Thread: Inverter and generator into one plug?

Originally Posted by Toxic_Avenger

I had a tour thru a power station once. I got to play on the simulator for a simulated turbine start-up. I had NFI what I was doing, but I do remember having to get the generator in phase with the grid.
This sort of makes sense now.

Yep, an out of sync closure of a large breaker will, um - break things... The magnetic forces involved are staggering. Have personally seen the engine mounts torn off a 2MVA genset that closed out of sync and I've seen a video of a similar unit rolling over through a brick wall when the same thing happened.

Thankfully modern microprocessors and sync check relays make this a rare occurrence, but still possible if you're not careful.

Paralleled a 1250KVA Gen to the mains through a 22kv stepup transformer yesterday - you need to cross your t's and dot your i's before doing that.

Originally Posted by Homestar

Have personally seen the engine mounts torn off a 2MVA genset that closed out of sync

That wasn't at the transmitter site at Shepparton in the '70's was it? IF it was, that was me.... BIG mess...

Originally Posted by Markf

That wasn't at the transmitter site at Shepparton in the '70's was it? IF it was, that was me.... BIG mess...

Nope - you just dobbed yourself in. Was a large Detroit unit in the City - had to go and sort out why it closed out of sync - remember those big horrid Woodward load sharing controllers? One of those had gone to god.

Used to manually sync units too - I had one setup that I could only adjust the speed from the genset - you'd fiddle the governor until the syncroscope was right, then have to run over to the switchboard and throw the breaker - usually by the time you got to the breaker the load had changed and the syncroscope was whizzing around again so you had to start all over again.

Originally Posted by Homestar

Used to manually sync units too

Let's just say that the SEC supply is a VERY low impedance supply and that about 15 degrees is a LOT at those power levels.....

For the purpose of the current discussion. Connecting a small ~2kW gennie and a ~1kW inverter together at some unspecified phase angle difference will certainly let the smoke out somewhere.

Yep, we won't close more that 5 degrees out when connecting to the grid, wouldn't dream of trying at 15 - thankfully modern control systems make this a snap.