Patent ID: 6446745
Filing Date: 2002-09-10
Classification: B60L,B62M

Abstract:
A control system for an electric powered vehicle, comprising:a motor; a motor drive control circuit coupled to said motor and providing a motor drive signal thereto; a throttle control circuit providing a throttle signal to said motor drive control circuit corresponding to a desired speed of said motor, said throttle signal comprising a current level; a heat control circuit electrically connected to said motor, said heat control circuit making an estimate of an amount of heat within said motor, based on a measured current load of said motor and comparing said estimated amount of heat to a threshold level, said heat control circuit adding heat credits if said estimated amount of heat is below said threshold level and subtracting heat credits if said estimated amount of heat is above said threshold level; and a motor current select circuit providing a motor current signal to said motor drive control circuit, said motor current signal corresponding to said current level of said throttle signal if an available amount of said heat credits exceeds an amount of said heat credits needed by said current level of said throttle signal, and said motor current signal being reduced if said available amount of said heat credits fails to exceed said heat credits needed by said current level of said throttle signal.