Position sensorless vector control of permanent magnet synchronous motors for electrical household appliances

A position sensorless vector control for a Permanent Magnet Synchronous Motor (PMSM) suitable for electrical household appliance motor drives is described in this paper. As a position sensorless control, a simple position estimate equation is presented. The derivation of the equation is described. A simplified vector control method for position sensorless PMSMs is proposed. The proposed method does not employ any automatic speed regulator or automatic current regulator. However, since the motor supply voltage V-d and V-q are calculated on the control rotation axis, the drive performance of our method is almost the same as that of a conventional vector control under a steady-state condition, i.e. constant load and constant speed. Simulation and experimental results are shown. Finally, the authors applied the proposed method to a battery-driven cordless vacuum cleaner. By experiment, a stable drive of 50,000 min(-1) was confirmed.