This paper proposes a rotor speed identification method for sensorless induction motor drives based on a model reference adaptive system (MRAS). In this scheme, the error between estimated stator current and real stator current is regarded as the system error to estimate the rotor speed. Adaptive fullorder flux observers for estimating the rotor speed are developed using Lyapunov’s stability th...

Separation of differentially isotope-labeled bacterial RNA by isopycnic density gradient centrifugation is a critical step in RNA-based stable isotope probing analyses, which help to link the structure and function of complex microbial communities. Using isotope-labeled Escherichia coli RNA, we showed that an 8 mL near-vertical rotor performed better than a 2 mL fixed-angle rotor, thereby corro...

-This paper develops a novel spectrum enhancement method to simplify the spectrum representation. It uses a forward synchronous transform to convert three phase current signals into the two current signals in the synchronous reference frame. The spectrum obtained by applying Fast Fourier Transform (FFT) to one of the transformed current signals is then maximized by varying the initial phase in ...

A rotor configuration on a graph contains in every vertex an infinite ordered sequence of rotors, each is pointing to a neighbor of the vertex. After sampling a configuration according to some probability measure, a rotor walk is a deterministic process: at each step it chooses the next unused rotor in its current location, and uses it to jump to the neighboring vertex to which it points. Rotor...

The subject of this article is to optimize the design of synchronous reluctance machines with massive rotor and multi-flux barrier rotor. The optimization procedure, which aims to improve simultaneously the machines’ torque and the power factor, uses the cyclic coordinate method coupled with the magnetostatic finiteelement (FE) field solutions. The optimization results regarding these two types...

The Brushless DC (BLDC) motor is a simple robust machine which has found application over a wide power and speed of ranges in different shapes and geometry. This paper briefly reviews the fundamentals behind the motor and also the different types of BLDC motors with different geometries and then presents a new configuration for BLDC motor/generator, which does not use a permanent magnet in the ...

Switched reluctance motor (SRM) is an energy converter that converts an electrical energy to mechanical energy in motoring operation and vice-versa in generating operation. When the rotor is out of alignment, the inductance is very low and the current also increase rapidly. The rotor is aligned with the stator then the inductance become very large. In the simulation results, how the rotor minim...

The detection of faults in a dynamic system can help to avoid severe damage where system reliability and safety are essential. An induction motor can fail either due to internal faults such as short circuit of motor leads; broken rotor bar and cracked rotor end rings or by external faults such as phase failure, asymmetry of main supply and mechanical overload (Karami et al 2010). Detection and ...

This paper presents a novel method for the rotor resistance identification of an indirect rotor field oriented (IRFO) control system of a saturated induction motor. A saturated induction motor is an induction motor with a variable (saturable) mutual inductance. Saturation of the mutual inductance appears in operating conditions with variable rotor flux levels in the IRFO control system of an in...