High-voltage Linear LED Driving for Three-phase AC Power Grids: A Competitive Scheme for General Lighting

AbstractThis work investigates the high-voltage linear multi-string LED driving scheme for three-phase AC power grids and confirms the superiority and practicality of this scheme in lighting applications for the first time. Three-phase AC power amplifies the excellent performance of linear multi-string LED driving systems in comparison to single-phase AC power. Based on the features of the rectified voltage waveform in the three-phase AC power supply, the LED distributions of the linear multi-string LED driving scheme were calculated with a unique optimization method to balance LED power and driving efficiency within ± 10% voltage fluctuations. And a double-string LED lighting system was constructed as a module prototype with the capability of scaling up. The experimental results exhibit high driving efficiency (~ 94% @380V line voltage), high power factor (~ 0.952), flicker-free, and high reliability at an extremely low cost (~$0.005/W).