Generalized Analysis and Comparison of High-Power-Factor Integrated Topologies to Supply Metal Halide Lamps with Low Frequency Square Waveform

This paper presents a generalized analysis of several integrated topologies with high power factor to supply metal halide lamps. The analyzed topologies that provide power factor correction are: buck, boost, buck-boost, flyback, sepic and zeta converters. These topologies are integrated with an output flyback converter to obtain the complete ballast. The output flyback converter is composed of one primary and two secondary windings that are switched at low frequency. In this way, the lamp is supplied with a low frequency square waveform, and acoustic resonances can be avoided. The proposed analysis makes use of the graft switch technique to obtain the different integrated topologies. The design methodology that can be employed to calculate the circuit parameters is also presented in detail. Finally, some simulation results are shown in order to confirm the design methodology and to compare the proposed integrated converters.