Power transformers represent the largest portion of capital investment in transmission and distribution substations. In addition, power transformer outages have a considerable economic impact on the operation of an electrical network. One of the most important parameters’ governing a transformer’s life expectancy is the hot-spot temperature value. Due to under estimation of stray losses in powe...

The objective of this research is to compute the mechanical stresses in power transformer resulting from the currents more than rated value during its operation. Due to this high fault current, mechanical stresses are produced indifferent directions which may cause the damage of winding insulation. Various techniques have been adopted to analyze the stresses on transformer windings. For the acc...

Power transformers are key components for electrical energy transfer in a Power system. In order to protect the transformers from these faults different protective methods are adopted. Some of them are differential protection, over excitation Protection, etc. In this Paper Over Voltage protection is established for the protection of the transformer. Microcontroller is used for the Power Transfo...

The restricted earth fault (REF) relay is a type of differential protection which is used for detection of internal ground faults of power transformers. But, during external faults and transformer energization conditions, the probability of current transformer (CT) saturation increases. Thus, the spurious differential current due to CT saturation, can lead to REF relay maloperation. In this pap...

Modal parameters of power transformer winding are closely related to transformer manufacturing and detection technology of winding deformation based on vibration analysis method. Aimed at identifying the modal parameters of transformer winding accurately, a modal experiment is designed and made on a real 10 kV power transformer. An improved Empirical Mode Decomposition (EMD) algorithm is propos...

This paper describes incorporation of a piezoelectric transformer into a laptop computer adaptor in order to miniaturize the size and improve the energy utilization. Conventionally, electromagnetic transformer is used in the adaptor for generating the 45W output power. In this study, we show that a multilayer piezoelectric transformer rated 30W output power can satisfy the laptop specifications...

The gases generated in oil filled transformer can be used for determination of incipient faults. Dissolved gas analysis (DGA) of transformer oil has been one of the most power full methods to detect the faults. The various methods such as liquid chromatography, acoustic analysis, and transformer function techniques are require some experience to interpret observations. The researchers have used...

At high frequency, the winding losses of power transformer due to skin and proximity effects becomes a significant component in the loss calculation of the transformer efficiency. This paper examines the winding losses associated with these effects for planar-type low-profile transformers that are suitable for high frequency high density soft switching power supply application. The transformer ...

Power transformers are essential components of substation equipment for the efficient and stable operation of electric power systems. There is demand for transformers with lower price and higher reliability. In addition, depending upon the onsite conditions, such as narrow roads, mountainous areas or highly congested urban areas, harmony with the surrounding environment is required throughout s...

Inductively coupling power transfer is an emerging technique, which enables power transfer to loads through air. The contactless transformer is the key component of it, and the design of a transformer is a timeconsuming work with a large number of tests. In this paper, a design method of contactless transformer with finite element analysis is presented. First the contactless transformer model i...