Speed Estimation Using Extended Filter Kalman for the Direct Torque Controlled Permanent Magnet Synchronous Motor (PMSM) [chapter]

2011 Advances in Motor Torque Control  
Introduction Permanent magnet (PM) synchronous motors have attracted increasing interest in recent years for industrial drive application. The high efficiency, high steady state torque density and simple controller of the PM motor drives compared with the induction motor drives make them a good alternative in certain applications. Moreover, the availability of low-cost power electronic devices and the improvement of PM characteristics enable the use of PM motors even in some more demanding
more » ... cations. Advantages of PMSM include low inertia, high efficiency, high power density and reliability. Because of these advantages, PMSM are indeed excellent for use in high-performance servo drives where a fast and accurate torque response is required. In PMSM drives, the electromagnetic torque is usually controlled indirectly via the stator current components in a reference frame fixed to the rotor flux field. The idea of combining the advantages of DTC and PMSM into a highly dynamic drive appeared in the literature in the late 1990's. In the past decade several authors have proposed ways to adapt DTC to work with PMSM. Moreover DTC uses no current controller and no motor parameters other than the stator resistance, which yields a faster torque response and lower parameter dependence than with field oriented control. Recently, motor drive systems without electromechanical sensors, so called 'sensorless drives', have gained increasing popularity in industrial applications because of inherent drawbacks of electromechanical sensors. In general, electromechanical sensors are used to obtain speed or position information of motors. A drawback of these sensors is performance degradation due to vibration or humidity . Consequently, the extended Kalman filter is considered to be the best solution for the speed estimation of an induction motor. The extended Kalman filter has been applied to the direct torque control control system . The Model of PMSM The electrical and mechanical equations of the PMSM in the rotor reference (d-q ) frame are as follows [6]: www.intechopen.com
doi:10.5772/21033 fatcat:f7dx24erfvb7dcnsyvqsfwsroa