Muhammet Köksal

Derivation of state and output equations for systems containing switches and a novel definition of a switch using the bond graph model

Abstract This study gives a novel switch definition which is at the same time simple and more general. In addition, a formulation giving state and output equations is presented by using the bond graph model of switch-containing systems. The use of a computer program called BONDSO is described and examples of the application are given.

Solution of eigenproblems for state-space transient analysis of transmission lines

Abstract When lumped parameter models are used for transmission lines, which are originally distributed parameter systems, the set of first order ordinary differential equations (ODEs) of the lumped parameter equivalent circuit can be arranged so that the coefficient matrix is in the tridiagonal form. In the circuit theory, these equations are called as state-equations and in the analytical solution of these equations computation of matrix exponential takes an important part. One way to calculate the matrix exponentials and other matrix functions is to use similarity transformations, which requires eigenanalysis of the coefficient matrix. In this study, state-space technique for computation of transmission line transients is given. Calculation of matrix exponentials for coefficient matrices having tridiagonal structures and eigenproblems associated with it are investigated. QR algorithm, LR algorithm and characteristic equation method for eigenvalue calculation are treated for this type of matrices in both accuracy and computer run time point of views. Several cases are considered and effect of matrix dimension and ill-conditions are also examined.

Analysis of nonlinear circuits by using differential Taylor transform

Abstract An effective but not widely used method, differential Taylor transform, is introduced for the analysis of the nonlinear electrical circuits. To apply the method the differential transform of the mathematical model of the system is obtained first, and then the response function is evaluated by using the inverse transform of the differential spectra. The inverse transform can be written in the form of Taylor series. The method is described with two examples for nonlinear electrical circuits.

Theory of high-gradient magnetic filter performance

A unique general model for high-gradient magnetic filters is presented. The functional dependence of the filter performance on the systems physical and geometrical parameters is derived. The derived theoretical expression makes it possible to explain both of the two different, apparently opposite, experimental results reported in the literature. The new quality factor does not include the suspension viscosity, but instead depends on the suspension density, which leads to the application of the formula for a larger class of filtration media including liquids, gases, and vapors.

Particle capture in axial magnetic filters with power law flow model

A theory of capture of magnetic particle carried by laminar flow of viscous non-Newtonian (power law) fluid in axially ordered filters is presented. The velocity profile of the fluid flow is determined by the Kuwabara-Happel cell model. For the trajectory of the particle, the capture area and the filter performance simple analytical expressions are obtained. These expressions are valid for particle capture processes from both Newtonian and non-Newtonian fluids. For this reason the obtained theoretical results make it possible to widen the application of high-gradient magnetic filtration (HGMF) to other industrial areas. For Newtonian fluids the theoretical results are shown to be in good agreement with the experimental ones reported in the literature.

Remark on the Lumped Parameter Modeling of Transmission Lines

Transmission lines are distributed parameter systems. Instead of distributed parameter models, lumped parameter models are also used for steady-state and transient analysis of transmission lines. Lumped parameter modeling for transmission lines is obviously an approximation. This paper aims to investigate the theoretical error in the lumped parameter modeling of transmission lines for steady-state and transient analysis. To determine the error, steady-state and transient responses of the transmission line are calculated by using both distributed and lumped parameter modeling. The effect of number of sections used for lumped parameter modeling is investigated. Obtained results can be used for the determination of the number of sections.Transmission lines are distributed parameter systems. Instead of distributed parameter models, lumped parameter models are also used for steady-state and transient analysis of transmission lines. Lumped parameter modeling for transmission lines is obviously an approximation. This paper aims to investigate the theoretical error in the lumped parameter modeling of transmission lines for steady-state and transient analysis. To determine the error, steady-state and transient responses of the transmission line are calculated by using both distributed and lumped parameter modeling. The effect of number of sections used for lumped parameter modeling is investigated. Obtained results can be used for the determination of the number of sections.

Analysis of switched systems using the bond graph methods

Abstract In recent years, the analysis of switching systems has gained importance. In this paper, the formulation of state and output equations and solutions of switched-systems are presented by using the bond graph model with a new simple and more general switch definition. The theory is illustrated by a few examples and the output of the computer programme called BOMAS is presented.

Transient analysis of nonuniform lossy transmission lines with frequency dependent parameters

Abstract An s-domain method for transient analysis of lossy, frequency dependent nonuniform transmission lines having parameters arbitrary varying with space is presented. Nonuniform line is divided into adequate number of sections which are then assumed uniform. The terminal equation for the nonuniform line is calculated by using the terminal equations of the uniform line sections. By using the boundary conditions, total response in s-domain is obtained. Fast inverse Laplace transform is used for frequency to time domain conversion. In one of the examples, the step response of an open ended nonuniform line is obtained and the results are compared with those obtained by lattice-diagram technique. The effect of number of sections is investigated and it is concluded that for sufficiently large number of sections, the results approach to the analytical solutions which can be obtained only for very special nonuniform lines. In the second example, the method is applied for the calculation of transmission tower lightning surge response.

Filtration model of high gradient magnetic filters with granular matrix

Abstract Considering the flow regime of the fluid through the pores of a magnetic filter having a granular matrix composed of ferromagnetic spheres and the accumulation process of the captured particles, the filtration mechanism is investigated. The effect of the different parameters of the filtration system on the efficiency of the magnetic filter is identified. New mathematical expressions are obtained to explain some events which take place in the filtration mechanism and which have not been described completely in the literature so far. The efficiency of the magnetic filter is expressed in terms of the ratios of the magnetic and static pressures which can be measured or identified easily. The theoretical results are compared with the experimental data and it is concluded that they are in good agreement.

REALIZATION OF A GENERAL RESISTORLESS ACTIVE BIQUAD USING CBTA

In this paper, a general electronically tunable resistorless biquad, which realizes current ratio transfer function using current backward transconductance amplifiers is proposed. The biquad contains only two active components and two grounded capacitors, which make it convenient for production by the integrated circuit technology. The proposed biquad realizes all of the basic second order filter characteristics: low pass, high pass, band pass, band reject, and finally all pass. It is convenient for cascading with other similar biquads as well as with any two-port circuit with low impedance input to achieve higher order filter characteristics. The simulations that are performed using PSPICE simulator exhibit satisfactory results coherent with the theory.