Pl. Jansen et Rd. Lorenz, TRANSDUCERLESS POSITION AND VELOCITY ESTIMATION IN INDUCTION AND SALIENT AC MACHINES, IEEE transactions on industry applications, 31(2), 1995, pp. 240-247
This paper presents a viable transducerless rotor position and velocit
y estimation scheme for PWM inverter driven induction, synchronous, an
d reluctance machines with the capability of providing robust and accu
rate dynamic estimation independent of operating point, including zero
and very high speeds, light and heavy loading, The injection of a bal
anced three-phase high frequency signal (500 to 2 kHz) generated by th
e inverter, followed by appropriate signal demodulation and processing
combined with a closed-loop observer, enable the tracking of rotor ma
gnetic saliencies from the machine terminals. Although rotor magnetic
saliency is inherent within reluctance machines, and most synchronous
machines, saliency in the induction machine is introduced via a modula
tion of the rotor slot leakage with minimal detrimental effects on the
machine performance, Experimental verification for the induction mach
ine is included.