ABSTRACTHIGH EFFICIENCY & HIGH PERFORMANCE CONVERTER/INVERTER SYSTEM CONFIGURATIONS FOR HEV/EV TRACTION DRIVESByCraig B. RogersAbstract--Hybrid and electric vehicles are becoming increasingly important as the cost of available resources increase and as pollution and greenhouse gasses become more pressing concerns. Hybrid and electric vehicles offer a means to increase efficiency and decrease pollution and greenhouse gasses. Whether the hybrid system is a series or series/parallel system, the vehicles discussed in this work use an internal combustion engine (ICE), an AC electric generator, a passive/active rectifier/inverter, a power storage system, a traction motor inverter, and a traction motor/brake. The value of the hybrid vehicle comes from its increased efficiencies. The hybrid system decouples the ICE's power and speed from that of the vehicle. This decoupling is accomplished by replacing the traditional mechanical or hydro mechanical transmission with power electronics and energy storage facilities. This decoupling allows ICE operation at its most efficient power versus speed point. During normal operation, the energy storage system can be used to handle the dynamic loads and the internal combustion engine can handle the steady state loading. This hybrid system also recaptures braking energy which is lost with conventional vehicle systems. The power electronics facilitate the process via control of power flow, battery management, motor control and generator control. The existing hybrid vehicle power electronics topologies are discussed which include the traditional back to back voltage source inverter to voltage source inverter configuration as well as the newer back to back Z-Source type configurations. Each of these designs has specific operation modes, control methods and features that are analyzed and discussed in this document. The advantages and disadvantages of each are discussed and this will form a basis upon which the new high efficiency designs proposed in this work can be compared. Finally, several new higher efficiency topologies are proposed and the basic features and functionality of these proposed configurations are discussed. These new configurations are then analyzed and quantified in terms of calculated efficiency.
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