EPE Association: EPE 2013 - LS2f: Electronic Ballasts and Solid State Lighting

EPE 2013 - LS2f: Electronic Ballasts and Solid State Lighting
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 17: Power supplies > EPE 2013 - LS2f: Electronic Ballasts and Solid State Lighting

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   A TRIAC Dimmable Driver Design for High Dimmer Compatibility in Low Power LED Lighting
By Hyunchul EUM, Youngjong KIM, Yongsang SHIN [View]
[Download]

Abstract: LED lighting driver design in TRIAC dimming application has been faced with the difficulties of dimmer compatibility due to low LED power. The LED current dimming is basically controlled by primary side regulation with feedback modulation in the proposed TRIAC dimmable driver. With system compactness and better dimmable compatibility, passive bleeder is designed to stabilize TRIAC turn-on and turn-off operation. Filter discharger is also introduced to keep uniformity of dimmer output voltage to remove visible flicker. The proposed TRIAC dimmable LED driver has been experimentally verified in 3W LED lamp system.

   Designing the high voltage transformer of power supplies for DBD: windings arrangment to reduce the parasitic capacitive effects
By Xavier BONNIN, Hubert PIQUET, Rafael DIEZ, Magin FLOREZ [View]
[Download]

Abstract: In Dielectric Barrier Discharges (DBDs), the control of the power transfer, from the low-voltage static converter to the high voltage DBD, is strongly affected by the parasitic capacitive effects of the step-up transformer. Minimizing these capacitances is of major importance and this paper aims to establish and validate analytical expressions in order to predict the values of the parasitic capacitances of high ratio, step-up transformers, according to different windings arrangements using cylindrical conductors. Afterward, experimental validations are performed on three transformers which have been realized according to same specifications, in order to show the accuracy of the method and to understand the influence the winding arrangements on the capacitive parasitic effects.

   Off-line Single-Stage SEPIC-Buck Converter for Dimmable LED Lighting withReduced Storage Capacitor
By Ricardo PRADO, Marcelo COSETIN, Paulo Cesar LUZ, Marcelo SILVA, Jose Marcos ALONSO [View]
[Download]

Abstract: This paper presents an analysis and design of a Light Emitting Diode (LED) driver aiming to substitute the electrolytic capacitors. Considering the low lifetime of electrolytic capacitors compared to LEDs, this topology aims for reducing the storage capacitance and replaces it by a longer lifetime capacitor, increasing the overall system life span. A Proportional Integral (PI) controller is designed to reduce the output current ripple. Consequently, it reduces the bus voltage which allows working with reduced bus capacitances. The input current distortion limit must be observed. The power factor correction (PFC) stage is based on a Single Ended Primary Inductance Converter (SEPIC) operating under discontinuous conduction mode (DCM) because of its low input current distortion characteristic making it possible to eliminate the electromagnetic interference (EMI) filter. The power control (PC) stage is performed by a Buck converter using its output current source behavior, suitable for LED application. A 107 W LED driver prototype is implemented resulting in 15.2\% total harmonic distortion (THD), 50\% current ripple on the LED and an efficiency of 90.1\% using a 35μF bus film capacitor. Furthermore a dimming strategy is proposed and implemented by an LED parallel active switch.

   Reduction of power losses in measurement subsystem for tapped-inductor based LED driver
By Olegs TETERVENOKS [View]
[Download]

Abstract: The shortage of energy resources as well as the increasing price of electrical power leads to new studies in the field of efficiency improvement for all kinds of electric devices. Lighting systems are not exception. Smart lighting systems are capable to reduce electrical power consumption significantly by the regulation of the illumination level in accordance with proper light regulation strategy. The main element of such a system is a lighting fixture with dimming possibilities. As the ballast of lighting fixture affects the overall efficacy of the device, it is important to evaluate ballast at all operation points (in the whole regulation range). Also the approach of the illumination level control should be taken into account. This paper considers tapped-inductor based driver (which is the key part of the ballast) for a dimmable LED luminaire. Brief description of tapped-inductor converters is given at the beginning of this article. The description of considered parameters is given in the following section. Next section of this paper presents search for the best configuration and topology among the family of tapped-inductor converters. Then the numerical calculations of the considered parameters as well as the results of experiments are summarized. Considerations on the construction of closed loop regulation also are given. Finally, the conclusions about the expediency of the use of tapped-inductor based LED drivers are given.

