New stand-still position detection strategy for PMSM drive without rotational transducers

This paper describes a new standstill rotor position detecting method for permanent magnet synchronous motor (PMSM) drives without any position sensors. Only two stator currents are required for rotor position detection and complete system operation. By injecting a test current with high frequency to the machine, the standstill rotor position can be detected with reasonable accuracy. The proposed method provides the maximum torque starting capability to the sensorless drive system by detecting the actual standstill rotor angle within /spl plusmn/10" error in electrical angle.<
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