This paper investigates protection integrity of distribution transformers in Ghana. The purpose of the study was to find the main causes of distribution transformer failures in Ghana. The study was conducted in the Ashanti East Region, one of the operational areas of Electricity Company of Ghana ECG with high incidence of distribution transformer burnouts. Data on status of protection systems o...

The three-phase power transformer in the transmission or distribution substations represents one of essential devices on electric networks. Losing this devise cause a disconnection utility to large number electrical loads. robust protection system must be designed protect device during abnormal operations. A complete for poly-phase Karbala networks (East substation) is modeled and simulated, ad...

This paper presents an efficient wavelet and neural network (WNN) based approach for distinguishing magnetizing inrush currents from internal fault currents in three phase power transformers. The wavelet transform is applied first to decompose the current signals of the power transformer into a series of detailed wavelet components. The values of the detailed coefficients obtained can discrimin...

Power transformers are among the most important and expensive equipments in the electric power systems. Consequently the transformer protection is an essential part of the system protection. This paper presents a new method for locating transformer winding faults such as turn-to-turn, turn-to-core, turn-totransformer body, turn-to-earth, and high voltage winding to low voltage winding. In this ...

In this paper a overcurrent protection using concept of symmetrical component for power transformer is presented .first we review the concept of symmetrical component. Secondly we investigate how the concept of symmetrical component can be used to improve the transformer protection scheme and how it helps to discriminate the fault and non fault events. For this an algorithm and discrimination c...

Three-phase synchronous motors are widely used in the industrial motor driven systems. Variable frequency drives (VFDs) which allow soft-start of motors produce PWM voltage. Numerical relays are used in the protection schemes of these high voltage motors. The location of current transformer (CT) is an important criterion in the protection circuit. Impact of harmonics and the location of current...

This paper proposed a new wavelet based method to identify inrush currents and to distinguish it from power system faults. The proposed algorithm extracts fault and inrush generated transient signals using DWT. Transient current signals at both sides of a transformer are firstly captured. The wavelet transform is a relatively new and powerful tool in the analysis of power transformer transient ...