A PFC Power Supply with Minimized Energy Storage Components and a New Control Ttechnique for Cascaded SMPS

• Main Author: Frost, Damien F.
• Other Authors: Lehn, Peter W.
• Language: en_ca
• Published: 2012
• Subjects: power factor corrected; PFC; smps; switch mode power supply; energy storage; minimized energy storage components; cascaded converter; cascade; duty mode control; dmc; new control technique; harmonic current; portable electronic equipment; 0544
• Online Access: http://hdl.handle.net/1807/33727

This Master of Applied Science thesis proposes a new design of low power, power factor corrected (PFC), power supplies. By lifting the hold up time restriction for devices that have a battery built in, the energy storage elements of the converter can be reduced, permitting a small and inexpensive power converter to be built. In addition, a new control technique for controlling cascaded converters is presented, named duty mode control (DMC). Its advantages are shown through simulations. The system was proven using a prototype developed in the laboratory designed for a universal ac input voltage (85 - 265VRMS at 50 - 60Hz) and a 40W output at 12V. It consisted of two interleaved phases sensed and digitally controlled on the isolated side of the converter. The prototype was able to achieve a power factor of greater than 0.98 for all operating conditions, and input harmonic current distortion well below any set of standards.