A simple predictive controller for use on large scale arrays of parabolic trough collectors

Abstract

Efficient operation of a distributed collector field requires effective regulation of the outlet temperature. Control schemes utilising PI based controllers, whether adaptive or fixed parameter, have been shown to be unsuitable for this application. The reason for this is that such collector fields possess resonance dynamics at a low frequency which tend to restrict the bandwidth of such controllers. In this article a predictive controller is proposed whose purpose is to effectively counter such dynamics. This control technique is based upon a simple transfer function representation of the resonance dynamics which can be tuned using easily obtained experimental data and is computationally efficient. When applied to a validated non-linear computer model of the collector field the controller is seen to exhibit a fast well damped control response superior to that achievable using PI control.