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7.3.3 Checking PV Array
Ensure the measuring devices are connected and used correctly. Otherwise,
there will be electric arc.
DC side voltage should be no more than the max. DC input voltage of the MV
Station.
Too high DC voltage may damage the module even cause safety incident.
To ensure system reliability and device operation, PV cells on the DC side of
the MV Station should be from the same manufacturer and the number of PV
cells in each string should be the same.
Check the PV arrays before grid-connection. The voltage of each DC main cables
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-1 curve. Commission the device when the PV array output situation 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 module).
•
Record accurately all the measured datas.
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 serious.
System Manual
Содержание SG4950HV-MV
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