CN1175813A - Power supply unit - Google Patents

Abstract

The invention discloses a power supply device, which has a simple structure and low cost, and can prevent harsh noise generated by a short circuit of a reactance coil. A zero point detection mechanism detects the moment when the AC voltage of an AC power supply passes through the zero point, and then a drive signal generating mechanism generates The power factor improves the pulse, so that the short-circuit element is driven by the short-circuit element driving mechanism, the AC power is short-circuited through the reactance coil and the first diode bridge, and the power factor of the power supply is improved. After that, an extremely short pulse width is generated by the drive signal generating mechanism The noise reduction pulse of the noise reduction pulse drives the short-circuit element to short-circuit the AC power supply through the reactance coil and the first diode bridge.

Description

power supply unit

The present invention relates to a power supply unit which has improved high power factor and rectifies AC voltage to DC voltage. Specifically, it relates to a power supply unit capable of reducing noise generated by the improvement process of power factor of power supply.

In order to extract more effective power from the power supply device, it is an effective way to improve the power factor of the power supply. For this reason, a method for simply improving the power factor of a power supply has been proposed in the prior art. In addition, by improving the power factor of the power supply, it is possible to reduce the high harmonic current of the power supply that has been solved in recent years, and it can also correspond to the high harmonic current limit at home and abroad.

As a conventional method for improving the power factor of a power supply device, there is, for example, the method disclosed in Japanese Patent Laid-Open No. 2-299470. In this method, the switch element is turned on only in a suitable short period after the AC input voltage passes through the zero point, and the AC power supply is short-circuited through the reactance coil, so as to extend the conduction period of the power supply current and improve the power factor of the power supply.

Another method for improving the power factor of a power supply is disclosed in JP-A-7-7946. In this method, too, the switch element is turned on for a predetermined time after a predetermined delay time from the moment when the AC voltage passes through the zero point, thereby Improve power supply.

The above-mentioned existing power factor improvement methods all start from the moment when the zero point of the AC voltage passes through, and after an appropriate delay time, the AC power supply is short-circuited through the reactance coil at a predetermined time, thereby expanding the conduction angle of the current waveform and improving the power supply. power. In these methods, since the reactance coil wires are short-circuited, the reactance coil generates harsh noises such as "squeaks".

In order to prevent such noise, it is necessary to increase the rigidity of the reactor coil to suppress the noise, or to cover the surrounding of the reactor coil for sound insulation, etc. Adopting the above-mentioned anti-noise method will cause the cost to increase. In addition, when adopting these anti-noise methods, problems such as the reliability of the materials used and changes over many years must be solved.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a power supply device capable of reducing harsh noise due to a short circuit of a reactor coil at low cost with a simple structure.

In order to achieve the above object, the present invention takes the following technical solutions:

A power supply device having a rectifying mechanism for rectifying an AC voltage from an AC power source into a DC voltage and a reactance coil connected in series with the rectifying mechanism, characterized in that it also has:

The first short-circuit mechanism and the second short-circuit mechanism; the first short-circuit mechanism short-circuits the AC power supply through the reactance coil in a predetermined short period after the AC voltage passes through the zero point; the second short-circuit mechanism short-circuits the AC power supply after the first short-circuit mechanism short-circuits the For a period shorter than the aforementioned predetermined short period, the AC power supply is short-circuited through the reactance coil.

The power supply device described above is characterized in that the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the one-time short-circuit operation of the first short-circuit mechanism.

The power supply device described above is characterized in that the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the several short-circuit operations of the first short-circuit mechanism.

The power supply device described above is characterized in that, for each of several short-circuit operations of the first short-circuit mechanism, the short-circuit operation of the second short-circuit mechanism is performed once or several times.

A power supply device having a rectifying mechanism for converting an AC voltage from an AC power source into a DC voltage and a reactance coil connected in series with the rectifying mechanism; it is characterized in that it also has a first short-circuit mechanism, a second short-circuit mechanism and a third short-circuit Mechanism; the first short-circuit mechanism short-circuits the AC power supply through the reactance coil in a predetermined short period after the AC voltage passes through the zero point; , short-circuit the AC power supply through the reactance coil; the third short-circuit mechanism short-circuits the AC power supply through the reactance coil in a period shorter than the predetermined short period after the first short-circuit mechanism short-circuits the AC power supply.

The above-mentioned power supply device is characterized in that, the above-mentioned short-term period during which the second or third short-circuit mechanism short-circuits the AC power supply, and the difference between the short-circuit operation of the first short-circuit mechanism and the short-circuit operation of the second or third short-circuit mechanism During the short circuit, it is determined according to the natural frequency of the reactance coil.

The power supply device is characterized in that the first, second and third short-circuit mechanisms are equipped with a switch mechanism, a drive signal generating mechanism and a drive mechanism; the switch mechanism short-circuits the AC power supply through a reactance coil; the drive signal generating mechanism generates a drive signal, the drive signal has a pulse width corresponding to each short-circuit period of the first, second and third short-circuit mechanisms; the drive mechanism receives the drive signal from the drive signal generating mechanism, and drives the above-mentioned switch mechanism according to the drive signal.

The power supply device described above is characterized in that the second or third short-circuit mechanism short-circuits the AC power supply for a short period, and the non-short-circuit period between the short-circuit operation of the first short-circuit mechanism and the short-circuit operation of the second or third short-circuit mechanism , is determined according to the natural frequency of the reactance coil in consideration of the delay time of the above-mentioned switching mechanism and the driving mechanism.

The power supply unit described above is characterized by having a supply mechanism for supplying the DC voltage rectified by the rectification mechanism constituting the power supply unit of the air conditioner to the air conditioner.

