Newton-Raphson algorithm for the reliable solution of large power networks with embedded FACTS devices

A new and efficient algorithm for the reliable load flow solution of power network branches controlled by flexible AC transmission systems (FACTS) is presented. General admittance-based models are given for series compensators, phase-shifters and tap-changers. Their inclusion in a Newton-Raphson load flow exhibiting quadratic convergence is described and the prowess of the algorithm is demonstrated by comparison with production-grade load programs where the state variables of controllable devices are updated at the end of each Newton-Raphson iteration. Control coordination and initialisation strategies for the controlled branches and nodes have been thoroughly investigated