KR101700804B1 - The power supply for driving lamp - Google Patents

Abstract

A power supply device for driving a lamp, comprising: a rectifying circuit part (105) for rectifying an input AC voltage to a DC voltage; A first inductor 112 connected to the rectifying circuit unit 105; A first switch 111 connected in series with the first inductor 112; A second switch 113 connected to one end of the rectifying circuit unit 105; A second inductor 114 connected in series with the second switch 113; A second diode 116 connected to the second inductor 114; A first diode 115 connected to a contact between the second switch 113 and the second inductor 114 and the other end of the first switch 111; A filter capacitor 117 connected between one end of the first switch 111 and one end of the second inductor 114; The first inductor 112 and the second inductor 114 are magnetically coupled to each other and receive a voltage at the rear end of the second diode 116 to supply power to the lamp. And a power supply for driving the lamp.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a power supply for driving a lamp,

The present invention relates to a power supply for driving a lamp with an electronic ballast.

Ballasts are essential in typical lamp-driven power supplies. Such a ballast is classified into a magnetic type and an electronic type, and the demand for an electronic ballast is advantageous in terms of the size and efficiency of the ballast.

The electronic system consists of three or two stages depending on the presence or absence of the DC / DC converter. In the case of the three-stage configuration, a power factor correction circuit (Power Factor Correction), a DC-DC converter and a DC-AC inverter are configured. The power factor correction circuit is a boost converter, (Buck) converters, and full-bridge circuits are commonly used as inverters. In the case of a two-stage configuration, the DC / DC converter is omitted, and a full-bridge or half-bridge circuit is used, unlike the three-stage configuration.

 In the case of the high-frequency driving method, a high-frequency current is injected into the lamp without filtering. In the low-frequency driving method, the high-frequency current is filtered by the LC filter So that low frequency alternating current is injected.

On the other hand, electronic ballasts consist of heat sinks including capacitors, inductors and semiconductor devices. However, in order to reduce the size and weight of the electronic ballast, the size and weight of each component must be reduced.

In terms of miniaturization and weight reduction, it has become possible to reduce the weight of a device according to the development of semiconductor integrated circuits, but research on miniaturization and weight reduction of inductors and capacitors is continuing.

Korean Patent No. 10-1220885 (Feb.

The embodiments of the present invention provide a lamp driving power supply capable of performing a boosting operation and a stepping-down operation by coupling a primary coil connected to a switching element of a boost stage and a secondary coil connected to a switching element of a buck converter stage, Device.

According to an exemplary embodiment of the present invention, there is provided a rectifying circuit unit that receives an AC input voltage and generates a rectified voltage; A first switch that is turned on when the rectified voltage is lower than the output voltage, a second switch that is turned on when the rectified voltage is higher than the output voltage, and a second switch that is turned on when the rectified voltage is higher than the output voltage, A first stage power conversion unit boosting a voltage induced in the first inductor in the boost mode based on the second inductor in the boost mode and reducing the rectified voltage using the inductor in the buck mode; And a two-stage power conversion unit converting the voltage output from the one-stage power conversion unit into an AC voltage to drive the lamp.

The first switch is connected in series with the first inductor of the inductor and the second switch is connected in parallel with the first inductor in the one-stage power converting unit of the lamp driving power supply. The second inductor of the inductor is connected in series with the second switch, and the first inductor and the second inductor are magnetically coupled to supply a boosted or reduced voltage to the lamp through the two-stage power converter. Supply.

In the power supply for driving the lamp, the first inductor and the second inductor of the inductor are coupled at a winding ratio of 1: 1.

The first inductor and the second inductor of the inductor may operate in a discontinuous current mode or a continuous current mode according to the switching operation of the first and second switches in the power supply for driving a lamp.

The power supply for driving the lamp includes an inverter that is coupled to an output terminal of the one-stage power conversion unit and operates in an alternating manner in a pair of diagonal switch elements to convert a DC voltage output from the one- In full bridge converter; An igniter circuit for receiving AC power output from the full bridge converter according to the operation and for initial driving the lamp; And a second-stage power conversion unit connected to the igniter circuit and having a primary coil to which an output voltage of the full bridge converter is applied at a rear stage, and a secondary coil magnetically coupled to the primary coil and connected to the lamp, . ≪ / RTI >

In the power supply for driving the lamp, the igniter circuit may include a triac to which an AC voltage of the full bridge converter is applied; And a capacitor coupled between the triac and the primary coil, wherein when the triac is turned on, energy generated through resonance between the primary coil of the transformer and the capacitor is coupled to the lamp through the secondary coil, So that the lamp can be initially driven.