A power supply device having a rectifying mechanism for rectifying an AC voltage from an AC power source into a DC voltage and a reactance coil connected in series with the rectifying mechanism; it is characterized in that it also has a first short-circuit mechanism and a second short-circuit mechanism; the first short-circuit The mechanism short-circuits the AC power supply through the reactance coil in a predetermined short period after the AC voltage passes through the zero point; AC power shorted.

The power supply device described above is characterized in that the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the one-time short-circuit operation of the first short-circuit mechanism.

The power supply device described above is characterized in that the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the several short-circuit operations of the first short-circuit mechanism.

The power supply device described above is characterized in that, for each of several short-circuit operations of the first short-circuit mechanism, the short-circuit operation of the second short-circuit mechanism is performed once or several times.

The power supply unit described above is characterized by having a supply mechanism for supplying the DC voltage rectified by the rectification mechanism constituting the power supply unit of the air conditioner to the air conditioner.

The present invention adopts the following technical solutions: the power supply device of the present invention described in the claims has a rectifying mechanism for rectifying the AC voltage from the AC power source into a DC voltage and a reactance coil connected in series with the rectifying mechanism; it is characterized in that it also has a second The first short-circuit mechanism and the second short-circuit mechanism; the first short-circuit mechanism short-circuits the AC power through the reactance coil in a predetermined short period after the AC voltage passes the zero point; the second short-circuit mechanism short-circuits the AC power after the first short-circuit mechanism short-circuits the AC power For a shorter period than the above-mentioned predetermined short period, the AC power supply is short-circuited through the reactance coil.

In the described invention, in a predetermined short period after the AC voltage passes through the zero point, in order to improve the power factor, the AC power supply is short-circuited through the reactance coil, and then the AC power supply is short-circuited through the reactance coil during a short period of time. The power factor is improved, and the noise generated by the short circuit of the reactor coil can be reliably prevented with a simple structure and low cost.

The power supply device of the present invention described has a rectification mechanism for rectifying the AC voltage from the AC power supply into a DC voltage and a reactance coil connected in series with the rectification mechanism; it is characterized in that it also has a first short-circuit mechanism and a second short-circuit mechanism; The first short-circuit mechanism short-circuits the AC power supply through the reactance coil in a predetermined short period after the AC voltage passes through the zero point; The reactance coil short-circuits the AC power supply.

In the power supply device of the present invention, the AC power supply is short-circuited through the reactance coil for a short period of time before the AC power supply is short-circuited through the reactance coil in order to improve the power factor in a predetermined short period after the AC voltage passes through the zero point, so, Not only can the power factor be improved, but also the noise caused by the short circuit of the reactor coil can be reliably prevented with a simple structure and low cost.

The power supply device of the present invention is characterized in that the short-circuit operation of the second short-circuit mechanism is performed once or several times relative to the one-time short-circuit operation of the first short-circuit mechanism.

In the above-mentioned invention, since the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the one-time short-circuit operation of the first short-circuit mechanism, not only the power factor can be improved, but also the short-circuit of the reactance coil can be reliably prevented. noise.

The power supply device of the present invention is characterized in that the short-circuit operation of the second short-circuit mechanism is performed once or several times relative to the several short-circuit operations of the first short-circuit mechanism on the basis of the above-mentioned invention.

In the above-mentioned invention, since the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the several short-circuit operations of the first short-circuit mechanism, not only the power factor can be improved, but also the short-circuit of the reactance coil can be reliably prevented. noise.

The device of the present invention described above is characterized in that the short-circuiting action of the second short-circuiting mechanism is performed once or several times for each of several short-circuiting actions of the first short-circuiting mechanism.

In the above invention, since the short-circuit operation of the second short-circuit mechanism is performed once or several times for each operation of the several short-circuit operations of the first short-circuit mechanism, not only the power factor can be improved, but also the reactance can be reliably prevented. Noise generated by a short circuit of the coil.

The power supply device of the present invention described has a rectifying mechanism for converting an AC voltage from an AC power source into a DC voltage and a reactance coil connected in series with the rectifying mechanism; it is characterized in that it also has a first short-circuit mechanism, a second short-circuit mechanism and a first 3 short-circuit mechanism; the first short-circuit mechanism short-circuits the AC power supply through the reactance coil during the predetermined short period after the AC voltage passes through the zero point; During the period, the AC power supply is short-circuited through the reactance coil; after the first short-circuit mechanism short-circuits the AC power supply, the AC power supply is short-circuited through the reactance coil for a period shorter than the above-mentioned predetermined short period.

In the above invention, since the AC power is short-circuited by the reactance coil before and after the AC power is short-circuited by the reactance coil for a predetermined short period after the AC voltage passes the zero point, not only the power can be improved, but also the power can be improved. Simple structure, low cost, and reliable prevention of noise caused by short circuit of the reactor coil.

According to the power supply device of the present invention, the following features are added on the basis of any one of the above inventions, that is, the short period during which the second or third short-circuit mechanism short-circuits the AC power supply, and the short-circuit operation of the first short-circuit mechanism and the first short-circuit mechanism. The non-short-circuit period between the short-circuit operations of the second or third short-circuit mechanism is determined based on the natural frequency of the reactance coil.

In the above invention, since the short short-circuit period and non-short-circuit period of the second or third short-circuit mechanism are determined according to the natural frequency of the reactor coil, the noise generated by the short-circuit of the reactor coil can be reliably prevented.

