Certain investigations on single Stage type 3 bridgeless cuk Converter for current harmonics Mitigation in led lighting Applications

Abstract

Light Emitting Diodes (LEDs) are used in many applications such as general lighting, automotive lamps, aviation lighting, biomedical devices etc. LED lighting applications are more beneficial in terms of reduced size, minimum cost and increased efficiency. However, the input current of the power supply used for driving LEDs has high harmonic content and low Power factor (PF). Harmonic pollution is created at the input side because of the nonlinear nature of the switching devices. Therefore, Power Factor Correction (PFC) converters are employed to reduce the major issues like line current distortion, heat, noise etc. This in turn increases the quality of power delivered and thereby increasing the efficiency of the entire power system. newlineThe use of DC-DC power converters used in the power supply for lighting LEDs for conversion of AC-DC signal has the disadvantages of poor power quality at the source side due to injected current harmonics and reduced PF. Hence PFC circuits are inherently required to reduce the harmonic contents of the line current to meet the specifications as per the standards IEC 61000-3-2 and IEEE 519. Total Harmonic Distortion (THD) plays a vital role in deciding the power factor for LED lighting applications. For obtaining the Unity Power Factor (UPF), % THD has to be zero. The reduction of % THD is necessary to meet the limits defined by the international standards in LED lighting applications. newlineThe major conductive losses incurred by the four input diodes in Diode Bridge Rectifier (DBR) - fed PFC power converter, increases the losses in the LED driver and creates the cross over distortion during zero crossing. As a result, with fewer components running over a single half-wave cycle and reduced on-state losses in the semiconductor devices, a bridgeless newline