Estimation of rotor resistance rapidly and accurately has received a lot of attention due to its significance in improving the performance of induction motor(IM) vector control system. In this paper, algorithm of estimating rotor resistance of IM based on extended Kalman filter(EKF) is presented. The algorithm can estimate the rotor resistance on line by measuring the voltage, current and speed...

A rotational magnetic brake with a solid iron rotor is excited by a DC current (Fig. 1). The magnetic properties of the rotor are highly nonlinear. Currents are induced in the moving conductive rotor. The magnetic flux is swept along in the direction of the rotation (Fig. 2). The oscillations appearing in the finite element solutions at high speeds (Fig. 3), have a non-physical nature and are r...

-During normal operation of a three-phase AC induction motor, the magnetic flux in a healthy rotor forms a sinusoidal pattern. Typically, in healthy rotors, little residual flux will remain after the motor is de-energized. However, as rotor anomalies such as cracked or broken bars develop, a net residual flux may be established. This additional flux appears as a variation in the residual flux a...

In this paper, grid disturbances like asymmetrical sag and swell faults in phase-A are analyzed for the grid connected DFIG. The dynamic behavior of DFIG is compared and tabulated with results using state error compensators like PI, PI with resonant (PIR) and internal model control (IMC) on rotor side converter (RSC). The RSC is designed analytically with enhanced field oriented control (EFOC) ...

SUMMARY Electromagnetic field theory is applied to the analysis of performance of an induction-motor rotor when it is exposed to a rotating magnetic field of constant amplitude. An idealized model of the rotor is taken and the analysis is simplified by the application of the concept of wave impedance. The model rotor is capable of simulating the effects of tooth-top and zigzag leakage fluxes, b...

In renewable power generation doubly fed induction generators (DFIG) are used, in which the stator of the generator is directly connected to mains, while the converter for the rotor is rated only for slip power. Due to the interaction of rotor and stator windings in a DFIG, the high-frequency harmonics caused by the pulsed output of rotor power converters are transmitted into the stator current...

This paper analyzes some basic design aspects for a three phase diamagnetic levitating rotor. A proposed design uses a triangular configuration of magnets for a levitating rotor. A formula for finding a the approximate levitation point of the rotor is given. The proposed system uses three phase alternating current and a nine coil configuration to drive the levitating rotor. For this configurati...

the rotor of enegelberg whitener was equipped with a screw conveyor to reduce broken rice percentage. according to preliminary experiments this modification could reduce broken rice percentage about 2.5%. further experiment was performed to determine the effect of rotor speeds and blade positions on white rice quality. to do this, five rotor speeds, consisting 500, 600, 700, 800 and 900 r.p.m a...

Double frequency tests are used for evaluating stator windings and analyzing the temperature. Likewise, signal injection on induction machines is used on sensorless motor control fields to find out the rotor position. Motor Current Signature Analysis (MCSA), which focuses on the spectral analysis of stator current, is the most widely used method for identifying faults in induction motors. Motor...

This paper have studied the dynamic of a 2.0 MW Doubly Fed Induction Generator (DFIG) during a severe voltage sag. Using the dynamic model of a DFIG, it was possible to determine the current, Electromagnetic Force and flux behavior during three-phase symmetrical voltage dip. Among the technologies of wind turbines the DFIG is widely employed; however, this machine is extremely susceptible to di...