Multivariable controller for stationary flat plate solar collectors*

Abstract

The water flow rate control, which is the principal control loop required to operate stationary solar fields, can be as simple as designing a PID controller for a unique pump whose behavior can be approximated by a first-order system with delay. Nevertheless, when the water flow rate is manipulated with multiple actuators (pumps or valves), the problem presents some challenges due to hydraulic interactions. This paper presents a multivariable controller scheme to deal with the control of a solar field with five pumping systems. Simulation and experimental results are included to demonstrate the effectiveness of the proposed controller.