Transient Control of a Non-Linear Turbo-Generator using Multiple Shooting, Differential Dynamic Programmingand Quasi-Linearization Technique

Abstract

The main objective of this paper is primarily on practical solution to transient control problem of a non-linear turbo-generator model through the application of classical optimal control principle. The well-known two point boundary value problem that usually results from such optimal control problem formulation is iteratively solved using the approach of multiple shooting algorithm. In order to focus on the advantages of proposed technique, the same two point boundary value
problem has been consistently solved using the existing differential dynamic programming and quasi-linearization technique with comparison offered from the stand points of execution time and
core memory requirements. The derived open-loop optimal control laws for fast valving and forced excitation resulted in significant transient performance improvement of the nonlinear turbogenerator model feeding an infinite bus system after being subjected to a three phase short circuit fault at its terminals. In addition, a suboptimal feedback control simulations yielded somewhat less satisfactory results but found to be easily implementable from practical view point. Thus a microcomputer based suboptimal feedback control concept is evolved; and specific hardware configuration for such a controller is propose .