The inverse system method applied to the derivation of power system nonlinear control laws

Abstract

The differential geometric method has been applied to a series of power system nonlinear control problems effectively. However a set of differential equations must be solved for obtaining the required diffeomorphic transformation. Therefore the derivation of control laws is very complicated. In fact because of the specificity of power system models the required diffeomorphic transformation may be obtained directly, so it is unnecessary to solve a set of differential equations. In addition inverse system method is equivalent to differential geometric method in reality and not limited to affine nonlinear systems. Its physical meaning is able to be viewed directly and its deduction needs only algebraic operation and derivation, so control laws can be obtained easily and the application to engineering is very convenient. Authors of this paper take steam valving control of power system as a typical case to be studied. It is demonstrated that the control law deduced by inverse system method is just the same as one by differential geometric method. The conclusion will simplify the control law derivations of steam valving, excitation, converter and static var compensator by differential geometric method and may be suited to similar control problems in other areas.