New "Mirror-Phase vector control" for sensorless drive of IPM synchronous motor

This paper proposes a new sensorless vector control method for salient-pole permanent magnet synchronous motor. The proposed method is directly based on a new principle called as the "mirror-phase characteristics" and can have the following attractive features and high- performance. 1) It is insensitive to all of motor parameters. 2) It is also insensitive to saturation phenomena of stator flux. 3) It is so simple that it can be implemented with no additional hardware. 4) It can allow 250% rated torque at standstill, under which strong flux saturation usually occurs. 5) It can allow ultra low speed control. The observed minimum speed ratio to the rated speed under the rated motoring or regenerating load is 1/1800. 6) Notwithstanding the ultra low speed performance, it can operate up to the rated speed. 7) It accepts instant injection of the rated load even for zero-speed control, 8) It accommodates a load with huge moment inertia. The high performance and usefulness of a new "mirror-phase vector control" method are verified through experiments.