Abstract
The work is dedicated to modeling&turbine control systems and studying the stability of a nonlinearsystem. The dynamics of the turbine regulation system is described by a nonlinear&system of fourdifferential equations. This system of equations describes the mathematical model of a turbine operatingin condensing mode. Using the transformation&way, the mathematical model of the steamturbineregulation system is reduced to the conclusion of a problem about the unconditional stability of anonlinear stationary system of indirect control. In the study of a nonlinear system, the Lyapunov functionwas applied and the circumstances of unconditional stability were obtained. The conclusion of differentialequations systems is executed in vector-matrix form. The results&obtained for a nonlinear systemare&used to study the durability of a steam turbine. Numerical calculations are presented that illustratethe probability of using the proposed layout and studying the stability of nonlinear control systems forpower turbines. Key words: stability of a nonlinear system, differential equation, Lyapunov function, mathematicalmodel of a turbine, asymptotic stability, characteristic of nonlinearity.