EPE 2013 - LS2f: Electronic Ballasts and Solid State Lighting
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2013 ECCE Europe - Conference > EPE 2013 - Topic 17: Power supplies > EPE 2013 - LS2f: Electronic Ballasts and Solid State Lighting
	[return to parent folder]

	A TRIAC Dimmable Driver Design for High Dimmer Compatibility in Low Power LED Lighting By Hyunchul EUM, Youngjong KIM, Yongsang SHIN	[View] [Download]
Abstract: LED lighting driver design in TRIAC dimming application has been faced with the difficulties of dimmer compatibility due to low LED power. The LED current dimming is basically controlled by primary side regulation with feedback modulation in the proposed TRIAC dimmable driver. With system compactness and better dimmable compatibility, passive bleeder is designed to stabilize TRIAC turn-on and turn-off operation. Filter discharger is also introduced to keep uniformity of dimmer output voltage to remove visible flicker. The proposed TRIAC dimmable LED driver has been experimentally verified in 3W LED lamp system.

	Designing the high voltage transformer of power supplies for DBD: windings arrangment to reduce the parasitic capacitive effects By Xavier BONNIN, Hubert PIQUET, Rafael DIEZ, Magin FLOREZ	[View] [Download]
Abstract: In Dielectric Barrier Discharges (DBDs), the control of the power transfer, from the low-voltage static converter to the high voltage DBD, is strongly affected by the parasitic capacitive effects of the step-up transformer. Minimizing these capacitances is of major importance and this paper aims to establish and validate analytical expressions in order to predict the values of the parasitic capacitances of high ratio, step-up transformers, according to different windings arrangements using cylindrical conductors. Afterward, experimental validations are performed on three transformers which have been realized according to same specifications, in order to show the accuracy of the method and to understand the influence the winding arrangements on the capacitive parasitic effects.

	Off-line Single-Stage SEPIC-Buck Converter for Dimmable LED Lighting withReduced Storage Capacitor By Ricardo PRADO, Marcelo COSETIN, Paulo Cesar LUZ, Marcelo SILVA, Jose Marcos ALONSO	[View] [Download]
Abstract: This paper presents an analysis and design of a Light Emitting Diode (LED) driver aiming to substitute the electrolytic capacitors. Considering the low lifetime of electrolytic capacitors compared to LEDs, this topology aims for reducing the storage capacitance and replaces it by a longer lifetime capacitor, increasing the overall system life span. A Proportional Integral (PI) controller is designed to reduce the output current ripple. Consequently, it reduces the bus voltage which allows working with reduced bus capacitances. The input current distortion limit must be observed. The power factor correction (PFC) stage is based on a Single Ended Primary Inductance Converter (SEPIC) operating under discontinuous conduction mode (DCM) because of its low input current distortion characteristic making it possible to eliminate the electromagnetic interference (EMI) filter. The power control (PC) stage is performed by a Buck converter using its output current source behavior, suitable for LED application. A 107 W LED driver prototype is implemented resulting in 15.2\% total harmonic distortion (THD), 50\% current ripple on the LED and an efficiency of 90.1\% using a 35μF bus film capacitor. Furthermore a dimming strategy is proposed and implemented by an LED parallel active switch.

	Reduction of power losses in measurement subsystem for tapped-inductor based LED driver By Olegs TETERVENOKS	[View] [Download]
Abstract: The shortage of energy resources as well as the increasing price of electrical power leads to new studies in the field of efficiency improvement for all kinds of electric devices. Lighting systems are not exception. Smart lighting systems are capable to reduce electrical power consumption significantly by the regulation of the illumination level in accordance with proper light regulation strategy. The main element of such a system is a lighting fixture with dimming possibilities. As the ballast of lighting fixture affects the overall efficacy of the device, it is important to evaluate ballast at all operation points (in the whole regulation range). Also the approach of the illumination level control should be taken into account. This paper considers tapped-inductor based driver (which is the key part of the ballast) for a dimmable LED luminaire. Brief description of tapped-inductor converters is given at the beginning of this article. The description of considered parameters is given in the following section. Next section of this paper presents search for the best configuration and topology among the family of tapped-inductor converters. Then the numerical calculations of the considered parameters as well as the results of experiments are summarized. Considerations on the construction of closed loop regulation also are given. Finally, the conclusions about the expediency of the use of tapped-inductor based LED drivers are given.