Series input modular architecture for driving multiple LEDs

This paper introduces a modular power converter architecture based on series input connected converter cells with independent outputs that each drive a small series string of LEDs. The approach provides the benefits of operating from a high bus voltage while using low voltage cells that independently regulate LED currents for improved light uniformity and LED failure mitigation. Stability of the series converter string and independent regulation of the floating LED output currents are achieved using a two-loop controller that relies on chain control communications between cells to share system information. Experimental verification of input bus voltage sharing and independent cell current regulation is provided using a prototype of the proposed system with four series buck-boost converter cells, where each cell drives four 700 mA LEDs.

[1]  K. Siri,et al.  Uniform Voltage Distribution Control for Paralleled-Input, Series-Output Connected Converters , 2005, 2005 IEEE Aerospace Conference.

[2]  V. Yousefzadeh,et al.  Hybrid DPWM with Digital Delay-Locked Loop , 2006, 2006 IEEE Workshops on Computers in Power Electronics.

[3]  Dragan Maksimovic,et al.  Nonlinear-carrier control for high-power-factor rectifiers based on flyback, Cuk or Sepic converters , 1996, Proceedings of Applied Power Electronics Conference. APEC '96.

[4]  Fred C. Lee,et al.  A generalized technique for derivation of average current mode control laws for power factor correction without input voltage sensing , 1997, Proceedings of APEC 97 - Applied Power Electronics Conference.

[5]  K. Siri,et al.  Uniform voltage distribution control for series-input parallel-output, connected converters , 2006, 2006 IEEE Aerospace Conference.

[6]  John W. Curran,et al.  Replacement of fluorescent lamps with high-brightness LEDs in a bridge lighting application , 2006, SPIE Optics + Photonics.

[7]  P.T. Krein,et al.  Series-parallel approaches and clamp methods for extreme dynamic response with advanced digital loads , 2004, 2004 IEEE Workshop on Computers in Power Electronics, 2004. Proceedings..

[8]  D. Maksimovic,et al.  Current Sharing in Digitally Controlled Masterless Multi-phase DC-DC Converters , 2005, 2005 IEEE 36th Power Electronics Specialists Conference.

[9]  Robert W. Erickson,et al.  Fundamentals of Power Electronics , 2001 .

[10]  M. Craford,et al.  Status and Future of High-Power Light-Emitting Diodes for Solid-State Lighting , 2007, Journal of Display Technology.

[11]  Michael S. Shur,et al.  Solid-State Lighting: Toward Superior Illumination , 2005, Proceedings of the IEEE.

[12]  Ned Mohan,et al.  Series-parallel connection of DC-DC converter modules with active sharing of input voltage and load current , 2002, APEC. Seventeenth Annual IEEE Applied Power Electronics Conference and Exposition (Cat. No.02CH37335).

[13]  A. K. Behera,et al.  A comparison between hysteretic and fixed frequency boost converters used for power factor correction , 1993, Proceedings Eighth Annual Applied Power Electronics Conference and Exposition,.