Helicopter flight control law design including rotor state feedback (RSF) is considered. A mathematical model suitable for analysis and design of RSF control systems is obtained and a structured Hinfinity approach to the problem is proposed, capable of guaranteeing stability and performance robustness. The framework also encompasses fault tolerance with respect to failures of the rotor state se...

The nonlinear dynamic model of rotor-bearing-seal system with crack in shaft is set up based on the coupling model of nonlinear oil-film force and Muszyska’s nonlinear seal fluid force. The dynamic vibration characteristics of the rotor-bearing-seal system and the effects of physical and structural parameters of labyrinth seal and crack fault on movement character of the rotor were analyzed. Th...

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...

Turbochargers are widely used on commercial automotive vehicles, power generation and marine applications. A comprehensive model for a turbocharger would be an effective tool for fault detection. In this paper, research focus on mathematical modelling of turbochargers supported on floating ring bearings in rotordynamics. Nonlinear hydrodynamic forces are considered in order to describe the dyna...

One of the most critical problems in induction motor drive is the knowledge of the current value of some induction motor parameters such as the rotor time constant, which depends strongly on temperature and frequency. This problem won’t be easy to solve because of the high coupling between parameters in the nonlinear induction motor model. In order to determine the rotor time constant, this pap...

A new method has been developed for the detection of broken rotor bars fault in squirrel cage induction motor during startup regimes. The incipient detection of fault is made by using DWT analysis of FIR low pass filtered original startup transient current signal. The extracted particular characteristic evolution of the time-varying signal is used as a fault index. The method was tested using h...

The behavior of a railway traction squirrel cage induction motor under rotor fault conditions is simulated by a complete phase model. A simple and direct procedure for model parameters identification by finite elements method (FEM) is described.

This paper proposes the use of the Teager–Kaiser energy operator (TKEO) for the detection of a broken rotor bar (BRB) in a squirrel cage induction generator, which is used usually in wind energy systems. The TKEO is investigated using the non-stationary signals representation in the time/frequency domain by sensing the estimation of the instantaneous amplitudes and frequencies present on the st...

Wind is one of the most widely used nonconventional sources of energy. A back-to-back PWM converter is used as the excitation power supply for the doubly fed induction generator (DFIG) wind power generation of variable speed constant frequency (VSCF).The Simulink model and control strategy of converter which is connected between rotor and grid is analyzed. Stator-flux oriented vector control ap...

Broken rotor bars and end-ring are common faults in three-phase squirrel-cage induction motors. These faults reduce the developed toque and increase the speed fluctuations of the motor. Meanwhile, developed unsymmetrical magnetic generates noise and vibration in the motor. Local heat around the broken bars may gradually break the adjacent bars and the motor will be finally out of service. Finit...