Measurement Tests and FEM Calculations of DC Excited Flux Switching Motor Prototype

Abstract

The paper presents the results of laboratory tests and FEM 2D calculations of the DCEFSM (Direct Current Excited Flux Switching Machine) electric motor prototype, made based on the stator ferromagnetic sheets of the induction motor. Static measurements of torques, currents, power, efficiency, electromotive forces, and voltages of the motor under various operating conditions were performed, as well as the recordings of its currents and back-EMFs waveforms. FEM calculations of measured values were also performed. The obtained results allow us to conclude that the motor has the operating properties of an under-excited synchronous cylindrical motor and can be vector controlled like the PMSM motor. The results of measurements and calculations indicate the need to redesign the magnetic circuit of the stator.

Reduction in the Cogging Torques in the DCEFSM Motor by Changing the Geometry of the Rotor Teeth

“…The rated motor speed of 1500 rpm was achieved with a supply voltage frequency of 375 Hz. The rated motor parameters (obtained from measurements [1]) are presented in Table 1. The rated values of both currents result from the admissible temperature of both windings during their operation (due to the thermal class of their insulation).…”

“…Compared to 10 A, it results in torque that is only about 5% lower (for a set armature current). The measurements, the results of which are presented in a previous paper [1], were made at the speed of 1200 rpm, instead of the rated speed of 1500 rpm, due to technical limitations on the test bench. Therefore, the calculations in this paper were also carried out at a speed of 1200 rpm, for the sake of consistency with the earlier paper [1].…”

“…The measurements, the results of which are presented in a previous paper [1], were made at the speed of 1200 rpm, instead of the rated speed of 1500 rpm, due to technical limitations on the test bench. Therefore, the calculations in this paper were also carried out at a speed of 1200 rpm, for the sake of consistency with the earlier paper [1]. The results of the FEM 3D calculations performed at that time (taking into account the power losses in ferromagnetic sheets) show that the results of the FEM 2D calculations obtained for the speed of 1200 rpm can be extrapolated to the speed of 1500 rpm.…”

“…Previous research [1] presented the results of measurements and FEM calculations of a prototype of a three-phase Direct Current Excited Flux Switching Motor (DCEFSM) with 36 stator slots and 15 rotor teeth. The results of measurements and calculations of this motor indicate the necessity to make some structural changes in order to increase the rated torque, reduce the temperature of the windings during rated operation, and reduce the cogging torque of the machine.…”