Multivariable MAC control based on residual error gray feedback correction and its application

Unit load system of power plant is a double-input and double-output multivariable system with big inertia. The conventional control method cannot get satisfactory result. In this paper, the system is firstly decomposed into two double-input and single-output subsystems and two MAC controllers are designed accordingly. By solving the two controllers’ equations, predictive control sequence is obtained. As to system’s uncertainty such as time-varying characteristics, residual error gray multi-step feedback correction (REGFC) method takes the place of the conventional single step feedback correction method. The new method can better predict the error sequence between the object output and the MAC model output so that a better feedback correction effect can be achieved. The simulation of 125MW unit load system proves that the new method has satisfactory performance.