Comparison of differential, adaptive proportional and adaptive quadratic controls applied for a recent collector-solar pot system

The present study focuses on applying the well-known differential (on/off) and proportional control strategies and a new, quadratic one, proposed in the paper, for a measured solar collector-solar pot system. The solar pot in this paper is a recent invention. Because of the special practical task (cooking), it is enough to keep the pot’s (tank) temperature above a certain level, for sufficient time. This is the control task, not to maintain or follow a reference temperature. For this aim, the applied control methods prove to be satisfactory.The proportional and quadratic controls are used in a novel, adaptive way. Explicit mathematical expressions are provided for all controls to give the required flow rate value, in real-time. These expressions are gained by new analytical solutions with respect to already existing physically-based mathematical models, in the form of differential equations, in case of the adaptive proportional and quadratic controls. The solar collector-solar pot system model, operated with all three controls, is validated and the controls are compared based on modeled (simulated) and measured data. Advantages and drawbacks of the controls are discussed. Finally, conclusions and suggestions are provided regarding the practical applicability of the controls and possibilities for future research.