Model studies to identify input parameters of an algorithm controlling electric supply/consumption process by underground iron ore enterprises

Abstract

Purpose is the development of the research format of a mathematical model to select and assess input parameters of an algorithm controlling distribution of electric energy flows in the monitoring structure of electricity supply/consumption by using equipment of mining enterprises engaged in underground iron ore raw materials extraction. Methods. The analytical research involved a theory of random processes adapted to the real conditions. For the purpose, results of experimental measurements have been applied obtained under the conditions of active iron ore enterprises using underground procedures of the raw materials mining. Methods of random functions (i.e. elements of correlation theory) have helped identify the basic input and output parameters characterizing rather completely electric supply consumption as a stochastic process to develop a control algorithm for the process. Findings. A mathematical model of an electric supply/consumption complex as a stochastic process has been developed to assess its features as well as its levels of influence on the economic operational indices of electric power system of under-ground mining enterprises. Formation of the algorithm to control distribution of electric power flows among consumers of the analyzed types of iron ore enterprises took into consideration stochastic nature of the mentioned complex activity. Originality. The procedure of electric supply/consumption by underground iron ore enterprises has been analyzed in the format of process of a stochastic process of their operation. For the first time, the synthesized mathematical model has been built; both average and disperse stochastic characteristics of electric consumption capacity have been identified; average period of electric energy consumption as a stationary random function during the specified time has been determined; and average number of electric consumption peaks for the interval has been defined as well as average duration of their surges. Analysis of the electric supply/consumption process as a stochastic process has helped solve a problem of the peak influence on the modes of electric energy consumption by receivers of the enterprises, i.e. the random function crossing the specified electric consumption level. Practical implications. According to the available computing formats, a calculation procedure of the operation parameters of electric supply/consumption is of insufficient accuracy since average values are applied and stochastic nature of the process is ignored, which is typical for the analyzed mining enterprises. The abovementioned restricts the possibility to develop adequate system to control the electric power process in terms of the types of mining enterprises and specificity of their operational technology. The developed methods of electric supply/consumption functioning dynamics as a stochastic process help expand its use while forming and making efficient managerial decisions in the context of the analyzed process.

Estimation of an Extent of Sinusoidal Voltage Waveform Distortion Using Parametric and Nonparametric Multiple-Hypothesis Sequential Testing in Devices for Automatic Control of Power Quality Indices

“…The expressions for the complex amplitudes of the positive A and negative B sequences, included in Expression (11), can be obtained using Expressions (16) and (17):…”

“…An analysis of expression (17) shows that in a balanced three-phase voltage system (U a = U b = U c ), the complex amplitude of the negative-sequence component of the space vector (expression (11)) becomes zero.…”

“…At each time instant, module 2 calculates the phase voltage amplitudes U a , U b , U c . The device (Figure 9) does not calculate the space vector, and the coefficient µ is obtained using Expressions ( 16) and (17).…”