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 Vd and Vq 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.