SHORT-RANGE OPTIMAL ECONOMIC DISPATCHING OF A HYDRO-THERMAL SYSTEM

Abstract

Pontryagin's Maximum Principle is applied to the problem of determining the operation of Hydro-Thermal, generating system for the minimum generation coats. The general formal ae are deriv-ed for power systems with hydroelectric plants having constant heads. Only the costs for steam generation are considered and no expense for water utilization is included in the performance evaluation. An attempt was made to investigate the utility of an Analogue Computer In solving the problem, which is a two-point, boundary value problem, in which Pontryagin's Maximum Principle has been applied. In the Numerical solution of the problem, first the convergence behaviour of the adjoint variable was studied, which resulted in poor convergence characteristics. Secondly, help of digital computer was taken for ,numerical integration of the differential equations to determine the value of adjoint van -able to match the two-point boundary conditions. And in the last case considering the system to be quesilinear, an attempt was made to find the solution, by first order or linear approxi-mation upon which the correction terms In the form of power series are superimposed. Although the numericalsolution was obtained for a simpli-fied model system only, the method can be extended to any size system, of course with the increased complexity of the problem due to large number of variables.