Hardware-in-the-loop testing of control of a precooled desiccant air-cooling system

Increasing the energy efficiency of cooling in buildings is an important component of the management of global energy consumption. A super-efficient cooling system based on the evaporation concept has been developed, and initial simulation results using the MATLAB/Simulink software tool have already been published by our team. In this paper, we present the results of hardware-in-the-loop (HIL) testing of the real-time controller for the cooler. HIL testing is an engineering process in which the actual controller hardware and software are implemented and interfaced with a real-time simulated model of the controlled system. Using HIL testing, many real-world problems can be fixed before testing on the actual prototype. The controller design is implemented on a small-footprint industrial PC with CODESYS RTE and application code, while control software is implemented using IEC 61131-3 programming languages. Similarly, a real-time thermodynamic and input-output variable-based model of the room, environment, and cooler and its mechanical components (sensors and actuators) are modeled using another industrial PC with the same software tools. HIL test results show very good agreement with the offline simulations.