A new proposal of rotor position estimation in IPM motor drives based on PWM current harmonics

The paper investigates successfully the possibility of extract rotor position information of Interior Permanent Motors from PWM current harmonic contents. To this aim, a general description of PWM voltage harmonics is at first given. Current harmonics are then derived assuming an anisotropic rotor. It is proved that rotor position information can be derived if single edge PWM is adopted. A speed and position estimation scheme is illustrated and the new rotor position estimation technique is then validated by simulations.