Estudo, análise e implementação de formas de onda de tensão sintetizadas através de PWM, com estágio de ignição e de correção de fator de potência para reatores eletrônicos para lâmpadas HPS

Abstract

This work presents the study of a method for synthesize of voltage waveforms with special characteristics, with the purpose of feeding High-Pressure Sodium (HPS) lamps in order to avoid acoustic resonance. Acoustic resonance is the main problem found when it works with high frequency inverters to the operation of High Intensity of Discharges (HID) lamps. Studies on HPS lamps have been done, emphasizing the acoustic resonance problem, plus the analysis of the passive ballasts and the electronic ones, operating at high and low frequencies. The proposed study of the voltage waveforms is made by their synthesis via PWM, using a full bridge inverter and an LC filter specifically designed for this purpose. For this method, two techniques are proposed: voltage waveforms with injection of harmonics to the fundamental one; and modulated signals with saturation. Experimental results of the ignitor integrated to the $LC$ filter are presented, allowing the lamp ignition and increasing its lifetime. The power factor correction (PFC) stage of such converter is also presented, by means of a repetitive controller. Simulation results and design methodologies are presented, as well as experimental results, showing the efficacy of the method.