The vibration characteristics of a rub-impact rotor system with different parameters are investigated using Hilbert-Huang Transform (HHT)-a relative novel time-frequency analysis method. Firstly, the rotor with rub-impact at fixed limiter is modeled by finite element method (FEM). Then, system simulation signals at different rotating speeds, rub-impact clearances and rub-impact rod stiffness ar...

The concept that changes in the dynamic behaviour of a rotor could be used for general fault detection and monitoring is well established. Current methods rely on the response of the machine to unbalance excitation and are mainly based on pattern recognition approaches. However these methods are relatively insensitive and the crack must be large before it can be robustly detected. Active magnet...

This paper deals with the development of a model based method for bearing fault diagnostics. This method effectively combines the information available in the data and the model for efficient classification of the bearing and the type of defect. A four degrees of freedom nonlinear rigid rotor model is used to simulate the rotor bearing system. Precession of the shaft is measured using proximity...

The induction motor is one of the most used electric machines in the industry because of its strong and simplicity. This paper investigates the performance of conventional techniques such as sideband analysis in detecting broken rotor bars when the motor is fed from a common pulse width modulation voltage source inverter PWM‐VSI drive for variable speed drives. The phase current signals are obt...

Recently a new and simple method to mitigate the transient instability of squirrel cage induction generators (IG) without using any additional equipment. The majority of the fixed speed wind turbines are equipped with squirrel cage IG and ac connected to the power system. During a fault in power system, voltage and rotor speed instability may occur, especially when the strength of the system co...

this work deals with effects of asymmetric stiffness on the dynamic behaviour of the rotor system. the analysis is presented through an extended lagrangian hamiltonian mechanics on the asymmetric rotor system, where symmetries are broken in terms of the rotor stiffness. the complete dynamics of asymmetries of rotor system is investigated with a case study. in this work, a mathematical model is ...

Wound-Rotor (WR) resolvers are the most widely used position sensors in applications with harsh environmental conditions. However, their performance is exposed to failure due to the high risk of short circuit (SC) fault. Although the output current of the resolver is negligible, its thin copper wires increase the probability of the short circuit fault. To avoid the propagation of the turn-to-tu...

The present paper approaches the comparative design and analysis of 5 SRM topologies for an EPAS application. Different number of phases and different combination of stator and rotor pole number will be considered, keeping the same main dimensions (outer and inner stator diameter, airgap length, stack length, stator pole height, stator yoke width, rotor pole height) and the same winding per pha...