JP3134958B2 - Power supply device, discharge lamp lighting device and lighting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for generating a high-frequency voltage from a DC voltage obtained by rectifying an AC power supply voltage, a discharge lamp lighting device, and a lighting device using the discharge lamp lighting device.

[0002]

2. Description of the Related Art Conventionally, a power supply device for generating a high-frequency voltage from a DC voltage has been proposed as shown in FIG. In this figure, e is an AC power supply, 100 is a rectifier, and 110 is an inverter for converting the output voltage of the rectifier 100 into a high-frequency voltage. Inverter 110 in FIG. 9 is a field effect transistor as switching devices 111 and 112, and a pair of capacitors 113 and 1 for voltage division.
14 and a load circuit 115. The load circuit 115 includes an inductor 116, a fluorescent lamp 117, and a capacitor 118. The inductor 116, the fluorescent lamp 117, and the capacitor 118 resonate in series in response to high-frequency switching of the switching devices 111 and 112, and start and turn on the fluorescent lamp 117. Reference numeral 200 denotes an auxiliary DC power supply which supplies a DC voltage to the inverter 110 in place of the rectifier 100 during a valley where the instantaneous value of the output voltage from the rectifier 100 is lower than a predetermined value. It is. In FIG. 9, the capacitor 20
1, a series circuit of a diode 202 and a capacitor 203 is provided between the output terminals of the rectifier 100, and a diode 204 forming a discharge circuit of the capacitor 201 is connected in series with the capacitor 201; A diode 205 for forming a discharge circuit 203 is provided in series with the capacitor 203. Note that F is a high-frequency blocking filter.

The operation of this conventional device will be described. AC source
The output voltage waveform of e is as shown in FIG. 10 (a), and the output voltage waveform of the rectifier 100 is as shown in FIG. 10 (b).
The inverter 110 basically operates by being supplied with the output voltage of the rectifier 100 and generates a high-frequency voltage of, for example, 20 KHz or more. The instantaneous value of the output voltage from the rectifier 100 is During the peak period higher than the predetermined value, power is supplied from the rectifier 100 to the inverter 110, and the positive output terminal of the rectifier 100-the capacitor 201-the diode 202.
-Capacitor 203-A current flows through the path of the negative output terminal of the rectifier 100 to charge the capacitors 201 and 203. When the instantaneous value of the output voltage from the rectifier 100 is in a valley period lower than a predetermined value,
The voltage across the series circuit of the capacitor 201 and the diode 204, or the capacitor 203 and the diode 205
When the voltage across the series circuit becomes higher than the instantaneous value of the output voltage from the rectifier 100, the inverter 110
In this case, the electric charge of the capacitor 201 is supplied from the auxiliary DC power supply 200 through the diode 204, and the electric charge of the capacitor 203 is supplied through the diode 205. Therefore, the waveform of the supply voltage to the inverter 110 is as shown in FIG. The input current waveform to the rectifier 100 is the first.
0 (d).

As described above, since the input voltage to the inverter 110 is a pseudo-smoothed voltage that fills the valley of the rectified waveform, the high-frequency output of the inverter 110 is a rectified pulsating voltage. The envelope does not have a portion that once drops to zero voltage, as in the case where it is supplied. Therefore, when the load is a discharge lamp such as a fluorescent lamp, the pulsating voltage is 1
The luminous efficiency can be increased without extinguishing in each cycle and re-ignition in the next cycle. Moreover, the input power factor can be remarkably improved as compared with the case where a smoothing capacitor is simply provided between the output terminals of the rectifier.

[0005]

As described above, in the prior art, a DC voltage which has been smoothed to some extent can be supplied to the inverter without significantly lowering the input power factor.

