PREDICTIVE FUNCTIONAL CONTROL FOR MULTIPLE VARIABLE SYSTEM BASED ON FEED-FORWARD DECOUPLING COMPENSATION

In view of multi-input multi-output (MIMO) system that can be equivalently described by first order plus pure time-delay in each process channel, multi-variable PFC is presented based on feed-forward compensation decoupling technique. The new method is designed by decomposing the MIMO system into multi-input single-output (MISO) systems, in each MISO system, the other inputs are seemed as measurable disturbances during control strategy is being deduced, and PFC principle is used to design controllers, PFC decoupling control is realized by solving equivalence group. The presented control strategy and its algorithm is applied to a multi-variable steam temperature process with steam-steam heat exchanger in a 200MW unit, computer simulation results show that the control strategy is effective, the almost dynamic decoupling and completely static decoupling function are obtained, and the closed loop system has zero static error, many mismatches between the controlled plant and the predictive model demonstrate the strong robust ability and disturbances rejection. The control algorithm has the merit of simple, less calculation load, and is easy to be realized in Distributed Control System (DCS), so it has hopeful application prospect.