Optimal power flow by a nonlinear complementarity method

A nonlinear complementarity method for solving nonlinear optimal power flow problems is presented. This method stems from recently proposed reformulat ion of complementarity problems as nonlinear systems of equations which age , in turn, solved by a Newton-type method, To reformulate optimal power flo w problems as nonlinear systems of equations we employ a function psi(mu): R-2 --> R that satisfies the property psi(mu)(a, b) = 0 double left right a rrow a > 0, b > 0 and ab = mu, for any mu > 0, Then, unlike interior-point methods, the nerv method handles the complementarity conditions for optimal ity, S-i greater than or equal to 0, pi(i) greater than or equal to 0 and S (i)pi(i) = 0, without requiring that S-i > 0 and pi(i) > 0 be satisfied at every iterate. Numerical results illustrate the viability of the proposed m ethod as applied to several power networks. A comparison with two interior- point algorithms is discussed.