Paper Conference

Proceedings of Building Simulation 2021: 17th Conference of IBPSA


Modelica-json: Transforming energy models to digitize the control delivery process

Michael Wetter 1, Jianjun Hu 1, Anand Prakash 1, Paul Ehrlich 2, Gabe Fierro 3, Milica Grahovac 1, Marco Pritoni1, Lisa Rivalin4, Dave Robin 5
1 Berkeley Lab, Berkeley, CA
2 Building Intelligence Group, Portland, OR
3 University of California at Berkeley, Berkeley, CA
4 Facebook, Menlo Park, CA
5 BSC Softworks, Atlanta, GA

Abstract: Building simulation models are typically not used to generate the documentation required for bidding and project delivery of commercial building systems, or for their semantic modeling and commissioning. This paper presents a software tool that aids in digitizing the control delivery process, spanning simulation during design to implementation and formal verification during commissioning. The tool can generate from Modelica models digital documentation of control sequences. This digital documentation, along with other project drawings and specifications can be used for project bidding. It can also be used for implementation of control sequences through machineto-machine translation to commercial legacy control products, for which we are currently developing the proposed ASHRAE Standard 231P based on the presented work. Moreover, as-installed control sequences can be formally verified against the design specification, and a semantic model in Brick can be exported to aid in configuration of building analytics and fault detection. The paper presents what we believe is the first translation of a Modelica-implemented control sequence to a native implementation on a commercial control platform, using the webCTRL product line from Automated Logic. The paper also shows how a webCTRL implementation can be formally verified against its Modelica specification. These use cases have all been demonstrated with a prototype implementation that is now being further developed.
Keywords: Controls, Modelica, semantic models
Pages: 1 - 8