Described power supply device is to increase following feature on the basis of any one of the above-mentioned inventions, that is, the above-mentioned first, second and third short-circuit mechanisms are equipped with switch mechanism, drive signal generating mechanism and drive mechanism; switch mechanism passes reactance The coil short-circuits the AC power supply; the driving signal generating mechanism generates a driving signal, and the driving signal has a pulse width equivalent to each short-circuit period of the first, second and third short-circuiting mechanisms; the driving mechanism receives the driving signal from the driving signal generating mechanism, according to The drive signal drives the switch mechanism described above.

In the said invention, since the driving signal is generated by the driving signal generating mechanism, the driving signal has a pulse width corresponding to each short-circuit period of the first, second and third short-circuiting mechanisms, and the switching mechanism is driven by the driving signal through the driving mechanism. , The AC power supply is short-circuited by the switch mechanism through the reactance coil, so the noise generated by the short-circuit of the reactance coil can be reliably prevented with a relatively simple circuit structure.

The power supply device of the present invention described has the following features added to the above invention, that is, the short period during which the AC power supply is short-circuited by the second or third short-circuit mechanism, and the short-circuit operation of the first short-circuit mechanism is different from that of the second or third short-circuit mechanism. The non-short-circuit period between the short-circuit operations of the mechanism is determined according to the natural frequency of the reactance coil in consideration of the delay time of the switching mechanism and the drive mechanism.

In the above invention, since the delay time of the switch mechanism and the drive mechanism is considered, and the short short-circuit period and non-short-circuit period of the second or third short-circuit mechanism are determined according to the natural frequency of the reactance coil, the reactance can be reliably prevented. Noise generated by a short circuit of the coil.

The described power supply device of the present invention has the following feature added on the basis of any one of the above inventions, that is, it has a supply mechanism for supplying the DC voltage rectified by the rectification mechanism constituting the power supply part of the air conditioning device to the air conditioning device. .

In the above invention, since the power supply unit of the air conditioner is constituted by the power supply unit of the present invention, it is possible to provide an air conditioner capable of improving the power factor and reliably preventing noise at low cost.

The present invention has positive effect:

As described above, according to the present invention as described, since the AC power supply is short-circuited through the reactance coil for improving the power factor in a predetermined short period after the AC voltage passes through the zero point, the AC power supply is short-circuited through the reactance coil for a short period of time, Therefore, not only can the power factor be improved, but also the noise generated by the short circuit of the reactor coil can be reliably prevented with a simple structure and low cost. Especially in terms of structure, it is only necessary to add the second short-circuit mechanism on the basis of the first short-circuit mechanism. Specifically, in addition to the power factor improvement pulse, the addition of the noise reduction pulse can be added, through a simple It can be completed by changing or adding circuits, so no vibration-proof materials, sound-proof materials, etc. are required, the price hardly increases, and the reliability is high, and there is no change in long-term use.

According to the described invention, since the AC power supply is short-circuited through the reactance coil in a short period of time before the AC power supply is short-circuited through the reactance coil in order to improve the power factor in a predetermined short period after the AC voltage passes through the zero point, not only can The power factor is improved, and the noise generated by the short circuit of the reactor coil can be reliably prevented with a simple structure and low cost.

According to the present invention described, since the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the one-time short-circuit operation of the first short-circuit mechanism, not only the power factor can be improved, but also the short-circuit of the reactor coil can be reliably prevented. noise.

According to the present invention described, since the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the several short-circuit operations of the first short-circuit mechanism, not only the power factor can be improved, but also the short-circuit of the reactor coil can be reliably prevented. the noise produced.

According to the present invention described, since the short-circuit operation of the second short-circuit mechanism is performed once or several times for each operation of the several short-circuit operations of the first short-circuit mechanism, not only the power factor can be improved, but also the reactance can be reliably prevented. Noise generated by a short circuit of the coil.

According to the present invention described, since the AC power supply is short-circuited by the reactance coil before and after the AC power supply is short-circuited by the reactance coil for a predetermined short period after the AC voltage passes the zero point, not only the power can be improved, but also the power can be improved. The noise generated by the short circuit of the reactor coil is reliably prevented with a simple structure at low cost.

According to the present invention described, since the short short-circuit period and the non-short-circuit period of the second or the third short-circuit mechanism are determined according to the natural frequency of the reactance coil, the noise generated by the short-circuit of the reactance coil can be reliably prevented, At the same time, after the reactance coil is determined, the most suitable state does not change due to power frequency, load, etc.

According to the present invention described, since the driving signal is generated by the driving signal generating mechanism, the driving signal has a pulse width corresponding to each short-circuit period of the first, second and third short-circuiting mechanisms, and the switching mechanism is driven by the driving signal through the driving mechanism. , The AC power supply is short-circuited by the switch mechanism through the reactance coil, so the noise generated by the short-circuit of the reactance coil can be reliably prevented with a relatively simple circuit structure.

According to the present invention described, since the delay time of the switching mechanism and the driving mechanism is considered, and the short-circuit period and the non-short-circuit period of the second or third short-circuit mechanism are determined according to the natural frequency of the reactance coil, the reactance can be reliably prevented. Noise generated by a short circuit of the coil.

According to the present invention described, since the power supply unit of the air conditioner is constituted by the power supply device of the present invention, an air conditioner capable of improving the power factor and reliably preventing noise at low cost is provided.

Embodiments of the present invention are described in detail below with reference to the accompanying drawings:

FIG. 1 is a circuit configuration diagram of a power supply device according to an embodiment of the present invention.

FIG. 2 shows signal waveforms of various parts of the power supply unit shown in FIG. 1 .

Fig. 3 shows signal waveforms of each part of the power supply device according to the second embodiment of the present invention.

Fig. 4 is a diagram showing a circuit configuration of a power supply unit according to a third embodiment of the present invention.

Fig. 5 shows signal waveforms of each part of the power supply device according to the fourth embodiment of the present invention.

