Injection of third-order spatial field harmonics for sensorless speed estimation in multiphase induction motor drives

Abstract

It is well-known that in multiphase drives the spatial harmonics of the air-gap magnetic field can be controlled independently of each other. In this paper it is shown how the third-order spatial harmonic of the magnetic field can be used to estimate the rotor speed without the need of a mechanical sensor. Experimental results confirm the feasibility of the developed sensorless speed observer.