Tesis
Projeto de reatores eletronicos para hid baseado no conversor chopper AC
Fecha
2007-08-24Registro en:
TOMM, Fabio Luis. Design of a Chopper-based Electronic Ballast to Supply HID Lamps. 2007. 84 f. Dissertação (Mestrado em Engenharia Elétrica) - Universidade Federal de Santa Maria, Santa Maria, 2007.
Autor
Tomm, Fabio Luis
Institución
Resumen
This thesis proposes a design of a power supply for high-pressure discharge lamps based on a high efficiency and high power factor electronic ballast, without exciting the
intrinsic acoustic resonance. The ballast consists on a bipolar buck chopper operating in continuous conduction mode (CCM), with an input filter, and an igniter circuit. It works with a switching frequency of 33 kHz and supplies the lamp in the mains frequency. The igniter circuit provides the necessary high voltage for the lamp's startup initial procedure. It is controlled by an 8 bits microcontroller, thus contributing to reduction in the number of parts and the ballast final cost, without compromising its reliability. Two possible solutions for an
igniter circuit are proposed, the first based on a igniter device, and the second on a LC resonant circuit. A study on the ignition process and the required circuits to guarantee it, and a brief review on the electrical characteristics of electromagnetic ballasts are also included as secondary contributions. Experimental results with a 70W HPS lamp supplied by a 220V±20% and 60 Hz mains, are presented to validate the proposed ballast. The behavior of the experimental ballast shows that it is a good choice in avoiding unstable effects provoked by acoustic resonance phenomenon.