A High-Voltage SiC-Based Boost PFC for LED Applications

This paper reports a single-stage grid-supplied boost converter with power factor correction for light-emitting diode (LED)-applications using Silicon-Carbide (SiC) and operating at the boundary between continuous and discontinuous conduction modes to reduce switching losses. The converter is supplied by a 230 VRMS grid voltage, and attains 1200-V dc at the output port, where a-spot of 320 LEDs connected in series is supplied at constant current. The sliding-mode control theory is employed to analyze the switching regulator dynamics, assuring the system stability. The controller is easily implemented by means of a hysteretic comparator avoiding the risk of modulator saturation. The converter can operate in a normal mode, in which all the input current semicycles are employed, and in a burst mode where only a fraction of all the current semicycles is used. The power switch is realized with silicon carbide (SiC) devices to improve the performance of low-power -grid -supplied LED-based lighting systems. The experimental results are in perfect agreement with the theoretical predictions and demonstrate the feasibility of the proposed approach.