High power HID lamps electronic ballast based on the interleaved buck converter

This paper presents an electronic ballast to supply high power (> 400 W) high intensity discharge (HID) lamps based on interleaved converters. Due to HID lamps voltage source characteristics and their acoustic resonance issue, it is necessary to drive them with nearly constant current (reduced ripple) with a square-wave shape. Interleaved topologies become widely used as the output current levels of power converters increases. A well-known topology is the interleaved buck converter (IBC), which presents as main characteristic a low ripple output current source behavior. Therefore, an IBC can be advantageous for supplying high power HID lamps. The main goal of this paper is to introduce an IBC operating in continuous conduction mode (CCM) applied to electronic ballasts, in order to supply high power HID lamps. The IBC inductor design is the target point, since the number of cells, losses and inductor value strongly influence the overall performance in terms of size and efficiency. Inductances, magnetic core and semiconductors are analyzed and compared across the number of cells. Results are verified through simulation in PSIM software and experimentally.