In the power supply for driving the lamp, the inductance of the primary coil of the transformer may be 22 μH to 25 μH, and the inductance of the secondary coil may be 215 μH to 225 μH.

Wherein the lamp driving power supply apparatus includes first and second switches for turning on and off the first and second switches through comparison between a DC voltage output from the first stage power converting unit and a rectified rectified voltage of the rectifying circuit unit, And may further include a controller for providing a switching signal.

According to an embodiment of the present invention, a buck-boost converter is implemented by one inductor magnetically coupled to a first inductor and a second inductor, and by performing power factor correction and step-up and step- The size and the volume of the electrodes can be reduced.

In addition, according to the embodiment of the present invention, the cost of the power supply device can be reduced by using the coupling inductor having a small power loss when the lamp is separated from the ballast when the lamp is turned on.

1 is a circuit diagram showing a power supply for driving a lamp according to an embodiment of the present invention;
2 is a view for explaining a process of applying first and second switching signals to a first stage power conversion unit according to an embodiment of the present invention;
3 is a view for explaining an internal configuration of an igniter circuit connected to a full bridge converter according to an embodiment of the present invention;
FIG. 4 is a circuit diagram when the one-stage power conversion section operates in the boost mode according to the embodiment of the present invention
5 is a circuit diagram when the one-stage power conversion section operates in the buck mode according to the embodiment of the present invention
6 is a circuit diagram for simulating a buck-boost converter
7 is a waveform diagram showing a simulation result of the buck-boost converter of Fig. 6
8 is a circuit diagram for simulating a buck-boost converter corresponding to a one-stage power conversion unit according to an embodiment of the present invention.
Fig. 9 is a waveform diagram showing a simulation result of the coupled-buck-boost converter of Fig. 8

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The following detailed description is provided to provide a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, this is merely an example and the present invention is not limited thereto.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intention or custom of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification. The terms used in the detailed description are intended only to describe embodiments of the invention and should in no way be limiting. Unless specifically stated otherwise, the singular forms of the expressions include plural forms of meaning. In this description, the expressions "comprising" or "comprising" are intended to indicate certain features, numbers, steps, operations, elements, parts or combinations thereof, Should not be construed to preclude the presence or possibility of other features, numbers, steps, operations, elements, portions or combinations thereof.

1 is a circuit diagram showing a power supply 100 for lamp driving according to an embodiment of the present invention.

As shown in FIG. 1, the lamp power supply 100 is a two-stage power converter. The power supply 100 includes a rectifier circuit 105, a first stage power converter 110, a second stage power converter 130, Controller 150 may be included.

The rectifying circuit section 105 rectifies the input AC voltage to a rectified voltage and outputs it to the one-stage power converting section 110. [ The output voltage of the rectifying circuit section 105 may be input to the controller 150 for sensing.

The one-stage power converting unit 110 is connected to the output terminal of the rectifying circuit unit 105 and receives the rectified voltage outputted from the rectifying circuit unit 105 and outputs the required direct current voltage by stepping up or stepping down with the power factor correction . The one-stage power conversion unit 110 can realize the step-up and step-down by using an inductor composed of two magnetically coupled windings.

In some embodiments, the one-stage power conversion unit 110 is defined as a coupled-buck-boost converter.

The controller 150 may output the first and second switching signals based on the rectified voltage applied to the first stage power conversion unit 110 and the output voltage of the first stage power conversion unit 110. [

2, the controller 150 compares the rectified half-wave voltage waveform 160 with the output voltage waveform 170 of the one-stage power conversion unit 110 to determine whether the first or second switching A signal can be output. Specifically, the controller 150 compares the rectified half-wave voltage waveform 160 with the output voltage waveform 170 to obtain a first-stage power conversion section 110 at a portion (A) where the half- Stage power conversion unit 110 in order to operate in the boost mode and operates the first stage power conversion unit 110 in the buck mode at the portion B where the half-wave voltage rectified to be higher than the output voltage is higher than the output voltage Stage power conversion unit 110. The first switching signal may be output to the first-stage power conversion unit 110. [

Meanwhile, when the one-stage power conversion unit 110 operates in the buck mode and the boost mode, the switch duty ratios are equal to d1 162 and d2 172, respectively.

