This article discusses the problem of designing a nonlinear combined controller for a steam pressure control system in the main pipeline of a thermal power plant. The mathematical model of this system is represented as a dynamic plant with a constant and known delay in control. The operation of this system takes place under conditions of structural and parametric uncertainties and switching. The hyperstability criterion and the approach for designing L-dissipative dynamic systems are used to develop dynamic feedback algorithms for a control scheme with an implicit reference model and correction filters. In the simulation stage, we conducted a simulation that clearly illustrated the quality of our control system.