On Identifying and Calculating Electricity Losses with Automated Metering Systems in Distribution Networks in Case of Unauthorized Consumption

Abstract

A 0.4 kV distribution network equipped with an automated information and measurement electricity metering system is considered. It is assumed that the metering system receives data on active and reactive power, and on the effective voltage values that correspond to the same time interval and are received at the distribution network beginning and from all subscribers. It is also assumed that the impedances of the phase wires are the same for each inter-subscriber section of the network, but differ from the impedance of the neutral one and are considered to be unknown during the initial calculation. The problem is formulated as follows: arrange, by means of the metering system, online calculation and monitoring of non-technical losses of electric energy in the network that contains several simultaneously operating subscribers connected to the network phases, from which incorrect energy consumption data are received. It is also necessary to identify such subscribers and evaluate the amounts of their unauthorized taps of electricity. The known approach to solving the formulated problem is analyzed, and its shortcomings are revealed. A new method is proposed, which is based on taking into account the phasor relationships for the operating parameters that determine the three-phase network electrical state and calculating the impedances of the distribution network inter-subscriber sections when there are no unauthorized taps of electricity and the currents through these sections when there are unauthorized taps of electricity. By using the proposed method, it becomes possible to determine non-technical losses of electricity in the distribution network for the reporting period and to identify subscribers with incorrect electricity consumption data. It is shown that the unaccounted consumption of electricity in each individual subscriber can be calculated if there are several subscribers with unauthorized taps of electricity connected to one phase of the network, whereas there are no more than one of such taps in the other phases. The obtained results can find application both in existing automated electricity metering systems and in the development of new ones.

Development Issues of Systems for Automation and Digitalization of Power Distribution Networks

“…As is known, electricity losses in low-voltage distribution networks are caused by such main factors as: current and voltage unbalance [5,17]; unauthorized electricity consumption (theft) in PDNs [14,18]; nonlinear properties of loads of network consumers [17,19]; exceeded critical levels of wear of wires of backbone network lines. These factors cause the networks to deviate from their rated operating conditions.…”

“…The practice of their use has shown that they fail to adequately ensure the desired level of electricity losses, since these automated systems are mainly designed for electricity revenue metering. Analysis indicates that to significantly reduce electricity losses in the PDN it is necessary to additionally perform the optimization of operating conditions of facilities [5][6][7][8], diagnostics of critical states of distribution grids [9][10][11], including the identification of places of unauthorized consumption (theft) of electricity [12][13][14], and the monitoring of electricity losses [15,16] in real time. The existing (conventional) ASEMMs do not address this set of tasks.…”