| A multilevel DC-DC converter converts a DC source from one voltage level to another level. DC-DC converters are important in portable devices like cell phones, laptops, etc., as well as in applications such as electric vehicles, which have sub-circuits operating at voltages different from the supply voltage. In this thesis, two new multilevel DC-DC converter system modules: one-to-many topology and cascaded topology are presented. Comparisons are made for the proposed multilevel DC-DC converter systems along with the existing multilevel DC-DC converter system. The comparisons are made in the terms of range of the output voltage, maximum output voltage, number of steps of output voltages, number of switches operated for any given output voltage, and the ripples in the output voltage Among all the proposed converter system topologies, cascaded topology with even number of modules turned out to be more efficient in terms of maximum output voltage and number of steps of output voltages.;Two new different multilevel DC-DC converter modules are presented in this thesis. However only one of them facilitates the implementation of cascaded topology of DC-DC converters and decrease the transition currents, while other just decrease the transition currents. Comparisons are based on different losses during the circuit operation, ripple voltages, and efficiency. One of the proposed converter modules limits the transient currents significantly over existing converters during the output voltage transition in multilevel DC-DC converter topologies for a given transition time. Though the efficiencies of the proposed modules are slightly less (< 1%) than the existing converter modules they facilitate the implementation of cascading converters. Also the reduction in the transition currents can potentially increase the life of the converter modules. |
