The influence of the probabilistic nature of the graphs of the electrical load of river port cranes on the additional calculated power losses

Abstract

Provides an assessment of additional estimated losses of electricity in power systems cranes in river ports. The cause of additional calculated power losses is the use of step load graphs instead of the original graphs as the initial information. Clarification of the calculated power losses is achieved by taking into account the unevenness, characterized by the coefficient of form, and the probabilistic nature of the initial load graphs on the steps. For this purpose, the initial diagrams of the electric load of river cranes are represented by a probabilistic model in the form of a random, stationary Markov process with an exponential-cosine-sine correlation function that determines the probabilistic relationship between the ordinates of the original graphs. The method of probabilistic modeling is used for analytical expression on the restoration of the coefficients of the shape of the initial graphs. The expression relates the variance of the initial and step diagrams of the electrical load through the correlation function, which determines the probability relationship between the ordinates of the initial graphs. The parameters of the correlation function were obtained in experiments and cover river cranes with lifting capacity from 3 to 16 tons when working with bulk cargo. It is shown that the area of the restored coefficients of the shape of the original graphs is in the range: the lower - from 1.21 to 1.28, and the upper-from 1.48 to 1.63. An additional increase in the estimated power loss is in the range of 10 to 46%. The results of the work can be used to improve the method of calculating power losses in the power supply systems of river port cranes