Multiple coupled circuit modeling of squirrel-cage induction motors, or winding function approach is the most detailed and complete analytical model used to analyze the performance of the faulty induction motors. This paper extends the above-mentioned model to a saturable model including variable degrees of the saturation effects using an appropriate air gap function and novel techniques for lo...

A new torque control strategy for brushless motors with minimum torque ripple and minimum copper losses while maintaining the phase currents under magnetic (or current) saturation is presented. The optimal control { a nonlinear map from desired torque and position to the motor's phase currents { is the closed form solution to a quadratic programming problem. Experimental results demonstrate vir...

We present a detailed study of the high-current transport properties of graphene devices patterned in a four-point configuration. The current tends to saturate as the voltage across graphene is increased but never reaches the complete saturation as in metallic nanotubes. Measurements are compared to a model based on the Boltzmann equation, which includes electron-scattering processes due to cha...

There is usually no information about permissible error of current transformers in modes succeed by large relative short-circuit current, at which microprocessor-based protections operate stably. By this reason, it necessary to use data, defined for analog relays. It leads value appreciation a project because often essential reduce transformers’ case short circuit fault. Therefore, define the e...

Magnetic core saturation of transformers and rotating machines generate harmonics. Harmonics are integer multiples of the fundamental frequency. Harmonics is caused by nonlinear devices in the power system. Due to the non-linear loads, power frequency harmonics exist mainly in distribution systems. The current harmonics cause voltage harmonics, hence resulting in nonsinusoidal supply voltage in...

the simultaneous flow of oil and water in porous media is described by relative permeability curves, mainly derived from laboratory experiments. relative permeability is of paramount importance in predicting reservoir production performance and drive mechanisms and its value depends largely on the volume fraction of fluids present in the test samples. nowadays x-ray scanners are one of the most...