Control of DC-excited flux switching machines for traction applications

Abstract

Electrical traction motors face challenging torque-speed requirements. DC-excited flux switching machine (FSM) offers inherently a good torque capability along with an effective controllability thanks to its DC field windings. These machines have been evaluated mainly over their performance with little consideration on their control. This paper proposes a control strategy, applied on a 3-phase 6/5 DC-excited FSM for traction applications. To obtain the non-linear magnetic behavior of the machine, 2D finite element method (FEM) simulations are performed. The controller regulates the DC field current before reaching base speed to minimize the iron and copper losses. Due to the high armature reaction of the motor the speed range is extended by limiting both the field and armature currents as a function of the speed and inverter supply voltage. Torque control of the machine is performed throughout its complete speed range. © 2014 IEEE.