Modular sensorless control of high speed, fault tolerant machines

Abstract

Electrical machines used in aerospace applications require fault tolerance to ensure high availability. This frequently includes partitioning, increasing the number of machine and drive phases. Fitting every partitioned phase with a localised controller increases the autonomy of each phase. Using the magnetisation of the rotor as reference, minimal communication between phases is required. An overhead controller is used for open loop startup. Due to the high rotor speed, sensorless control is implemented to avoid reliability problems with encoders. Low frequency commutation is used to lower computational effort and converter loss.