Abstract In order to effectively detect the waveform characteristics of closing inrush current distribution transformers and distinguish between magnetizing fault when closing, this paper proposes a new method based on neighborhood preserving embedding (NPE) principal component analysis (PCA) transformer detection method. This can process global local feature information data. First, NPE-PCA al...

Power quality is the major problem in fast growing electical systems. Persistent increase non linear loads have caused distortions distribution system leading to becoming unbalanced current and voltage waveforms which affect of power.The power issues analyzed this paper relate sag, reactive power, harmonics, interharmonics, subharmonics, voltage, current, inrush Induction motor.Also line ground...

In current design specifications for deep excavation, the determination of safety factors against groundwater inrush only considers self-weight effect soil mass at bottom. However, shear strength and its spatial variability in a cement-solidified bottom layer also plays an important role factor estimation. Based on that, this study, reduction method was introduced into reliability analysis exca...

In deep tunnel engineering, water inrush disasters caused by filling faults occur frequently, which has generated wide interest in the fields of rock mechanics and fluid mechanics. The mass similar material was prepared with river sand as aggregate, cement a binder, clay regulator, fault composed gravel, laid good foundation for development physical model experiment. Then, using self-designed v...

In order to prevent the multi-dynamic disasters induced by rock burst and roof water inrush in strong coal seams under multi-aquifers, such as is case with 207 working face Tingnan mine considered this study, exhibited characteristics of two types dynamic disasters, namely inrush, were analyzed. Based on lithology predicted caving height roof, contradiction between was light these analyses, an ...

The inrush currents of transformers are among the main causes which compromise performance protection relays in practice. Therefore, discrimination between and faults is very important. A new technique proposed this paper to distinguish internal fault other normal transient conditions (such as current). Accordingly, a operational characteristic defined for feature extraction classification inst...

Abstract Limiting inrush currents is usually necessary when AC-DC conversion used to supply DC loads such as battery chargers in particular, it must comply with IEC 61000-3-3. This document discusses the suitability of an active current limiter that can be replace traditional thermistors and NTC relays. strategy based on control phase shift thyristor type power components. It has been implement...