A dimmable Ćuk half-bridge single-stage converter applied to electrodeless fluorescent lamps

Abstract

A dimmable high-power-factor electronic ballast is proposed in this paper. The electronic ballast is intended to feed a 100 W electrodeless fluorescent lamp (EFL) at 250 kHz. The proposed topology consists of a Ćuk converter, as power factor correction (PFC) stage, associated with a resonant half-bridge inverter, used as lamp power control (PC) stage. In this work, the integration of both stages is proposed in order to reduce the number of active switches, as well as to simplify the required driving and control circuitry for this application. The dimming system is implemented by the shared switch duty ratio control, attaining a power variation from 100 W to 42 W. The implemented topology achieved a high power factor (PF), varying between 0.984 and 0.978. The line current total harmonic distortion (THD) varied from 17.538% to 11.941%, while the measured efficiency was around 80%.

Iterative Method for Analysis of Dimmable Self-oscillating Electronic Ballast Under Bus Voltage Control

“…3) RFL(Pi) -In this step the FL resistance is calculated by (9), which represents the FL resistance as a function of its own power according the FL model shown in 0.…”

“…Manuscript received 04/02/2014; revised 10/07/2014; accepted for publication 01/12/2014, by recommendation of the Special Section Editor Mário Lúcio da Silva Martins. variation, changing the resonant filter parameters (ZFILTER) and by controlling the bus voltage (VBUS) [9]. In practice the combination of these methods can be used in order to improve the performance of electronic ballasts.…”

A Loss-Free Resistor-Based Versatile Ballast for Discharge Lamps

“…Regarding IEFLs, J. Tae-Kun et al [16] present a comparison between two power control methods: the variable switching frequency control and the variable DC-link voltage control method, to conclude that the latter is more suitable for linear dimming operation of the lamp. Later, several authors presented power conversion topologies dedicated to regulating the light in the IEFL [17][18][19][20] with the aim to compare performance and efficiency in the converters. In all these cases dimming control is achieved by adjusting the DC-link voltage.…”