Sensorless vector control of permanent magnet synchronous motor using adaptive identification

Vector controlled drives of a PMSM (permanent magnet synchronous motor) are proposed without position and speed sensor. The conventional pole position and speed sensors are eliminated by means of estimation using adaptive identification, for which stator voltages and currents are measured. To realize the proposed algorithm, a d-q current detecting method, which is independent of the rotor speed and position, is proposed. Simulation and experiment show that the proposed sensorless algorithm has good adaptation with load condition variation. Simulation results show that the position error at the steady state is within one electrical degree. In the experiment, however, the error becomes larger than that value, because of the sensing error and the long sampling time