The primal-dual and predictor-corrector versions of interior point methods are developed for an optimal DC power flow model where Kirchhoff law's are represented by a network flow model with surrogate constraints. The resulting matrix structure is explored reducing the linear system to be solved either to the number of buses or to the number of independent loops, leading to very fast iterations. Either matrix is invariant and can be factored off-line. As a consequence of such matrix manipulations, a linear system which changes at each iteration must be solved; its size, however, reduces to the number of generating units. Numerical results with C implementation are presented for IEEE test systems and large scale Brazilian systems. The interior point method shows to be robust, achieving fast convergence in all instances tested.
Electrical networks; optimal power flow; interior point methods; quadratic programming; network flow models
