Development of a two quadrant boost DC-DC converter

Abstract

Switch mode DC-DC converters are attractive for their small size, ease of control and efficient power conversion. The voltage regulation is achieved by duty cycle control of the switching signal of the semiconductor switch of the SMPS. In a practical SMPS, the efficiency and the voltage-gain are function of the duty cycle. Basic DC-DC converters are all one quadrant chopper converters. In one quadrant operation the current through the load or from the source can flow in one direction only. With the increase of battery storage based conventional and renewable energy conversion, and rise of DC-DC converter in DC drives of electrical and hybrid vehicles, research is growing in multiquadrant DC-DC converters. The building blocks of multi-quadrant DC-DC converters available in literature are two quadrant DC-DC converters based on the combination of Boost and Buck or Buck and Boost converters. Two quadrant DC-DC converter building blocks based on Buck and Buck, or Boost and Boost are very hard to find in references. As per need, any of the conventional SMPS circuit may be modified for two quadrant operation with the use of two switching devices in the circuit instead of one. In this thesis, conventional Boost-Boost chopper circuit arid modified Boost-Boost chopper circuit are proposed for two quadrant operation. In these converters, it is required to set duty cycle in both part of the Boost-Boost converter unlike Boost-Buck and Buck-Boost two quadrant DC-DC converter. The efficiency in general is almost similar in case of conventional and modified Boost-Boost two quadrant DC-DC converter. The said converters can be used to supply power to any DC load by keeping it at any end of the circuit and by keeping a DC source at another end as power can flow in any direction. So there is no requirement of removing or repositioning an item with this converter depending on whether it is a source or a load unlike a Boost-Buck or Buck-Boost two quadrant DC-DC converter.