Novel electronic ballasts for the solar-energy HID lamp

This paper presents two novel electronic ballasts for solar-energy HID lamps, voltage feedback ballast and current feedback ballast. These two ballasts adopt different strategies to control the working point of the HID lamp. The voltage feedback ballast controls the output voltage and series-wounds large inductor in order to make the virtual current invariable while the current feedback ballast controls the output current directly. The output current of the current feed back ballast is nearly square waveform which can restrain the acoustic resonances effectively. In this paper the circuit topologies, control principle, the simulation and experiment results of the two ballasts are given. Subsequently, comparisons of these two ballasts are analyzed.