Analysis and Simulation of a Non-Isolated Cascaded High Gain Boost Converter
Swarnali Jhampati, Palash Mondal, Shib Sankar Saha
Department of Electrical Engineering, Kalyani Govt. Engineering College, Kalyani, W.B., India
Conventional dc-dc boost converters can’t practically achieve a voltage gain beyond 6 to 7 due to the requirement of high duty ratio above 0.9, which causes increased switching losses and subsequently lower operational efficiency. Two or more boost converters in cascade can help in achieving high voltage gain but with the cost of two-stage conversion loss and high initial cost of investment. On the other hand, generation of 230 V ac supply using conventional single phase inverter requires input dc bus level of at least 360 V. In this work, a single stage non-isolated cascaded boost converter using a coupled inductor is presented to step up a dc source from 48 V to the level of 360 V, as required for single phase inverter. This converter can find wide applications in telecommunication systems for supply of ac power to local loads like modems, LANs, lights, fans etc. at base transceiver stations. Only few passive components like a coupled inductor, two capacitors and three diodes, in addition to the required minimum components of conventional boost converter are required for this converter. The operating modes and key waveforms of the developed converter have been presented along with key mathematical equations governing dynamic behavior of the converter. Computer simulation using MATLAB/Simulink of the present converter at different load conditions has been carried out to verify its performance and the important results are presented in this paper.
Boost –converter; coupled inductor; duty-ratio, cascade; voltage gain