Background:
The SUN2000MA-15KTL-M0 inverter is used, but one PV string does not generate electricity.
Analysis process:
The PV string voltage is normal, as shown in the following figure.
Connect the PV string to another PV port to connect to the grid. The log information is as follows:
No alarm was reported on March 18, and the inverters were connected to the grid.
According to the onsite communication, one string of the two PV strings under the same MPPT faces north and has little illumination. The other string faces south and has good illumination. According to the logs, the operating power of the PV string facing north is very low. It is not because the inverter string does not generate power. When the PV string is connected to the same MPPT with the high power string, the MPPT tracing is affected. The highest power points of the two PV strings are not synchronized, and one of the two PV strings is blocked, if the current deviation is large, current backfeed may also occur.
Suggestion:
Connect PV strings with the same open-circuit voltage and same number of PV strings to the same MPPT. Do not mix them.
