Survivable Operation of Induction Machine Drives With Smooth Transition Strategy for EV Applications

In electric vehicle (EV) applications, the failure of phase current sensors often leads to emergency shutdown of induction machine (IM) drive to avoid system malfunction and protect the driver and hardware. However, emergency stop is not necessarily the best way to react if current sensor fails. This paper proposes a survivable operation technique for three-phase IM drives in the event of current sensor failure. The basic objective of survivable operation for IM is to seamlessly switch the control method from vector control to a simplified digital control with smooth transition strategy in the event of current sensor failure. Using this technique, the IM system can be kept running even when there are current sensor faults. It can therefore add one extra redundancy in EVs and make them safer and more reliable. Simulation and experimental results, including current sensor failure detection, speed and torque response, voltage vector, and phase-current waveforms, are included to show the effectiveness of the proposed strategy.