Multi-variable Extremum Seeking Control for Mini-split Air-conditioning System

In this study, a multi-variable extremum seeking control (ESC) scheme is proposed for a variable-speed mini-split air-conditioning system. The control inputs are the evaporator and condenser fan speeds, respectively. While the total power consumption is used as the feedback. The multi-variable ESC can optimize the control inputs for each channel in real-time, without relying on the accurate model of the system. This nearly model free feature makes the system more easily to be designed and deployed. First, the multi-variable ESC algorithm is deployed on a Dymolabased ASHP model to show its effectiveness in searching the optimal working point. Then, an experiment set-up is built to further demonstrate the promising performance in improving the efficiency of the mini-split AC system via multi-variable ESC.