Sensorless Torque and Speed Control of Traction Permanent Magnet Synchronous Motor for Railway Applications based on Model Reference Adaptive System

In recent years, by improving performance of magnet material and decreasing the cost, interest is growing in utilization of Traction Permanent Magnet Synchronous Motor (Traction PMSM) in propulsion systems. In this paper a speed sensorless control method for Traction PMSM, based on Model Reference Adaptive System (MRAS) is represented. In the proposed method the stator current is used to estimate the motor speed. The direct axis reference current (id) is considered to be zero for vector control. By implementing this assumption on stator current, only quadrature axis current (iq) is used for estimation the speed. Therefore the error would be simplified and the error controller, which is a PI controller, follows the rotor speed easily and causes the error to be zero. Stability analysis for proposed MRAS would be inspected and proved by Popov Hyperstability theory. Simulation results clearly show the suitable performance of the estimator in low and high speeds

Keywords:

Traction PMSM , Vector Control , Speed Estimation , MRAS