In addition, when the controller 74 detects the second zero crossing point T63, the control unit 74 controls the switching unit 72 to perform a switching on operation at that point, and the switching unit 72 controls the next off control point T64. Keep switching on until

FIG. 12 illustrates output signal waveforms according to the operation of the phase controller when the phase control is performed using the phase controller 70 of FIG. 7. In particular, FIG. 12 illustrates an output signal waveform when the phase on control and the phase off control are sequentially performed within a half period, and the phase off control is performed at a voltage lower than a predetermined reference voltage.

Hereinafter, an operation of the phase control apparatus according to FIG. 7 will be described with reference to FIG. 12.

As shown in FIG. 12, in the phase control method according to the present embodiment, phase on control and phase off control are sequentially performed within a half period. In addition, although not shown in the drawing, phase-off control and phase-on control may be sequentially performed within a half period. 12 is an embodiment where both phase on control and phase off control are performed at or below a predetermined reference voltage.

First, the switching unit 72 is controlled to be in a switched off state from the first zero crossing time point T71 to the on control time point T72. That is, the controller 74 detects the first zero crossing point T71 through the zero crossing detection unit 71 and controls the switching unit 72 to maintain the switching off state at the first zero crossing point T71. do.

On the other hand, the switching element 732 of the voltage divider 73 performs a switching-on operation at the first zero crossing point T71 under the control of the control unit 74 and closes to the on control point T72. Therefore, the voltage signal supplied from the input terminal is applied to the resistive element 731 and the load 76 of the voltage divider 73. At this time, when the resistance value of the resistive element 731 is much larger than the resistance value of the load 76, most of the voltage is applied to the resistive element 731 of the voltage divider 73 according to the law of voltage division.

When the controller 74 controls the switching unit 72 to perform the switching on operation at the on control time point T72, the voltage signal supplied from the input terminal is output toward the load 76.

In this case, the point in time at which the switching element 732 of the voltage distribution unit 73 performs the switching off operation may be performed simultaneously with the switching on operation of the switching unit 72 or immediately before the switching on operation of the switching unit 72. Can be.

However, in order to prevent impulse noise generated due to the switching-on operation of the switching unit 72, the switching element 732 of the voltage distribution unit 73 is turned on for a while even after the switching unit 72 performs the switching-on operation. It is preferable to control to maintain the state and to perform the switching off operation when a certain time point. That is, the switching off operation of the switching element 732 is preferably performed immediately after the switching on operation of the switching unit 72.

The switching unit 72 maintains the switching on state from the on control time point T72 to the off control time point T73.

Under the control of the controller 74, when the switching unit 72 performs the switching off operation at the off control time point T73, the voltage signal supplied to the load 76 from the input terminal is cut off.

In order to prevent inductive kickback caused by the switching-off operation of the switching unit 72, the controller 74 allows the switching element 752 of the discharge circuit unit 75 in the switching-off state to perform the switching-on operation. To control. Therefore, when the switching unit 72 performs the switching off operation, the counter electromotive force energy generated by the switching off operation of the switching unit 72 is dissipated through the discharge element 751 of the discharge circuit unit 75.

In this case, the controller 74 preferably controls the switching device 752 of the discharge circuit unit 75 to perform the switching on operation immediately after the switching off operation time T73 of the switching unit 72.

The switching element 752 of the discharge circuit unit 75 maintains the switching on state immediately after the off control time point T43, and performs a switching off operation at the second zero crossing time point T74.

That is, when the controller 74 detects the second zero crossing point T74 through the zero crossing detection unit 71, the control unit 752 of the discharge circuit unit 75 performs a switching off operation at that point. do.

In addition, the controller 74 controls the switching device 732 of the voltage distribution unit 73 in the switched off state to perform a switching on operation at the second zero crossing time point T74.

On the other hand, the switching unit 72 that performs the switching off operation at the off control time point T73 maintains the switching off state until the next on control time point T75.

FIG. 13 illustrates output signal waveforms according to the operation of the phase controller when the phase control is performed by using the phase controller 70 of FIG. 7. In particular, FIG. 13 shows a signal waveform when the phase on control phase off control is sequentially performed within a half period, and the phase off control is performed at a voltage higher than a predetermined reference voltage.

