Novel induction motor control optimizing both torque response and efficiency is proposed in the paper. The main contribution of the paper is a new structure of rotor flux observer aimed for the speed-sensorless operation of induction machine servo-drive at both, low and high speed, where rapid speed changes can occur. The control differs from the conventional field-oriented control. Stator and ...

When investigating limits of rotor aerodynamic models, the Betz limit serves as a solid marker of an upper limit which no model should be able to exceed. A century ago Joukowsky (1912) proposed a rotor aerodynamic model utilizing a rotating actuator disc with a constant circulation. This model has since then been the subject of much controversy as it predicts a power performance that for all ti...

In this paper we present a design procedure for disturbance attenuation with internal stability of a rotor supported by magnetic bearings, over the whole interval of the rotor operating speeds. The nonlinear gyroscopic equations can be simpliied to a set of linear, time-varying diierential equations, owing to the linear dependence of the rotor speed in the plant dynamics. For rotors operating i...

Controlled induction motor drives without mechanical speed sensors at the motor shaft have the attractions of low cost and high reliability. To replace the sensor, the information on the rotor speed is extracted from measured stator voltages and currents at the motor terminals. Vector controlled drives require estimating the magnitude and spatial orientation of the fundamental magnetic flux wav...

According to tradition, permanent maglev cannot achieve stable equilibrium. The authors have developed, to the contrary, two stable permanent maglev impeller blood pumps. The first pump is an axially driven uni-ventricular assist pump, in which the rotor with impeller is radially supported by two passive magnetic bearings, but has one point contact with the stator axially at standstill. As the ...

In this paper a numerical study is presented with the aim of evaluating the performance output of three Vertical Axis Wind Turbine (VAWT) configurations. Here using Computational Fluid Dynamics (CFD) a two-dimensional Multi Reference Frame (MRF) approach has been used to perform steady state simulations. For this purpose an inlet velocity of 4m/s has been used along with rotor blade Tip Speed R...

This paper presents the design, fabrication and experimental power analysis of a novel double-stator magnetic geared permanent magnet (DSMGPM) machine which comprises of a doublestator permanent-magnet (PM) machine integrated a with triple rotor magnetic gear. The proposed machine can upscale the low-speed rotating magnetic field of the prime PMs on the prime rotor by using the modulation effec...

The cage and reluctance rotors are two major types of rotor structures used in the doubly fed brushless machine (DFBM). In order to study comparatively the effects of different rotor structure on the DFBM, a prototype machine has been specially designed and built. The experimental parameter and performance comparisons between the axially laminated anisotropic (ALA) and cage-rotor machines are p...

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 ...

A speed estimation method is presented in this paper for a grid-connected doubly-fed slipring induction machine drive. The proposed method is formulated with reactive power based model reference adaptive system (MRAS). The method does not require the estimation of stator/rotor flux. So, the integrator related problems at synchronous speed are overcome. Also, the estimation method is independent...