Digital Control of Induction Machines as a Backup Control Strategy for Fault Tolerant Operation of Traction Motors

Induction machine (IM)-based electric vehicle applications have gained significant popularity over recent years. However, failure of IM drivetrain components can lead to system malfunction and result in vehicle shutdown. Controller redundancy method is often used to tolerate microcontroller failure. However, this method results in high cost and complicates system design in terms of controller synchronization. This paper proposes a simplified digital control method for IM with low hardware requirements. Potentially, digital control method can work using simple auxiliary circuits without a microcontroller and can be used as a backup control strategy to maintain continuous operation of the IM in the event of microcontroller failure. This paper focuses on introducing the principle and implementation of digital control for IM and evaluating its performance. This digital control method can control three-phase squirrel cage IM system and enables motoring and generating operation. This method is extremely simple in design and implementation. Simulation and experimental results are included in this paper to validate our claims.