Sensor fault detection and validation of VAV terminals in air conditioning systems

Sensor failure and bias are harmful to the process control of air conditioning systems, resulting in poor control of the indoor environment and waste of energy. A strategy is developed for the flow sensor fault detection and validation of variable air volume (VAV) terminals in air conditioning systems. Principal component analysis (PCA) models at both system and terminal levels are built and employed in the strategy. Sensor faults are detected using both the T2 statistic and square prediction error (SPE) and isolated using the SPE contribution plot. As the reliability and sensitivity of fault isolation may be affected by multiple faults at the system level, a terminal level PCA model is designed to further examine the suspicious terminals. The faulty sensor is reconstructed after it is isolated by the strategy, and the FDD strategy repeats using the recovered measurements until no further fault can be detected. Thus, the sensitivity and robustness of the FDD strategy is enhanced significantly. The sensor fault detection and validation strategy, as well as the sensor reconstruction strategy for fault tolerant control, are evaluated by simulation and field tests.

[1]  Thomas F. Edgar,et al.  Identification of faulty sensors using principal component analysis , 1996 .

[2]  Arthur L. Dexter,et al.  Fault-tolerant supervisory control of VAV air-conditioning systems , 2001 .

[3]  C. B. Dorgan,et al.  VAV systems work despite some design and application problems , 1997 .

[4]  D. Ngo,et al.  A robust model-based approach to diagnosing faults in air-handling units , 1999 .

[5]  Shengwei Wang,et al.  Law-based sensor fault diagnosis and validation for building air-conditioning systems , 1999 .

[6]  Hongwei Tong,et al.  Detection of gross erros in data reconciliation by principal component analysis , 1995 .

[7]  Srinivas Katipamula,et al.  Diagnostics for Outdoor Air Ventilation and Economizers , 1998 .

[8]  J. E. Jackson.  A User's Guide to Principal Components , 1991 .

[9]  Fu Xiao,et al.  AHU sensor fault diagnosis using principal component analysis method , 2004 .

[10]  Shengwei Wang,et al.  Dynamic simulation of building VAV air-conditioning system and evaluation of EMCS on-line control strategies , 1999 .

[11]  Jose A. Romagnoli,et al.  A strategy for detection and isolation of sensor failures and process upsets , 2001 .

[12]  Youming Chen,et al.  Fault-tolerant control for outdoor ventilation air flow rate in buildings based on neural network , 2002 .

[13]  Masami Suzuki,et al.  Typical faults of air conditioning systems and fault detection by ARX model and extended Kalman filter , 1996 .

[14]  S. Qin,et al.  Determining the number of principal components for best reconstruction , 2000 .

[15]  Krishnan Gowri,et al.  Automated Fault Detection and Diagnostics for Outdoor-Air Ventilation Systems and Economizers: Methodology and Results from Field Testing , 1998 .

[16]  Shengwei Wang,et al.  An Integrated Robust Strategy for Diagnosing Sensor Faults in Building Chilling Systems , 2002 .

[17]  Arthur L. Dexter,et al.  Fault Diagnosis in Air-Conditioning Systems: A Multi-Step Fuzzy Model-Based Approach , 2001 .

[18]  Shengwei Wang,et al.  Automatic sensor evaluation in BMS commissioning of building refrigeration systems , 2002 .

[19]  Sanjay Kumar,et al.  ARX and AFMM model-based on-line real-time data base diagnosis of sudden fault in AHU of VAV system , 1999 .

[20]  Sanjay Kumar,et al.  Online fault detection and diagnosis in VAV air handling unit by RARX modeling , 2001 .

[21]  Fu Xiao,et al.  Detection and diagnosis of AHU sensor faults using principal component analysis method , 2004 .

[22]  Ali Cinar,et al.  Intelligent process monitoring by interfacing knowledge-based systems and multivariate statistical monitoring , 2000 .

[23]  John F. MacGregor,et al.  Process monitoring and diagnosis by multiblock PLS methods , 1994 .

[24]  W. Y. Lee,et al.  Fault diagnosis and temperature sensor recovery for an air-handling unit , 1997 .