However, as shown in FIG. 10 (d), the input current waveform is a distorted waveform and contains a considerably high harmonic component unlike a sine wave. This is because the input current from the AC power supply is stopped while the inverter is supplying power from the auxiliary DC power supply, and the charging current to the auxiliary DC power supply increases near the peak value of the pulsating voltage, and the input current is peaked. −
It may appear. For this reason, it cannot be adapted to a low distortion input current waveform which has recently been particularly demanded. Distorts the input current (including harmonic components)
This causes a problem in that the supply voltage to another device connected to the AC power supply is distorted.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems of the conventional apparatus, and provides a power supply apparatus having a high input power factor and a small distortion of an input current waveform while obtaining a smoothed DC voltage. It is intended to do so.

Further, according to the present invention, a smoothed DC voltage can be input as described above, so that a discharge lamp can be lit with a high-frequency voltage having an envelope that does not decrease to zero potential, while having a high input power factor and a high input power. It is an object of the present invention to provide a discharge lamp lighting device having a small current waveform distortion.

It is another object of the present invention to provide a lighting device which can efficiently light a discharge lamp, has a high input power factor, and has a small distortion of an input current waveform.

[Structure of the Invention]

[0011]

According to a first aspect of the present invention, a rectifying device is connected in series with each other and connected in series with each of a pair of switching devices for switching the output voltage of the rectifier at a high frequency. A pair of inductors is provided on each non-common connection side of the pair of switching devices, and a pair of rectifying elements are provided at the non-switching device side end of each of the pair of inductors with a polarity opposite to the polarity of the rectified voltage, and A pair of capacitors that are charged with the stored power of the inductor when the switching device is turned off are provided in parallel with each of the series circuits of the inductor and the rectifying element, and the charges of the capacitors are supplied to a load circuit. It was made.

According to a second aspect of the present invention, in addition to the first aspect, a pair of switching devices and a pair of inductors are connected in parallel with a series circuit of the pair of inductors via the pair of rectifying elements. A second capacitor is provided, and a load circuit is provided between the middle of the switching device and the middle of the second capacitor.

According to a third aspect of the present invention, in addition to the first aspect, a pair of third capacitors provided between one end portions of the respective capacitors having different polarities, and a pair of the third capacitors connected to each other. A second rectifying element provided between the other ends having different polarities, and a load circuit is provided between the switching device and each of the third capacitors.

According to a fourth aspect of the present invention, in the power supply device according to any one of the first to third aspects, each of the power supply devices is connected in series between the output terminals of the rectifier device and the intermediate portion of the pair of switching devices. , And a pair of fourth capacitors connected to the second capacitor are provided.

According to a fifth aspect of the present invention, a discharge lamp is energized by using the power supply device according to any one of the first to fourth aspects.

According to a sixth aspect of the present invention, a discharge lamp mounted on a lighting fixture body is lit by the discharge lamp lighting device according to the fifth aspect.

[0017]

According to the first aspect of the present invention, a high-frequency voltage is supplied to the load circuit by turning on / off a pair of switching devices, while the high-frequency voltage is stored in an inductor connected in series corresponding to the switching devices that are turned on. Power is charged to the capacitor via the rectifier while the switching device is off. Thereby, for example, a boosted voltage is stored in the capacitor. Then, when the switching device that has been turned off is turned on again, the charge of the capacitor is supplied to the load circuit via the switching device that has been turned on. Such an operation is performed for the other switching device and the inductor and the capacitor corresponding to the other switching device, and also over the entire period of the peak and the valley of the rectified voltage. Therefore, a voltage obtained by converting a voltage obtained by boosting a rectified voltage (for example) into a high frequency can be supplied to the load circuit, and the input current from the AC power supply is not stopped by the voltage of the capacitor, so that a sine wave having no pause period Which is similar to

According to the second aspect of the invention, the operation is basically the same as that of the first aspect. However, since the second capacitor is provided, the power supply at the time of turning on the power is provided by the second capacitor. Inrush current can be suppressed.

According to the third aspect of the present invention, since the third capacitor is provided, the inrush current when the power is turned on can be suppressed by the third capacitor. According to the fourth aspect of the present invention, since the fourth pair of capacitors for voltage division is provided, the voltage applied to one switching device can be reduced.

