Transducerless position and velocity estimation in induction and salient AC machines

Abstract

Abstract-This paper presents a viable transducerless rotor position and velocity estimation scheme for PWM inverter driven induction, synchronous, and reluctance machines with the capability of providing robust and accurate dynamic estimation independent of operating point, including zero and very high speeds, light and heavy loading. The injection of a balanced three-phase high frequency signal (500 to 2 kHz) generated by the inverter, followed by appropriate signal demodulation and processing combined with a closed-loop observer, enable the tracking of rotor magnetic 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 modulation of the rotor slot leakage with minimal detrimental effects on the machine performance. ExDerimental verification for the induction machine is NOMENCLATURE Denotes estimated and commanded quantities, respectively.

Zero-speed sensorless drive capability of fractional-slot inset PM machine

“…With this type of injection, the estimation scheme to estimate the electrical position is reported in Fig. 2 [7]. By means of some transformations of the HF current vector i dq h , it is possible to recognize the maximum axis direction of the ellipse which should be the same of the d-axis.…”

“…In the last years, the tracking of the rotor saliency has been largely adopted as solution for the electrical position purpose [7,8]. The sensorless capability of the motor is related to its anisotropic rotor characteristic.…”

Analysis of rotor slotting saliency in induction motor sensorless control

“…In this kind of sensorless technique, a polyphase rotating carrier at pulsation ω c is usually added to the fundamental voltage generated by the PWM (Pulse Width Modulation) system [3,8]. This term is of the type:…”

“…To the first category belong the MRASs (Model Reference Adaptive Systems) [5], the fullorder [6] and reduced order observers [7] and the open-loop speed estimators. To the second category belong all those methodologies based on high frequency signal injection [8][9][10][11] or test vectors [12][13][14][15][16][17]. This paper addresses, in particular, those methodologies based on the rotating voltage carrier injection.…”

Adaptive interconnected observer for sensorless induction motor

“…. State estimation based on high-frequency signal injection and/or saliency-induced effects on the stator voltage (Jansen and Lorenz 1995;Holtz 2000). .…”