Method for determining the angular position of a permanent magnet rotor of a polyphase electric motor
AssigneeBien-Air S.A.
InventorJean-Pierre Voillat
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Abstract
This method consists in supplying at least a first alternating signal, at a determined frequency, to one end of a stator coil and recuperating a measurement signal at a second end of said coil, said measurement signal being provided to electronic processing means, which are arranged to extract data relating to a periodic variation of the effective inductance of the stator coil. This variation is a function of the angular position of the rotor. By alternately carrying out such a measurement on the stator coils, three periodic curves can be extracted (SPCA, SPCB, SPCC) defining a zigzag curve (70) allowing the angular position of the rotor to be determined.
Claims14
Method for determining the angular position of the permanent magnet rotor of a multiphase electric motor including at least two stator coils, characterised in that:
- a first alternating signal is supplied, having a first determined frequency, to a first end of at least a first of said coils,
- a measurement signal is recuperated, via conductor means connected to a second end of said at a least first coil, which is supplied to electronic processing means arranged to extract from said measurement signal data relating to a periodic variation in the effective inductance of said at least a first coil as a function of said angular position of the rotor.
Method according to any of the preceding claims, characterised in that said electronic processing means are arranged to measure an amplitude modulation of said measurement signal which is a function of said periodic variation of said effective inductance.
Method according to any of the preceding claims, characterised in that said electronic processing means are arranged to follow the evolution of the rotation of the rotor so as to provide the angular position of the rotor univocally over a range of 360°.
System for detecting the angular position of the permanent magnet rotor of a multiphase electric motor including at least two stator coils, characterised in that it includes:
- means for supplying an alternating signal having a first frequency to a first end of at least a first of said coils;
- electronic means for processing a measurement signal supplied by conductor means connected to the second end of said at least a first of said coils;
- said electronic processing means being arranged to extract from said measurement signal data relating to a periodic variation of the effective inductance of said at least a first of said coils as a function of said angular position of the rotor.
Dependencies are inferred from the claim text.