According to the fifth aspect of the present invention, it is possible to provide a discharge lamp lighting device having high luminous efficiency and input power factor and low harmonic components of the input current.

According to the invention described in claim 6, it is possible to provide an illuminating device having high luminous efficiency and input power factor and low harmonic components of the input current.

[0022]

An embodiment of the present invention will be described below with reference to FIG. The same parts as those in FIG. 9 are denoted by the same reference numerals. Reference numerals 1 and 2 denote switching devices provided in series with each other, which alternately turn off and off at a high frequency of, for example, 20 KHz or more. Reference numerals 3 and 4 denote inductors provided in series with the switching devices 1 and 2, respectively.
Reference numerals 5 and 6 denote rectifiers which are connected in series to each other and have a polarity opposite to the polarity of the output voltage of the rectifier 100 and are provided on the non-switching device side of the inductors 3 and 4. Reference numeral 7 denotes a capacitor provided in parallel with the inductor 3 and the rectifying element 5, and reference numeral 8 denotes a capacitor provided in parallel with the inductor 4 and the rectifying element 6. In the present invention, serial or parallel means that other parts may be interposed in the middle. 10 is a load circuit
The middle of the switching devices 1 and 2 and the rectifying elements 5 and 6
Between the two. In the present embodiment, a series circuit of an inductor 11, a fluorescent lamp 12, and a parallel circuit of a capacitor 13 is used. The inductor 11 and the capacitor 13 (including the fluorescent lamp 12 as necessary) are set to be capable of series resonance with the switching frequency of the switching devices 1 and 2.

In the present embodiment, the rectifier 10
A pair of fourth capacitors 15 and 16 are provided between the zero output terminals to divide the output voltage of the rectifier 100. The middle of the capacitors 15 and 16 is connected to the middle of the switching devices 1 and 2. Reference numerals 17 and 18 denote diodes for preventing backflow. In this manner, by dividing the voltage of the rectifier 100, the voltage applied to the switching devices 1 and 2 can be reduced, and a switching device with a lower withstand voltage, that is, an inexpensive switching device can be used. However, as will be described later, a voltage obtained by rectifying the AC power supply voltage may be directly applied to the switching device.

In this embodiment, the switching devices 1 and 2 are so-called separately driven, and C is a driving device therefor. Of course, self-excitation driving may be performed, and a driving means in that case can be appropriately configured by those skilled in the art.

Next, the operation of this embodiment will be described. Now, when the switching device 1 is on and the switching device 2 is off, the electric charge of the fourth capacitor 15 is transferred to the diode 17.
It is released on the path of the inductor 3 and the switching device 1. Further, as the voltage of the fourth capacitor 15 decreases, a current flows from the rectifier 100 through the path of the diode 17, the inductor 3, the switching device 1, and the fourth capacitor 16. Further, the rectifier 100 is connected to the fourth capacitor 15-
A charging current flows through the capacitor 16.

Next, when the switching device 1 is turned off and the switching device 2 is turned on, the power stored in the inductor 3 is released to the capacitor 7 and the rectifying element 5 to charge the capacitor 7. On the other hand, on the switching device 2 side, the charge of the fourth capacitor 16 is transferred to the switching device 2-inductor 4-
It is released by the route of diode 18. Then, as the voltage of the fourth capacitor 16 drops, the rectifier 100 switches the fourth capacitor 15 -the switching device 2 -the inductor 4-
A current flows through the path of the diode 18. In addition, rectifiers
The charging current flows from 100 to the fourth capacitor 15 -capacitor 16.

Further, when the switching device 1 is turned on again and the switching device 2 is turned off, the switching device 1
Side, the current flows as before, and the capacitor
7 charge is switching device 1-load circuit 10-capacitor
Released via route 7. On the other hand, on the switching device 2 side, the stored power of the inductor 4 is
And the capacitor 8 is charged.

Hereinafter, the same operation is repeated, whereby the DC voltage smoothed by the capacitors 7 and 8 is switched and the high frequency voltage is supplied to the load circuit 10.

