A linear programming implementation of a interval method for global non-linear DC analysis

A modification of Kolev´s (1997) previous method for finding the set of all operating points of non-linear resistive circuits is suggested. The original method is based on an approximation of every single variable function (circuit equations are in a hybrid representation form) by an appropriate linear interval function, i.e. by a real linear function having an additive interval constant. The improved approach uses linear programming technique to update the current interval “box” instead of the originally used interval hull of the solution set of the linearized interval system. Numerical experiments show that the version suggested reduces almost double the number of the iterations in comparison with the original method for the examples considered