Detecting and removing minor faults in power transformer winding is essential because minor faults may develop and lead to major faults and finally irretrievable damages occur. In this paper in order to detect the position of short-circuit in the winding, frequency response of the input impedance of a power transformer is analyzed. Common short-circuits are categorized and the results are compa...

Under the limitation of investment budget, a utility company is required to maximize the utilization of their existing assets during their life cycle satisfying both engineering and financial requirements. However, utility does not have knowledge about the status of each asset in the portfolio neither in terms of technical nor financial values. This paper presents a knowledge based model for th...

This paper presents a study to estimate the composition of an electric load, i.e. to determine the amount of each load class by the direct measurements of the total electric current waveform from instrument reading. Kalman filter algorithm is applied to estimate the electric load composition on a consumer side of a distributed power system. The electric load supplied from the different voltage ...

This paper presents a new approach to identify distributed parameters of a lumped-element model for a power transformer. A simplified circuit of a lumped-element model is developed to calculate frequency responses of transformer windings in a wide range of frequency domain. In order to seek optimal parameters of the simplified circuit of the transformer, an intelligent learning technique, based...

In this paper, a new algorithm based on processing differential current harmonics is proposed for digital differential protection of power transformers. This algorithm has been developed by considering different behaviors of second harmonic components of the differential currents under fault and inrush current conditions. In the new method, a criterion function is defined in terms of the time v...

Faults and damage in oil-filled power transformers has a devastating effect on the overall reliability of electrical power systems. Several factors, especially electrical and thermal stresses age the transformer and subject them to incipient faults. These faults, if left undetected will cause deterioration and eventually lead to failure of the transformer [1]. The presence of faults such as arc...

This paper studies the effect of new suggested ferroresonance limiter on controlling ferroresonance oscillations in the power transformer. It is expected that this limiter generally can control the ferroresonance. For studying these phenomena, at first ferroresonance is introduced and a general modeling approach is given. A simple case of ferroresonance in a three phase transformer is used to i...

In this paper, a model predictive framework is used to optimize the operation and maintenance actions of power system equipment based on the predicted health sate of this equipment. In particular, this framework is used to predict the health state of transformers based on their usage. The health state of a transformer is hereby given by the hot-spot temperature of the paper insulation of the tr...

An overview of the research and developments into new transformer design, undertaken in the Department of Electrical and Computer Engineering, University of Canterbury, is presented. Initially, single phase, 50 Hz, l1/0.23kV pole mount distribution transformers were fitted with either silicon or amorphous steel cores. The transformer tanks were filled with either standard transformer oil or liq...

Thermal modeling of transformer is necessary to ensure the optimal design and cost of manufacture of transformer. Either of the empirical formulae available from the standards and practical measurement techniques used in the industries as an alternative to the formulae will not be able to answer the problem exactly and hence the development of software based thermal modeling techniques that use...