The paper documents a new transformer model in ATPDraw called XFMR. This model handles 3-phase transformers with two or three windings. Autotransformers and all Wye and Delta couplings are supported. The model includes an inverse inductance matrix for the leakage description, optional frequency dependent winding resistance, capacitive coupling, and a topologically correct core model (3and 5-leg...

This paper presents an improvement of digital differential relay reliability for protecting a large power transfer is discussed. First, the Fourier sine and cosine coefficients required for fundamental, second third and fifth harmonies determination have been calculated using rectangular transfer technique. Then, these harmonics have been used in harmonics restrain and blocking techniques used ...

For there are few samples of water inrush from coal floor, how to dig wider information under the circumstance of limited sample data is to improve the prediction accuracy of water inrush form coal floor. Therefore, prediction model of water inrush is established based on correlation analysis and support vector machine (SVM). Not only does the model simplify the influenced indexes to construct ...

Transformer inrush currents are high-magnitude, harmonic-rich currents generated when transformer cores are driven into saturation during energization. These currents have undesirable effects, including potential damage or loss-of-life to the transformer, protective relay misoperation, and reduced power quality on the system. Controlled transformer switching can potentially eliminate these tran...

In this work, a new approach applied to digital differential protection relay for a large power transformer is presented. First, the Fourier sine and cosine coefficients required for fundamental, second, third and fifth harmonic extraction have been determined using rectangular transfer technique. Then, these harmonics have been used in harmonics restrain and blocking techniques applied to diff...

This paper presents a new approach to power transformer differential protection based on HS-transform and SVM (support vector machine). Here, HS-transform is used to generate frequency contours from samples of differential current and parseval’s theorem is used to extract the features like energy and standard deviation. Subsequently these features are used as inputs to SVM for fault classificat...

Sudden water inrush has been a deadly killer in underground engineering for decades. Currently, especially in developing countries, frequent water inrush accidents still kill a large number of miners every year. In this study, an approach for predicting the probability of fault-induced water inrush in underground engineering using the adaptive neuro-fuzzy inference system (ANFIS) was developed....

This paper presents the development of a wavelet based algorithm, for distinguishing between magnetizing inrush currents and power system fault currents, which is quite adequate, reliable, fast and computationally efficient tool. The proposed technique consists of a preprocessing unit based on discrete wavelet transform (DWT) in combination with an artificial neural network (ANN) for detecting ...