As apparent from the above description, there is no pause in the input current from the AC power supply, and FIG.
As shown in FIG. Note that the high-frequency ripple component slightly contained in the input current
Is removed at. FIG. 2 (a) shows the AC power supply voltage, and FIG. 2 (c) shows the voltage of the capacitor 7 or 8, and the broken line in the figure shows the rectified pulsating voltage.

The voltage of the capacitor 7 or 8 is preferably set to be higher than the rectified pulsating voltage, as shown in FIG. 2 (c). By doing so, the charging current of the capacitors 7 and 8 does not flow from the rectifier 100 through the path of the diode 17, the inductor 3, the capacitor 7, the capacitor 8, the inductor 4, and the diode 18. Can be approximated to a sine wave. However, in the present invention, the charging current may be allowed to flow within an allowable range. How to set the voltage values of the capacitors 7 and 8 can be changed by designing the capacitance of the inductors 3 and 4, the switching frequency, and the like.

In the embodiment, since the voltage applied to the load circuit 10 has a smooth envelope, the luminous efficiency of the fluorescent lamp 20 can be increased.

FIG. 3 shows a comparison of the content of the harmonic component contained in the input current between this embodiment and the prior art shown in FIG. Note that the AC power supply voltage in both FIG. 1 and FIG.
0V, 50Hz, the switching frequency of the switching device is 45
KHz, the capacitors 201 and 203 of FIG. 9 are 47 μF, the capacitors 113 and 114 are 0.22 μF, and the inductor of FIG.
3 and 4 are 0.9mH, capacitors 7 and 8 are 68μF, capacitor 15,
16 is 47 nF. As is clear from FIG. 1, the harmonic components in FIG. 1 are remarkably reduced.

Next, a second embodiment of the present invention will be described with reference to FIG. The same or corresponding parts as those in FIG. 1 are denoted by the same reference numerals. In the present embodiment, a pair of second capacitors 20 and 21 are provided in parallel with a series circuit of switching devices 1 and 2 and inductors 3 and 4 via rectifying elements 5 and 6. And 2 of the second capacitor
Diodes 22 and 23 are connected in parallel to 0 and 21, respectively. In addition, the rectifier 100 ′ of the present embodiment includes a rectifier 24 inserted at one end of an AC power supply e, one end of a series circuit of the inductors 3 and 4 and the switching devices 1 and 2, and a rectifier 24 of the AC power supply e. Pole side and inductor 3, 4 and switching device
And a rectifier 25 interposed at the other end of the series circuits 1 and 2. The other pole of the AC power supply e is connected to the middle of the switching devices 1 and 2. In this embodiment, the configuration of the filter F 'is slightly different from that of FIG. 1, but the operation is the same.

The operation of the present embodiment is basically the same as that of FIG. 1, but additionally prevents the inrush current from flowing when the power is turned on.
That is, assuming that the pair of second capacitors 20 and 21 are not present, when the power supply e is turned on, the filter F ′ is switched from the AC power supply e.
Rectifier 24-Inductor 3-Capacitor 7-Capacitor 13 of the load circuit 10-Similarly to the inductor 11 or from the AC power supply e via the filter F '. The inrush current is about to flow. On the other hand, since the second capacitors 20 and 21 have the second capacitors 20 and 21, the inrush current is effectively reduced by the second capacitors 20 and 21 acting as current limiting impedance elements. Things. The diode 22,
23 functions as a bypass.

FIG. 5 shows a comparison of the content of the harmonic component contained in the input current between this embodiment and the prior art shown in FIG. The conditions in FIG. 9 are the same as those described with reference to FIG. 3, and those in FIG.
200V, 50Hz, switching frequency of switching devices 1 and 2 is 45KHz, inductors 3 and 4 are 0.9mH, capacitors 7 and 8 are
68 μF, and capacitors 20 and 21 are 0.33 μF. As is clear from FIG. 5, the harmonic component in FIG. 5 is remarkably reduced.

