Harmonic vibrations of high-speed rotors in momentum exchange devices are primary disturbances for attitude control of spacecraft. Active magnetic bearings (AMBs), offering the ability to control the AMB-rotor dynamic behaviors, are preferred in high-precision and micro-vibration applications, such as high-solution Earth observation satellites. However, undesirable harmonic displacements, curre...

Results of a comparative experimental investigation of various media for noninvasive diagnosis of rotor faults in induction motors are presented. Stator voltages and currents in an induction motor were measured, recorded, and employed for computation of the partial and total input powers and of the estimated torque. Waveforms of the current, partial powers and , total power, and estimated torqu...

Induction motors are becoming familiar these days and is being employed in most of the industrial processes. This “Analyzing And Detection Of Rotor Faults In Squirrel Cage Induction Motor Drives Using Matlab” presents a simulation of detecting the rotor faults such as broken rotor bars or end rings in squirrel cage induction motor drives. It enables detection of those faults, which may arise du...

This paper proposes a terminal crowbar protection technique for Doubly Fed Induction Generators (DFIG) to protect the rotor converter and enhance network stability during grid disturbances. Simulation test using MATLAB-Simulink toolbox is implemented on a 9 MW wind farm exports its power to 120 KV grid. The simulation is performed using different values of crowbar resistances. The variations of...

The current paper describes the design and fabrication of a micromachined electrostatically suspended gyroscope. Electrostatic levitation is employed to suspend the rotor, eliminating the mechanical bearing and thus friction effects between the rotor and the substrate, hence improving long-term stability. The rate of rotation can be measured by detecting the torque-induced displacement of the s...

This paper proposes a competent and effective scheme to enhance the ride-through capability of DFIGbased wind turbines under unbalanced voltage dip conditions. The proposed method is realized through joint use of the rotor-side converter control and a three-phase stator damping resistor (SDR) placed in series with the stator windings. By means of an asymmetrical SDR idea, during the unbalanced ...

This paper evaluates different types of AC machines and various control techniques for their suitability for the drive system of Alternative Energy Vehicles (AEV). An Indirect Field Oriented (IFO) drive system for the AEV application is chosen and its major problem of detuning is addressed by designing an offline and an online rotor resistance adaptation technique. The offline scheme sets the s...

Detection and identification of induction machine faults through the stator current signal using higher order spectra analysis is presented. This technique is known as motor current signature analysis (MCSA). This paper proposes two higher order spectra techniques, namely the power spectrum and the slices of bi-spectrum used for the analysis of induction machine stator current leading to the de...

Unbalance in magnetically levitated rotor (MLR) can cause undesirable synchronous vibrations and lead to the saturation of the magnetic actuator. Dynamic balancing is an important way to solve these problems. However, the traditional balancing methods, using rotor displacement to estimate a rotor’s unbalance, requiring several trial-runs, are neither precise nor efficient. This paper presents a...

This paper presents separation harmonics to discriminate rotor failure from low frequency load torque oscillations in three phase induction motors. The most common method for detecting broken rotor bar faults is to analyze the corresponding sidebands through motor current signature analysis (MCSA). If a motor is subjected to load fluctuation, then the oscillation related sidebands exhibit simil...