7 Commissioning
SMA Solar Technology AG
Operating manual
SI44M-80H-13-BE-en-15
94
If the reverse power for the set time is exceeded, all Sunny Island inverters disconnect the generator from the stand-
alone grid and block the connection of the generator to the stand-alone grid for the minimum stop time.
NOTICE
Generator damage
In the event of reverse power, the AC sources in the stand-alone grid drive the generator. The generator can be
damaged as a result.
• Observe the manufacturer’s information on reverse power protection of the generator.
• Set the generator reverse power and permitted time for reverse power according to the manufacturer’s
specifications.
The basic procedure for changing operating parameters is explained in another section (see Section 8.6, page 113).
Procedure:
1. Select
Generator > Generator > Power monitoring
.
2. Set the parameter
Voltage monitoring generator maximum reverse power
to the active power of the
generator reverse power.
3. Set the parameter
Volt. monit. gener. max. reverse power trip. time
to the time of the generator reverse
power.
7.8.1.5
Configuring the Current Limit for the Generator Depending on the Frequency
Relevant for off-grid systems
The higher the generator current, the higher the torque for the generator. With unregulated generators, the speed of
rotation decreases with increasing torque. If the speed of rotation decreases, the frequency of the generator voltage is
reduced.
If the frequency of the generator voltage falls below the rated frequency, the generator management can place
additional limits on the generator current. The lower the frequency, the more the generator current is limited by the
generator management. This setting is useful if the generator is supplying other loads parallel to the Sunny Island. This
setting allows the maximum load to be placed on the generator without overloading it.
The basic procedure for changing operating parameters is explained in another section (see Section 8.6, page 113).
Requirement:
☐ The generator must not be an inverter generator. The output frequency of the inverter generator is fixed.
Procedure:
1. Select
Generator > Generator
.
2. Set the parameter
Rated generator current
to the desired value. Tip: A suitable value for the parameter
Rated
generator current
is 80% of the maximum generator current per line conductor.
3. Select
Generator > Operation
.
4. Set the parameter
Limitation type of generator current
to
Frequency-dependent current limitation
. This
will activate the frequency-dependent current limiting.
7.8.2
Changing the Type of the Generator Interface
Relevant for off-grid systems
If you have installed a generator in the system, the type of generator interface determines how the generator is
controlled.
The basic procedure for changing operating parameters is explained in another section (see Section 8.6, page 113).
