electrical power quality pdf free download

To read the full-text of this research,
you can request a copy directly from the authors.

Andrey Karpachevskiy

Currently in the field of transport geography, the spatial evolution of electrical networks remain globally understudied. Publicly available data sources, including remote sensing data, have made it possible to collect spatial data on electrical networks, but at the same time a suitable data structure for storing them has not been defined. The main purpose of this study was the collection and structuring of spatiotemporal data on electric networks with the possibility of their further processing and analysis. To collect data, we used publicly available remote sensing and geoinformation systems, archival schemes and maps, as well as other documents related to the Moscow power grid. Additionally, we developed a web service for data publication and visualization. We conducted a small morphological analysis of the evolution of the network to show the possibilities of working with the database using a Python script. For example, we found that the portion of new lines has been declining since 1950s and in the 2010s the portion of partial reconstruction reached its maximum. Thus, the developed data structure and the database itself provide ample opportunities for the analysis and interpretation of the spatiotemporal development of electric networks. This can be used as a basis to study other territories. The main results of the study are published on the web service where the user can interactively choose a year and two forms of power lines representation to visualize on a map.

K.-X. Wang
Z.-X. Song
D.-G. Chen
Y.-S. Geng

Voltage sag due to line fault, transformer energizing and induction motor starting were analyzed based on an EMTP simulation model in this paper. The analysis results illustrate that characteristics of voltage sag is correspond to certain interference source. Based on these characteristics, a new interference source identification method is brought forward by using B spline wavelet transform. Using singularity theory of wavelet transform, voltage transform characteristics are extracted easily and accurately, so interference sources such as line fault, transformer energizing and induction starting, are identified at the same time. The results of simulation show this method is simple, accurate.

Ding Ning
Li Guodong
Xu Yonghai

A classification method of detecting the voltage sag sources based on Mamdani fuzzy inference is introduced in this paper. Three main sag reasons of short-faults, transformers energizing and large-capacity induction motor starting are analyzed. There are some different phenomena during the voltage sags caused by different sources. The characters of the balanced of the three phases, the changing trend of the voltage when the sag ends and voltage harmonic ratio during the sag are considered to be the criteria of recognizing the different voltage sag sources by using Mamdani fuzzy inference. Mamdani fuzzy inference uses the rules which are already known to carry out the reasoning computations from input to output. The correction of this method is proved by some simulations taken in the paper.

Graph computing based power distribution system modeling and analysis