Fig. 6 shows signal waveforms of each part of the power supply device according to the fifth embodiment of the present invention.

FIG. 7 is a diagram illustrating the structure of a drive signal generating mechanism for generating power factor improvement pulses and noise reduction pulses.

FIG. 8 shows the intermittent time between the power factor improvement pulse and the noise reduction pulse and the short-circuit time of the noise reduction pulse.

FIG. 9 shows the power factor improvement pulse and the pause time between the noise reduction pulses and the short-circuit time of the noise reduction pulse when there are 1, 2, and n noise reduction pulses.

FIG. 10 shows the definitions of the rising and falling timings of the i-th noise reduction pulse.

FIG. 11 shows the relationship among power factor improvement pulses, pause time, and short-circuit time when there are two noise reduction pulses.

FIG. 12 shows how to correct the intermittent time and the short-circuit time with respect to the delay of the short-circuit element driving mechanism, the on-delay time and the off-delay time of the short-circuit element.

Fig. 13 shows the configuration when the power supply unit of the present invention is used in an air conditioner.

Fig. 14 is a graph showing noise characteristics of an air conditioner incorporating a power supply unit of the present invention and an air conditioner incorporating a conventional power supply unit without a noise reduction function.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a circuit configuration diagram of a power supply device according to an embodiment of the present invention. FIG. 2 shows signal waveforms of various parts of the power supply device shown in FIG. 1 . The power supply device shown in FIG. 1 has a reactance coil 2 connected to an output end of an AC power supply 1 at one end, and the other end of the reactance coil 2 is respectively connected to one input of the first diode bridge 3 and the second diode bridge 5. The first diode bridge 3 is composed of 4 diodes with the same current direction, and the second diode bridge 5 constitutes a full-wave rectifier. The other input terminals of the first and second diode bridges 3 and 5 are connected to the other output terminal of the AC power supply 1 .

The two output terminals of the first diode bridge 3 are connected between the commutator and the emitter of the short-circuit element 4. The short-circuit element 4 is, for example, a switching element composed of a bipolar transistor, IGBT, MOSFET, etc. When the short-circuit element 4 is turned on When the AC power supply 1 is short-circuited through the first diode bridge 3 and the reactor coil 2, the power factor of the power supply device can be improved. The gate of the short-circuit element 4 is connected to the short-circuit element drive mechanism 12, and the short-circuit element 4 is driven by the short-circuit element drive mechanism 12 to bring the short-circuit element 4 into an ON state.

The two output terminals of the AC power supply 1 are connected with a zero-cross detection mechanism 10 composed of, for example, an optocoupler, a converter, etc., and the zero-cross detection mechanism 10 detects the AC voltage of the AC power supply 1, that is, has the voltage indicated by the reference numeral 21 in FIG. The detection signal is supplied to the driving signal generating mechanism 11 at the moment when the AC voltage showing a sinusoidal waveform passes through a zero point, that is, a zero crossing point.

Drive signal generator 11 is for example made up of microcomputer, dedicated circuit etc., produces the power factor improvement pulse shown in Fig. 2 and 26a respectively and the noise reduction pulse that pulse width is much smaller than this power factor improvement pulse, These power factor improvement pulses 24 a and noise reduction pulses 26 a are supplied to the short-circuit element driving mechanism 12 . The short-circuit element driving mechanism 12 responds to these power factor improvement pulses 24a and noise reduction pulses 26a, and drives the short-circuit element 4 to the ON state, thereby short-circuiting the AC power source 1 through the first diode bridge 3 and the reactor coil 2 . As a result, when the power factor improvement pulse 24a makes the short-circuit element 4 connected, the AC power supply 1 is short-circuited by the first diode bridge 3 and the reactance coil 2, and the power factor of the power supply can be improved. At the same time, the noise reduction pulse 26a makes the short-circuit element 4 When turned on, it can reduce the noise generated when the reactance coil 2 is short-circuited in order to improve the power factor of the power supply.

The output end of the second diode bridge 5 is connected to the load 9 through the smoothing electrolytic capacitors 6, 7, 8, so that the AC voltage from the AC power source 1 is received by the second diode bridge 5 and the smoothing electrolytic capacitors 6, 7, 8 After double voltage rectification, it is supplied to the load 9 as a DC voltage.

In the power supply unit with the above structure, when the AC power supply 1 supplies the AC voltage shown by the reference numeral 21 in FIG. The constructed voltage doubler rectifier circuit supplies the load 9 as a DC voltage, and at the same time, when the AC voltage passes through a zero point, the zero point is detected by the zero cross detection mechanism 10, and the drive signal generation mechanism 11 is driven by the detection signal.

When the drive signal generator 11 is driven by the zero detection output signal of the zero cross detection mechanism 10, the power factor improvement pulse 24a and the noise reduction pulse 26a shown in FIG. 2 are generated after the zero point of the AC power supply passes. The power factor improvement pulse 24 a and the noise reduction pulse 26 a drive the short-circuit element 4 to the ON state through the short-circuit element drive mechanism 12 , thus short-circuiting the AC power supply 1 through the first diode bridge 3 and the reactor coil 2 . As a result, when the short-circuit element 4 responds to the power factor improvement pulse 24a and short-circuits the AC power supply 1 through the reactance coil 2, the conduction period of the power supply current is extended to improve the power factor of the power supply device. In addition, the short-circuit element 4 responds to the noise reduction pulse When 26a operates, the noise of the reactor coil 2 can be reduced. This noise is generated when the reactor coil 2 is short-circuited by the power factor improving pulse 24a, the short-circuit of the reactor coil 2 is released, and the short-circuit current is cut off.

