This study concerned the dynamic behavior of the wind turbine rotor. Before all we have studied the loads applied to the rotor, which allows the knowledge their effect on the fatigue, also studied the rotor with longitudinal crack in order to determine stress, strain and displacement. Firstly we compared the first six modes shapes between cracking and uncracking of HAWT rotor. Secondly we show ...

Rotor Fed Induction generators are an exception to DFIGs. Small scale wind farms are easy to build in remote, windy areas where standalone systems seem ideal choice for electrical power generation. For these systems, rotor excitation is a critical part. The paper does a comparative analysis of inverter schemes i.e. PWM inverter or pure sine wave inverter, the associated harmonic generation and ...

Reliability assessment and risk analysis of rotating machine rotors in various overload and malfunction situations present challenge to engineers and operators. In this paper a new analytical method for evaluation of rotor under large deformation is addressed. Model is presented in general form to include also composite rotors. Presented simulation procedure is based on variational work method ...

This paper presents a means for reducing the torque variation during the revolution of a vertical-axis water turbine (VAWaterT) by increasing the blade number. For this purpose, twodimensional CFD analyses have been performed on a straight-bladed Darrieus-type rotor. After describing the computational model and the relative validation procedure, a complete campaign of simulations, based on full...

Dynamics of a rotor supported by air bearings is strongly depends on the pressure distribution between the rotor and the bearing. In this study, internal pressure in air bearings is numerical and experimental analyzed for different radial clearances. Firstly the pressure distribution between rotor and bearing is modeled using Reynold's equation and this model is solved numerically. The rotor-be...

A Rotary Disc Contactor with inner diameter of 9.1cm and maximum operating height of 40cm has been used to investigate break up phenomenon. Water-Toluene, Water as continuous phase and Toluene as dispersed phase, was selected as chemical system in the experiments. The mentioned chemical system has high interfacial tension so it was possible to form big drops which permit accurate investigation ...

In this paper, a new technique to detect broken rotor bars in polyphase induction machines is presented. Like most techniques, we employ the Fourier Transform of one stator current to make detection. But where the other methods use the Fourier Transform modulus, we propose an alternative approach by analyzing its phase. As shown by results, the Fourier Transform phase allows to detect one broke...

Induction machine models used for steady-state and transient analysis require machine parameters that are usually considered design parameters or data. The knowledge of induction machine parameters is very important for Indirect Field Oriented Control (IFOC). A mismatched set of parameters will degrade the response of speed and torque control. This paper presents an improvement approach on roto...

This paper uses a new position sensor less drive for brushless DC (BLDC) motors. In conventional sensor less control methods such as the back-EMF detection method, the performance is high only at a high speed range due to the fact that the magnitude of the back-EMF is dependent on the rotor speed. A solution is derived that estimates the rotor position by using an unknown input observer over a ...

Rotor dynamics plays an important role in many engineering fields such as gas turbine, steam turbine, reciprocating and centrifugal compressors, the spindle of machine tools, and so on. Owing to the growing demands for high power, high speed, and light weight of the rotor-bearing system, computations of critical speeds and steady-state response at synchronous and sub critical resonances become ...