Sungrow SG125HX, Руководство пользователя

Страница: 41 / 103

31
•
The line-to-line voltage on the LV side of the transformer should endure the output
voltage of inverter. When the transformer is connected to the IT grid, to-ground
withstanding voltage of the LV winding of the transformer, the AC cables, and the
secondary equipment (including the relay protection device, detection & measuring
device, and other related auxiliary devices) should not be lower than 1,500V.
•
The line-to-line voltage on the HV side of the transformer should comply with the
local power grid voltage.
•
A transformer with a tap changer on the HV side is recommended in order to keep
consistent with the grid voltage.
•
At an ambient temperature of 45℃, the transformer can run in 1.1 times of load for
long time.
•
A transformer with a short-circuit impedance 6% (permissible tolerance: ±10%) is
recommended.
•
The voltage drop of system cable is no more than 3%.
•
The DC component that the transformer can withstand is 1% of the fundamental
current at rated power.
•
For thermal rating, the load curve of the transformer and environment conditions
should be taken into account.
•
The apparent power of the inverter should never exceed the power of the
transformer. The maximum AC current of all inverters connected in parallel must be
taken into account. If more than 30 inverters are connected to the grid, contact
SUNGROW.
•
The transformer must be protected against overloading and short circuit.
•
The transformer is an important part of grid-connected PV generation system. The
fault tolerance capacity of the transformer should be taken into account at all times.
The fault include: system short circuit, grounding fault, voltage drop, etc.
•
Take ambient temperature, relative humidity, altitude, air quality, and other
environmental conditions into account when selecting and installing the transformer.
•
When the anti-PID function is enabled, observe the following items:
– If the LV side winding is in Y shape, neutral point grounding is prohibited.
– Surge protective devices (SPD) for the AC combiner box and on the LV side of
the transformer are recommended to be connected in the "3 +1" manner, as
shown in the figure below. The Min. continuous operating voltages of M1-M4 are
690VAC.
– The LV side winding of the transformer, AC cables, and secondary devices (-
including protective relay, detection and measurement instruments, and related
auxiliary devices) must withstand the voltage to ground of at least 1,500 V.
User Manual 5 Electrical Connection