High power factor dimmable self-oscillating electronic ballast with variable inductor control

Abstract

This paper presents a new high power factor dimmable self-oscillating electronic ballast (DSOEB), in which a variable inductor (VI) is used to control the fluorescent lamp (FL) power. Two different approaches are proposed to provide a wide dimming range using a self-oscillating electronic ballast, and a power factor correction (PFC) stage. In the first one, the VI is placed in the series resonant parallel-loaded filter (SRPLI), controlling the rms value of the lamp current with the dc bus voltage supplied by the PFC stage in a closed loop, and in the second one, the VI is placed in the PFC stage, controlling directly the power feeding the inverter. Experimental results for both topologies are presented to evaluate the preliminary performance of the circuit for a 32 W FL.

Analysis and experimentation of the quad‐U variable inductor for power electronics applications

“…These devices have successfully been applied in many power electronics applications, in which they can provide additional control parameters to optimise the converter operation. For instance, they have been used as an additional strategy to control output power in electronic ballast applications [2][3][4][5][6][7]; to provide constant frequency operation in DC-DC resonant converters [8]; to optimise core size in bidirectional DC-DC converters [9]; to improve switching behaviour in DC-DC converters [10]; to provide an independent method to control the current through different LED arrays in a one-stage converter [11,12]; to optimise the operation of power factor correction (PFC) converters [13,14]; and to improve regulation and voltage gain in DC-DC converters [15].…”