Fomenko B. Automation of control processes of the once-through boilers taking into account technological constraints

The thesis is devoted to the development of automated control system with constraints. In the dissertation was considered the following problems: the necessity of taking in account constraints on control and output signals into the control algorithms; it was proposed nonlinear structural solutions, based on typical local control systems, with the possibility of using technological constraints; it was proposed design of local nonlinear control systems with regard to restrictions of the limitations in synthesis of the multiloop control systems with the proposed control algorithms; it was investigated the problems of absolute stability of all nonlinear solutions; it has developed a system of temperature control along the path water-steam boiler direct flow, taking into account technological constraints. It was proposed the nonlinear system of temperature control of the overheated steam with temperature constraints after desuperheater, based on a typical control system with the regulator and the differentiator, which is complemented with the regulator of constraints, which operates when the steam temperature after the desuperheater exceeds technological limits. It was proposed in MIMO system of heat load and temperature control to use a nonlinear structural solution based on the developed algorithms which are providing a possibility to change the fuel input according to the reference of the heat load to keep the steam temperature in the crosscut in the upper radiation section of a boiler in the given technology range.