A number of facts about quadratic algebraic problems and applied Newton-Rap
hson like methods are presented. The main results are about solution struct
ure, loading trajectories, load how feasibility boundaries and Newton-Raphs
on solutions. Various practically important applications of these propertie
s are discussed. Although motivated by power flow problems, the results are
valid for any problem described by an algebraic system of quadratic equati
ons. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.