Using the Virtual Cybernetic Building Testbed and FDD Test Shell for FDD Tool Development.
Using the Virtual Cybernetic Building Testbed and FDD
Test Shell for FDD Tool Development.
(889 K)
Bushby, S. T.; Castro, N. S.; Galler, M. A.; Park, C.;
House, J. M.
NISTIR 6818; 45 p. October 2001.
Sponsor:
Architectural Energy Corp., Boulder, CO
Keywords:
BACnet; building automation; building control; direct
digital control; energy management systems; fault
detection and diagnostics; cybernetic building systems;
heating; ventilation; air conditioning; architecture
Abstract:
Advances in building automation technology have taken
place for a variety of building services including
heating, ventilating, and air conditioning (HVAC)
control systems, lighting control systems, access
control systems, and fire detection systems. In spite of
these advances in technology, many building control
systems do not work as intended. It is evident that the
industry needs to learn how to take advantage of the new
ability to interconnect traditionally independent
systems in a building. Commissioning, automated fault
detection and new approaches to applying system
integration are all areas of active research. However,
it can be difficult to conduct this research in actual
buildings because of the need to maintain comfortable
and safe conditions for the building occupants. This
report describes two enabling tools that have been
developed to advance these research efforts. It focuses
on the use of these tools to develop and test automated
fault detection and diagnostic (FDD) technology for HVAC
systems and their application in the area of Fault
Detection and Diagnosis. The two enabling tools are the
Virtual Cybernetic Building Testbed (VCBT) and the FDD
Test Shell. The VCBT consists of a variety of simulation
models that together emulate the characteristics and
performance of a cybernetic building system. The
simulation models are interfaced to real
state-of-the-art BACnet speaking control systems to
provide a hybrid software/hardware testbed that can be
used to develop and evaluate control strategies and
control products that use the BACnet communication
protocol. The FDD Test Shell is a data-sharing tool that
was developed to enable side-by-side testing and
comparison of two or more FDD tools and to support the
integration of information from multiple FDD tools.
Preliminary tests of some of the faults modeled in the
VCBT are described in this report. The primary goal of
the tests was to quantify the impact of valve and damper
leakage for typical air-handling unit (AHU) with
variable-air-volume (VAV) box configurations. In this
study, testing revealed that leakage through the outdoor
air damper and a stuck open outdoor air damper fault
have almost no measurable impact on the operation of the
system.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899