The power flow equations model the relationship between voltage phasors and power injections at nodes (buses) in an electric
power system and are fundamental in their analysis and operation. A wealth of literature exists on these equations, many providing
different representations of them. This monograph provides the first comprehensive survey of representations in the context
of optimization. To achieve this the power flow representations surveyed are categorized as either relaxations or approximations.The
techniques described in here form the basis of running an optimally efficient modern day power system. A Survey of Relaxations
and Approximations of the Power Flow Equations is a must-read for all students and researchers working on the cutting edge
of electric power systems.