Specifically, as shown in Fig. 2, label 22 represents the power supply current waveform before the power factor is improved, and label 23 represents the power supply current waveform after the power factor is improved by the power factor improvement pulse 24a, thus it can be seen that the power supply current after improvement The conduction period of the power supply is extended, so the power factor of the power supply is improved. After the power factor improvement pulse 24a, the noise reduction pulse 26a with a very small pulse width is output immediately to short-circuit the short-circuit element 4. In this way, when the reactance coil 2 is short-circuited by the power factor improvement pulse 24a, the noise of the reactance coil when the short-circuit current is cut off can be reduced, while the waveform of the power supply current and the power factor of the power supply are almost unchanged.

Fig. 3 shows signal waveforms of each part of the power supply device according to the second embodiment of the present invention. The difference between the second embodiment and the above-mentioned first embodiment is only that the order of the power factor improvement pulse 24a and the noise reduction pulse 26a is reversed, and other structures and functions are the same as the first embodiment.

The circuit structure of the second embodiment is basically the same as that shown in FIG. 1, but the generation order of the power factor improvement pulse 24a and the noise reduction pulse 26a generated from the drive signal generating mechanism 11 is reversed, that is, as shown in FIG. The noise reduction pulse 26a is generated, and the power factor improvement pulse 24a is generated again. In addition, in the signal waveform diagram of FIG. 3 , as in FIG. 2 , symbols 21 and 22 represent the AC voltage waveform of the AC power source 1 and the current waveform before the power factor improvement of the AC power source 1, respectively, and the symbol 25 represents the power factor improvement. And the current waveform after noise improvement.

In the second embodiment, the noise reduction pulse 26a is generated before the power factor improvement pulse 24a, and before the AC power supply 1 is short-circuited by the power factor improvement pulse 24a through the reactor coil 2, the reactor coil 2 is momentarily short-circuited by the noise reduction pulse 26a , can reduce the noise when the short-circuit current of the reactor coil 2 is cut off. Then, the AC power supply 1 is short-circuited by the power factor improving pulse 24a through the reactance coil 2. Like this, as shown by the symbol 25 in FIG.

In the first and second embodiments shown in FIGS. 1 to 3, the noise reduction pulse 26a is made to occur before or after the power factor improvement pulse 24a. In this way, the AC power supply 1 is short-circuited through the reactor coil 2, and the reactor coil 2 can be reduced. Noise when the short-circuit current is cut off or turned on. If the noise reduction pulse 26a occurs before and after the power factor improvement pulse 24a, the noise when the short-circuit current of the reactor 2 is cut off and on can be further reduced.

Fig. 4 shows a circuit configuration of a power supply unit according to a third embodiment of the present invention. In the power supply device shown in this figure, one output end of the second diode bridge 5 constituting the full-wave rectifier is connected to one end of the reactor coil 2, and the other end of the reactor coil 2 is connected to the other end of the second diode bridge 5 to output The commutator and the emitter of the short-circuit element 4 composed of switching transistors are connected between the terminals. When the short-circuit element 4 is turned on, the AC power supply 1 is short-circuited through the reactance coil 2 and the second diode bridge 5 . The other end of the reactor coil 2 is connected to an electrolytic capacitor 8 for smoothing and a load 9 through a diode 13 for backflow prevention. The function of the diode 13 is to short-circuit the electrolytic capacitor 8 for smoothing by the short-circuit element 4 when the short-circuit element 4 is turned on and the AC power supply 1 is short-circuited through the reactance coil 2 and the second diode bridge 5 .

The structure and function of the zero-cross detection mechanism 10, the driving signal generating mechanism 11, and the short-circuit element driving mechanism 12 connected to the two output ends of the AC power supply 1 are the same as those shown in Figure 1. As shown in Figure 2, the driving signal generating mechanism 11 generates The power factor improvement pulse 24a and the noise reduction pulse 26a following the power factor improvement pulse 24a make the short-circuit element 4 driven by the short-circuit element driving mechanism 12 into an on state, thereby, similar to the first embodiment , the power factor of the power supply can be improved by the power factor improvement pulse 24a, and the noise when the short-circuit current of the reactor coil 2 is cut off can be reduced by the noise reduction pulse 26a. In addition, the order of the power factor pulse 24a and the noise reduction pulse 26a is changed. As shown in FIG. The driving mechanism 12 drives the short-circuit element 4 into the on state. Like the second embodiment, the noise when the short-circuit current of the reactor coil 2 is cut off can be reduced by the noise reduction pulse 26a, and the power factor of the power supply can be improved by the power factor improvement pulse.

Fig. 5 shows signal waveforms of each part of the power supply device according to the fourth embodiment of the present invention. The fourth embodiment differs from the first embodiment above only in that several (two in this embodiment) noise reduction pulses 26a, 26b are generated after the power factor improvement pulse 24a. Other structures and functions are the same as those of the first embodiment. That is, in FIG. 5, reference numerals 21 and 22 respectively represent the waveform of the AC voltage of the AC power source 1 and the current waveform before the power factor improvement, 27 represents the current waveform after the power factor improvement and noise improvement, and 24a represents the power factor improvement pulse , 26a, 26b represent noise reduction pulses.

The circuit structure of the power supply device of the fourth embodiment is basically the same as that shown in Fig. 1 or Fig. 4, except that the driving signal generator 11 generates several noise reduction pulses 26a, 26b after the power factor improvement pulse 24a.

In the fourth embodiment, several noise reduction pulses 26a, 26b are generated after the power factor improvement pulse 24a. After the power factor is improved by the power factor improvement pulse 24a, the short-circuit current of the reactor coil 2 can be more reliably reduced. noise. In addition, the above sequence can also be changed, that is, as shown in FIG. 3, several noise reduction pulses 26a, 26b occur before the power factor improvement pulse 24a. At this time, the noise when the short-circuit current of the reactor coil 2 is turned on can be reduced. .

