Sampled Values
Configuration Example
TEST UNIVERSE
Manual Version: OMSV.AE.2 - Year 2010 © OMICRON electronics. All rights reserved. This manual is a publication of OMICRON electronics GmbH.
Testing an IEC 61850 Compliant Relay
with a CMC Test Set and the
Sampled Values Configuration Module
Introduction
This example focuses on the configuration of the Sampled Values (SV) features of a CMC test set. The details of protection testing are not covered. Thanks to OMICRON's smart implementation of the features, the established methods for protection testing are not affected by the new signaling mechanism.
The example is performed using a protective relay REL 670 series manufactured by ABB. Some of the screenshots shown below are taken from the configuration tool PCM600. Some of the terms and settings are also specific due to this specific product reference, but similar methods and tools will apply for other vendor's relays and software as well.
The detailed explanation of the internal structure of a relay modeled according to IEC 61850 and the related services is also beyond the scope of this document. In the following, it is assumed that the reader is familiar with the basic principles of IEC 61850.
Terms: IEC 61850, SV, 9-2LE
IEC 61850, the international standard for communication networks and systems for power utility automation, defines (among many other items) mechanisms for real-time messaging over Ethernet networks.
Sampled Values (SV) (sometimes also called Sampled Measured Values (SMV) or Sampled Analog Values (SAV)) services are defined in IEC 61850-7-2. Their transmission via Ethernet networks is defined in IEC 61850-9-2. This part of IEC 61850 applies to electronic current and voltage transformers, merging units, and intelligent electronic devices for example protection units, bay controllers and meters. To allow an easier implementation, the UCA International Users Group published the document
"Implementation Guideline for Digital Interface to Instrument Transformers using IEC 61850-9-2". As this implementation guideline defines a subset of IEC 61850-9-2, it is commonly referred to as "9-2 Light Edition" or short "9-2 LE".
The SV Configuration module sets up the test set to publish sampled values. It provides automatic configuration during testing and proper documentation of the settings.
The Test Set
The applicable test sets need to have an Ethernet interface for IEC 61850 communication: At the time of writing, these are the CMC 256 with NET-1 Option, the CMC 256plus, the CMC 353, the CMC 356 and the CMC 850.
In the remainder of this document, this specific type of equipment is simply referred as the "Test Set". It provides the following features:
• Publishing sampled values according to 9-2LE. • Configuration software module,
which is used to set up the publishing of SVs. This module can be embedded in an OMICRON
Control Center test plan to reconfigure the test set during a test of a multifunctional relay.
OMICRON has integrated the SV features into the test set in a way that the sampled values published are mapped to the secondary voltage outputs and the current output group A of the test set. The published sampled values are scaled to primary values according to the settings in the Test Object.
The SV configuration module enables or disables the publishing of the SV stream and allows the setup the parameters of the stream.
The configuration is performed via the SV Configuration module and is kept completely outside of the other test modules. The test modules do not even know if the IED receives the simulated values via secondary quantities or as sampled values.
This way, all OMICRON test modules are immediately available for testing IEC 61850 compliant IEDs. The method of using the protection testing functions of the software remains completely unchanged and does not need to be further explained in this example.
About the Internet Protocol
The Internet Protocol (IP) is not used for the transmission of sampled values.
Anyway, it is used for controlling the test set from the PC. The related settings are made in the test set
Association and Configuration utility which can be accessed from the OMICRON Start Page. Further details
can be found in the related help and documentation.
IP may be also used for setting the relay. In this given case, the relay setting program PCM600 can access the relay via the Ethernet using IP.
The ABB relay uses local control to set an IP address. This device only works with a fixed (static) IP address. The IP settings of the relay must always be set manually to match the network configuration that the relay is connected to.
Protection Testing with Sampled Values
Configuration of the Relay / Subscriber of SV
PCM600 allows the configuration of your IED regarding control, protection and communication. It can import engineering files according to IEC 61850-6 (scd-file substation configuration description) and is connected to a system configurator so far.
With this software you have to prepare the IED to subscribe the SVs. The steps necessary will be described in this chapter.
First of all you have to assign the data from the merging unit to a software slot (SW_slot). This has to be done in the configuration software of PCM600- CAP (Figure 1)
Figure 1 Function Selector Tool
Once the merging units are configured and the configuration in the IED is compiled, the inputs for sampled values can be used as normal analog inputs. To connect the inputs you have to open the "Signal Matrix Tool" (Figure 2) in PCM600 and connect all signals.
Figure 2 Signal Matrix Tool
The last step is the configuration of SV streams to be subscribed in the IED (Figure 3). The most important is the Sampled values ID (SvID). The other parameters describe the name of the inputs, CT star point and synchronization mode.
Configuration of the Publisher
The SV configuration module you can find on the Start Page of OMICRON's Test Universe under the item "IEC 61850" (Figure 4)
Figure 5 SV Configuration
To publish SV with the test set, the following parameters must be known: • Sampled Value ID (svID)
• Multicast MAC Address of the SV-stream • Application ID (APPID)
• VLAN ID and VLAN Priority
The ID of the SV refers to the setup of the IED (Figure 3) – in our case "ABB_MU0101".
SV are published as multicasts, the Multicast-MAC-Address is defined by the system configurator. In our case this is the first recommended MAC address for SV: 01-0C-CD-04-00-00
The APPID has to be unique, in our case 16384 (0x4000).
IEC 61850 uses VLANs (virtual LANs) according to IEEE 802.1q. VLANs allow a segregation of networks and the usage of priorities. The VLAN ID and the priority have to be defined for the publisher. In our case the test set publishes in VLAN 0 (common in substations) with medium priority (4).
To produce faulty or invalid SV streams the quality information can be changed. 0x0 indicates a proper stream.
By pressing the start button, the SV configuration is transferred to the test set. The progress bar indicates the progress of the configuration process. The "Test State" indicates if the new configuration could be successfully established (Figure 6).
Figure 6 Configuration Finished
The published sampled values are scaled to primary values (as defined in the test object -Figure 7). They correspond to the analog voltage and current values generated at the voltage outputs and the current output group A of the test set.
Figure 7 Test Object
The specified hardware configuration for using sampled values is 3 voltages and 3 currents (current group A; see Figure 8).
Performing the Tests
From the test module's view, the analog outputs are configured in the hardware configuration and applied for the testing as usual.
Using any module a protection test can be performed, for instance with State Sequencer as shown in Figure 10. In this example the IED trips with a GOOSE, to test this an GOOSE configuration is necessary.
