JP2007110800A - Motor input controller and vacuum cleaner using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that, recently as a motor control method, a system for changing a phase to be large or small near a mark is used for the reduction of higher harmonics, but there is a necessity to take the variation of a phase angle large, in the case of suppressing the higher harmonics to a higher input of a motor, and therefore vibration is generated and noise becomes large, and that the life of the motor becomes short. <P>SOLUTION: This motor controller sharply reduces low-order harmonics by interlacing the cycle of starting power supply to a motor at a specified phase angle, using a switching element and stopping the power supply in the vicinity of a 180° phase and the cycle of performing the power supply to the motor from the vicinity of a 0° phase and stopping the power supply to the motor at a specified phase angle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a motor control device for consumer equipment connected to an AC power source and a vacuum cleaner using the same, and more particularly to an input control method thereof.

In general, a phase control method is widely used as a motor control method for devices connected to an AC power supply. An AC power supply, a motor, and a bidirectional thyristor that phase-controls the voltage applied to the motor are connected in series, and the bidirectional thyristor is turned on at a predetermined phase angle so that the motor has a predetermined input. It is. However, when the phase angle is always constant, the generated harmonic components are also biased, resulting in the generation of large harmonics. It is already well known that the generated harmonics are maximum (especially at odd-order frequencies), especially when the phase angle is 90 °. In recent years, various control methods have been proposed as countermeasures. Among them, as a highly effective method, the generated harmonics are not generated by changing the phase angle in the vicinity of the target rather than making the phase angle constant. One example is to disperse the frequency of waves (see, for example, Patent Document 1).
JP-A 63-274396

  However, in the conventional configuration, when the harmonics are to be suppressed for a higher input motor, the change amount of the phase angle is considerably large (in terms of input, when using a 1500 W motor, 90 ° (Change amount of 200W or more at the time of phase), and therefore, there is a problem that vibration is generated, noise is increased, and the motor life is shortened. There was a limit in the conventional method for higher output.

  The present invention solves the above-described conventional problems, and provides a motor control device that suppresses the generation of higher harmonics, an electric device using the same, and a vacuum cleaner in a completely different manner from the conventional one. .

  In order to solve the above-described conventional problems, the present invention includes a motor connected in series to an AC power supply and a switching element for turning on / off power supply to the motor, and the motor is connected to the motor at a predetermined phase angle. Power supply is started, the power supply is stopped in the vicinity of the 180 ° phase (hereinafter referred to as normal phase control), and the motor is supplied with power in the vicinity of the 0 ° phase, and the motor is supplied at a predetermined phase angle. The number of periods for performing the normal phase control is equal to the number of periods for performing the anti-phase control in a plurality of consecutive periods. To be controlled.

  In the conventional method, the frequency of the current supplied to the motor is changed by changing the phase angle and the harmonic frequency is dispersed. However, the control method of the present invention is a cycle in which the first half of the AC half cycle is turned on. And the cycle to turn on the second half. That is, the frequency of the current supplied to the motor is not greatly changed, but the timing of supplying the current is changed instead. As a result, when the motor supply current is averaged over a plurality of AC cycles, the frequency is infinitely equal to the sine wave, that is, the AC power supply frequency, so the generation of harmonics (especially low-order harmonics) is dramatic. It will be suppressed.

  Further, unlike the conventional method, the amount of current supplied to the motor for each cycle of the AC power supply can be made substantially constant, so that vibration can be reduced and the life can be reduced.

  As described above, according to the present invention, even for a high-input motor, harmonics can be dramatically suppressed while suppressing vibrations and a reduction in motor life.

  1st invention has the motor connected in series with AC power supply, and the switching element which turns on and off the electric power supply to the said motor, The electric power supply to the said motor is started at a predetermined phase angle, When the power supply is stopped in the vicinity of the 180 ° phase (hereinafter referred to as normal phase control), the power is supplied to the motor from the vicinity of the 0 ° phase, and the power supply to the motor is stopped at a predetermined phase angle. (Hereinafter referred to as anti-phase control) and a motor control that controls the number of periods for performing the normal phase control and the number of periods for performing the anti-phase control to be equal between a plurality of consecutive periods. When the motor supply current is averaged over a plurality of AC cycles, the frequency is infinitely equal to the sine wave, that is, the AC power supply frequency, and therefore harmonics (especially low-order harmonics) are generated. Is dramatically It can be suppressed.

