Device for detecting the angular position of a rotor of a polyphase rotary electrical machine and rotary electrical machine containing such a device

A device for detecting an angular position of a rotor of a polyphase rotary electrical machine containing a stator and a plurality of magnetic field sensors, fixed with respect to the stator and capable of delivering first signals representing a rotating magnetic field detected by said sensors, comprising:

• means for generating (201), from linear combinations of said first signals (2001-2003), at least a first sinusoidal signal (2010) phase-shifted by a fixed value φ1 and a second sinusoidal signal (2011) phase-shifted by a fixed value φ2, wherein a fixed phase shift value φ is different from zero and from 180°, and wherein said sinusoidal signals represent a real angular position of the rotor (100);
• means for detecting an estimated angular position value of the rotor (100) by locking from said real angular position using a feedback tracking loop and injecting at least a third and a fourth sinusoidal signals as an input, wherein said third and fourth sinusoidal signals are determined based on said estimated angular position value and are phase-shifted from said fixed phase shift value φ;
• means for multiplying (208) said first sinusoidal signal and said third sinusoidal signal to obtain a first result (2080);
• means for multiplying (209) said second sinusoidal signal and said fourth sinusoidal signal to obtain a second result (2090);
• and
• means for subtracting (210) said first and second results, so that the following relation is satisfied at any instant:
• sin(θreal+φ1)·sin(θest+φ2)−sin(θreal+φ2)·sin(θest+φ1)=sin(φ2−φ1)·sin(θreal−θest), wherein θreal and θest are said real and estimated angular positions, φ1 and φ2 are phase shifts of said first and second sinusoidal signals in relation to a reference marker (RRef θ) linked to said stator (104) and said fixed phase shift φ being equal to (φ2−φ1).