© 2023 by XOLTA
20
GRID MONITORING RELAY:
Definition and terms:
C&I
XOLTA C&I stands for XOLTA Commercial and Industrial
systems (BAT-79, BAT-80). It could be single rack or multirack
installation at specified location.
Grid code
Grid codes define rules that generation systems must obey
to gain access to the grid. In particular, these rules regulate
behavior in the event of grid fluctuations.
The grid operator determines the behavior of systems in the
event of undervoltage, overvoltage, and frequency deviation,
and also defines the connect and disconnect conditions.
NA Schutz relay (grid feeding monitoring relay)
NA (Netz und Alagenschutz). It is a device that monitors and
detects unusual events in the public grid and automatically
disconnects and reconnects the battery system following
specific grid codes.
Point of common coupling (PCC)
Point of Common Coupling or PCC - means the point where
the Generating Facility’s (e.g. battery system) local electric
power system connects to the Utility’s Electric System.
Installation:
Introduction
Decentralized energy generation systems, such as battery
systems generate decentralized electricity that is fed into the
power grid. The feed-in must be controlled in order to ensure a
stable frequency and voltage grid quality. Each decentralized
energy generation system must be monitored with grid and
system protection – NA Schutz protection for short.
The inverters of the Xolta C&I are setup to follow the spe-
cific country/region grid code (e.g. over or under frequency
response, etc.), but for full grid code compliance, they require
a single and external NA Schutz relay for entire XOLTA C&I
installation. NA Schutz is monitoring grid voltage at the point
of common coupling (PCC) and disconnects or reconnects
the system according to the specific grid code requirement
NA Schutz installation:
NA Schutz recommendation
XOLTA is recommending the following two brands of NA Schutz
for XOLTA C&I installations (Table 1). However, other suppliers
of NA Schutz are possible if product follows specific grid code
requirement. There is no requirement to have a version with
Modbus connection.
The grid codes that are supported (certified) for these NA
Schutz (as it is on 22.06.2023) are presented in Table 2.
However, please note that all devices’ settings can be para-
metrized to follow other grid code requirements (refer to their
Manual documents for the latest list of available grid codes).
SUPPLIER
VERSION WITHOUT MODBUS
VERSION WITH MODBUS
ABB
CM-UFD.M31 (or CM-UFD.M33)
CM-UFD. M31M (or CM-UFD.M33M)
Ziehl
UFR1001E
UFR1002IP
GRID FEEDING MONITORING MODEL
SUPPORTED GRID CODES
Ziehl 1001E, UFR1002IP
VDE 4105:2018, VDE 4110:2018 (Germany), TOR A, B, C, D
(Austria), NA/EEA-NE7 CH 2020 (Switzerland), G98, G99 (UK),
Synegrid C10/C11 (Belgium), SFS-EN50549-1+2:2019 (Finland),
EN50549 -+2 (Ireland), NEN-EN50549-1:2019 (Netherlands), VDE
0126, VFR2019 (France), AS4777.2 (Australia)
ABB CM-UFD.M31, ABB CM-UFD.M31M
VDE 4105:2018, VDE 4110:2018 (Germany)
ABB CM-UFD.M33, ABB CM-UFD.M33M
G98, G99 (UK)
