looks like both you and I are trying to get more details on AC55/UMOC systems we have.
I've managed to get mine to run on the bench:
There is a fellow who lives near me who has experience with the somewhat newer but nearly identical, Azure AC55/DMOC system in a passat station wagon. (He had the system in a vanagon for several years and has been driving it successfully, but he recently moved it over to the passat as it is a better commuter for him). He was kind enough to take me for a test drive in it, although he was still working the bugs out of the swap so we weren't able to run around too much. My main observation was it seemed the car wasn't as powerful as it probably should be. Specifically if these motors are designed for direct drive, why would it stall on a roughly 10% grade (unable to start from a dead stop)? This was in 3rd gear, about a 5.7:1 overall gear ratio with 23" diameter tires which is right in the range azure/solectria suggests for these motors, and the car plus passengers probably weighed about 3700lbs which is also well within the recommended range. If you do the math the motor should only have needed about half its 230nm peak torque rating to get going on that hill under those circumstances.
Also, I just recently discovered the delta vs. wye differentiation you are asking about, and was trying to determine what setup my motor is as well (also an AC55-A). My UMOC440TF doesn't have anything on the label to suggest which way it is programmed for.
The UMOC service manual PDF I have (found on the metadope site; I downloaded everything they had) only has a brief mention of delta-wye switching capability in some vehicles these inverters were used with, but there is nothing about programming the inverter for it. That does however suggest that this is a possibility. I also just found this:
which seems like a decent layman's explanation of the benefits and tradeoffs of delta vs. wye. It is aimed at machinists but they are still talking about inverters and 3 phase motors. the basic takeaway seems to be you want wye for low speed, high torque operation and delta for a wider peak torque RPM range. The Azure documentation I found (newer than the solectria stuff) lists two AC55 part numbers, a delta and a wye one, and I am wondering which one the fellow with the passat has.
I'll share anything I learn if you do