Hedges
I See Electromagnetic Fields!
- Joined
- Mar 28, 2020
- Messages
- 20,052
With "the latest UL 1741SA is the one that includes frequency shift with modulation", if frequency sits at 61.5Hz for a long time, does the inverter remain on-line indefinitely? Or after the time specified by UL 1741SA does it shut off? If shut off, how long before it reconnects?
"Ride through 299 seconds, trip within 300 seconds"
Sunny Boy inverters have up to three modes:
UL1741, just what the standard says.
Island (or off-grid), tolerate a wide range of frequency and voltage variation. Don't drop off and stay off unless frequency exceeds 64.5Hz; otherwise, adjust output up and down.
Backup - given a signal (by RS485 or Speedwire), switch between UL1741 or Island. (I think this is protection in case Sunny Island fails to implement UL1741, for instance if its relay gets welded shut. No explanation of why we should use "backup" not "island" is provided by SMA)
If a GT inverter drops off either immediately or after a delay, the battery has to repeatedly cycle, charging and discharging.
I think only a GT inverter that knows it is in an off-grid or backup configuration, and does not follow UL 1741SA, can perform as desired.
Figure 2: Frequency ride through regions from UL 1741SA [2]. b. GERMAN...
Download scientific diagram | Frequency ride through regions from UL 1741SA [2]. b. GERMAN APPLICATION GUIDE (VDE AR- N 4105) from publication: ADVANCED PV INVERTER FUNCTIONS: VERIFICATION TEST PROCEDURE | In recent years the installed PV and wind capacity increased significantly. Due to the...
www.researchgate.net
"Ride through 299 seconds, trip within 300 seconds"
Sunny Boy inverters have up to three modes:
UL1741, just what the standard says.
Island (or off-grid), tolerate a wide range of frequency and voltage variation. Don't drop off and stay off unless frequency exceeds 64.5Hz; otherwise, adjust output up and down.
Backup - given a signal (by RS485 or Speedwire), switch between UL1741 or Island. (I think this is protection in case Sunny Island fails to implement UL1741, for instance if its relay gets welded shut. No explanation of why we should use "backup" not "island" is provided by SMA)
If a GT inverter drops off either immediately or after a delay, the battery has to repeatedly cycle, charging and discharging.
I think only a GT inverter that knows it is in an off-grid or backup configuration, and does not follow UL 1741SA, can perform as desired.