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The development of a high-performance battery and safe and reliable charging methods are two important factors for commercialization of the Electric Vehicles(EV) Hyundai and Ovonic together spent many years in the research on optimum charging method for Ni-MH battery This paper presents in detail the results of intensive experimental analysis, performed by Hyundai in collaboration with Ovonic An on-board Ni-MH battery charger and its controller which are designed to use as a standard home electricity supply are described In addition, a 3 step constant current recharger with the temperature and the battery aging compensator is proposed This has a multi-loop algorithm function to detect its 80% and fully charged state, and carry out equalization charging control The algorithm is focused on safety, reliability, efficiency, charging speed and thermal management (maintaining uniform temperatures within a battery pack) It is also designed to minimize the necessity for user input.

It has been recently reported that the crankshaft vibration provides the main exciting source in the power train vibration. This paper presents the analytical method for the vibration of crankshaft by using the finite element method. The optimization process is employed so that the beam model of the crankshaft can have the same natural frequencies as those of solid model on the free-free condition. The mode analysis of the crankshaft whirling is made in the consideration of the gyroscopic effect and the changes of the natural frequencies are also studied with the increase of the engine speed. Finally, the forced vibration of the crankshaft is solved on the time domain and the results are compared with those of the experimental measurements of bending moment by using the strain gage. This crankshft system model can be used to analyze the forced vibration of the full power train as well.

The crankshaft torsional vibration angle is measured from a running engine, using a toothed wheel attached to the front of crankshaft. The torsional vibration stress near the node of torsional vibration is also measured by using strain gages mounted on the journal of crankshaft in a running engine. A theoretical analysis of torsional vibration of crankshaft is performed with a simplified model subject to the excitation torque. The comparison between the theoretical and experimental results shows that the idealized approach is applicable to predict the torsional vibration of crankshaft. It is found that the torsional vibration of crankshaft is mainly dependent upon the characteristics of rubber damper, i.e., the stiffness and damping coefficient of rubber, and the inertia of damper ring. It is recognized that the rubber damper should be carefully selected considering the variation in the dynamic characteristics of rubber.