An electronic HID lamp ballast based on single-stage power conversion

This paper presents a single-stage electronic ballast for the high-intensity-discharge (HID) lamp with high power factor. The presented ballast consists of a discontinuous-conduction-mode (DCM) operated bridgeless boost converter to achieve input current shaping and a high-frequency combined with low-frequency square-wave-driven full-bridge-type inverter for supplying the HID lamp with low-frequency square-wave sources. The features of the proposed ballast are high power factor, low total harmonic distortion (THD) of input utility-line current, cost-effectiveness and freedom from acoustic resonance. This paper presents the operational principles and experimental results of the proposed ballast for one 70W MH-type HID lamp operating with 110V-rms input utility-line voltage.