A Newton Optimal Power Flow Program for Ontario Hydro EMS

A Newton optimal power flow program was developed for the Ontario Hydro Energy Management System. Each iteration minimizes a quadratic approximation of the Lagrangian. All the equations are solved simultaneously for all the unknowns. A new technique based on linear programming is used to identify the binding inequalities. All binding constraints are enforced using Lagrange multipliers. The algorithm combines the fast convergence of the Newton technique with the speed and reliability of Linear programming. Most cases converged in three iterations or less.