Slobodian R. Improving the Reliability and Efficiency of Distribution System Operators' Power Grid

2.англ. Ph.D. thesis: 141 p., 14 tables, 44 figures, 3 appendixes, 107 references. In the dissertation work, the urgent task of increasing the reliability and efficiency of power grids of distribution system operators was set and solved. A method for controlling Soft Open Point (SOP) is proposed for the first time, based on the use of the ratio of the difference in complex voltage values at the ends of the feeders and at their beginning to the complex impedance of these feeders. This approach allows for determining near-optimal values of reactive and active power for the SOP to minimize energy losses in the power grid in real-time. The matrix method for determining the reliability indices of distribution power grids has been improved by using a path matrix (current distribution). The method accounts for the belonging of individual sections of overhead lines (OL) to the mainline and branches, considering their differentiated impact on reliability indices. This simplifies the calculation and partially automates the determination of reclosing device installation locations. The method for reconfiguring distribution power grids has been further developed based on the criterion of minimizing energy losses and reliability indices of power supply to consumers, with a check of constraints on maximum voltage loss values at load nodes and maximum load currents of distribution lines. This method is based on analyzing the sensitivity of reducing active power losses or energy losses, involving the closing of a chord and the opening of a tree branch. It is based on selecting the most distant branch within the loop for opening, with the chord and branch to be opened located on adjacent branches. The initial orientation in choosing branches for opening is performed based on the calculation of the closed grid. Branches with relatively low currents are identified as potentially optimal for opening.