Abstract: Aiming at the fault-tolerant operation problem of induction motor driving system with sensor

failures，a smooth fault-tolerant control strategy combining indirect field-oriented control（IFOC），direct torque

control（DTC）and V/f control was proposed. The indirect field-oriented controller and the direct torque controller

were properly modified and integrated with the V/f controller in synchronous coordinate system，which allowed the

DC-type voltage commands of different controllers to switch，so that the three controllers could replace with each

other when the speed，current or voltage sensor failed and restored. At the same time，a rate limiter with a simple

structure was used to achieve a smooth switching transition between different controllers. Experiments were carried

out using a 1.2 kW induction motor driving test platform. The results show that the new fault-tolerant control

strategy achieves fault-tolerant operation under various sensor failures of the induction motor drive system by

smooth switching of the different controllers.

      Key words: induction motor；fault-tolerant contro（l FTC）；sensor failure；smooth switching