Building Digital Twin Simulator

Building digital twin simulator

A digital twin simulator was developed to describe the chilled water pump differential pressure control loop in actual building operations. The simulator was constructed on a BIM environment using Revit Dynamo, and simulations were executed through Dynamo Player within the Revit interface. Additionally, it reflects the logic and mechanisms of the actual control loop, while simulation calculations and data processing are conducted in real-time using Python scripts embedded in the Dynamo workflow.

The simulator input variables are defined as the setpoint variable, which is the chilled water pump differential pressure, and the disturbance variable, which is the water valve opening rate. The simulator output variables are defined as the control variables, which include the chilled water pump frequency and chilled water pump differential pressure, and the plant output variables, which include the chilled water flow rate and chilled water pump energy consumption.

During the building operation period (07/05–07/11), a comparison between the simulator results and actual control loop variables showed that the mean absolute percentage error (MAPE) was calculated as 0.88%. This result showed that the simulator accurately replicates the physical behavior of the actual control loop with high performance. In the future, the digital twin simulator will be utilized to develop AI agent-based optimal control and autonomous operation technologies. This will be explored to further advance intelligent and efficient energy optimization strategies.