| As the rotor of linear induction motor is of such some characters as cut-off ends, big air gap length, and so on, its performances are largely different from general rotating motor even if they are of the same working theory, efficiency, power factor and starting performance are all much lower than general rotating induction motor. But the linear induction motor has many advantages such as simple structure, high mechanic reliability, high control accuracy, directly driving linear motion, and so on, which make linear induction motor to be wide use in many fields, especially in linear motion, because of the special advantage, linear induction motor absolutely replaces rotor induction motor.In this paper, firstly the solved region, boundary condition and hypothesis condition in starting for linear induction motor is given. In virtue of electromagnetic theory and variation method, element analysis, dispersion format, and collective composite equation are given. In the process of numerical computation of electromagnetic field, primary ending voltage is taken as constraint condition, primary starting current is iterated, and stating current and starting torque at rated voltage is obtained. At last, by comparing calculated results of sinusoidal electric magnetic field with testing result. We find that the result of starting performance for linear motor induction motor meet project practice. On the basis of theoretical calculation above, by changing the resistivity of secondary material, the effect of electric performance of secondary material upon starting performance is studied. According to solution of nonlinear transient field for linear induction motor, primary leakage inductance of eight slots at one phase is calculated. Calculated results show that respective slot leakage inductance is different, and differences between them is bigger, so the method to calculate slot starting parameter by studying one slot is not accurate in the previous period.
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