Reducing storage capacitance in off-line LED power supplies by using integrated converters

Matching LED and Driver Life Spans: A Review of Different Techniques

“…This happens because using two separate power-processing stages somehow results in the decoupling of the PFC from the PC functions, whereas the introduction of a new variable (i.e., the dc bus voltage) allows for one additional degree of freedom in the converter design. Increasing the designed bus voltage at the nominal operating point results in lower capacitance needed to bear the same amount of power handling; also, the second stage (i.e., the PC) can perform some sort of passive ripple compensation or attenuation without affecting the PFC stage [15], even when both stages are integrated and there is a loss in control freedom. This is because the power imbalance that each stage has to deal with is always less than the total amount of power imbalance that a single-stage converter would have to buffer, given the same load power rating.…”

“…Because the frequency of interest in the sizing of the capacitor is low (twice the line frequency), multiple-stage lEd drivers in general are usually very effective in reducing the overall capacitances but may impair the conversion efficiency due to redundant power processing and increased semiconductor stresses. the capacitance required for such filter is usually large [15].…”

Fuzzy LPCM controlled buck integrated PFC convert-er for Class-C&D appliances

“…To meet IEC regulations, considered conduction angle is 1300 to reach highest PF of 0.96 as in ref [4]. Table.2 shows few defined specifications.…”

“…PFC converter in this paper is realized by integrating buck and flyback converters. The load is fed from the source through buck and flyback converters, both are operating in DCM mode to deliver high PF [2], [3], [4]. In recent year, an Artificial Intelligent technique like Fuzzy control is adopted to improve the gains of the controllers to give better performance.…”

Analysis of a Resonant AC‐AC LED Driver

“…It is well known that many electronic converters are using an input rectifier and a high-electrolytic filtering capacitance [1,2]. In high frequency commutations, this electrolytic capacitors have reliability issues, and this fact is limiting the lifetime of the overall LED system [3][4][5][6][7]. In addition, the use of high capacitance electrolytic capacitors remains a problem in achieving high power density and high power factor.…”