Mitigation of Power Unbalance in Electrical Distribution Transformers with Solar Photovoltaic Panels

Abstract

In this article, a design is proposed to improve the power unbalance between the phases of three-phase electricity distribution transformers with the help of photovoltaic (PV) solar panels to be mounted on the roof of transformer centers. Simulation studies of the design were performed via MATLAB/Simulink and simulation results were observed and compared with real-time phase current data from four transformer centers. In the Transfer Switcher and Control System (TSCS) algorithm developed in the design, the percentage current unbalance rate (PCUR%) of the transformer is determined and the power produced from the PV panels is injected into the appropriate phase of the transformer. Phase lock loop (PLL) is used to ensure this connection occurs smoothly. In this study, performance analysis was made based on simulation results for the phase unbalance seen in the transformer before TSCS was activated and for the phase unbalance seen in the transformer after TSCS was activated. In simulation studies conducted on real-time data taken from a total of four transformers in Erzurum, Ağrı and Erzincan provinces, it was seen that the proposed approach had a reducing effect on the power unbalance in the transformer. In addition, approximately 3.6 kW of additional energy is provided to the distribution system for each transformer. In addition, it has been observed that the average current values drawn from the transformers has also decreased.