In the fourth embodiment, even if several noise reduction pulses 26a, 26b occur, the pulse width of these noise reduction pulses is extremely short compared with the power factor improvement pulse 24a, so the current waveform of the power supply device is almost unchanged, and the power factor No effect either.

Fig. 6 shows signal waveforms of each part of the power supply device according to the fifth embodiment of the present invention. In the fifth embodiment, while a plurality of power factor improvement pulses 24a, 24b are continuously generated, noise reduction pulses 26a, 26b are respectively generated after each power factor improvement pulse. FIG. 6 shows a case where there are two power factor improvement pulses 24a, 24b and two noise reduction pulses 26a, 26b, respectively.

While successive power factor improvement pulses 24a, 24b are generated, a noise reduction pulse 26a, 26b is generated immediately after each power factor improvement pulse 24a, 24b, so that while improving the power factor of the power supply device, it is possible to reliably Reduce the noise when the short-circuit current of the reactor coil 2 is cut off. In the fifth embodiment shown in Fig. 6, a noise reduction pulse occurs after each of several power factor improvement pulses, but a noise reduction pulse can also occur before each of several power factor improvement pulses, such that , can also improve the power factor of the power supply device, and can reduce the noise when the current of the reactor coil 2 is turned on.

In the fifth embodiment shown in Fig. 6, one noise reduction pulse 26b is generated corresponding to each power factor improvement pulse, but it is also possible to generate several noise reduction pulses 26b corresponding to each power factor improvement pulse. In this case, The noise reduction pulse can occur before or after the power factor improvement pulse, or both before and after the power factor improvement pulse. When the noise reduction pulse occurs before and after the power factor improvement pulse, the noise of the short-circuit current of the reactor 2 can be reliably reduced when it is turned on and when it is cut off.

Next, the drive signal generator 11 for generating the power factor improvement pulse 24a and the noise reduction pulse 26a will be described with reference to FIG. 7 . In order to reduce the noise caused by the vibration of the reactor coil 2, the noise reduction pulse 26a that short-circuits the reactor coil 2 through the short-circuit element 4 is the same as the power factor improvement pulse 24a that short-circuits the reactor coil 2 through the short-circuit element 4 in order to improve the power factor of the power supply device. Ratio is a pulse with a very short pulse width, basically does not change the current waveform, and has no influence on the power factor.

The driving signal generating means 11 may be configured by, for example, a timing function incorporated in a microcomputer, or may be constituted by a dedicated waveform generating circuit. In FIG. 7, the operation when using a counter, a comparator, and four registers A, B, C, and D is explained. The 4 registers store the period between each pulse and the width of each pulse respectively. Specifically, the period from the zero-cross occurrence time output from the zero-cross detection means 10 to the generation of the power factor improvement pulse 24a is stored in the register A as D1. The value obtained by adding the pulse width of the power factor improvement pulse 24a to D1 is stored in register B as D2. A value obtained by adding to D2 the value obtained during the pause period between the power factor improvement pulse 24a and the noise reduction pulse 26a is stored in the register C as D3. The value obtained by adding the pulse width of the noise reduction pulse 26a to D3 is stored in the register D as D4.

At the zero-cross occurrence time output by the zero-cross detection mechanism 10, the zero-cross interrupt is made, and the counter is started, and the value of the counter is compared with the value of each register with a comparator. When the value of the counter reaches the value D1 stored in the register A, The power factor improvement pulse 24a is generated, and when the value of the counter reaches the value D2 stored in the register B, the power factor improvement pulse 24a is stopped, and when the value of the counter reaches the value D3 stored in the register C, the noise reduction pulse 26a occurs, when the counter When the value of D reaches the value D4 stored in the register D, the noise reduction pulse 26a is stopped. By appropriately setting the value of each register, the power factor improvement pulse 24a and the noise reduction pulse 26a can be easily and reliably generated with the desired pulse width and pause period.

In FIG. 7, the noise reduction pulse 26a is generated after the power factor improvement pulse 24a is generated, but the noise reduction pulse 26a can be simply generated before the power factor improvement pulse 24a by changing the values of each register. In addition, by increasing the number of registers, or not increasing the number of registers but by sequentially rewriting the value of a register, several power factor improvement pulses and several noise reduction pulses can also be generated, or one or more pulses corresponding to each power factor improvement pulse can be generated. Several noise reduction pulses.

Next, the intermittent period between the power factor improvement pulse and the noise reduction pulse, the pulse width of the noise reduction pulse, that is, the short-circuit time of the reactor coil 2 will be described in detail with reference to FIGS. 8 to 11 .

The noise of the reactor coil 2 is generated because the reactor coil vibrates when the current is suddenly turned on and off, and the reactor coil vibrates at a natural frequency. As the current increases and decreases, forces in opposite directions are generated. Therefore, the vibration of the reactance coil continues at T=1 ms.

Referring first to Fig. 8 and Fig. 9 where the number of noise reduction pulses = 1, the situation when there is one noise reduction pulse will be described. As shown in Figure 8, let the end time of the power factor improvement pulse be t=0, the intermittent time between the generation of the noise reduction pulse be x, the short-circuit time of the noise reduction pulse be y, the natural frequency of the reactance coil be f, and the angle Frequency ω=2πf, then the vibration generated by the reactance coil when the current is turned on and off is shown in the following formula.

