Improved Power Quality Switched-Mode Power Supply Using Buck-Boost Converter

The analysis, design, modeling, and development of a switched-mode power supply (SMPS) for computers are presented here for improved power quality (PQ). The proposed SMPS is capable of mitigating PQ problems associated with a conventional SMPS. It is designed to attain unity power factor and low-harmonics distortion at the input ac mains with regulated multiple dc output voltages. The front-end converter is designed in discontinuous-conduction mode of operation for inherent power factor correction and reduced size of the inductor. Simulated performance of the proposed SMPS is presented to validate its design and to demonstrate its improved PQ performance. Experimental validation of the proposed power supply is also carried on a prototype, and the test results are compared with the simulation results to corroborate the design and modeling. It is found that the proposed SMPS possesses an improved input PQ for a wide range of variations in the supply voltage and loads.