Methodology of substantiation of the base of initial data of individual electric loads of mass electric consumers

The problem of calculating electrical loads for industrial enterprises is a fundamental stage in the design of factory power supply systems. The article deals with the methodological problem of determining such a base of initial data, providing the development of physically justified methods of selecting conductor cross-sections by heating. The aim of the article is to theoretically justify the initial data providing a scientific approach to the selection of conductors by heating. The paper uses a probabilistic model of group electrical load in the form of a random stationary ergodic pro-cess with an exponential correlation function and obeying the normal distribution law. The research results are obtained by probabilistic and statistical modeling. It is shown that the existing database of individual parameters of electric con-sumers is based on incorrect assumptions: correlation between mean values and standard deviations of normally dis-tributed group loads. The model of group electric load in the form of stationary random process with normal distribution of ordinates and exponential correlation function is quite correct for solving the problem of selection of conductors by heating. However, within its framework the volume of the existing base of initial information on the indicators of indi-vidual loads of electric consumers is insufficient. It is proposed to consider the following data as a basis for calculations: average values and standard deviations of individual electrical loads, as well as the attenuation coefficient of correla-tion functions of group electrical load. The proposed approach allows developing methodologically justified statistical methods for solving the problems of selecting conductors by heating in power supply systems.