Coordination optimization-based variable structure control for main steam pressure of power plant

An optimal variable structure control (VSC) based on a coordination genetic algorithm has been developed. Steady-state error and control switching frequency are used to constitute the system performance indexes in the coordination optimization, while the tuning rate of boundary layer width (BLW) is employed as the optimization parameter. Then based on the mathematical relationship between BLW tuning law and steady state error, an optimized BLW tuning rate is added to the nonlinear control term of VSC. Simulation experiment results applied to the main steam pressure control (MSPC) of power plant show the comprehensive superiority of dynamical and static state performance by using the proposed controller over that of by using an optimized PID control. The proposed VSC system has better robustness against large parameter variations and disturbances. This succeeds in coordinately considering both chattering reduction and high-precision control in VSC.