A Soft-Switched Boost Converter Based LED Driver With Reduced Input Current Ripple

Abstract

This paper proposes a soft-switched paralleled boost converter based LED driver for street lighting application. Output of paralleled boost converter (BC) in the form of full-bridge feeds a buck-boost converter (BBC). The outputs of paralleled BC and BBC are added to power LED lamps. The paralleled boost converters help in reducing the source current ripple with small inductors and also can handle large power. Regulation of the load voltage is achieved by BBC which handles small power without significantly affecting the overall efficiency. Soft switching of the devices in boost converters is achieved with a ZVS inductor resulting in high efficiency. PWM based dimming control is employed. The LED driver can be fed from batteries, ultra-capacitor, etc. A prototype of 65 W DC-DC converter for LED lighting is developed. The experimental results are in good agreement with simulation results. The proposed converter offers high efficiency of 93.42%, reduced source current ripple, and dimming control. Efficiency of the proposed converter with SiC MOSFETs is around 95% at all voltage variations.

Keywords

• Synchronous boost converter
• ripple cancellation
• synchronous rectification
• zero voltage switching
• LED lighting
• buck-boost converter