A novel implementation of low speed sensorless vector control of synchronous reluctance motors with a new online parameter identification approach

Rotor angle calculation using flux estimation is a straightforward approach to sensorless control of synchronous reluctance motor (SYRM), but the dc offset can cause an increasing error in pure integrator used in this estimator. In this paper to control motor at low speed region a modified programmable cascaded low pass filters (MPCPLF) is proposed. MPCLPF is suggested because programmable cascade low pass filters (PCLPF), which has previously been applied to induction motors, has some problems in low speed area. In addition PCLPF is affected by the parameter fluctuation. To overcome the problem an online parameter identification method based on block pulse function also is proposed. In this method the parameter identification is not affected by position estimation accuracy. The experimental system includes a PC-based control with real time Linux as operating system. And to acquire data form sensors and to send commands to the system an ALTERA complex programmable logic device (CPLD) is used. The experimental results show the proposed method performs well and speed estimation, angles estimation and parameter identification are correct. Also it is shown sensorless vector control is achieved at low speed as well as high speed using proposed method