A linear load flow technique for power system reliability studies

In power system reliability applications, an approximate load flow solution of each contingency state is normally sufficient to determine if the desired limits of bus voltages and line ratings have been violated. The total possible line outage states to be investigated for a practical system are very large. A.C. load flow techniques are computationally expensive whereas a d.c. load flow technique does not provide the bus voltage magnitudes. In this paper, a load flow technique which provides an approximate solution of the bus voltage magnitudes and phase angles in a single iteration is described. The suitability of this approach for obtaining load flow solutions of test systems ranging from 5 to 118 buses is briefly discussed. The effectiveness of this technique for contingency evaluation is also investigated.