The one-stage power conversion unit 110 operates in accordance with the first and second switching signals to operate in a boost (boost) mode and a step-down (buck) mode. Specifically, the one-stage power conversion unit 110 performs power factor correction on the alternating current, boosts the output to the two-stage power conversion unit 130, or performs power factor correction on the alternating current, ).

The first stage power conversion unit 110 includes a first inductor 112 connected to the output terminal of the rectifying circuit unit 105, a first switch 111 connected in series with the first inductor 112, The second switch 113, the second inductor 114 and the second switch 113 may be connected in series and include a second inductor 114 magnetically coupled to the first inductor 112.

In some embodiments, the one-stage power conversion unit 110 includes a first diode 115 connected in parallel with the second switch 113 and the second inductor 114 and connected to the ground terminal, And a second diode 116 connected in series to the second inductor 114. Specifically, a first diode 115 is connected in inverse parallel to the front end of the second inductor 114, and a second diode 116 is connected in series to the rear end of the second inductor 114.

In addition, the one-stage power conversion unit 110 may include a filter capacitor 117 in parallel between the rear ends of the second inductor 114.

The rectified voltage applied to the first inductor 112 through the above-described structure can be induced in the second inductor 114 magnetically coupled. Current flows through the first and second inductors 112 and 114 due to the rectified voltage and the first inductor 112 and the second inductor 114 are switched in accordance with the switching operation of the first and second switches 111 and 113 Current continuous mode or discontinuous mode. Specifically, when current is continuously flowing through the first and second inductors 112 and 114, the first and second inductors 112 and 114 operate in the current continuous mode, and the first and second switches 111 and 112, The first and second inductors 112 and 114 operate in the current discontinuous mode when the current flowing through the first and second inductors 112 and 114 becomes zero during a certain period of the switching period of the first and second inductors 112 and 113.

The first and second switches 111 and 113 may be turned on / off according to the first and second switching signals of the controller 150. Specifically, the first switch 111 is turned on in accordance with the first switching signal to operate the first stage power converter 110 in the boost mode, and the second switch 113 is turned on in response to the second switching signal, The power conversion unit 110 can be operated in the buck mode. The second switch 113 is turned off when the first switch 111 is turned on and the first switch 111 can be turned off when the second switch 113 is turned on.

Also, the first and second switches 111 and 113 use MOSFETs, and the first and second switching signals may be applied to the gates of the first and second switches 111 and 113, respectively.

In some embodiments, the first-stage power conversion unit 110 may be coupled to the first inductor 112 and the second inductor 114 by magnetic coupling (coupling) between the first inductor 112 and the second inductor 114 in the buck mode or the boost mode, And can rectify or boost the rectified voltage through the rate of change of the switch. The second switch 113 is turned off and the first inductor 112 and the second inductor 114 are magnetically coupled to each other so that the power applied to the first inductor 112 is applied to the second inductor 114 Lt; / RTI >

In the boost mode, the one-stage power conversion unit 110 having the above-described configuration improves the power factor of the electronic ballast by adjusting the waveform of the power supply current, and can output a stable high DC voltage. Specifically, when the first switch 111 is turned on, energy is stored in the first inductor 112 and energy is accumulated in the second inductor 114 magnetically coupled to the first inductor 112. The energy charged in the first inductor 112 before the first switch 111 is turned off and the second switch 113 is turned on is transmitted to the filter capacitor 117 and the second diode 116 The power conversion unit 130 may be provided.

The first stage power conversion unit 110 may be connected to the boost converter to output a stable current for driving the lamp 145 in the buck mode. More specifically, when the first switch 111 is turned on, current energy is accumulated in the first inductor 112 and the second inductor 114. When the second switch 113 is turned on in the buck mode, the second inductor 114 Is input to the two-stage power conversion unit 130 through the second diode 116. The two- The power can be stabilized through the return period of the first diode 115 until the second switch 113 is turned off and the first switch 111 is turned on.

The two-stage power conversion unit 130 is connected to the output stage of the one-stage power conversion unit 110. The diagonal direction switching devices of the plurality of switches Q1 to Q4 are alternately operated, And a transformer 140 connected to the igniter circuit 132. The transformer 140 is connected to the exciter circuit 132. The exciter circuit 132 includes a transformer 140, can do.

In some embodiments, the lamp 145 may be connected in parallel to the output stage of the one-stage power conversion unit 110 to connect the contacts between the switches Q1 and Q3 and the contacts between the switches Q2 and Q4.

The igniter circuit 132 receives an AC voltage from the full bridge converter and provides a basic resonant circuit upon initial operation of the lamp 145.

