Comparison of the Characteristice of Linear Induction Motors with Various Secondary-Side Conductors on the Basis of the Simple Calculation Method Using DC Decay Test

This paper presents a method to calculate the characteristics of linear induction motors by a simple standstill testing method using a small-capacity DC power supply unit, tentatively called the DC decay testing method. This method can determine by a single test the accurate impedance of linear induction motors from the vicinity of commercial frequencies to less than 0.1Hz. The characteristics at each slip are predicted using the two-reaction theory. Comparisons of measured and calculated results for starting thrusts and starting currents demonstrate the validity of the proposed testing method. In addition, we evaluate how conditions (i.e., gap, structure and material) of the secondary-side conductor affect the linear induction motor's performance, i.e., thrust, current and impedance characteristics as calculated by the proposed testing method. This method is suited to calculating the performance of linear induction motors because it does not require no-load tests, which is difficult to carry out for linear induction motor for control use, or locked tests, where the mover must be braked.