INTEGRATING BMS AND SIMULATION TOOLS FOR MONITORING ANDPERFORMANCE ANALYSIS

Control related problems significantly contribute to high energy consumption in office andcommercial buildings. Today, building management systems (BMS) are commonlydesigned to control the technical building equipment in order to reach comfortable climaticconditions in the controlled spaces. This setpoint orientated control strategy does normallynot contain any active supervisory instruments to control the energy consumption of thebuilding. As a consequence, no error messages will occur as long as the setpoints arereached, sometimes even if in the worst case the cooling and heating system are workingagainst each other. Furthermore, standard BMS control algorithms are only able to detectabrupt changes in the conditions of e.g. HVAC-Systems, but they do not offer significantfault detection and diagnostic information and are unable to detect gradual degradations insystem performance (Buswell R.A. et. al., 2003 and others). On the other hand, dynamicsimulation tools are so far only used during the planning phase for the building design andthe dimensioning of the technical equipment like the heating and cooling system. Controlalgorithms are then well developed under consideration of simulation results and theplanned equipment, but the implementation is later normally done by system engineers ofthe chosen BMS company. Due to information losses interpretation and implementationerrors are nearly unavoidable and lead to suboptimal system control. To reduce suchproblems new strategies are required to directly implement well tested control algorithmsfrom simulation programs into the building control system. During building operation thesimulation tools can then e.g. be used in the energy management system for onlinesimulation and control, e.g. to check the control actions and measurement data against thesimulation results (Clarke, J.A. 2004; Gouda M.M. 2003; Hao, X. 2005 and others). Usingthe means of information technology, control and simulation actions can also take place atdifferent locations, so that there are apart from usable software interfaces no additionalrequirements on site for the building automation system.