The igniter circuit 132 includes a triac 134 and a capacitor 136 connected between the triac 134 and the transformer 140 to which an alternating voltage is applied, . ≪ / RTI >

The transformer 140 may be comprised of a primary coil 142 connected to the capacitor 136 and a secondary coil 144 magnetically coupled to the primary coil 142.

 The inductance of the primary coil 142 of the transformer 140 may be 22 μH to 25 μH and the inductance of the secondary coil 144 may be 215 μH to 225 μH.

On the other hand, the capacitor 136 of the igniter circuit 132 may be between 8 and 12 nF.

This igniter circuit 132 is for initially driving the lamp 145 such that when the triac 134 is turned on the primary coil 142 and the capacitor 136 of the transformer 140 resonate, The energy generated by the resonance can be transmitted to the lamp 145 through the secondary coil 144. This energy will instantaneously supply a high voltage to the lamp 145 to light the lamp 145.

Thus, after the lamp 145 is driven, the triac 134 is turned off because the output voltage of the full bridge converter is lower than the breakdown voltage of the triac 134. Accordingly, the lamp 145 is driven by the output voltage of the full bridge converter.

The operation of the one-stage power conversion unit 110 having the above structure will be described with reference to FIGS. 4 and 5. FIG.

First, when an operation for boosting the rectified voltage is required in the boost mode, the first switching signal is applied to the first stage power conversion unit 110 in the controller 150. Accordingly, the one-stage power conversion unit 110 can operate with a circuit as shown in FIG. Specifically, the one-stage power conversion unit 110 turns on the first switch 111 and turns off the second switch 113 in response to the first switching signal so that the first inductor 112 is connected to the first switch 111, And a rectified voltage is applied to the first inductor 112. The voltage applied to the first inductor 112 may be induced in the second inductor 114 in a magnetic coupling relationship. In this case, the power induced in the second inductor 114 is supplied to the second diode 116 while the first switch 111 is turned on, as well as the first inductor 112, Stage power conversion unit 130 through the first and second stages.

Next, when a buck mode, that is, an operation for reducing the rectified voltage is required, the controller 150 applies a second switching signal to the first stage power conversion unit 110. [ The one-stage power conversion unit 110 can operate with the circuit shown in FIG. 5 by the second switching signal. Specifically, the one-stage power conversion unit 110 turns on the second switch 113 and turns off the first switch 111 in response to the second switching signal to supply the voltage to the first inductor 112 and the second inductor The voltage applied to the second inductor 114 may be input to the second stage power converter 130 through the second diode 116. [

The operation characteristics and waveforms of the coupled buck-boost converter and the general buck-boost converter of the power supply device 100 for driving a lamp according to the present invention having the above structure are compared through simulation.

6 is a circuit diagram for simulating a buck-boost converter and may be roughly composed of an input stage 188, a bridge diode 189, a buck-boost power conversion stage 191, and a control unit 190 . The control unit 190 may include a controller IC 5555 for verifying the operation of the buck-boost converter 191.

FIG. 7 is a diagram showing a simulation result of the buck-boost power conversion stage 191 of FIG. 7 shows the relationship between the drain-source voltage VDS1 and the current IQ1 of the first switch of the input voltage Vin, the input current Lin, the buck-boost power conversion stage 191, The source-drain voltage VDS2 and the current IQ2 of the second switch, and the application rates S1 and S2 of the respective switches.

As can be seen from the duty ratio waveforms S1 and S2 of the above switches, each of the switches alternately operates 180 degrees out of phase.

The waveform of the coupled-buck-boost converter corresponding to the one-stage power conversion unit 110 of the lamp power supply 100 according to the embodiment of the present invention and the operation result based thereon are shown in FIG. 8 Will be described with reference to FIG.

8 is a simulation circuit diagram of a coupled buck-boost converter corresponding to the one-stage power converter 110 of the power supply 100 for lamp driving according to the embodiment of the present invention. 206, a bridge diode 207, a coupled buck-boost power conversion stage 209, and a control unit 208. The controller IC 5555 is used to verify the operation thereof. In the present invention, each of the inductors, that is, the first inductor 112 and the second inductor 114, is coupled 210 in a buck-boost converter to transfer power.

  FIG. 9 is a diagram showing a simulation result waveform of the coupled-buck-boost converter of FIG. 8. FIG. Specifically, FIG. 9 shows the relationship between the drain-source voltage VDS1 of the first switch 111 of the input voltage Vin, the input current Lin, the buck-boost power conversion stage 209, The source-drain voltage VDS2 and the current IQ2 of the second switch 113 and the application rates S1 and S2 of the first switch 111 and the second switch 113, respectively.

