IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS, VOL. 49, NO. 2, MARCH/APRIL 2013 769 A Novel Flyback-Based Input PFC Stage for Electronic Ballasts in Lighting Applications Jorge Garcia, Senior Member, IEEE, Marco Antonio Dalla-Costa, Member, IEEE, André Luis Kirsten, Student Member, IEEE, David Gacio, Student Member, IEEE, and Antonio J. Calleja, Senior Member, IEEE Abstract—This paper proposes an electronic driver for public lighting systems. The input stage is based on the integration of two flyback converters with different polarities, in order to avoid the use of the input diode bridge rectifying stage. The output stage is a boost converter with an output current control. The proposed circuit is introduced and analyzed, and a design example for a 50-W light-emitting diode lamp is presented. The most relevant simulation and experimental results are also shown, in order to validate the idea. A comparison in terms of efficiency for the input stage is carried out between the proposed topology and the con- ventional flyback converter, showing an efficiency enhancement in the proposed converter. However, the most important advantage of the proposed converter is outlined in the final part of this paper. This advantage comes from the avoidance of the input diode bridge, thus enabling the bidirectional power flow at the input stage. Therefore, the topology can be used to deliver energy into the power grid. In recent lighting applications, the use of micro renewable generators in lighting points has made the use of special electronics to handle the energy flows in the ballast necessary. The present topology is an alternative to standard bidirectional input stages. Index Terms—Bidirectional converters, integration, lighting electronics, microgenerators, power factor correction (PFC). I. I NTRODUCTION L IGHTING electronics remains as a major research topic in the most significant technical conferences and publica- tions due to its relevance in power saving strategies, techniques for rational use of energy, and energy efficiency. Given the importance of these topics in the current global scenario of energy management concerns, the efforts in new light sources Manuscript received June 30, 2011; revised January 19, 2012 and May 28, 2012; accepted May 29, 2012. Date of publication February 1, 2013; date of current version March 15, 2013. Paper 2011-ILDC-344.R2, presented at the 2011 IEEE Industry Applications Society Annual Meeting, Orlando, FL, USA, October 9–13, and approved for publication in the IEEE TRANSACTIONS ON I NDUSTRY APPLICATIONS by the Industrial Lighting and Display Committee of the IEEE Industry Applications Society. This work was supported in part by the Spanish Government Innovation and Science Office (MCINN) under Grant DPI-2010-15889, project “ENERLIGHT”, in part by the European Union through the European Regional Development Fund Structural Funds (Fondo Europeo de Desarrollo Regional), and in part by the Spanish and Brazilian governments under Grant DPI2010-15889, Grant DGPU PHB2010-0145-PC, Grant CAPES/DGU/5267, and Grant CEEE-D. J. Garcia, D. Gacio, and A. J. Calleja are with the Department of Electrical Engineering, Electronics, Computers and Systems, University of Oviedo, 33003 Gijón, Spain (e-mail: J. Garcia@uniovi.es; garciajorge@ uniovi.es; gacio@ate.uniovi.es; calleja@uniovi.es). M. A. Dalla-Costa and A. L. Kirsten are with the Electronic Ballast Research Group (GEDRE), Federal University of Santa Maria, 97105 Santa Maria, Brazil (e-mail: marcodc@gedre.ufsm.br; kirsten.andre@gmail.com). Digital Object Identifier 10.1109/TIA.2013.2244545 Fig. 1. (a) Different stages of an electronic ballast for lighting systems (HID lamps, LED lamps, etc.). (b) Proposed scheme stages for lighting systems. development, research on new electronic topologies, or op- timization and management of lighting systems have turned into the most important research trends in lighting electronics [1]–[6]. The study, analysis, and design of the power topologies used as lighting ballasts are usually carried out considering the different operational blocks that these systems present. Usually, the block diagram of such systems can be represented by the one depicted in Fig. 1(a). As can be seen, this dia- gram consists of an electromagnetic interference (EMI) filter plus a diode bridge rectifying stage in series with an input active power factor correction (PFC) stage. The output of this PFC stage supplies a capacitor, which provides the dc input voltage waveform for the output stage. For high-intensity discharge (HID) lamps supply, this output stage must address the current control, the current inversion, and the ignition. For light-emitting diode (LED) applications, the output stage must cover the current control and the dimming scheme, if featured. In the literature, there are many approaches to deal with this input stage, which usually add some constraints for the output stage design [7]–[11]. For instance, the use of a boost converter as PFC for universal input voltage forces a bus value higher than 400 V, in order to achieve a power factor (PF) close to unity and to fulfill the IEC61000-3-2 standard. This relatively high voltage value determines the design of the power topology of the output stage. On the other hand, if an isolated input stage is used, the output voltage bus value can be lower, as the turns ratio value adds a degree of freedom in the design. This paper deals with the use of a flyback-based topology, which aims to remove the input diode bridge by using the integration of two power topologies, each one for a different polarity of the input voltage [see Fig. 1(b)]. 0093-9994/$31.00 © 2013 IEEE www.IranSwitching.ir