〔Formula 1〕

The vibration generated when t=0 is sin(ωt)

The vibration generated when t=x is sin(ω(t-x)-π)

The vibration generated when t=x+y is sin(ω(t-x-y))

The effective value of the vibration of the reactor coil is as follows between t=0 and T.

[Formula 2] $V_{\mathrm{eff}}=\sqrt{\frac{1}{T}{\∫}_0^T{\left(f\left(t\right)\right)}^2\mathrm{dt}}$ in,

[Formula 3]

F(t)＝sin(ωt)+sin(ω(t-x)-π)+sin(ω(t-x-y))

The minimum value of the effective value of the vibration of the reactance coil can be obtained from V _eff in the above formula, but it is only necessary to satisfy F(t)=0. When the minimum value of vibration is calculated from this formula, as shown in Fig. 9 when the number of noise reduction pulses = 1, the intermittent time x between the power factor improvement pulse and the noise reduction pulse and the short-circuit time y of the noise reduction pulse are respectively

x=y=π/(3ω).

In the above description, the situation that the intermittent time and the short-circuit time are equal has been explained. Since the vibration of the reactor coil is a periodic function, even if the respective phases of the intermittent time and the short-circuit time are staggered by 2aπ/ω (a=0, 1, 2, 3...) and 2bπ/ω (b=0, 1, 2, 3...), the same effect can also be achieved, and the intermittent time x and the short-circuit time y are as shown in the following formulas.

x＝±π/(3ω)+2aπ/ω

y＝±π/(3ω)+2bπ/ω

At this time, x>0, y>0, and a and b may have different values. However, when the symbol of the first item in the formula of intermittent time x is +, the symbol of the first item in the formula of short-circuit time y is +, conversely, when the symbol of the first item in the formula of intermittent time x is -, The symbol of the first item in the formula of short-circuit time y is also -.

The above has explained the case where the number of noise reduction pulses is one. Next, the case where there are n noise reduction pulses (n=1, 2, 3...) will be described. The general expression is expressed by comparing the effective value F(t) of the above-mentioned reactance coil vibration, and the display of the noise reduction pulse generation time is performed as shown in FIG. 10 . That is, taking the end time of the power factor improvement pulse as the reference time (t=0), assuming the rise and fall times of the i-th noise reduction pulse are respectively αi and βi, then the effective value of the reactor coil vibration between 0 and T is as follows shown in the formula.

[Formula 4] $V_{\mathrm{eff}}=\sqrt{\frac{1}{T}{{\∫}_0^T\left(G\left(t\right)\right)}^2\mathrm{dt}}$ in,

G(t)＝sin(ωt)

[Formula 5] $+\underset{i=1}{\overset{\mathrm{no}}{\mathrm{\Σ}}}\sin (\mathrm{\ω}(t-{\mathrm{\α}}_i)-\mathrm{\π})+\underset{i=1}{\overset{\mathrm{no}}{\mathrm{\Σ}}}\sin \mathrm{\ω}(t-{\mathrm{\β}}_i)$

The minimum value G(t)=0 of the effective value of the reactance coil vibration is sufficient. There are many relationships between αi and βi that satisfy this G(t)=0. As an example, as shown in FIG. 9, the intermittent time x and the short-circuit time When y is equal, the number of noise reduction pulses n=2, as shown in the following formula.

xi=yi=π/5(ω)

Similarly, when there are n (n=1, 2, 3, . . . ) equal noise reduction pulses, it is as shown in the following formula.

xi=yi=π/((2n+1)ω)

Considering the nature of the periodic function, when the phase is staggered by 2aπ/ω (a=0, 1, 2, 3...), it is shown in the following formula.

[Formula 6]

xi=yi=π/((2n+1)ω)+2aπ/ω

As another example, when n=2, noise reduction pulses shown in FIG. 11 can also be easily imagined, and they are also included in the relationship satisfying the above-mentioned G(t)=0. In addition, other conditions satisfying G(t)=0 also exist, and their descriptions are omitted.

As described above, by determining the intermittent time x and the short-circuit time y of the noise reduction pulse according to the natural frequency of the reactor coil, the noise of the reactor coil can be reduced most effectively. This determination method does not change the optimum conditions depending on the state of power supply frequency, load, etc. After determining the reactance coil to be used, the natural frequency can be determined to determine the most appropriate noise reduction pulse.

Next, a method of correcting the above-determined intermittent time and short-circuit time with respect to the delay of the short-circuit element driving mechanism 12 and the delay of the ON time and the OFF time of the short-circuit element 4 will be described with reference to FIG. 12 . FIG. 12 shows a situation in which the short-circuit element drive mechanism 12 and the short-circuit element 4 are corrected assuming that the cut-off time is faster than the turn-on time.

In order to minimize the noise and determine the on/off of the current of the short-circuit element 4, the output signal of the drive signal generating mechanism 11 sets the intermittent time to be short, which is only equivalent to the delay time between the short-circuit element drive mechanism 12 and the short-circuit element 4. , set the short-circuit time of the noise reduction pulse long. In this way, the short-circuit element 4 can be operated at the ON/OFF timing calculated above. In addition, in FIG. 12, the current waveform of the short-circuit element 4 is simply shown as a rectangular wave. In FIG. 12, the noise reduction pulse is generated after the output of the power factor improvement pulse. However, if the noise reduction pulse is generated before the output of the power factor improvement pulse, the noise of the reactor coil can also be reduced by performing the same correction. In addition, when there are several noise reduction pulses, the noise of the reactor coil can also be prevented by performing the same correction.