The third embodiment will be described with reference to FIG. Also in the present embodiment, the same or corresponding parts as those in FIG. 1 are denoted by the same reference numerals. The driving means of the switching devices 1 and 2 are not shown. In this embodiment, a third pair of capacitors 30 and 31 are provided at one end of the capacitors 7 and 8 having different polarities of voltage, and a diode 32 is provided at the other end of the capacitors 7 and 8. is there. This embodiment can also reduce the inrush current. In this embodiment, the bypass diode 32 is used.
4 is superior to that of FIG.

FIG. 7 shows a fourth embodiment.
The same or corresponding parts as those in FIG. 4 are denoted by the same reference numerals. This embodiment is provided with a protection means 40 for forcibly turning off the switching devices 1 and 2 or reducing the on-duty when the voltage value across the capacitors 7 and 8 rises and exceeds a predetermined value. Such a protection means 40 can be constituted by a voltage detection section, a comparison section, and the like, and can be appropriately implemented by those skilled in the art.

In this embodiment, for example, when the discharge lamp 12 is not mounted (at a light load) and the voltage value of the capacitors 7 and 8 rises due to the chopper effect, the protection means 40 activates the switching devices 1 and 2. Forcibly reduce the off or on duty. For example, the switching devices 1 and 2 are turned off. On the other hand, without the protection means 40, if the switching devices 1 and 2 are turned on and off at the same duty as the normal load, despite the light load, the voltage of the capacitors 7 and 8 rises excessively. There is a possibility that it will be. On the other hand, in the case of the present embodiment, the voltage values of the capacitors 7 and 8 are excessively increased to destroy the switching devices 1 and 2, or the switching devices 1 and 2 need to have a high withstand voltage. Never do.

The protection means 40 is connected to the switching devices 1 and 2
May be reduced.

The protection means may be responsive to, for example, the discharge current value of the capacitor. In this case, the discharge current value may be detected by a current transformer or the like.
In addition, the protection means only needs to be able to reduce the OFF or ON duty of the switching device, and those skilled in the art can appropriately change and implement the protection device.

Further, the protection means may reduce or stop the output by changing the switching frequency of the switching device. And
Those skilled in the art can appropriately implement those specific configurations.

FIG. 8 shows an embodiment of the lighting equipment according to the present invention. Reference numeral 70 denotes an appliance main body, in which a discharge lamp lighting device 71 according to the present invention is provided. Numerals 72, 72 are lighted by the discharge lamp lighting device 71. It is needless to say that FIG. 8 shows only an example and various changes such as the shape of the appliance and the number of lamps are possible.

The present invention is not limited to the above embodiment, but can be modified without departing from the scope of the claims. For example, the load circuit may be any type other than the one including the discharge lamp. The various embodiments described above can be combined or replaced with one another as appropriate.

[0044]

As described in detail above, the first aspect of the present invention provides a switching device and an inductor,
Alternatively, through the fourth capacitor, the input current of the rectifier flows continuously for substantially the entire period of each half cycle of the AC power supply voltage waveform, and its waveform approximates a sine wave,
Harmonic components contained in the input current can be reduced while improving the input power factor. In addition, the supply voltage to the load circuit can be a smoothed DC voltage. According to the second aspect of the present invention, the rush current at the time of turning on the power can be reduced in addition to the first aspect.

According to the third aspect of the present invention, the number of components can be reduced and the cost can be reduced.

According to the fourth aspect of the present invention, the power supply voltage is divided to reduce the voltage applied to the switching device, so that the switching device having a low withstand voltage can be used, and the cost can be reduced accordingly.

According to a fifth aspect of the present invention, the luminous efficiency can be increased by turning off the discharge lamp every cycle of the pulsating voltage and continuously lighting it without repeating re-ignition.

According to the invention described in claim 6, it is possible to provide a lighting fixture having a high luminous efficiency similarly to the invention described in claim 6.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

FIG. 2 is a voltage and current waveform diagram showing the operation of FIG.

