www.tjprc.org editor@tjprc.org A STOCHASTIC FUZZY CONTROLLED RESONANT CONVERTER FOR DISCHARGE LAMPS WITH PFC M. VIJAYASANTHI 1 & M. SUSHAMA 2 1 EEE, CMRCET, Secunderabad, Telangana, India 2 EEE, JNTUH, Hyderabad, Telangana, India ABSTRACT The brightness of discharge lamps is controlled by varying the frequency of the resonant converter for high efficiency operation. In this paper we introduce a resonant converter with a magnetic energy recovery switch along with power factor correction. The PFC converter generates DC voltage controlled by fuzzy controller as a feedback system connected to discharge lamp through high frequency resonant converter. The complete analysis with different frequencies and graphical representations of output voltage and current of the lamp are presented using MATLAB software with dynamic operating states. KEYWORDS: Resonant Converter, Fuzzy Logic, PFC, Discharge Lamp & Ballistic Inductance Received: Jan 28, 2017; Accepted: Mar 12, 2017; Published: Mar 16, 2017; Paper Id.: IJEEERAPR20177 INTRODUCTION Most of the lamp applications in commercial or industrial usage need brightness control with respect to the demand by the user. In conventional controller a resistive type control is adopted for the brightness control which has high conduction loses. With high power consumption of the lamp the power loss during the control of brightness is also high. It is very vital to save the energy consumed by the lamp and increase the efficiency. Due to the plasma characteristics of the discharge lamps it is very difficult to control the brightness. By controlling the voltage amplitude using variable resistor in series works for filament lamps but the same may not be suitable for discharge lamps [1]. Several research papers are released with emphasis on brightness control of discharge lamps and efficiency with drawbacks of complicated designs and uneconomical costs of the circuit topologies. The high frequency operation of the converter leads to acoustic resonance problems reducing the reliability of the converter and also the lamp. To avoid this issue of acoustic resonance magnetic ballast has to be introduced in place of electronic ballast [1]. The replacement of electronic ballast with magnetic ballast may increase complications during the construction of the circuit topology. There are many traditional methods for ballast applications [2] in which the most common method [2] is changeable ballast inductance method with different possible ballasts on the lamp. The ballast control can only be done by step process as the resolution of inductance values may not be high. The brightness of the lamp cannot be adjusted precisely to a specific value, to overcome this issue larger values of inductances need to be taken which increases the size, weight and cost of the ballast circuit topology [2]. Discharge lamps are categorized into High Intensity discharge lamps and fluorescent lamps. High intensity discharge lamps include metal halide lamps, mercury lamps and high pressure sodium lamps. As compared to Original Article International Journal of Electrical and Electronics Engineering Research (IJEEER) ISSN(P): 2250-155X; ISSN(E): 2278-943X Vol. 7, Issue 2, Apr 2017, 55-62 © TJPRC Pvt. Ltd.