Failsafe Control Methods for EVs with the Structure Driven by Front and Rear Independently

摘要

This paper describes failsafe control methods for electric vehicles (EVs) with the failsafe structure that are driven front and rear wheels independently. Based on failure-diagnosis results, the failsafe control is performed by dividing fault states into two states, i.e. a slight failure such as a current or a speed sensor failure and a serious failure such as an inverter or a motor failure. When the latter serious failure takes place, the EV keeps on driving with only the healthy drive system by separating the drive system including the failed inverter or motor. On the other hand, in the former failures, a fault tolerant control is performed that keeps on driving while compensating for the function of the failed sensors so that the drive performance before failure can maintain as much as possible. Effectiveness of the proposed methods is verified through simulations and experiments using the bench test equipment which is equivalent to the actual EV drive systems and the prototype EV.