FIG. 3 is a diagram comparing harmonic components included in the input currents of FIG. 1 and FIG. 9;

FIG. 4 is a circuit diagram showing a second embodiment of the present invention.

FIG. 5 is a diagram comparing harmonic components included in the input currents of FIG. 4 and FIG. 9;

FIG. 6 is a circuit diagram showing a third embodiment of the present invention.

FIG. 7 is a circuit diagram showing a fourth embodiment of the present invention.

FIG. 8 is a plan view schematically showing an example of a lighting fixture according to the present invention.

FIG. 9 is a circuit diagram showing a conventional technique.

FIG. 10 is a voltage and current waveform diagram showing the operation of FIG. 9;

[Explanation of symbols]

1,2… Switching device, 3,4… Inductor, 5,6… Rectifier, 7,8… Capacitor, 10… Load circuit, 12… Discharge lamp,
15, 16 ... fourth condenser, 20, 21 ... second condenser, 30, 31 ... third condenser, 70 ... instrument body, 100 ...
Rectifier, e: AC power supply, F, F ': High frequency blocking filter.

Claims (6)

(57) [Claims] A rectifier for rectifying an AC power supply voltage; provided in series with each other and provided between output terminals of the rectifier, and alternately turned on and off to switch the output voltage of the rectifier at a high frequency. A pair of switching devices; a pair of inductors provided on each non-common connection side of the pair of switching devices and storing power according to a current flowing through the corresponding switching device; A pair of rectifiers provided between the non-switching device side ends in a direction opposite to the polarity of the rectified voltage; and an off-state of the switching device provided in parallel with each of the series circuits of the inductor and the rectifier. A pair of capacitors that are charged by the stored power of the inductor at some point; Power supply, characterized in that provided with the; a load circuit provided between the intermediate element. 2. A rectifier for rectifying an AC power supply voltage, which is connected in series with each other and provided between output terminals of the rectifier, and alternately turns on and off to switch the output voltage of the rectifier at a high frequency. A pair of switching devices; a pair of inductors provided on each non-common connection side of the pair of switching devices and storing power according to a current flowing through the corresponding switching device; A pair of rectifiers provided between the non-switching device side ends in a direction opposite to the polarity of the rectified voltage; and an off-state of the switching device provided in parallel with each of the series circuits of the inductor and the rectifier. A pair of capacitors that are sometimes charged with the stored power of the inductor; and the pair of switches via the pair of rectifying elements. A second capacitor provided in parallel with the device and a series circuit of the pair of inductors; and a load circuit provided between the switching device and the second capacitor. A power supply device characterized by the above-mentioned. 3. A rectifier for rectifying an AC power supply voltage; connected in series with each other and provided between output terminals of the rectifier, and alternately turned on and off to switch the output voltage of the rectifier at a high frequency. A pair of switching devices; a pair of inductors provided on each non-common connection side of the pair of switching devices and storing power according to a current flowing through the corresponding switching device; A pair of rectifiers provided between the non-switching device side ends in a direction opposite to the polarity of the rectified voltage; and an off-state of the switching device provided in parallel with each of the series circuits of the inductor and the rectifier. A pair of capacitors that are sometimes charged with the stored power of the inductor; between one ends of the capacitors having different polarities. A pair of third capacitors separated from each other; a second rectifying element provided between the other ends of the capacitors having different polarities; and a middle of the switching device and a middle of the third capacitors. And a load circuit provided in the power supply device. 4. A pair of fourth capacitors, each of which is connected in series with an intermediate portion between the output terminals of the rectifier device, the intermediate portion being connected between the output terminals of the pair of switching devices. 4. The power supply device according to any one of 3. 5. A discharge lamp and lighting the discharge lamp.
And a power supply device according to any one of (4) to (4). 6. A lighting apparatus comprising: a lighting fixture main body; a discharge lamp provided in the fixture main body; and the discharge lamp lighting device according to claim 5 for lighting the discharge lamp.