This paper presents a new synchronization algorithm for grid connection of a doubly fed induction generator (DFIG) in a variable speed wind generation system. Stator flux-oriented vector control for backto-back PWM converters in the DFIG rotor circuit is used for synchronization process. By controlling the rotor d-axis current, the magnitude of the stator EMF is adjusted to be equal to the grid...

The bacterial flagellar motor is an intricate nanomachine which converts ion gradients into rotational movement. Torque is created by ion-dependent stator complexes which surround the rotor in a ring. Shewanella oneidensis MR-1 expresses two distinct types of stator units: the Na(+)-dependent PomA4 B2 and the H(+)-dependent MotA4 B2. Here, we have explored the stator unit dynamics in the MR-1 f...

Received Sep 19, 2017 Revised Oct 27, 2017 Accepted Nov 11, 2017 This paper present steady state and dynamic (Transient) models of the doubly fed induction generator connected to grid. The steady state model of the DFIAG (Doubly Fed Asynchronous induction Generator) has been constructed by referring all the rotor quantities to stator side. With the help of MATLAB programming simulation results ...

This paper proposes a control methodology for compensation of grid voltage unbalances using a new scheme of doubly fed induction generator (DFIG) based on a series grid side converter (SGSC), the seriesDFIG scheme. In such DFIG scheme, the grid side converter (GSC), which is usually connected in parallel to the machine stator, is replaced by the SGSC, connected in series with the machine stator...

In this work we present the modelling of the induction machine, taking into consideration the stator defects of the induction machine. It is based on the theory of electromagnetic coupling of electrical circuits. In fact, for the modelling of stationary defects such as short circuit between turns in the same phase, we introduce only in the matrix the coefficients of resistance and inductance of...

In this paper, we show that the association of the PI regulators for the speed and stator currents with a control strategy using the linearization by state feedback for an induction machine without speed sensor, and with an adaptation of the rotor resistance. The rotor speed is estimated by using the model reference adaptive system approach (MRAS). This method consists of using two models: The ...

This paper presents an investigation on the undesirable vibration of an oblique-stud stator frame in a large hydropower generator by means of experimental and finite element (FE) analysis. First, field experimental tests were performed, and the results indicate that the main vibration component comes from electromagnetic factors. Then, a 2D-magnetic and 3D-mechanical FE model was developed to i...

In this paper, accelerated multi-factor aging tests in laboratory have been conducted on the stator ham of a large generator. During the period of aging, the temperature spectra of dielectric dissipation factor tan 6 of stator insulation were employed to investigate aging characteristics of insulation materials. Test results showed that the peak temperature T,,, of the tan 6 -T curve under 0.2U...

This paper presents a speed sensorless direct torque control scheme using space vector modulation (DTC-SVM) for permanent magnet synchronous motor (PMSM) drive based a Model Reference Adaptive System (MRAS) algorithm and stator resistance estimator. The MRAS is utilized to estimate speed and stator resistance and compensate the effects of parameter variation on stator resistance, which makes fl...

This project presents a method of improving the speed profile, torque and flux using stator estimation method. This discusses the problems associated with the error in stator Resistance and proposes an analytical approach to investigate its effect on the actual and estimated variables of a induction motor. Based on how this error affects the estimated angle between the stator flux and current v...