Abstract:
Switch mode dc-dc converters are attractive for their small size, ease of control and
efficient power conversion. Output voltage is regulated by duty cycle control of
semiconductor switch of switch mode dc-dc converters. The voltage gain and
efficiency of practical switching regulators deviate from ideal values at extreme duty
cycles. Also, desired gain /attenuation is not achievable at high/low duty cycles. In
applications where high gain or high attenuation of voltage is desired with acceptable
energy conversion efficiency, hybrid dc-dc switching converters are used. Hybrid dcdc
converters are combination of voltage multiplier/division circuit with appropriate
SMPS circuits. By incorporating voltage multiplier/division cell with conventional
converters like Buck, Boost, Buck-Boost, Cuk and SEPIC converters, desired voltage
gain (either very low or very high) may be achieved at acceptable energy conversion
efficiency. In the present work with an aim to attain very high voltage gain by
conventional Boost, Buck-Boost, Cuk, and SEPIC topologies, a new voltage
multiplier cell consisting of multiple inductors and diodes is proposed. The proposed
voltage multiplier cell can be duplicated in multiple number and attached at the input
side of Boost, Cuk, and SEPIC converters for hybrid operation to attain very high
voltage gain at acceptable energy conversion efficiencies. In the present work,
proposed multi-inductor voltage multiplier cell is attached to input side of Boost, Cuk,
SEPIC and Buck-Boost converters and the performance of the resulting hybrid
converters are studied generically by simulation. The performances of proposed
hybrid converters have been compared with the performance of a previously reported
two inductor voltage multiplier cell based hybrid dc-dc converters. The performance
results were almost similar for both hybrid high gain dc-dc converters. However, it
has been shown that the voltage gain can be further enhanced by more than two
inductor cell voltage multiplier in the proposed circuits. The inductor numbers are
limited to two in previously reported high gain hybrid dc-dc converter. Hence, the
investigation of this research has come up with a new proposed multiplier, which
when attached to the front end of dc-dc Boost, Cuk and SEPIC converters may
provide very high voltage gain at acceptable energy conversion efficiency.
