An Equivalent Circuit of Single-Sided Linear Induction Motors with Composite Sheet Secondary

Abstract

Since the single-sided linear induction motor has a finite length along the direction of its movement, the non-linear phenomena have significant impacts on the traction characteristics. The equivalent circuit of the linear induction motor is mainly established by two methods: the hypothetical distribution model and the quasi-1-D field analytical method. This paper mainly introduces a T-type equivalent circuit based on the quasi-1-D field analytical method, and comprehensively compares that based on the hypothetical distribution model. First, it proposes the transformation of the T-type equivalent circuit for the linear induction motor, and analyses the physical meaning of each parameter in the circuit. Second, an analysis method is briefly introduced, and the important correction coefficients to the end effects and other non-linear phenomena are derived. Third, the calculation procedures of thrust, vertical force and efficiency are proposed. Then, the characteristics in a prototype motor are calculated by using the T-type equivalent circuit derived from the analytical method, and the calculation results are compared with that based on the hypothetical distribution model. Finally, the experimental measurement results obtained by using a test rig verify the validity of the equivalent circuits.