Evaluation of the intrinsic fault tolerance of an EMA landing gear based on a five-phase SM-PMSM

Nowadays, aircraft electrification is being intensively investigated by the industry and academia in order to meet the actual environmental goals regarding pollutant emissions. In this context, the More Electric Aircraft (MEA) initiative is leading to the progressive substitution of hydraulic systems by power electronics based electromechanical actuators (EMA). Although three-phase electrical machines are the industry standard, the introduction of multiphase systems provides a number of benefits, such as an increased fault tolerance. Taking this into account, this paper analyses, the intrinsic fault tolerant performance of an EMA landing gear (for extension/retraction operation) based on a five-phase surface mounted permanent magnet synchronous machine (SM-PMSM) in terms of torque regulation under a variety of open circuit fault conditions. A detailed simulation model has been implemented in order to carry out the analysis. The obtained results demonstrate that the usage of the conventional field oriented control (FOC) can be enough to operate the system in a pseudo-optimal fashion for this particular landing gear application.