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Appendix
②
Grid off
In this case, the hybrid inverter will simulate the grid so as to make the on-grid inverter can
still work. Hybrid and on-grid inverter will power the EPS loads together. If there is surplus
energy, it will charge the battery.
EPS loads
On-grid inverter
Common loads
CT
Grid
PV
X-
CLOUD
DC
AC
COM
Meter
PV
Figure 15-15 Power flowing when grid off
NOTICE!
• In EPS mode, the battery charging power is limited, and the energy storage inverter
increases the EPS output frequency to restrict and shut down the grid connected
inverter, ensuring the stability of the entire system. During this time, the grid
connected inverter may report Grid Freq Fault which is a normal occurrence.
Notice for micro-grid application
• Any brand of on-grid inverter that supports "frequency adaptation".
• On-grid inverter output power≤Max hybrid inverter EPS output power.
• On-grid inverter output power≤Max battery charging power.