Karl Walther

Karl Walther’s research focuses on control of building and district energy systems, model-based building and HVAC design in Building Performance Simulation, and digitalized design-build-operate workflows. He holds a PhD from the University of Wuppertal, Germany, and is currently a postdoctoral researcher in the Thermal Systems Simulation team at KU Leuven, Belgium.


Session

09-09
15:10
25min
CDL-PLC translator: From Modelica HVAC control design toIEC 61131 PLC implementation
Michael Wetter, Karl Walther, Jianjun Hu, Anand Prakash

This paper presents the CDL-PLC translator, a tool to convert control sequences for building heating, ventilation, and air conditioning (HVAC) systems expressed in a subset of Modelica called Control Description Language (CDL) which is undergoing standardization via the voluntary ASHRAE Standard 231P into the IEC 61131-10 XML format. Such a translation is a step in a model-based design workflow and contributes to digitalizing the control delivery process in the building sector. The translation into the IEC 61131-10 XML is the last step in the implementation of control logic developed in CDL on programmable logic controllers (PLCs) standardized in IEC 61131. The paper presents the details of the translator, an example for the validation of a CDL block vs. the corresponding IEC block, and a practical application example for the translation of a control sequence for a hybrid heat pump plant from a case study neighborhood in Belgium. Practical applications, use cases, and future developments are discussed in the context of building industry processes.

Control for HVAC and Buildings
Audi-Midi