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In general, switched reluctance motors (SRMs) are driven by the unipolar current excitation. The conventional drive technique requires simultaneous optimization process for some controlled-parameters: the turn-on angle, turn-off angle, and current chopping level. The difficulty in the current command generation makes the torque controller design complicated. In the previous paper, to give a general solution for the problem, the authors have described the vector control specialized for SRM drives. In the proposed technique, the maximum torque per ampere (MTPA) condition is mathematically given and the SRM drive can be easily controlled by a single parameter under the MTPA operation. This paper presents an improved current controller for the vector control. The current control system can achieve the wide driving area without the parameter tuning and mitigate vibration and noise levels in operation. The proposed vector control using the improved current controller is evaluated by comparing with the conventional drive technique on a 1kW three-phase SRM. I.978-1-4799-5776-7/14/$31.00 ©2014 IEEE

The measurement method on the basis of locked rotor tests has been developed for the estimation of magnet PWM carrier eddy current loss in synchronous machines. In the measurement, the magnet eddy current loss is separated from the other losses by subtracting the loss of the machine without the magnets from that with the magnets under the appropriate control of armature currents and voltages. The 3-D finite element analysis is also carried out in order to confirm the validity of the proposed measurement method. The measured and calculated results are found to be in good agreement. It is clarified that the magnet eddy current loss of the machine can be predicted from the results of the proposed measurement method.

This paper presents a new control method for a torque ripple compensation of permanent magnet synchronous motors (PMSMs). The control method is based on a new equation to estimate the instantaneous torque. The equation can accurately take into account variations of both a magnetic energy and a magnetic co-energy. To achieve a stable and an effective torque ripple reduction, a feedforward control and a feedback control are applied to the proposal system. In this paper, the simulation results show that the instantaneous torque estimation result is more accurate than the conventional method. In addition, the effectiveness of the control method is verified by both the simulation and the experiment.