Fronius Dynamic power reduction for mixed systems with Fronius GEN24 Plus inverters Whitepaper [EN]
Dynamic power reduction for
mixed systems with Fronius
GEN24 Plus inverters
Application Guide
© Fronius International GmbH
Version 1 04/2021
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TABLE OF CONTENTS
1 General ............................................................................................................................................................ 3
How can a dynamic power reduction be implemented? ..................................................................................... 3
2 Example 1 - Scenario A .................................................................................................................................. 5
2.1 Web interface settings ............................................................................................................................ 5
2.1.1 Settings on the web interface of the Fronius GEN24 10.0 Plus ......................................................... 5
2.1.2 Settings on the web interface of the Fronius Symo 7.0-3-M (additional inverter) .............................. 6
2.2 System diagram ...................................................................................................................................... 6
2.2.1 Solar.web connection ......................................................................................................................... 8
3 Example 2 - Scenario A .................................................................................................................................. 8
3.1.1 Settings on the web interface of the Fronius GEN24 10.0 Plus: ........................................................ 8
3.1.2 Settings on the web interface of the Fronius Symo 7.0-3-M (additional inverter): ............................. 9
3.2 System diagram .................................................................................................................................... 10
3.2.1 Solar.web connection ....................................................................................................................... 10
4 Example 3 - Scenario B ................................................................................................................................ 11
4.1 Web interface settings .......................................................................................................................... 11
4.1.1 Settings on the web interface of the Fronius GEN24 10.0 Plus ....................................................... 11
4.1.2 Settings on the web interface of the Fronius Symo 20.0-3-M (additional inverter) .......................... 11
4.2 System diagram version 1 – Display as two systems in Solar.web ..................................................... 12
4.2.1 Solar.web connection ....................................................................................................................... 12
4.3 System diagram version 2 – Display as one system in Solar.web ....................................................... 13
4.3.1 Solar.web connection ....................................................................................................................... 13
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1 GENERAL
When the Fronius GEN24 Plus is operated in combination with additional inverters, the following particularities
must be observed with regard to dynamic power reduction.
This planning aid is intended to help you to identify the necessary components and apply specific settings
depending on the system configuration.
How can a dynamic power reduction be implemented?
For the time being, a distinction must be made between two main types of mixed systems.
Scenario A: The GEN24 Plus inverter takes care of the power reduction of the entire system.
Scenario B: The additional inverters in the system take care of the power reduction of the entire system.
There is also the option of deploying an external control unit for the power reduction of the inverters. This is
particularly recommended for large photovoltaic systems with several inverters operating in combination.
Tested third-party components:
/ Solar-Log: Base Series (15, 100, 2000)
/ meteocontrol: blue’Log X-Series
IMPORTANT!
Zero feed-in with mixed systems (GEN24 Plus in combination with other inverters) is possible only with the
specified third-party components.
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Scenario A
Scenario B
Type of mixed system:
Example: 10 kW 5 kW
Example: 10 kW 20 kW
Conditions:
Feed-in limit for the entire system [W]
≥
Generator output to additional
inverter(s) [Wp]
+10% AC nominal capacity GEN24 [W]
Feed-in limit for the entire system [W]
<
Generator output to additional inverter(s)
[Wp]
+10% AC nominal capacity GEN24 [W]
Rule of thumb:
Systems in which the output of the
additional inverter(s) is smaller than or
equal to that of the Fronius GEN24
Plus inverter can usually effect the
dynamic power reduction without
additional components.
Systems in which the output of the
additional inverter(s) is greater than that
of the Fronius GEN24 Plus inverter
usually require an additional Fronius
Smart Meter for the dynamic power
reduction.
Regulation of the
dynamic power
reduction by:
Fronius GEN24 Plus
The additional inverters in the system take
over regulation
Additional
components required:
None
Fronius Smart Meter
Necessary settings:
- Power limit on the GEN24 Plus
- No limit for the additional
inverter(s)
- Power limit for the additional
inverter(s)
- No limit on the GEN24 Plus
System diagram:
Note
It is essential to create the two
subsystems in Solar.web as separate
systems.
A third Smart Meter is required if you want
to display these as a single system
(special case – see Example 3)
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2 EXAMPLE 1 - SCENARIO A
Total system power: 20 kWp
Feed-in limit: 70% of the total system power = 14 kW
System configuration:
Fronius GEN24 10.0 Plus 12 kWp
Fronius Symo 7.0-3-M 8 kWp
Conditions: 14000 W ≥ 8000 Wp + 10% of 10000 W 14000 W ≥ 9000 W Conditions met
Scenario A
In this example, the Fronius GEN24 Plus can take over full regulation for the dynamic power reduction of the
entire system. No additional components are required!
2.1 Web interface settings
2.1.1 Settings on the web interface of the Fronius GEN24 10.0 Plus
Safety and grid requirements Feed-in limit:
/ Select "Limit for the entire system." Enter the DC system power and feed-in limit
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