Hybrid Excitation Type Linear Synchronous Motor And Its Drive System

Further study on Hybrid Excitation Linear Synchronous Motor (LSM) is presented in this thesis. When applying permanent magnets to excitation system of long stator linear synchronous motors used in the Maglev vehicles, a novel hybrid excitation linear synchronous motor is introduced with evenly distributed permanent magnets and electric excitation windings. Those permanent magnets, as the main parts, could provide the propulsion during normal operation. Only in such conditions as start, halt, acceleration and deceleration, can the excitation windings be activated functioning to produce the adjustable flux in the air gap.The main content of this dissertation is as follows,1. This dissertation describes the basic theory of linear synchronous motors and discusses the specialties and applications of the rare earth permanent magnet linear motor. Under the dq0-coordinate system, the mathematic models of electric excitation and permanent magnet LSM are deduced respectively.2. This dissertation also analyzes the magnetic fields and thrust characteristics of this hybrid excitation LSM. On the basis of equivalent magnetic circuit and FEA methods the in-depth research on magnetic fields is carried out, at the same time, the electromagnetic thrusts in one pair-pole are calculated utilizing Maxwell Stress Tensor and Virtual Work methods. Finally, the model motor is examined through contrastive experiments with normal electric excitation and other hybrid linear synchronous motors.3. The mathematic model and control scheme on this linear motor are proposed in this thesis. Moreover, the drive system, including hardware and software, is realized, and some waveform results are achieved through experiments.