Fault tolerant control of outdoor air and AHU supply air temperature in VAV air conditioning systems using PCA method

This paper presents a fault tolerant control method to control the outdoor air ventilation and AHU supply air temperature, which concerned indoor air quality and humidity, respectively to satisfy ASHRAE Standard in VAV systems. The principal component analysis method, joint angle method, and compensatory reconstruction are used to detect, isolate, and reconstruct the fault, respectively for fault tolerant control. They are tested and evaluated in a simulation environment under the condition of temperature and flow sensors with fix bias faults.