Comparison of NiMH and Li-Ion Batteries in Automotive Applications

The pressing need to decrease the greenhouse gases and to improve the efficiency of the existing fleet of vehicles it is imperative that they use some cleaner energy to run the vehicle. Electrical energy can be used in addition with gasoline used by the internal combustion engine of a conventional vehicle to supplement the incremental demand of power above the average power required by the vehicle. This requires for an on-board energy storage system and batteries like NiMH and Li-ion have proven to be efficient storage devices. This paper provides a comprehensive comparison of these batteries used in hybrid electric and plug-in hybrid electric vehicles

Efficiency Analysis and Comparative Study of Hard and Soft Switching DC-DC Converters in a Wind Farm

This paper focuses on efficiency analysis and comparative study of hard-and soft-switching dc-dc boost converters in wind farms. The efficiency of an ac or a dc-based wind farm is dependent on the efficiency of its key components such as dc-dc converters. The demand for dc-dc converters depends on how voltage fluctuations are adjusted. This paper analyzes the efficiency of the switching method used in dc-dc converters. The switching and conduction losses of all the components of the dc-dc converters are modeled and the efficiency is calculated accurately. The power rating vs. efficiency of the dc-dc converters is also considered. The efficiency of the converter in soft switching mode is greater than in hard switching mode. The efficient operation of the converter at a given power rating is shown graphically