Highly Integrated and Fault-Tolerant Actuator for Next Generation Electric Aircraft Doors

To realize More Electric Aircraft (MEA), there is a need for compact, lightweight and fault-tolerant actuators for several applications in an aircraft. This paper presents a highly integrated and fault-tolerant actuator for an electric door application in future aircraft. The drive system consists of a fault-tolerant inverter and a dual three phase permanent magnet synchronous machine (PMSM). The six phase inverter consists of two separated three phase inverters with individual DC link capacitors. In case of a short circuit in the inverter or the motor, the circuit breaker automatically turns off the corresponding faulty three phase subsystem. The remaining healthy three phase system can still perform an emergency opening without overheating. In addition, thermal fuses are installed inside the actuator, releasing a fire-extinguishing gas in the event of a fire inside the door actuator. The motor has a concentrated single-tooth winding, which reduces the axial winding head and the magnetic coupling between the phases. This enables easier motor control in the event of a failure of a three phase system. The phases are also spatially separated around the circumference of the stator.The inverter has a cylindrical design to make optimum use of the available installation space. The net weight of the inverter, including the electromagnetic interference (EMI) filter is approximal 0.27 kg and the net weight of the motor is approximately 0.68 kg. The maximum output power is about 1.1 kW at a 48 V DC supply.