In this paper a method in intelligent monitoring of the power quality events is presented. The main objectives are the identification and classification of these events. A method for classification is used based on the combination of S-transform and neural networks. The S-transform, which is based on the wavelet transform with a phase correction, provides frequency dependent resolutions that si...

This paper presents a hybrid scheme using a Fourier Linear Combiner and a fuzzy expert system for the classification of transient disturbance waveforms in a power system. The captured voltage or current waveforms are passed through a Fourier Linear Combiner block to provide normalized peak amplitude and phase at every sampling instant. The normalized peak amplitude and computed slope of the wav...

According to the physical process of discharge development of insulator that is struck by lightning, the lightning flashover model for quadruple-circuit transmission line with dual voltage 220kV/110kV in same tower is established basing on EMTP. The actual evaluation index of lightning protection performance is adopted with the consideration of influence of system voltage. The characteristics o...

This paper presents an algorithm based on a combination of Discrete Wavelet Transforms and neural networks for detection and classification of internal faults in a twowinding three-phase transformer. Fault conditions of the transformer are simulated using ATP/EMTP in order to obtain current signals. The training process for the neural network and fault diagnosis decision are implemented using t...

A new one-end fault location algorithm designated for series-compensated transmission lines is delivered in this paper. It is based on differential equation approach, which allows good reflection of the dynamic phenomena relevant for faults occurring behind the bank of series capacitors (SCs) equipped with metal oxide varistors (MOVs). As a result of that, a good stabilisation of the estimation...

This paper presents a time-domain model of a MV/LV bidirectional solid state transformer (SST). A multilevel converter configuration of the SST MV side is obtained by cascading a single-phase cell made of the series connection of an H bridge and a dual active bridge (dc-dc converter); the aim is to configure a realistic SST design suitable for MV levels. A three-phase four-wire converter has be...

The aim of this research article is to determine the way to install surge arresters close to a power transformer to provide protection against lightning overvoltage. Depending on the length of the cables used in the installation, the insulation levels in base insulators of surge arresters and bushings of transformers change according to the voltage they support. For validation purposes, the vol...

This paper describes the design of a new PC-based open-loop digital simulator for relay testing. The simulator is aimed at the users that want flexibility and power of transient relay testing at a price comparable to the price of conventional test sets. The simulator can use several different I/O hardware platforms enabling the users to match simulator configuration with their testing requireme...

Because of the random characteristics of lightning, the Monte Carlo method is applied to estimate the flashover rate due to lightning, however, the simulations using previous methods are difficult to both beginner and expert in power corporations. Therefore, this paper proposes the new and easy method to simulate the flashover rate by connection of electromagnetic transients program (EMTP) and ...