EXPLICIT LOSS FORMULA, VOLTAGE FORMULA AND CURRENT FLOW FORMULA FOR LARGE-SCALE UNBALANCED DISTRIBUTION-SYSTEMS

Explicit formulas for determining system loss, current hows and voltag es in terms of system and network data are developed for large-scale u nbalanced distribution systems. The three-phase formulas consider mult i-phase grounded or ungrounded loads and lines, cogenerators, multi-ph ase shunt elements and transformers of different connections all of wh ich exist in large-scale unbalanced distribution systems. Test results on a number of distribution systems, including an actual 394-bus dist ribution network, are included to illustrate the accuracy and speed of the proposed formula for real-time analysis and control of distributi on systems. It is shown numerically that the results given by these cl osed-form formulas are very close to those obtained by rigorous three- phase power how methods. Applications of the explicit expressions to r eal-time control of distribution systems are also identified. Also, so me features of the explicit formulas which are not possible with tradi tional power flow studies are discussed.