| This work is concerned with the mathematical modeling, simulation, and the control of a proposed hybrid energy system. The energy system which utilizes a combined photovoltaic/thermal collector has been designed to supply electrical and thermal energy requirements of a rural village. The main objective of this work, however, is concerned with the development of a controller that maximizes the system's useful energy collection and delivery to the end user.; The control method is based on a new concept which deals with the regulation of the solar cell temperature for the array's maximum power output. The control objective has been realized by simulating three control models in which their respective performance and control energy expenditure has been tested with varying operating conditions. The control systems incorporate a conventional on-off controller which uses a specific hysteresis function designed for the purpose at hand, a suboptimal controller of the linear regulator type which solves the system dynamics for the control variables while minimizing a linear quadratic performance index, and a proportional controller which is a novel design concept that utilizes the natural behavior of the solar insolation for the production of the control energy.; Results of the simulation studies indicate that the design objective has been achieved. The collector operating temperature has been regulated to a desired level where high collector electrical and thermal efficiencies are obtained. The performance of the controllers has been evaluated based on system's net useful energy output. In this respect, the suboptimal controller has shown considerable performance improvement over the conventional controller in all simulated conditions, especially when cloud conditions prevail where as much as 42.21% improvement in system's useful electrical energy has been obtained. |
