BUG: Fast DER model is gives erroneous results with PSS/E 33.

[sibyjackgrove]

Describe the bug
It seems the power output from the Fast DER model as seen by the distribution system and transmission system is 0 when used with PSS/E 33. Due to this all the results from this co-simulation are erroneous. Co-simulation is completed normally with no errors. Note that the same config file when used with PSS/E 35 is giving correct results.

To Reproduce
Run any co-simulation with fast DER on PSS/E 33.

Expected behavior
Using Fast DER with PSS/E 33 should give same results as PSS/E 35

Screenshots
The below diagram shows load at bus 1 with different DER penetration (for fast DER with PSS/E 33). Notice that there is a negligible difference when compared to the no DER scenario.

Desktop (please complete the following information):

• OS: Windows 10
• PSS/E Version: 33.3.0