摘要 |
A pole position detector correctly detects a pole position of a permanent magnet motor. Each magnetic sensor (27) provides an electric signal in response to leakage flux from a magnet rotor (17). A computation unit (2) detects a change in the output of the magnetic sensor as a base pole position theta, corrects the base pole position by Deltatheta according to the base pole position, the magnitude of each stat or current (IU, IV, IW), and a current phase, and calculates correct rotation angles thetare and thetare' accordingly. With low-cost magnetic sensors (27), the pole position detector corrects the outputs of the magnetic sensors affected by stat or current and provides a correct pole position or a correct rotor rotation angle.
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