Linear synchronous motor feedback controls

This paper is concerned with the theoretical behaviour of the linear synchronous motor as a propulsion means for a high speed vehicle. The performance during acceleration and steady state operation is obtained from a set of state variable equations which are solved using a digital computer. The inherent performance is oscillatory with little damping. A general feedback control scheme is presented which provides damping and control of the force angle (the angle between the vehicle field and track field). Velocity and force angle errors control voltage magnitude and frequency of the power conditioner (cycloconverter). The effectiveness of the control scheme is measured in terms of its ability to have the vehicle follow a velocity profile, to maintain a constant force angle and to eliminate fast changes in the cycloconverter output voltage. The study shows that effective damping and control of the force angle can be obtained when the cycloconverter voltage and frequency are simultaneously controlled by velocity and force angle feedback signals.