mathematical simulation of flow toward drains is an important and indispensable stage in drainage design and management. many related models have been developed, but most of them simulate the saturated flow toward drains without a due consideration of the unsaturated zone. in this study, the two dimensional differential equation governing saturated and unsaturated flow in porous media is numeri...

a simple method is described for analysis of transients in power network. the method is developed for analysis of transformer and generator winding resonances due to their interaction with transmission lines caused by switching surges. the method is already used for calculation of overvoltages which had resulted in damages in the transformer winding of a hydro power plant. nonlinearity in the i...

An interleaved high step-up converter topology based on the coupled inductor (CI) and built-in transformer (BIT) is proposed in this study to provide voltage gain efficiency with a low number of power electronic components for renewable energy applications. The increased by both turns’ ratio CI BIT, so there no need extend duty obtain gain. much more flexible than those only either or BIT. More...

We developed a resonance control method to generate high-speed rotating magnetic field in three-phase navigation system composed of three electromagnets. The proposed calculates the amplitudes and phases voltages, while capacitances suppressing self mutual inductances electromagnets keep currents magnitude constant, even if frequency increases. Finally, we prototyped variable capacitor module v...

We address the objective of the generation of finite magnetic flux out of unbiased thermal current fluctuations in a collection of identical mesoscopic cylinders which are coupled via mutual inductances. The influence of thermal Nyquist fluctuations are described in terms of a set of Langevin equations or a corresponding Fokker–Planck equation, respectively. In the limit of infinitely many cons...

In terms of torque capability, power factor and efficiency, synchronous reluctance machines with high-anisotropy rotors represent an alternative to conventional induction machines. In particular, they have very robust rotors and can therefore operate at constant power in a wider field-weakening range. The paper discusses a comparison of the various machine concepts using an identical machine ge...

The paper deals with modeling of synchronous reluctance motor (SynRM) accounting for all phenomena responsible for torque ripple. Based on winding function approach, the proposed model consists in computing self and mutual inductances considering no sinusoidal distribution of stator windings, slotting effect and no sinusoidal reluctance variation caused by the rotor saliency. Then, optimal curr...

Ferroresonance is a highly dynamic and nonlinear power quality phenomenon caused by nonlinear inductances in ferromagnetic materials and power system capacitances. It is notorious for causing severe damage to power systems. This paper carries out an investigation into single-phase transformer ferroresonance initiated by switching transients. A hysteretic core model is implemented which includes...

A simple method for birdcage coil design (high pass, low pass, and band pass) is presented. Rather than iteratively approaching the Larmor resonant frequency with known capacitances and calculated inductances, a more versatile approach to birdcage coil design is developed and validated, in which the necessary capacitances are calculated using a desired current pattern, a calculated inductance, ...