Aplicación de fusibles en automóviles eléctricos

The overcurrent protection using fuses is a very established technology, in use for more than a hundred years, for what their advantages and application disadvantages in the traditional electric systems are broadly well-known. The use of this protection type in traditional automobiles (with explosion engine) has been made from the beginnings of their history, being at the present time extended their application to the hybrid or fully electric automobile. The simple extension of the fuse use to these new types of automobiles has shown a new series of application problems that demands a re-study of the protection scheme. Several reports of accidents are already known, being reached in some cases fires with total destruction of the automobile. The main challenges reside in: high voltage, of the order of several hundreds of volts in dc; low fault overcurrents and with low time constant; elevated environmental temperatures; vibrations and strongly variable loads, etc. This last aspect is of great importance, due to the strong thermal and mechanical stresses of the fuse in presence of recurrent loads, reason why classes of service are settling down, similarly to that introduced in the use of motors. Some of the current solutions and the necessity of providing something of intelligence in the traditional fuse are presented. It concludes in the necessity of a new type of fuses for this particular application, detailing their main constructive characteristics.