Closed mwetter closed 1 day ago
What are the outside conditions when a simulation is started in a scenario like this with a negative start time? I need to correlate with a time in the weather file.
If the E+ weather file is from t=0 to t=365 days, then you can look up the outside conditions at t-365 days.
Yikes!
In FY21 AOP for NREL.
Todo for the release:
@kbenne : This issue is not yet fixed in the latest build that is merged through https://github.com/lbl-srg/modelica-buildings/pull/2984
Commit 06cc58dc25 on branch issue1938_spawn_negative_startTime
adds the validation case Buildings/Resources/Scripts/Dymola/ThermalZones/EnergyPlus_9_6_0/Validation/RunPeriod/NegativeStartTime.mos
which produces the following output:
Hmm. That's interesting. I can't perceive why it is doing this, although the testing I'm doing at my level doesn't attempt actual simulation. Take a look at the unit test in this commit.
I'll have to dig a bit deeper.
You may need to check if E+ does internally the right thing, for example by verifying that it picks the same weather data for t=-1 days as it does for t=364 days; or whether the simulations for these two day specifications produce the same indoor temperatures.
Yeah I certainly have some investigation to do. But the whole point of the strategy was that EnergyPlus would never actually see a negative time. I probably need to rig up a test that actually does simulation for day 364 and day -1, which will be a bit more involved.
Note how this so closely relates to https://github.com/lbl-srg/modelica-buildings/issues/2453 because simulating day 364 actually requires EnergyPlus to simulate through the first 363 days to arrive at the start time.
Delay for later, not part of release 9.0.
Problem is that if simulation starts at -1 day, then week-day of Jan 1 must be the same as if it were to start on Jan 1.
The following command
produces![image](https://user-images.githubusercontent.com/1329080/81738527-b0099780-944e-11ea-91a1-5defead0b4e6.png)