Dimming control by variation of the switching frequency for high-intensity discharge lamps

Abstract

In this paper, a high-frequency dimmable electronic power supply for the highpressure sodium lamp is presented. The method includes a full bridge rectifier generating a dc-link voltage and a half bridge inverter to generate a frequency swept lamp power signal to drive the lamp while avoiding acoustic resonance. A dimming technique for a resonant circuit electronic ballast based on a variable frequency is introduced. In addition, the ability in the dimming range is demonstrated by experiments and simulation in order to verify the performance of the proposed circuit. A dimming range from 100% to 50% has been achieved. The efficiency is always higher than 89% and the ballast can accurately follow a fixed dimming plan.

Wattage-independent dynamic conductance model of compact fluorescent lamps: Validation and application in high-frequency operation

“…Hence, design of frequency dimmable e-ballast for a particular CFL requires R lamp versus P lamp characteristics of the lamp. 23,27–29…”

A design methodology for acoustic resonance-free, high-frequency, dimmable electronic ballast for high-pressure sodium-vapour lamps

“…Conventionally, the dimming action is accomplished by switching frequency variation of the inverter of an e-ballast. 10–12,18 In spite of these earlier significant contributions in e-ballast design procedures, a few research gaps are identified in these works as mentioned below lack of a systematic and generalized methodology to determine AR-free driving frequencies of e-ballast for a wide dimming range; a single lamp wattage is taken into consideration; an ‘equivalent resistance’ of the HF inverter stage is considered instead of actual arc impedance of the lamp. Because of this approximation, complex equations need to be solved to estimate the ballast circuit parameters. …”

“…Although the LFSW topology is well accepted among ballast designers, it possesses some limitations -(i) sizes of inductor and capacitors are bigger due to low-frequency operation, (ii) separate power stage for lamp power control requires additional circuit components which affect the overall circuit efficiency and (iii) design and fabrication of the control circuit is complex. The aforesaid limitations can be addressed by highfrequency (HF) e-ballast with the following attributes [9][10][11][12] (i) smaller inductors and capacitors due to HF operation; (ii) fewer power stages and circuit components; (iii) simpler control circuitry; (iv) improved system efficacy and (v) enhanced life expectancy of the operated lamp due to disappearance of reignition and extinction peaks of lamp voltage waveform.…”

“…Conventionally, the dimming action is accomplished by switching frequency variation of the inverter of an e-ballast. [10][11][12]18 In spite of these earlier significant contributions in e-ballast design procedures, a few research gaps are identified in these works as mentioned below (i) lack of a systematic and generalized methodology to determine AR-free driving frequencies of e-ballast for a wide dimming range; (ii) a single lamp wattage is taken into consideration;…”

Intelligent Control Strategy for Ceramic Metal Halide Lamps

“…Ceramic Metal Halide (CMH) lamps with merits of high efficiency and high color rendering are becoming increasingly popular in publish lightings [1,2]. In previous studies, CMH lamps using inductive ballasts exhibit disadvantages of low power factors and high energy consumption [1].…”