Hereinafter, an operation of the phase control apparatus according to FIG. 7 will be described with reference to FIG. 13.

As shown in Fig. 13, in the phase control method according to the present embodiment, phase on control and phase off control are sequentially performed within a half period. In addition, although not shown in the drawing, phase-off control and phase-on control may be sequentially performed within a half period. This embodiment is an embodiment where the phase off control is performed above a predetermined reference voltage.

First, the switching unit 72 maintains the switching off state from the first zero crossing time point T81 to the phase on control time point T82. That is, the controller 74 detects the first zero crossing point T81 through the zero crossing detection unit 71, and controls the switching unit 72 to maintain the switching off operation at the first zero crossing point T81. do.

On the other hand, the switching element 732 of the voltage divider 73 performs a switching on operation at the first zero crossing point T81 under the control of the controller 74 and closes to the phase on control point T82. Since it is in the state, the voltage signal supplied from the input terminal is caught by the resistive element 731 and the load 76 of the voltage divider 73. At this time, when the resistance value of the resistive element 731 is much larger than the resistance value of the load 76, most of the voltage is applied to the resistive element 731 of the voltage divider 73 according to the law of voltage division.

Under the control of the controller 74, when the switching unit 72 performs the switching on operation at the phase-on control time point T82, the voltage signal supplied from the input terminal is output toward the load 76.

As shown in Fig. 13, the input voltage at the phase off control time point T83 is higher than the reference voltage. In this situation, when the switching unit 72 performs the off operation, there is a problem in that only the discharge circuit unit 75 cannot remove all the counter electromotive force energy generated by the high voltage. Therefore, it is necessary to drop the voltage applied to the discharge circuit portion 75 by using the voltage divider 73.

Therefore, the control unit 74 controls the switching element 732 of the voltage distribution unit 73 to perform the switching-on operation immediately before the phase-off control time point T83, thereby reducing the voltage applied to the discharge circuit unit 75 to a reference voltage or less. Drop to.

When the switching unit 72 performs the switching off operation at the phase off control time point T83, the voltage signal supplied to the load 76 from the input terminal is cut off under the control of the controller 74.

At this time, the controller 74 preferably controls the switching element 752 of the discharge circuit unit 75 to perform the switching on operation immediately after the switching off operation time T83 of the switching unit 72.

That is, the voltage divider 73 performs a switching-on operation immediately before the switching-off time point T83 for phase-off control, and immediately after the switching element 752 of the discharge circuit unit 75 performs the switching-on operation. It is desirable to perform the off operation.

On the other hand, the switching element 752 of the discharge circuit unit 75 maintains the switching on state immediately after the off control time point T83, and performs a switching off operation at the second zero crossing time point T84.

That is, when the controller 74 detects the second zero crossing point T84 through the zero crossing detection unit 71, the control unit 752 of the discharge circuit unit 75 performs a switching off operation at that point. do.

In addition, the controller 74 controls the switching element 732 of the voltage distribution unit 73 in the switched off state to perform a switching on operation at the second zero crossing time point T84.

Meanwhile, the switching unit 72 that performs the switching off operation at the phase off control time point T83 maintains the switching off state until the next phase on control time point T85.

The present invention can be applied to control the phase of alternating current in an alternating current circuit.

Claims

Switching unit for supplying or cutting off the AC power to the load;

A voltage distribution unit electrically connected to the switching unit or connected in parallel;

A zero crossing detection unit detecting a zero crossing time point from an input AC signal; And

And a control unit configured to control the switching unit to perform a switching-off operation at a first zero crossing point detected by the zero-crossing detection unit, and to perform the switching-on operation before a second zero crossing point. .
The method of claim 1,

The control unit,

When the switching off operation of the switching unit is performed, the voltage divider is electrically connected to the load, and when the switching on operation of the switching unit is performed, the voltage divider is controlled to be electrically disconnected from the load. Phase control apparatus made into.
The method of claim 1,