  The second invention includes a motor connected in series to an AC power source and a switching element that turns on and off power supply to the motor, and starts power supply to the motor at a predetermined phase angle. When the power supply is stopped in the vicinity of the 180 ° phase (hereinafter referred to as normal phase control), the power is supplied to the motor from the vicinity of the 0 ° phase, and the power supply to the motor is stopped at a predetermined phase angle. (Hereinafter referred to as anti-phase control), and a motor control device in which the number of cycles for performing normal phase control is greater than the number of cycles for performing anti-phase control between a plurality of consecutive AC cycles. is there. When the anti-phase control is performed using a general motor, the current when the power supply is turned off falls steeply, so that higher harmonics increase. According to this method, although the lower order harmonic components are slightly increased as compared with the first invention, the higher order harmonic components can be reduced.

  According to a third aspect of the present invention, the normal current flows through the motor during one cycle of the AC power source according to the first or second aspect of the invention so that the cycle in which the normal phase control is performed is substantially equal to the cycle in which the reverse phase control is performed. The motor control device sets the on phase angle of the phase control and the off phase angle of the anti-phase control, and the amount of current supplied to the motor for each cycle of the AC power supply can be kept almost constant, so that vibration is also generated. It can be reduced, and the lifetime reduction can be suppressed.

  4th invention has the period which performs normal phase control and antiphase control, respectively different control in 1st half and 1st half of 1 period of AC power supply of any 1st-3rd invention, and is continuous. In the first half of one cycle, the number of cycles for performing the reverse phase control in the first half of the cycle and the number of cycles for performing the reverse phase control in the second half are configured as a motor control device, Since the second half is controlled differently, even-order harmonics are slightly increased, but odd-order harmonics are further reduced.

  In the fifth aspect of the invention, instead of the normal phase control of any one of the first to fourth aspects of the invention, a plurality of on / off operations are performed during a half cycle, and the on / off state is substantially the same as the reverse phase control. The motor control device according to claim 1, wherein the motor control device is turned on / off at a reverse timing. Conventionally, a method of driving a motor at a high frequency has been widely performed (especially for a DC motor), but by adopting the ideas described in the first to fourth inventions, even a frequency drive lower than the conventional one can be achieved. Since a sufficient harmonic reduction effect can be obtained, harmonics can be reduced while suppressing adverse effects (for example, noise generation) due to high-frequency driving.

  The sixth invention is an electric vacuum cleaner using the motor control device according to any one of the first to fifth inventions, and can provide an electric vacuum cleaner capable of reducing a high frequency. is there.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiment.

(Embodiment 1)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a circuit block diagram of a motor control device, an electric device using the motor control device, and a vacuum cleaner according to the first embodiment of the present invention.

  In FIG. 1, a motor 1 and a switching element 2 are connected in series to a commercial power source 3, and the switching element 2 is formed by connecting two switching elements in antiparallel so that they can be controlled by an AC power source. . Further, a signal control means 4 for controlling the switching element 2 and an operation means 5 for a user to operate the device are connected to the signal control means 4.

  The circuit configuration in the control device of the present invention is not limited to the above configuration, and for example, as shown in FIGS. 2 and 3, a motor using an AC power source as a power supply source can be controlled by a switching element. It should be.

  Hereinafter, an operation using the above configuration will be described with reference to FIG.

  FIG. 4 is an operation waveform diagram of the first embodiment of the present invention. In FIG. 4, power supply to the motor 1 is started at a predetermined phase angle α corresponding to an input from the operation means 5, and power supply is stopped in the vicinity of 0 V (180 ° phase) at the end of the half cycle. This is performed twice (one AC cycle), and power supply to the motor 1 is started from around 0 V (0 ° phase) at the start of the next half cycle, and the power supply is stopped at a phase angle of 180 ° -α. This is performed twice (one AC cycle). These four energizations are defined as one cycle, and the same control is performed thereafter.

