Control variable adjustment in load flows

A linear programming type approach is used to adjust all adjustable loadflow variables with respect to specified constraints. The technique is applicable to the Newton-coupled (and -decoupled) as well as the fast-decoupled load flows. The coordinated adjustment of all adjustable variables improves the convergence of the load-flow program and results in a reduction in the number of iterations with a minimal increase in the computation required by each iteration. No change to the structure of the Jacobian results when constrained variables violate their limits. The variable set remains the same throughout all of the iterations. This algorithm was implemented in the Ontario Hydro energy management system. Test results show a considerable reduction in the number of iterations and computation saving when major adjustments to the adjustable variables are required.<>