Modular three-phase ac-dc LED driver based on summing the light output of each phase

Abstract

Abstract-This work proposes the driving of high power Light-Emitting Diodes (LEDs) luminaires in three phase power grids using each phase to drive an independent LED load. The driving is done by means of a boost converter in charge of controlling the current across its LED load. Moreover, each boost converter needs to achieve Power Factor Correction (PFC) to comply with IEC 61000-3-2 Class C requirements. Hence, achieving unity Power Factor (PF) and low Total Harmonic Distortion (THD). Taking advantage of the light properties, the output of the LED driver will be the sum of the light of each of the phases. Therefore, a theoretical study will be carried out to observe the feasibility of removing the electrolytic capacitor while guaranteeing a flicker free behaviour of the LED luminaire, even if the current of each string is pulsating at twice the mains frequency. In order to validate the study, a prototype has been built comprised of three PFC boost converters disposing of their electrolytic capacitors. The designed prototype operates in the full range of the European three-phase line voltage, which varies between 380 V and 420 V, and it supplies an output light of 42.000 lm at a maximum power of 300 W while achieving an electrical efficiency of 97.5%.

A Review on Flicker-Free AC–DC LED Drivers for Single-Phase and Three-Phase AC Power Grids

“…20. Multi-cell ac-dc LED driver based on summing the light output of each phase [233], [234]. However, the simplicity and cost efficiency of passive ac-dc LED drivers makes them overall a more attractive solution for LED lamps.…”

“…In contrast, the control and amount of components included in this solution increases dramatically, becoming of interest for high power luminaires (i.e., > 1 kW). In order to improve the efficiency, the multi-cell ac-dc LED driver based on summing the light output of each phase has been proposed in [233], see Fig. 20.…”

“…The total light output of this ac-dc LED driver would be constant, being the sum of lights of each phase, which is a method that was used during the Beijing 2008 Summer Olympics in the National Stadium, also known as Bird's nest, with several spotlights each of 1.5 kW and 125,000 lm [235]. In addition, [233] is able achieve a high efficiency, comply the regulations and achieve a very low Mod. (%), at the cost of having to correctly position the LED loads to adequately blend the light output and having an increased low frequency ripple across the LED loads.…”

Acionamento de Arranjos de LEDs de Altíssimas Potências Empregando Drivers Conectados à Rede Trifásica

“…Fig. 10: Driver multicelular baseado no somatório das saídas de luz (Castro et al, 2018(Castro et al, , 2019b Apresentadas as topologias, a Tabela 1 compara os drivers trifásicos revisados. Algumas considerações devem ser levadas em conta para analisar a Tabela 1:…”

“…Neste trabalho pretende-se abordar especificamente os drivers trifásicos. A utilização desse tipo de driver é interessante pois permite reduzir bastante a capacitância mesmo para LEDs com potências acima dos 300 W (Castro et al, 2018).…”