  According to the above configuration, when the motor supply current is averaged over a plurality of periods of alternating current, the frequency is infinitely equal to the sine wave, that is, the alternating current power supply frequency. Dramatically suppressed.

(Embodiment 2)
The second embodiment of the present invention will be described below with reference to FIG.

  The circuit configuration is the same as that of the first embodiment, and the description thereof is omitted.

  In FIG. 5, power supply to the motor 1 is started at a predetermined phase angle α corresponding to the input from the operation means 5, and the power supply is stopped in the vicinity of 0 V (180 ° phase) at the end of the half cycle. This is performed four times (two AC cycles), power supply to the motor 1 is started from around 0 V (0 ° phase) at the start of the next half cycle, and power supply is stopped at a phase angle of 180 ° -α. This is performed twice (one AC cycle). These six energizations are defined as one cycle, and thereafter the same control is performed.

  Generally, when the motor load is turned on (turned on) at a phase away from 0 V, the current flowing through the motor rises gently as shown in the figure. On the other hand, when the motor load is turned off (turned off) at a phase away from 0 V, the current instantaneously becomes zero (precisely, it becomes negative because of the counter electromotive force). Compared to the normal phase control that turns on the motor load at the predetermined phase α, the anti-phase control that turns off the motor load at the predetermined phase α causes higher-order harmonic components due to a sudden change in current at the time of turn-off. Tend to increase. Naturally, the higher the electric power of the motor itself, the higher the harmonic component increases in the entire frequency region. Therefore, when using a high input motor, it is necessary to reduce the higher order harmonic component in addition to the first embodiment.

  According to the above configuration, when the motor supply current is averaged over a plurality of periods of alternating current, it is not close to a sine wave as in the first embodiment, so that it has a lower order than the first embodiment. Although the harmonic component slightly increases, the period of performing the antiphase control, which is the main cause of the AC power supply frequency high-order harmonic component, can be reduced, so that the high-order harmonic component can be reduced.

(Embodiment 3)
Hereinafter, a third embodiment of the present invention will be described with reference to FIG.

  The circuit configuration is the same as that of the first embodiment, and the description thereof is omitted.

  In FIG. 6, power supply to the motor 1 is started at a predetermined phase angle α corresponding to the input from the operation means 5, and power supply is stopped in the vicinity of 0 V (180 ° phase) at the end of the half cycle. This is performed twice (one AC cycle), and the power supply to the motor 1 is started from around 0 V (0 ° phase) at the start of the next half cycle, and the power supply is stopped at a phase angle of 180 ° − (α + β). . This is performed twice (one AC cycle). These four energizations are defined as one cycle, and the same control is performed thereafter. Β at this time is a value set in advance so that the current flowing to the motor 1 in the first half cycle is equal to the current flowing to the motor in the second half cycle.

  According to the above configuration, since the amount of current supplied to the motor for each cycle of the AC power supply can be made substantially constant, vibration due to a change in current can be reduced, and a reduction in life due to vibration can be suppressed.

(Embodiment 4)
Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG.

  The circuit configuration is the same as that of the first embodiment, and the description thereof is omitted.

  In FIG. 7, power supply to the motor 1 is started at a predetermined phase angle α corresponding to the input from the operation means 5, and power supply is stopped around 0 V (180 ° phase) at the end of the half cycle. This is performed three times (one cycle of AC), and the power supply to the motor 1 is started from around 0 V (0 ° phase) at the start of the next half cycle, and the power supply is stopped at a phase angle of 180 ° -α. This is performed twice (one AC cycle). Further, power supply to the motor 1 is started at the phase angle α in the next half cycle, and the power supply is stopped in the vicinity of 0 V (180 ° phase) at the end of the half cycle. These six energizations are defined as one cycle, and thereafter the same control is performed.

  In general, since AC devices perform control based on one cycle of AC, odd-order harmonics are significantly larger than even-order harmonics. Odd order harmonics.

