Sungrow SG2500HV-30, Системное руководство

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DC side voltage should be no more than max. DC input voltage of the inverter.
Too high DC voltage may damage the inverter even cause safety incident.
To ensure the system reliability and device operation, PV cells on the DC side
of the inverter should be from the same manufacturer andnumbers of PV cells
in each string should be the same.
Check the PV arrays before grid-connection. The voltage of each DC main cable should
be the same and no more than the max. permissible DC voltage. Check carefully the
polarity of each DC main cable. Once the polarity in one DC main cable is incorrect, the
PV arrays may be damaged.
Make sure the environmental condition is stable since the voltage of PV array may
change with the solar radiation and the temperature of the PV cells. Record the PV array
status via the U-I curve. Commission the device when the PV array output status is
stable.
The PV field circuit fault (module fault or module numbers deviation in certain
array), cable damages or connection looseness may cause the voltage
deviation exceeding 3% under stable environmental conditions.
•
Record the environmental parameters (temperature, radiation, etc.).
•
Measure the resistance of cables (between the terminal box and the inverter).
•
Record accurately all the measured data.
7.3.4 Checking Grid Voltage
•
Measure accurately the grid 3-phase line-to-line voltages: L1-L2, L1-L3, and L2-L3.
The voltages should not exceed the grid permissible voltage and the three phases
are in balance.
Adjust the transfer ratio of the transformer by qualified personnel if the grid
voltage deviation is large.
•
Measure and record the grid frequency. Measured data should not exceed the grid
permissible frequency.
•
Measure the THD and check the curve if possible. The inverter will stop running if the
THD is serious.
•
Record accurately all the measured data.
System Manual 7 Commissioning