Performance Analysis of Linear Induction Motors Considering Space and Time Harmonics

Under inverter supply, linear induction motor (LIM) is affected by pulse width modulation (PWM) voltage and non-uniform magnetic circuit, which can produce time and space harmonics, and have a negative impact on the drive performance. In order to accurately study the traits and behaviors of the LIM under inverter supply, this paper proposes one comprehensive harmonics equivalent circuit for the LIM. Firstly, the main harmonic components in the motor are analyzed. Then, a harmonics equivalent circuit is proposed, including the derivation of circuit parameters and correction factors. Finally, the performance of LIM considering harmonics is fully investigated and then compared with that of traditional modelling only with fundamental excitation. Both simulation results and theoretical analysis are verified by related experiments.