Mathematical modeling of low-voltage distribution electrical networks

Abstract

Relevance: the current three-phase 0.4 kV distribution electrical networks are the main link in the power supply system. Load asymmetry in networks, phase imbalance, and insufficient real-time monitoring reduce the quality and reliability of electricity. Moreover, in the context of implementing an automated system for commercial electricity metering (ASCAE), an urgent task is to ensure the operational monitoring and analysis of the distribution electrical network through its mathematical modeling. This not only allows for the detection of electrical energy losses but also for the assessment of the main line parameters and the monitoring of dynamic load changes in real time. Therefore, the development of accurate mathematical models of unbalanced three-phase networks and the improvement of methods for their analysis are of significant practical importance.

Aim: development of a mathematical model of unbalanced three-phase 0.4 kV distribution electrical networks, improvement of methods for determining unmeasured currents and voltages in real-time, as well as the creation of efficient algorithms for their application in an ASCAE system.

Methods: the study employed a methodology of mathematical modeling based on electrical circuit theory, digital signal processing, and methods of identification and optimization. The current and voltage values in the unbalanced mode were decomposed into symmetrical components, and the unmeasured parameters were estimated using correlation and adaptive calculation methods. During the data collection and analysis process, ASCAE telecommunication modules and the corresponding functions of data concentrators were used.

Results: as a result of the study, a mathematical model of an unbalanced three-phase 0.4 kV network was developed, which improved the accuracy of determining unmeasured electrical quantities. The proposed method enables the assessment of power quality indicators in the network, the determination of the current values of the main line resistances, and the monitoring of energy losses. The obtained results can be implemented in the ASCAE system, which will significantly improve the efficiency of the distribution electrical network and the level of its control.