Publication

Abstract : QUANSER QNET 2.0 heating, ventilation and air-conditioning (HVAC) system is a hardware setup developed by National Instruments to study and analyze the thermal equilibrium in a ventilation chamber. The system comprises a brushless DC motor operated fan, a pulse width modulated power amplifier voltage controller and a heating element. The process variable under control is the temperature in the chamber, and the manipulated variable is the voltage across the heating element. This work deals with the conventional PI controller and the latest sliding mode controlling technique to control the temperature in the chamber. LABVIEW and NI-ELVIS II were used for the implementation of the controller on to the hardware setup and also to provide the required interface. The results are compared, and sliding mode control is found to provide better control over the process variable in both transient and steady-state conditions of operation.