Next, referring to Fig. 13, a description will be given of the case where the power supply unit of the present invention is used in an air conditioner. In Fig. 13, an AC power supply 1, a reactance coil 2, a first diode bridge 3, a short-circuit element 4, a second diode bridge 5, smoothing electrolytic capacitors 6, 7, 8, a zero-cross detection mechanism 10, and a short-circuit element drive mechanism 12 is the same as that in the power supply unit shown in FIG. 1 . 15 is a microcomputer, 16 is an inverter circuit, and 17 is a motor for a compressor.

The microcomputer 15 controls the inverter circuit 16 and operates the compressor motor 17 to control the entire air-conditioning device. At the same time, it receives the zero-cross detection output signal from the zero-cross detection mechanism 10 and performs the same operation as the drive signal generation mechanism 11. Action, the above-mentioned power factor improvement pulse and noise reduction pulse are generated, these pulses are supplied to the short-circuit element drive mechanism 12, and the short-circuit element 4 is driven by the short-circuit element drive mechanism 12, so that the reactance coil 2 and the first diode bridge 3 will The AC power supply 1 is short-circuited to improve the power factor of the power supply unit and reduce the noise of the reactance coil at the same time.

Fig. 14 is a noise characteristic graph showing an air conditioner incorporating a power supply unit of the present invention having a power factor improvement function and a noise reduction function, and an air conditioning unit incorporating a conventional power supply unit having only a power factor improvement function but no noise reduction function. Adjust the noise characteristics of the device. In the figure, curve Y represents the noise characteristic of the air conditioner incorporating the conventional power supply unit, and curve H represents the noise characteristic of the air conditioner incorporating the power supply unit of the present invention. It can be seen from the figure that the noise in the interval from 7KHz to 8KHz in curve Y is very large, while the noise in the interval from 7KHz to 8KHz in curve H is much reduced.

Claims (14)

1. A power supply device having a rectifying mechanism that rectifies the AC voltage from an AC power source into a DC voltage and a reactance coil connected in series with the rectifying mechanism, characterized in that it also has: The first short-circuit mechanism and the second short-circuit mechanism; the first short-circuit mechanism short-circuits the AC power supply through the reactance coil in a predetermined short period after the AC voltage passes through the zero point; the second short-circuit mechanism short-circuits the AC power supply after the first short-circuit mechanism short-circuits the For a period shorter than the aforementioned predetermined short period, the AC power supply is short-circuited through the reactance coil. 2. The power supply device according to claim 1, wherein the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the one-time short-circuit operation of the first short-circuit mechanism. 3. The power supply device according to claim 1, wherein the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the several short-circuit operations of the first short-circuit mechanism. 4. The power supply device according to claim 1, wherein the short-circuit operation of the second short-circuit mechanism is performed once or several times for each of several short-circuit operations of the first short-circuit mechanism. 5. A power supply device having a rectifying mechanism for converting an AC voltage from an AC power source into a DC voltage and a reactance coil connected in series with the rectifying mechanism; it is characterized in that it also has a first short-circuit mechanism, a second short-circuit mechanism and a first short-circuit mechanism 3 short-circuit mechanism; the first short-circuit mechanism short-circuits the AC power supply through the reactance coil during the predetermined short period after the AC voltage passes through the zero point; During the period, the AC power supply is short-circuited through the reactance coil; after the first short-circuit mechanism short-circuits the AC power supply, the AC power supply is short-circuited through the reactance coil for a period shorter than the above-mentioned predetermined short period. 6. The power supply device according to claim 5, characterized in that, the short-circuit operation of the second or third short-circuit mechanism short-circuits the AC power supply, and the short-circuit action of the first short-circuit mechanism is different from that of the second or third short-circuit mechanism. The non-short-circuit period between short-circuit operations is determined by the natural frequency of the reactance coil. 7. The power supply device according to claim 5, wherein the first, second and third short-circuit mechanisms are equipped with a switch mechanism, a drive signal generating mechanism and a drive mechanism; the switch mechanism short-circuits the AC power supply through a reactance coil; The driving signal generating mechanism generates a driving signal, and the driving signal has a pulse width corresponding to each short-circuit period of the 1st, the 2nd and the 3rd short-circuiting mechanism; the driving mechanism receives the driving signal from the driving signal generating mechanism, and drives the above-mentioned switch mechanism. 8. The power supply device according to claim 7, wherein the second or third short-circuit mechanism short-circuits the AC power supply for a short period of time, and the short-circuit operation of the first short-circuit mechanism and the short-circuit operation of the second or third short-circuit mechanism The non-short-circuit period between them is determined according to the natural frequency of the reactance coil in consideration of the delay time of the above-mentioned switching mechanism and the driving mechanism. 9. The power supply unit according to claim 1, further comprising a supply mechanism for supplying the DC voltage rectified by the rectification mechanism constituting the power supply unit of the air conditioner to the air conditioner. 10. A power supply device having a rectifying mechanism for rectifying an AC voltage from an AC power source into a DC voltage and a reactance coil connected in series with the rectifying mechanism; it is characterized in that it also has a first short-circuit mechanism and a second short-circuit mechanism; The first short-circuit mechanism short-circuits the AC power supply through the reactance coil within a predetermined short period after the AC voltage passes through zero; The coil shorts the AC supply. 11. The power supply device according to claim 10, wherein the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the one-time short-circuit operation of the first short-circuit mechanism. 12. The power supply device according to claim 10, wherein the short-circuit operation of the second short-circuit mechanism is performed once or several times with respect to the several short-circuit operations of the first short-circuit mechanism. 13. The power supply device according to claim 10, wherein the short-circuit operation of the second short-circuit mechanism is performed once or several times for each of several short-circuit operations of the first short-circuit mechanism. 14. The power supply unit according to claim 10, further comprising a supply mechanism for supplying the DC voltage rectified by the rectification mechanism constituting the power supply unit of the air conditioner to the air conditioner.

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