Electronic Ballast with Unity-Power-Factor Based on Current Injection technique

A new combination of power-factor-correction (PFC) and filter components in single-stage electronic ballast is presented in this paper. A symmetrical half-bridge inverter is used to drive the fluorescent lamp. The proposed topology is based on the high frequency current injection technique. The PFC components inject the current at switching frequency into the DC-bus capacitors and keeps the DC-bus voltage above the AC input peak voltage to achieve the ripple-free input current at unity-power-factor and high efficiency over the wide range of input line voltage. The principle of operation and analysis of the proposed electronic ballast is explained, and the experimental results of the laboratory prototype ballast for 2times36 W lamps operating at 50 kHz and 230 V, 50 Hz mains is also presented further