Mehmet Ali Yalçin

An application of chaos and bifurcation in nonlinear dynamical power systems

In this article, a nonlinear dynamical phenomena leading to bifurcation and chaos in power systems is explored using a sample power system. After giving an introduction to nonlinear dynamical power systems in section II a basic knowledge to nonlinear dynamics and chaos theory is given. Section III deals with bifurcation theory. In section IV a dynamical power system model has examined. In section V the theories are applied to a sample power system example and various bifurcation and chaotic phenomena are examined. The predicted behavior is verified by simulations using MATLAB tools.

Effects of transmission line faults on dynamic voltage stability

In recent years, there has been an increasing interest for the analysis of dynamic voltage stability on power systems. It is well known that induction motor loads have a particularly hazardous role in the voltage stability. On the other hand, in transmission systems loaded by induction motor loads, configuration changes such as line tripping, may cause voltage collapse. Moreover, if there is a fault on transmission lines, the disturbance effect will then significantly increase the possibility of voltage collapse. In this study, a transmission system subjected to different faults on different locations is examined from the viewpoint of voltage stability. The study shows that in the certain cases of paralleled transmission lines, single or double phase tripping of a faulted line will have positive effects on voltage stability, instead of all three phase tripping.

AN APPROACH FOR DESIGNING PASSIVE POWER FILTERS FOR INDUSTRIAL POWER SYSTEMS BY USING GRAVITATIONAL SEARCH ALGORITHM

Original scientific paper Harmonics are one of the important factors in determining the energy quality in power systems. Hence, eliminating or damping undesired harmonics is crucial in electrical power systems. Due to their low costs, Passive Power Filters (PPF) are widely used in industrial power systems to limit harmonics’ undesired affects. In this study, a new approach to design a PPF for power systems using heuristic Gravitational Search Algorithms (GSA) is proposed. Traditional Try and Error (TAE) method is, first, utilized to eliminate harmonics in our model power system. Then, GSA is adopted to minimize the effective current value of Point of Common Coupling (PCC) in the same model system. Our results yield that our proposed method with GSA eliminates the harmonics effectively.

The effects of faults on voltage stability of long electrical power transmission systems

Voltage stability is one of the most important problems faced in power system operation and control. Recently, a lot of attention has been paid to the subject of dynamic voltage stability. It is well known that the major components of the power system affecting the dynamic voltage stability are constant power loads and transmission lines. In this study, the effects of faults on transmission lines from the viewpoint of voltage stability are investigated. It is shown that transmission line faults significantly increase the disturbance effect, which causes dynamic voltage instability.

DEPO GAZINDAN ENERJİ ÜRETİMİ

Gelisen teknoloji ve sehirlesmenin cevresel acidan getirdigi en onemli problemlerden biri, her gun hepimizin evinden cesitli iceriklerde cikan kati atiktir. Kati atigin toplanmasi, tasinmasi ve depo edilmesi onemli bir cevre sorunudur. Fakat, depo alanlarinda olusan depo gazinin hem cevresel bem de insan sagligi uzerine olumsuz etkisi dusunuldugunde asil sorunun burada oldugu anlasilmaktadir. Bu yuzden meydana gelen bu depo gazinin olumsuz etkilerini en az duzeye indirmek gerekmektedir. Bunun icin de dunyada cesitli teknikler kullanilmaktadir. Bu tekniklerin icersinde en etkili olani, ekonomik acidan da dusunuld iiguiide depo gazinin yakit olarak kullanilmasi ve enerji uretilmesidir

An investigation of voltage stability in transmission systems considering compensation localization and ratio effects on static and dynamic loads

As power systems are operated under increasingly stressed conditions, the ability to maintain voltage stability becomes a growing concern. This paper discusses the voltage stability analysis of power systems which have both shunt and series compensation, by using static and dynamic analysis. Using a two-bus system, results of time domain simulation are presented to clarify of voltage instability, besides determining static voltage stability limits. It is shown that load models and compensation modes have significant effects on voltage stability.