Optimised Torque Control of Marine PM Propulsion Machines

摘要

In recent times there as been an increased interest expressed towards using advanced power dense PM (permanent magnet) motors as an alternative to traditional excited synchronous machines, in terms of power generation and utilisation. Specifically AFM and TFM (Axial and Transverse Flux machines), since they potentially offer a higher torque per unit mass than more traditional technology. Hence, much design work is being carried out to maximise the power to weight ratio for these machines. Although, in order to harness the full potential of these machines their control also needs to be optimised. This paper describes a generalised approach to torque control that utilises the motor's magnetic flux characteristic that ensures that maximum torque is produced for minimal input power. The method is generalised for any separately excited synchronous, permanent magnet or reluctance machine, including AFM and TFM. A TFM motor is used to illustrate the performance of this control algorithm, chosen because of its non-linear nature.