plug and play control of refrigeration systems based on online system identification

Superheat control is one of the essential parts of refrigeration systems for safety and efficiency. superheat control is performed with a pressure sensor, temperature sensor, electrical expansion valve, and control unit. in this work, robust control of superheat temperature of refrigeration systems’ evaporator have been explored by online system identification and linear quadratic regulator (lqr) based pi controller. the optimal pi controller parameters are obtained by a lqr on the open-loop system. this method needs the first-order model plus delay time (fopdt) parameters. so, a simple fopdt parameter estimation method is used. the plug-and-play and robustness of the proposed method are validated through simulation of the big variation in the operation condition which shows a different dynamic manner.