Reasoning the result of /examples/python/testcase1.py

[kefeimo]

Description

When running the example https://github.com/ibpsa/project1-boptest/blob/master/examples/python/testcase1.py and plot the result, it gives the following plot.

From GET/measurements

{"message":"Queried the measurements successfully.","payload":{"CO2RooAir_y":{"Description":"Zone air CO2 concentration","Maximum":null,"Minimum":null,"Unit":"ppm"},"PHea_y":{"Description":"Heater power","Maximum":null,"Minimum":null,"Unit":"W"},"TRooAir_y":{"Description":"Zone air temperature","Maximum":null,"Minimum":null,"Unit":"K"}},"status":200}

from @rlutes "When the PID signal (oveAct_u) goes negative the heating power (PHea_y) should be zero but it is not. It appears there is something in the model taking the absolute value of the PID signal controlling the heater inside the model."

Expected outcome

Would like to understand the simulation result and confirm it is behaving as expected.

[dhblum]

The performance is as expected, but the documentation of the model and example controller could be improved:

• The HVAC device controlled is actually better characterized as a "heater/cooler" rather than just "heater" since it can provide heating and cooling.
• The Power use of the device is calculated within the model simply as the absolute value of the heating or cooling thermal power delivered divided by an efficiency.
• The "PID" controller implemented in python is really just a "P" controller, as it only implements proportional control.

I suggest to address these confusions by appropriately fixing naming conventions.