Electromagnetic forces in power transformer windings are produced by interaction between the leakage fluxes and current passing them. Since the leakage flux distribution along the windings height is in two axial and radial directions, so the electromagnetic forces have two components, radial and axial. There is a risk that a large electromagnetic force due to the short circuit or inrush current...

In a power system, a contingency refers to an outage of power system components such as transformers, generators, lines, etc. due to faults or failure. A contingency could lead to voltage and power flow problems. This paper describes practical contingency studies based on a real power system provided by a utility. The aim of this study is to find out contingencies that cause undervoltage, overv...

Dry-type transformer becomes the preferable choice in many applications due to its construction specific advantages over oil-cooled transformers. However, the inherent low thermal conductivity of dry-type transformers gives the rise to high operating temperatures. The temperature rise of a transformer is an important factor deciding its safe operation and the useful life span. With the increase...

A load flow program is developed using MATLAB and based on the Newton–Raphson method,which shows very fast efficient rate of convergence as well computationally proposed method it requires less computer memory through use sparsing other methods in programming to accelerate run speed be near real time. The designed computes voltage magnitudes phase angles at each bus network under steady–state o...

Voltage instability is a major concern in operation of power systems and it is well known that voltage instability and collapse have led to blackout or abnormally low voltages in a significant part of the power system. Consequently, tracking the proximity of the power system to an insecure voltage condition has become an important element of any protection and control scheme. The expected time ...

Partial discharge (PD) pattern recognition is an important tool in high-voltage insulation diagnosis of power systems. A PD pattern classification approach of high-voltage power transformers based on a neural network is proposed in this paper. A commercial PD detector is firstly used to measure the 3-D PD patterns of epoxy resin power transformers. Then, the gray intensity histogram extracted f...

The paper presents a short overview of the state of the art for grid tied PV inverters at low and medium power level (1..100 kW), mainly intended for rooftop applications. The inverters are categorized according to the configuration of the PV system, the configuration of the conversion stages within the inverter and whether they use transformers or not [1], [3]. After the introduction of the st...

The mission of mechanized mathematics is to develop software systems that support the process people use to create, explore, connect, and apply mathematics. Working mathematicians routinely leverage a powerful synergy between deduction and computation. The artificial division between (axiomatic) theorem proving systems and (algorithmic) computer algebra systems has broken this synergy. To signi...

The development of power electrical systems causes attention to accuracy of protection elements and measurement values. So we need some new measuring devices with high accuracy for power transmission lines. One of these devices is Optical Current Transformer (OCT). Optical current transformers are suitable for power system protection and can replace the magnetic current transformers. In this pa...