Design of Fault-Tolerant Dual Three-Phase Winding PMSM for Helicopter Landing Gear EMA

On modern rotorcraft, electro-mechanical actuators (EMAs) are progressively replacing the bulky and more expensive hydraulic and/or pneumatic systems. Although the migration towards alternative actuation solutions, reliability remains a key requirement for aerospace applications. Fault-tolerant electrical machines are often employed for ensuring the demanded reliability level. In this paper, the design of a dual three-phase winding permanent magnet synchronous machine (PMSM) for helicopter nose landing gear extension/retraction EMA is addressed. Finite element (FE) simulations are used for evaluating the PMSM performance in both healthy and faulty conditions. The compensation strategy implemented on the healthy three-phase winding, while the second one is completely shorted, is also discussed. Finally, a purposely built dual three-phase winding PMSM model is implemented in Dymola environment, where the extension/retraction EMA is simulated. Hence, EMA behaviour under both healthy and faulty conditions is analysed.