A new feedback linearization approach to advanced control of multi-unit HVAC systems

A new feedback linearization approach to advanced control of multi-unit HVAC systems is developed. The central idea of this new nonlinear control is to include a model-based feedback linearization part to compensate for the nonlinearity in the system dynamics. Therefore, the evaporating temperature and superheat values can be controlled by linear PI control designs to achieve desired system performance and reliability. The main advantages of the new nonlinear control method include: (1) better performance even with large model errors, (2) being able to adapt to indoor unit turn on/off operation, (3) much smaller PI control gains compared to that of current feedback PI controls, and (4) much easier design procedures since there is no need for tuning the PI control gains over wide range operation.