Automated Control of Unauthorized Power Take-Offs in a Distributed Electrical Network

Abstract

A distributed electrical network (DEN) with a voltage of 0.4 kV operating in an unsymmetric mode is considered as an object of automated control. The problem of identification of places and control of unauthorized power take-offs (UPTO) in the DEN in the conditions of functioning of the automated system of control and accounting of electricity (ACMSE) is formulated. The primary source information for its solution is the data obtained from the head and subscriber electricity meters by synchronized remote measurements at discrete points in time. This problem belongs to the class of problems in which there is significant uncertainty about the current state of the object under study and the parameters of external disturbing influences, which are unauthorized consumers of electricity. Under these conditions, the primary measurement data on the characteristics of the network subscribers’ loads received from the counters of the automated system and recorded in its database are insufficient to solve the problem under consideration. In this regard, in order to reduce the level of uncertainty and obtain additional necessary information about the state of the object, the concept of a virtual DEN model is introduced into consideration, designed to describe its desired state, which is determined by the absence of these external random disturbances in the network. A new method for solving the formulated problem is proposed, based on the concept of a virtual DEN model. The conditions for identifying the current state of the DEN have been obtained. For this purpose, the desired input phase currents of the virtual network are determined by introducing equivalent complex resistances of certain parts of the three-phase network. The vectors of the effective values of currents and voltages on the loads of subscribers and inter-subscriber sections of the virtual network are identified. Criterion functions are introduced that determine the deviations of the corresponding components of the stress vectors on the loads of subscribers of the real DEN and its virtual model. Based on these functions, an identification criterion and an algorithm for monitoring unauthorized power take-offs in a three-phase distributed network are formulated. The obtained results are oriented for the creation of algorithmic and special software for the subsystem of automated control of UPTO as part of the ACMSE.