Driving method of stationary discontinuous-armature PMLSM by open-loop control for stable-deceleration driving

Abstract

Permanent-magnet linear synchronous motors (PMLSM) have been used as the driving source of transportation systems to satisfy requirements such as the speeding up of transportation systems and to simplify maintenance. The authors' laboratory has proposed a stationary discontinuous-armature PMLSM in which the armature is engaged only when accelerated and decelerated operation is necessary, to resolve the problem of higher costs when PMLSM is used with long-distance transportation systems in factories. A constant-torque angle control without position feedback has been proposed to suppress the velocity ripple that occurs at the re-acceleration portion' with the aim of maintaining smooth drive of the stationary discontinuous armature PMLSM. As a result of the examination of the re-acceleration characteristics a stable re-acceleration of the control is possible without position feedback is confirmed. To achieve stable-deceleration driving the velocity ripple that occurred using constant-torque angle control without position feedback during deceleration was examined. This paper describes the results obtained using constant-torque angle control without position feedback, proposed as an innovative driving method to suppress the velocity ripple which occurs in the deceleration portion, with the aim of maintaining smooth drive of the stationary discontinuous armature PMLSM. The characteristics of closed-loop control and the proposed deceleration method were compared to confirm the effectiveness of the proposed deceleration method.