Soft Switching Techniques and Transformer Optimization in Low and Medium Power SMPC

Abstract

newline The advent of semiconductors has contributed to the rapid development of electronic newlineappliances. Today, it is difficult to stay away from these devices in daily routine. newlineDuring the recent past, the number of electronic gadgets has grown exponentially, and newlineall these gadgets operate on stable low voltage DC. This power is derived directly newlinefrom AC mains or from DC batteries, which in turn are recharged from AC mains. newlineThus, all these gadgets have front end AC-DC or DC-DC converters. These newlineconverters are invariably Switch Mode Power Converters (SMPC) working at high newlinefrequencies, and the SMPC are compact and more efficient compared to their linear newlinecounterparts. newlineThe power consumption of appliances for the given tasks has been progressively newlinedeclining due to the invention of better materials, devices, topologies. This scenario newlinehas necessitated the development and use of low power SMPC and fueled the demand newlinefor the improvement of conversion efficiency even at lower powers. The users prefer newlinecompact appliances and expect a continual reduction in the dimensions. Therefore, newlinethe thrust is on achieving better efficiencies in low and medium power SMPC packed newlineinto smaller volumes. To meet these conflicting requirements, adapting soft switching newlineand increasing the switching frequency became ongoing requirements. Characterizing newlinethe losses in any system is the first step in improving efficiency. The majority of newlinelosses in SMPC occur in two elements, viz., MOSFET switches and high-frequency newlinemagnetic components. newlineInitially, the bulk of research done on soft switching related to converters in the range newlineof power higher than 500 watts, as the industry demanded the high power converters. newlineIn most such applications, soft switching is achieved with the addition of auxiliary newlineswitches and the associated control methodology. newlineIn the present day market, high volumes of low power converters in the range of 1 W- newline150 W are in use due to a surge in a variety of electronic gadgets.