  According to the above configuration, since the control in the first half and the latter half of one AC cycle includes different cycles (so-called asymmetric control), even-order harmonics are slightly increased, but conversely, odd-orders The harmonics of are reduced.

(Embodiment 5)
Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG.

  The circuit configuration is the same as that of the first embodiment, and the description thereof is omitted.

  In FIG. 7, energization to the motor 1 is started from the 0 ° phase for one week of alternating current, and chopper control is performed at a predetermined frequency according to the input from the operation means 5. The chopper control is performed at the same frequency in the next one-week AC period, but the timing of the turn-on and turn-off is reversed by shifting the phase angle at the start of control.

  According to the above configuration, when the motor supply current is averaged over a plurality of periods of alternating current, the frequency is infinitely equal to the sine wave, that is, the alternating current power supply frequency. It will be dramatically suppressed. As a result, even with chopper control at a lower frequency than in the prior art, a high harmonic reduction effect can be obtained, so that harmonics can be reduced while suppressing adverse effects (for example, noise generation) due to high frequency driving.

  In the present embodiment, the motor load has been described. However, the present invention can also be applied to a lamp load (where an inrush current is generated like a motor load).

  As described above, the motor control device of the present invention reduces harmonic currents by bringing the current waveform as a device closer to a sine wave by using different energization controls for each AC half cycle. You may implement | achieve using a load.

  As described above, the motor control method according to the present invention is particularly useful for motorized appliances, but can also be used for devices that perform input control by phase control, such as light dimmers and heater devices.

1 is a circuit block diagram of a motor control device showing Embodiment 1 of the present invention. Circuit block diagram showing another example of the motor control device Circuit block diagram showing another example of the motor control device Operation waveform diagram of the circuit block diagram Operation waveform diagram of motor control apparatus of embodiment 2 of the present invention Operation waveform diagram of motor control apparatus of embodiment 3 of the present invention Operation waveform diagram of motor control apparatus of embodiment 4 of the present invention Operation waveform diagram of motor control apparatus of embodiment 5 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motor 2 Switching element 3 Commercial power supply 4 Signal control means 5 Operation means

Claims (6)

A motor connected in series to an AC power supply and a switching element for turning on / off the power supply to the motor, start power supply to the motor at a predetermined phase angle, and power around 180 ° phase Supply power to the motor from the period of stopping supply (hereinafter referred to as normal phase control) and near the 0 ° phase, and stop supplying power to the motor at a predetermined phase angle (hereinafter referred to as anti-phase control) A motor control device for controlling the number of cycles for performing the normal phase control and the number of cycles for performing the anti-phase control to be equal between a plurality of consecutive cycles. . A motor connected in series to an AC power supply and a switching element for turning on / off the power supply to the motor, start power supply to the motor at a predetermined phase angle, and power around 180 ° phase Supply power to the motor from the period of stopping supply (hereinafter referred to as normal phase control) and near the 0 ° phase, and stop supplying power to the motor at a predetermined phase angle (hereinafter referred to as anti-phase control) The motor control device is characterized in that the number of cycles for performing the normal phase control is greater than the number of cycles for performing the anti-phase control between a plurality of successive alternating cycles. The on-phase angle of the normal phase control and the off-phase control off so that the current flowing to the motor during one cycle of the AC power supply becomes substantially equal between the cycle of performing the normal phase control and the cycle of performing the reverse phase control. The motor control device according to claim 1, wherein a phase angle is set. A cycle in which the normal phase control and the reverse phase control are performed differently in the first half and the second half of one cycle of the AC power source, and the reverse phase control is performed in the first half of one cycle among a plurality of consecutive cycles. 4. The motor control device according to claim 1, wherein the number is controlled to be equal to the number of periods in which the antiphase control is performed in the second half. 5. The on / off operation is performed a plurality of times during a half cycle instead of the normal phase control, and the on / off operation is performed at a timing almost opposite to the on / off operation instead of the reverse phase control. 5. The motor control device according to claim 4. The vacuum cleaner using the motor control apparatus of any one of Claims 1-5.

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