Enabling technologies for a fault tolerant linear actuation drive

In safety critical applications, such as for the aerospace industry, where fault tolerant systems are mandatory, the ability of an electric actuator to detect a malfunctioning and eventually operate in faulty conditions is of paramount importance. This paper is concerned with the fault tolerance operation of a linear actuation drive, consisting of a tubular, linear motor controlled and driven by a high performance matrix converter for an aerospace application. The aim of this work is thus to propose and validate techniques addressing specific faulty operation conditions. The main points of interest addressed in this paper are the operation of the position sensor and operation during a fault on one of the phases of the motor. An Extended Kalman Filter is adopted for the double goal of improving the measured data of the position sensor and to continuously monitor its condition. On the other hand, the TLPM motor is operated under the assumption of a total fault of a single phase. In this work the modification to the Field Oriented Control (FOC) with only two phases is described, and the results are compared to those of the healthy machine. Theoretical analysis, simulations and experiments confirms the feasibility of the described strategies.