Abstract-One of EV power system's important
characteristics is high voltage and large current. Creepage
distance ofEV on-board energy storage device should be less
than safety margin, for avoiding such harm that from
explosion, fire or toxic substances, the protection of power
battery overcorrect should have corresponding security
standard. The electric motor drive of EV may appear faults
when facing the special danger situation. So we should take
some measures to ensure that it could work normally and
avoid fault. It should be required that there are
corresponding safety measures to protecting personnel
electrocuting when EV without external power supplies. It
should be required the measures for in case of short circuit,
for protecting the harm to passengers and the third party
from on-board energy storage device when vehicles colliding,
too.