As can be seen from the waveforms above, the coupled buck-boost converter according to certain embodiments operates in the same manner as the buck-booster converter of the power supply for lamp driving of FIG.

9, it can be seen that the optimal coupling ratio of the first inductor 112 and the second inductor 114 is 1: 1, and the switching characteristic, the input voltage and the current waveform at the 1: It can be seen that it comes out stably.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, . Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by equivalents to the appended claims, as well as the appended claims.

100: Power supply for lamp drive
105: rectification circuit part
110: one-stage power conversion unit
111, 113: first and second switches
112, 114: first and second inductors
115, 116: first and second diodes
117: Capacitor for filter
130: Two-stage power conversion unit
132: igniter circuit
134: triac
136: Capacitor
140: Transformer
142: primary coil
144: secondary coil
145: Lamp
150:

Claims (8)

A power supply for driving a lamp,
A rectifying circuit section (105) for rectifying an input AC voltage to a DC voltage;
A first switch 111 connected in series with the first inductor 112 and a second switch 113 connected to one end of the rectifying circuit part 105. The first switch 112 is connected to one end of the rectifying circuit part 105, A second inductor 114 connected in series to the second switch 113, a second diode 116 connected to the second inductor 114, a second switch 113 connected to the second inductor 114, A first diode 115 connected to the other end of the first switch 111 and a filter capacitor 117 connected between one end of the first switch 111 and one end of the second inductor 114, A first-stage power conversion unit 110 including a first power conversion unit 110; And
And a two-stage power conversion unit (130) for receiving a voltage at the rear end of the second diode (116) and supplying power to the lamp (145)
Wherein the first inductor (112) and the second inductor (114) are magnetically coupled to each other.
A power supply for driving a lamp,
A rectifying circuit section (105) for rectifying an input AC voltage to a DC voltage;
A first switch 111 connected in series with the first inductor 112 and a second switch 113 connected to one end of the rectifying circuit part 105. The first switch 112 is connected to one end of the rectifying circuit part 105, A second inductor 114 connected in series to the second switch 113, a second diode 116 connected to the second inductor 114, a second switch 113 connected to the second inductor 114, A first diode 115 connected to the other end of the first switch 111 and a filter capacitor 117 connected between one end of the first switch 111 and one end of the second inductor 114, A first-stage power conversion unit 110 including a first power conversion unit 110; And
And a two-stage power conversion unit (130) for receiving a voltage at the rear end of the second diode (116) and supplying power to the lamp (145)
The first inductor 112 and the second inductor 114 are magnetically coupled to each other,
The igniter circuit 132 for initial operation of the lamp 145 in the two-stage power conversion unit 130 includes a transformer 140 connected to the lamp 145, a triac 134, and a capacitor 136 And a power supply for driving the lamp.
3. The method according to claim 1 or 2,
And the turns ratio of the first inductor (112) and the second inductor (114) are combined at a ratio of 1: 1.
3. The method according to claim 1 or 2,
Wherein the first inductor (112) and the second inductor (114) operate in a discontinuous current mode or a continuous current mode according to the switching operation of the first and second switches (111, 113).
3. The method according to claim 1 or 2,
The lamp driving power supply device
Stage power converter 110, and a plurality of switching elements are alternately operated by pairs of switch elements in the diagonal direction so that a DC voltage output from the first-stage power converter 110 is converted into an AC voltage A two-stage power conversion unit 130 for converting the output power of the power converter 130;
An igniter circuit 132 for receiving AC power output from the two-stage power conversion unit 130 and for initial driving the lamp 145; And
A primary coil 142 connected to the igniter circuit 132 and having a rear end to which the output voltage of the two stage power conversion unit 130 is applied and a secondary coil 142 magnetically coupled to the primary coil 142, And a transformer (140) composed of a secondary coil (144) connected to the secondary coil (144).
3. The method according to claim 1 or 2,
The power supply
The first and second switches 111 and 113 are turned on or off by comparing the DC voltage output from the first stage power conversion unit 110 and the rectified voltage of the rectifying circuit unit 105, Further comprising a controller (150) providing a second switching signal.
6. The method of claim 5,
Wherein an inductance of the primary coil 142 of the transformer 140 is 22 μH to 25 μH and an inductance of the secondary coil 144 is 215 μH to 225 μH.
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