The voltage divider includes a switching element and a resistive element, wherein the resistive element has a larger resistance value than the load.
Switching unit for supplying or cutting off the AC power to the load;

A voltage distribution unit electrically connected to the switching unit or connected in parallel;

A discharge circuit unit electrically connected to the load or connected in parallel;

A zero crossing detection unit detecting a zero crossing time point from an input AC signal; And

And a controller configured to sequentially control the switching-on operation and the switching-off operation of the switching unit between the first zero crossing point and the second zero crossing point detected by the zero crossing detecting unit.
The method of claim 4, wherein

The control unit,

The voltage divider is electrically connected to the load before the switching-on operation of the switching unit is performed, and the voltage divider is electrically disconnected from the load at or near the switching-on operation of the switching unit. And controlling the discharge circuit to be connected in parallel with the load at or near the time when the switching-off operation of the switching unit is performed.
The method of claim 4, wherein

The voltage divider includes a switching element and a resistive element, wherein the resistive element has a larger resistance value than the load.
The method of claim 4, wherein

The discharge circuit unit comprises a switching element and a discharge element, wherein the resistance value of the resistive element is a phase control device, characterized in that greater than the resistance value of the discharge element.
The method of claim 4, wherein

And the voltage divider is electrically connected to the load at a zero crossing time point.
The method of claim 4, wherein

And the control unit controls the discharge circuit unit to be electrically separated from the load at the zero crossing point.
Switching unit for supplying or blocking the AC power to the load;

A voltage distribution unit electrically connected to the switching unit or connected in parallel;

A discharge circuit unit electrically connected to the load or connected in parallel;

A zero crossing detection unit detecting a zero crossing time point from an input AC signal; And

Controlling the switching-on operation and the switching-off operation of the switching unit to sequentially occur between the first zero crossing point and the second zero crossing point detected by the zero crossing detection unit,

The voltage divider is electrically connected to the load before the switching-on operation of the switching unit is performed.

And a control unit which controls the voltage divider to be electrically disconnected from the load at or near the time when the switching-on operation of the switching unit is performed.
The method of claim 10,

The control unit,

The voltage divider is electrically connected to the load before the switching off operation of the switching unit is performed, and the voltage divider is electrically disconnected from the load after the switching off operation of the switching unit.

And the discharge circuit unit is connected in parallel with the load at or near the time when the switching-off operation of the switching unit is performed.
The method of claim 10,

Switching operation of the switching unit is a phase control apparatus, characterized in that performed at a voltage higher than a predetermined reference voltage.
The method of claim 10,

The voltage divider includes a switching element and a resistive element, wherein the resistive element has a larger resistance value than the load.
The method of claim 10,

The discharge circuit unit comprises a switching element and a discharge element, wherein the resistance value of the resistive element is a phase control device, characterized in that greater than the resistance value of the discharge element.
The method of claim 10,

And the voltage divider is electrically connected to the load at a zero crossing time point.
The method of claim 10,

And the control unit controls the discharge circuit unit to be electrically separated from the load at the zero crossing point.
A voltage divider having a large resistance value relative to the load is connected in parallel to a switching unit which performs a switching operation on the AC input power;

Performing a switching on operation of the switching unit so that the input power is supplied to the load;

At or near the switching-on operation point of the switching unit, electrically separating the voltage divider connected in parallel with the switching unit from the switching unit; And

The switching unit performing a switching off operation to block the input power from being supplied to the load

Phase control method comprising a.
The method of claim 17,

A discharge circuit unit connected to the load in parallel at or near the switching-off operation time point of the switching unit; And

Electrically discharging the discharge circuit part from the load, the discharge circuit part being connected in parallel to the load

Phase control method further comprises.
The method of claim 17,

Connecting the voltage divider in parallel to the switching unit and electrically disconnecting the discharge circuit unit from the load are performed at the time of zero crossing of the AC signal.
The method of claim 17,

When the switching-off operation of the switching unit is performed above the predetermined reference voltage,

Connecting the voltage distribution unit in parallel to the switching unit before the switching-off operation of the switching unit; And

After the switching-off operation of the switching unit, the voltage divider is electrically disconnected from the switching unit.

Phase control method further comprises.