Emergency control algorithm for maintaining power stability based on newton's method

The problem of stability boundary evaluation for the current power system state is of paramount importance for power system operation. In addition, maintaining stability after large scale disturbances has come to the fore in recent years. This paper presents the algorithm, which allows us to both evaluate the stability boundary of a power system and to calculate emergency control actions for maintaining stability in the case of blackout. The algorithm is based on Newton's method for solving optimization problems. There are a number of emergency actions algorithms in literature, but most of them use heuristic rules. On the contrary, the proposed method has a reasonable analytical background. Thus, having an adequate power system model, the proposed method is able to calculate more accurate control actions. The paper demonstrates the very basic idea of the approach with the simplest example. © 2014 WIT Press.International Journal of Safety and Security Engineering;International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

Spectral and photometric characteristics of mid-latitude auroras during the magnetic storm of March 17, 2015

We study the spatiotemporal dynamics of mid-latitude aurora from observations in the south of Eastern Siberia during St. Patrick’s severe geomagnetic storm on March 17, 2015. We perform a morphological analysis of characteristics of the observed auroras. A preliminary conclusion is drawn that the analyzed event is the result of the manifestation of mid-latitude auroras of two types (type “d” and SAR arc) and ordinary aurora observed at the northern horizon. The maximum intensity of the dominant emission [OI] at 630.0 nm (~14 kR) allows this mid-latitude aurora to be attributed to the extreme auroras occurring in mid-latitudes, which is second only to the November 20, 2003 superstorm (~19 kR)

Detection of the Initial Region of the Current Transformer Core Saturation

In the first part of the paper the detailed analysis of the existing current transformer (CT) saturation detection methods with their classification is presented. A new saturation detection method has been proposed in second part of the paper. Mathematical description of the method is given. In the next section of the paper a CT model with test scheme is presented. To identify the reliability of proposed method against nose and remanent flux density experiments have been produced in the fourth section. Comparative analysis between proposed and existing methods is also given. Finally, in conclusion a detailed description of the method is given regarding its behavior with respect to remanent flux and noise. © 2021, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). All rights reserved.Proposed results are the outcome of work on the topic "Development and testing algorithms and technical solutions for digital control of power facilities" within integrated project "Improvement of approaches to digital management of power facilities"

Industry experience of developing day-ahead photovoltaic plant forecasting system based on machine learning

This article highlights the industry experience of the development and practical implementation of a short-term photovoltaic forecasting system based on machine learning methods for a real industry-scale photovoltaic power plant implemented in a Russian power system using remote data acquisition. One of the goals of the study is to improve photovoltaic power plants generation forecasting accuracy based on open-source meteorological data, which is provided in regular weather forecasts. In order to improve the robustness of the system in terms of the forecasting accuracy, we apply newly derived feature introduction, a factor obtained as a result of feature engineering procedure, characterizing the relationship between photovoltaic power plant energy production and solar irradiation on a horizontal surface, thus taking into account the impacts of atmospheric and electrical nature. The article scrutinizes the application of different machine learning algorithms, including Random Forest regressor, Gradient Boosting Regressor, Linear Regression and Decision Trees regression, to the remotely obtained data. As a result of the application of the aforementioned approaches together with hyperparameters, tuning and pipelining of the algorithms, the optimal structure, parameters and the application sphere of different regressors were identified for various testing samples. The mathematical model developed within the framework of the study gave us the opportunity to provide robust photovoltaic energy forecasting results with mean accuracy over 92% for mostly-sunny sample days and over 83% for mostly cloudy days with different types of precipitation. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Behavior of the emission from atomic oxygen of the atmosphere at 557.7 nm during the events of stratospheric warming over East Siberia

The influence of stratospheric warming on the atomic oxygen emission at 557.7-nm wavelength (airglow) was investigated based on data obtained at the Geophysical Observatory of ISTP SB RAS (52°N, 103°E) in [1997][1998][1999][2000][2001][2002][2003][2004][2005]. In this period, several cases of anomalous behavior of the 557.7-nm emission intensity in the absence of strong geomagnetic disturbances have been recorded. It has been found that these cases of the growth of intensity of atmospheric emission at 557.7 nm in the height region of the mesosphere and lower thermosphere, have been caused by strong stratospheric warming when the disturbance covers a wide range of atmospheric altitudes. It should be emphasized that high concentration of centers of stratospheric warming is characteristic of Asia and, in particular, of the East Siberia that can result in the formation of regional peculiarities in characteristics of the airglow

STRUCTURAL SCHEMES OF MECHANISMS

The article is devoted to some aspects of the theory of mechanisms and machines, which are the basis for solving specific engineering problems. The purpose of the article is to consider in detail the features of structural schemes of mechanisms, the order and conditions of their construction Research objectives: to consider the sequence of construction and features of structural schemes of mechanisms. In the course of the study, the relevance of optimizing the design of mechanisms and machines is indicated, special attention is paid to the criteria for performance and reliability of mechanisms and machines. The order and sequence of construction of such schemes are considered in detail. special attention is paid to structural groups and their analysis. The results of using the algorithms for constructing structural schemes of mechanisms presented in the article are demonstrated using specific examples</jats:p