Optimal driving method of stationary discontinuous primary PM-LSM by open-loop control

Stationary discontinuous primaries that are used in permanent magnet linear synchronous motors (PM-LSM) have been proposed to satisfy requirements such as speeding up transportation systems and also to simplify maintenance. The synchronisation method of the stationary discontinuous primary PM-LSM was established by the authors’ laboratory. However, the velocity ripple of the secondary mover with PM occurs when the secondary mover overlaps with the primary section. The velocity ripple of the secondary mover is caused by the variation of the torque angle. Constant torque angle control without position feedback has previously been proposed and examined in order to suppress the velocity ripple that occurs at the re-accelerator with the aim of achieving smooth drive of the stationary discontinuous primary PM-LSM. The examination of constant torque angle control without position feedback with the aim of suppressing the velocity ripple, which occurs in the re-acceleration portion, is now described.