Iron loss analysis of moving-coil-type linear DC motor

Linear DC motors, LDMs, are applied to various apparatus, and therefore their improved performance is desired. In order to improve LDM performance, the losses of the LDM must be discussed and reduced. In this paper, the iron loss evaluation of a moving-coil-type and prototype cylindrical LDM is described. The copper and the iron losses of the LDM are separated from the input power in the measurements. The method of predicting hysteresis and eddy current losses from the measured iron loss is demonstrated. Moreover, the distribution of the eddy current loss is calculated by means of finite element analysis coupled with the equation of the excitation circuit. The predicted and computed values of the eddy current loss of the LDM are 20.5 W and 22.7 W, respectively. The eddy current losses computed by each method are compared, and the difference between the computed and predicted results is 11%.