ELECTRONIC BALLAST FOR METAL VAPOR LAMPS USING INTEGRATION TECHNIQUES FOR POWER FACTOR CORRECTION AND ACOUSTIC RESONANCE ELIMINATION

摘要

Electronic ballast for metal vapor lamps using integration techniques for power factor correction and acoustic resonance elimination describes high frequency electronic converters used with high intensity discharge metal vapor or metal halide lamps. Integration techniques are used to obtain a high power factor and to reduce the output power oscillation in order to eliminate the acoustic resonance phenomenon. Two controlled switches are used, which integrate the half-bridge voltage-source inverter function to supply the lamp and the power factor correction function. The integration of these functions is obtained by using two passive filtering structures (using inductors and capacitors). The output filtering elements are responsible for limiting the current supplied to the lamp and its harmonic content. The input filtering elements make it possible to achieve an input current with low harmonic content when charging the dc-link capacitors. Furthermore, if designed properly, the input filter capacitors in conjunction with the line impedance operate as a filter to reduce the harmonic current of the ballast's input current even further.