High efficiency single-stage Multi-Fluorescent Lamps Electronic Ballast

A single-stage electronic ballast topology with the properties of high efficiency and low stress is proposed in this paper. The ballast consists of a voltage fed half-bridge series-resonant series-parallel-load (SRSPL) inverter, playing the role of lamp driver, and a voltage boost converter, which shares low side switch device with half-bridge inverter and acts as power-factor-correction (PFC). The inverter of the ballast is loaded with resonant tanks which are designed and operated to be capacitive and inductive to theoretically achieve both of zero-voltage switching (ZVS) and zero-current switching (ZCS) that eliminate the reactive current circulating through the switches to prevent low switching and conduction losses. The boost converter of the ballast provides sufficient high voltage to ignite the lamp. In addition, prior to shaping the input current and reducing harmonic currents to ignite the lamp, a power factor correction stage is performed by the converter. The merit of a successive ignition of the lamps can be attained with proposed operation scheme so that current stress imposed on the switches can be reduced. The simulation results and experimental measurements are used to verify the theoretical prediction and analysis.