GE P741, Technical Manual

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P74x/EN SC/Na7 SCADA Communications
(SC) 13-20 MiCOM P741, P742, P743
SC
3.3 IEC 61850 in MiCOM relays
IEC 61850 is implemented in relays by use of a separate Ethernet card. This card manages
the majority of the IEC 61850 implementation and data transfer to avoid any impact on the
performance of the protection.
In order to communicate with an IEC 61850 IED on Ethernet, it is necessary only to know its
IP address. This can then be configured into either:
•
An IEC 61850 “client” (or master), for example a PACiS computer (C264) or HMI, or
•
An “MMS browser”, with which the full data model can be retrieved from the IED, without
any prior knowledge
3.3.1 Capability
The IEC 61850 interface provides the following capabilities:
1. Read access to measurements
All measurands are presented using the measurement Logical Nodes, in the
‘Measurements’ Logical Device. Reported measurement values are refreshed by the
relay once per second, in line with the relay user interface.
2. Generation of unbuffered reports on change of status/measurement
Unbuffered reports, when enabled, report any change of state in statuses and/or
measurements (according to deadband settings).
3. Support for time synchronization over an Ethernet link
Time synchronization is supported using SNTP (Simple Network Time Protocol); this
protocol is used to synchronize the internal real time clock of the relays.
4. GOOSE peer-to-peer communication
GOOSE communications of statuses are included as part of the IEC 61850
implementation. Please see section 6.6 for more details.
5. Disturbance record extraction
Extraction of disturbance records, by file transfer, is supported by the relays. The
record is extracted as an ASCII format COMTRADE file.
Setting changes (e.g. of protection settings) are not supported in the current IEC 61850
implementation. In order to keep this process as simple as possible, such setting changes
are done using S1 Settings & Records program. This can be done as previously using the
front port serial connection of the relay, or now optionally over the Ethernet link if preferred
(this is known as “tunneling”).
3.3.2 IEC 61850 configuration
One of the main objectives of IEC 61850 is to allow IEDs to be directly configured from a
configuration file generated at system configuration time. At the system configuration level,
the capabilities of the IED are determined from an IED capability description file (ICD) which
is provided with the product. Using a collection of these ICD files from varying products, the
entire protection of a substation can be designed, configured and tested (using simulation
tools) before the product is even installed into the substation.
To aid in this process, the S1 Support Software provides an IED Configurator tool which
allows the pre-configured IEC 61850 configuration file (an SCD file or CID file) to be
imported and transferred to the IED. Alongside this, the requirements of manual
configuration are satisfied by allowing the manual creation of configuration files for relays
based on their original IED capability description (ICD file).
Other features include the extraction of configuration data for viewing and editing, and a
sophisticated error checking sequence which ensures that the configuration data is valid for
sending to the IED and that the IED will function within the context of the substation.
To aid the user, some configuration data is available in the ‘IED CONFIGURATOR’ column
of the relay user interface, allowing read-only access to basic configuration data.