Nonresonant, quasi-square wave, high-frequency inverter for HID lamps operation from a DC bus

In this paper, a new current control method is applied to a nonresonant, quasi-square wave inverter used to supply HID lamps at high frequency. The chosen control method is previously compared to several current mode and voltage mode control methods. The selection criteria in order to choose a control method are stabilization of the ballast-lamp system and low power high frequency harmonics. With current stabilization, no intermediate stages are needed between the inverter and the DC source; with low power harmonics, decreases the risk of finding acoustic resonances in the high frequency steady state operation. The proposed circuit is specially suitable for the automotive industry, because the inverter can be connected directly to a DC bus.