2020 04 22_meeting - lbl-srg/soep GitHub Wiki

Date: April 22, 2020, 8:15am-9am Pacific Times

The purpose of this meeting is to coordinate the Modelica integration for SOEP.

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1. Previous action items.
2. Kyle, Michael: Refactoring room air heat and mass balance.
3. Kyle, Michael: EnergyPlus I/O variables.
4. Michael, Kyle: Support for radiant systems.
5. Stuart: FMI-QSS.
6. Kyle, Michael: Optimica license protection.
7. Jianjun: JSON representation for OS front-end to Modelica
8. Other items

This needs analysis of a Modelon staff who can look into the solver.

Branch issue1129_energyPlus_zone works for multiple buildings for JModelica, Dymola and OpenModelica.

Issues are at https://github.com/lbl-srg/modelica-buildings/issues?q=is%3Aissue+is%3Aopen+label%3Aspawn

Next, work on

• Kyle to implement schedules and EMS actuators on EnergyPlus side (blocker), https://github.com/lbl-srg/modelica-buildings/issues/1818. Support now implemented, schedules and actuators have unit not defined, will be fixed in the future.
• Michael to add validation for schedules and EMS actuators, https://github.com/lbl-srg/modelica-buildings/issues/1633
• Kyle to correct delayed output variable, https://github.com/lbl-srg/modelica-buildings/issues/1679 Should be addressed in next built.
• Kyle to support unit declarations (blocker), https://github.com/lbl-srg/modelica-buildings/issues/1680
• Kyle to support reading zone air temperature, https://github.com/lbl-srg/modelica-buildings/issues/1681. Should be addressed in next built.
• Kyle to make EnergyPlus ignore RunPeriod (currently Spawn just hangs), https://github.com/lbl-srg/modelica-buildings/issues/1678. Should be addressed in next built.
• Michael/Milica to use thermal zones in larger model, https://github.com/lbl-srg/modelica-buildings/pull/1663
• Michael/Kun to implement example with single zone model, https://github.com/lbl-srg/modelica-buildings/issues/1582
• Kyle to trigger an error if condition 1 below is not satisfied
• Kyle to make an FMU that does not compress the files. Should be addressed in next built, by default no compression, but also has option not to zip it.
• Kyle to look into generating all outputs in the folder tmp-simulation-TwoIdenticalZones. Kyle will add a flag to be used to specify the output file directory.
• Kyle to look into numerical instability (walls may be initialized to wrong temperature). See for example Experimental/EnergyPlus/Examples/VAVReheatRefBldgSmallOffice/FloorOpenLoop or Experimental/EnergyPlus/Validation/OneZone and set the initial room temperature to 10 degC.
• Kyle and Michael to work out how to filter level of info/error/fatal errors. See code near

const size_t nCat = fmi2_import_get_log_categories_num(bui->fmu); * Kyle to create installer package for all three platforms.

Kyle addressed start time. Next addressing zones that are not in Modelica but in idf.

Kyle posted new binary. Now all room air temperatures are computed using warm up, which is not good. Need to refactor to freeze room air temperatures at initial temperature as requested from Modelica. Rooms not in Modelica will do warm-up to compute their room temperature. Warm-up stops when all inside-facing surface temperatures stabilized at mid-night in all rooms, whether present or not in Modelica.

Actuators and schedule should work on the EnergyPlus side.

Goal is to have a Buildings library release with Spawn before the peer-review.

Kyle to work on emitting all EnergyPlus objects that are supported by Spawn.

1. If there is a thermal zone in Modelica, then there need to be a Zone object in the idf file. Otherwise the simulation stops with an error. EnergyPlus reports a Fatal Error to its error file and to the FMI API call.
2. If there is an Zone object in the idf file but no thermal zone in Modelica for this EnergyPlus zone, then EnergyPlus simulates the zone using free floating temperature. There is no HVAC system, but may be internal gains. EnergyPlus reports an information message to its error file and to the FMI API call.
3. All HVAC objects in the idf file will be removed by the Spawn executable before it writes the idf file to the FMU.
4. For the EnergyPlus envelope, either the CTF transfer function or the finite difference method can be used.
5. Output variables and EMS actuators need not be present in the idf file.

Posted specification.

Kyle to review specification.

Stuart to work on small example with time events (sampler) and with reinit. Need updated OCT distribution.

Decide when to update output variables that have no state dependency.

Output variables:

Make evaluating all internal (non-output) variables an optional flag at discrete sample times (say 2 minutes), and then benchmark using a large model to see the cost.

Optionally, allow all variables to be reported at each QSS step inside a user specified time interval.

No discussions.

Next:

• Work on experiment specification.

Included in this year's NREL contract. Support for Spawn on OS X (won't include the optimization and other Modelon libraries).

No discussion, waiting for NREL contract.

Potential paths: Modelon shared initial proposal.

Enabled installation and run on Windows OS. Fixed failed parsing due to the DynamicSelect.

To do:

Address TypeError issues reported in https://github.com/lbl-srg/modelica-json/issues/106 and https://github.com/lbl-srg/modelica-json/issues/107. Enable parsing packages in CDL mode. Handling replaceable models.

None.

See next steps under "Refactoring room air balance".

Michael to keep working with Modelon on making dp of pressure drop elements a state rather than p using stateSelect.