Performance Evaluation of Lithium‐Ion Batteries on Small Electric Bus

We evaluate performance of lithium‐ion batteries on the small electric bus, conducting tests of cell and battery pack using discharge/charge machine. We suggest the test item on distinction between good and bad of a battery. In the discharge/charge cycle tests of cell at environmental temperature (25 °C), the relative capacity was 60% at 10,000 cycles. In the discharge capacity test of battery packs on the small electric bus, the relative capacity maintained more than 90% in progress for approximately 900 days. Finally, based on these results, we analyzed about influence factor on a battery discharge capacity.     

Isolated Ac/Dc Converter Using Soft Switching Technique

This paper presents a high‐frequency isolated ac/dc converter using the soft switching technique. The ac/dc converter consists of a matrix converter for transforming three‐phase ac voltage to high‐frequency ac voltage, a high‐frequency transformer, and an ac/dc rectifier. In order to reduce the switching loss, soft switching at every commutation of the matrix converter and ac/dc converter is achieved. The effectiveness of the proposed converter and the control scheme was verified by experiments.