| Abstract |
Sensorless propulsion is one of the most important problems to be solved in practical linear
motor application. This paper presents a sensorless direct torque control (DTC) propulsion
method of a 1/2-scale controlled-PM linear synchronous motor (LSM) Maglev model vehicle in
our Laboratory. DTC can directly control the thrust force and stator flux linkage of linear
motor. Because the rated flux linkage of the LSM is too small, a duty control method is
combined with DTC to decrease the step of flux linkage between two sampling times. To verify
the performance of the sensorless DTC propulsion method, the model vehicle, which is not
levitated and supported by the rubber wheel, is used in a 3.5m-propelling-motion experiment.
Experimental results show that DTC can drive the vehicle to trace the demand position and
speed without position and speed sensor in acceleration, deceleration and constant speed
phases, even though there is a strong detent force due to the large semi-closed slots. |
