PRESS
RELEASE
FOR IMMEDIATE RELEASE
May 31, 2017
Marketing contact:
Martin Van Der Linde
Tel : +61 7 3907 8777
Fax : +61 7 3399 6777
[email protected]
www.nojapower.com.au
Practical uses for IEC 61850 in
Medium Voltage Reclosers
Field experience driven solutions for Automatic Circuit Reclosers
31 May 2017 Brisbane Australia – If a utility engineer has ventured anywhere
near an industry conference in the last 10 years it could be assumed that they
have been exposed to the new universal communications and substation
definition standard of IEC 61850. Whilst it has been successful in the
electricity transmission space, it has seen very little usage in distribution
networks. IEC 61850 has been generally constrained into deployment in
substations, allowing the replacement of conventional copper control
systems with optic fibre and greatly simplifying the mechanical development
of new substation builds. With these proven field benefits, it stands to reason
that the functionality would eventually move into the distribution space, as
manufacturers transfer capabilities from substation relays through to other
forms of distribution equipment. In practicality, many utilities around the
world don’t operate their transmission networks, and as such the appearance
of IEC 61850 on the distribution network can be an intimidating technological
step. Fortunately, there are others which have been through this, and with
the NOJA Power OSM Recloser system releasing IEC 61850 as standard in the
RC10 and RC15 Recloser Controllers it is well worthwhile to explore some of
the proven applications of this feature.
At the risk of a gross simplification, IEC 61850 is standard for the definition of
electrical distribution network assets. It uses an object based method for
defining what each substation entity is capable of. For example, there is a
standard name for a circuit breaker, or a Voltage Transformer, or a switch.
Any asset in an electrical network will fall into one of these categories, and
IEC 6180 defines a list of states or attributes to any asset, (eg, Circuit Breaker,
CB, has Open or Closed state). This object-oriented method of describing
assets is very useful when trying to merge a great variety of assets into a
single control centre. For many years, one of the most insurmountable
challenges for utility engineers is the development of a holistic standard for
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their network assets.
For integrated distribution devices, such as Automatic Circuit Recloser, the
device is a composite entity, in that it has a circuit breaker, relays, VTs, CTs,
and other attributes. Therefore, as far as IEC 61850 is concerned, a Recloser
can be broken up into its composite components and addressed individually.
IEC 61850 therefore provides utilities with the capability to integrate their
ACR assets with other IEC 61850 controlled devices, but most of all, provides
them with the ability to isolate individual functions and standardise control
and communications to these end assets.
NOJA Power recloser integrated into the substation control system
IEC 61850 has two major methods of communication, MMS and GOOSE. MMS
is analogous to the communications protocols of years gone by, such as DNP3
and IEC 60870-5-101/2/3/4. MMS is a direct communications method
between the Server and Client (or Master and Slave in DNP3 terms). The
greatest difference between the new and the old, is that the new system is a
self-describing system. Removing the communications packet format, a
reported DNP3 Binary point could be “DNPID 1 is 0”. If the master station
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doesn’t know what DNPID 1 is, then the message would be useless. IEC 61850
MMS would be far more verbose: “The Circuit Breaker Number 01 State is
now Open”.
It’s a concept which makes a lot of sense – when older generations were the
equivalent of “light on, light off” communications of the past, IEC 61850 has
full disclosure. In the case of an autorecloser, the message specifically tells
you what device it came from, what it says, and what needs to occur.
Obviously, the overheads associated with transmitting such large amounts of
data requires a fast communications network, and GOOSE messaging
especially should not be considered on anything less than fibre optic
communications. For MMS, the performance would be reasonably
competitive on a 4G or 3G network, but the advantages would certainly need
to outweigh the additional data charges. IEC 61850 is the equivalent of
removing the need for context in communication – no need for a matched
point map that IEC 60870 or DNP3 required.
Therefore, the first major advantage of IEC 61850 in Distribution Network
applications is the ability to standardise the points list. Since the IEC 61850
configuration file for any asset in the field can be easily standardised, this
translates to the end asset in the field. Furthermore, Substation Relay/Circuit
Breaker pairs can have the same data points as what field reclosers do. With
Automatic Circuit Reclosers being deployed more and more frequently in
substations, it is obvious why IEC 61850 is being deployed in these devices.
IEC 61850 also offers utility users another messaging specification: GOOSE.
Generic Object Orientated Substation Events are a form of short message
system, which has a very short communication time, an order of magnitude
faster than the MMS or DNP3 equivalent. GOOSE offers a high-speed
communication where there is no handshaking or confirmation of a received
message. It is a one-way communication, where the broadcaster proclaims
the message, and the onus to act is placed on the receiving devices. GOOSE
messaging is a method for communication which allows for blocking functions
between substation breakers or installations, replacing the need for wired
copper contacts for such schemes. GOOSE Messaging in reclosers is
particularly useful in substation environments where the devices are
deployed, as the blocking schemes can be used to prevent spurious trips due
to parallel feeder earth faults or network automation issues.
“IEC 61850 is definitely gaining momentum amongst our global customer
base,” says NOJA Power Group Managing Director Neil O’Sullivan. “Where
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reclosers are used to build economic zone or rural substations it is viable to
use IEC 61850 in those substations very economically. Equally the GOOSE
messaging component of IEC 61850 can be used for high speed automation
with or without a IEC 61850 MMS implementation. Customers can use DNP3
for their communications protocol to their SCADA and GOOSE messaging for
high speed automation. I can imagine significant hybrid schemes
implemented in the coming years.”
The deployment of IEC 61850 in distribution switchgear is a natural
progression from the successes of the transmission service providing world.
The NOJA Power OSM Recloser is one of the first Automatic Circuit Reclosers
to be offered with IEC 61850 as standard. The benefits of utilities being able
to standardise communications and configuration across multiple network
assets is too good to remain a minor technology, and it is likely that there will
be a proliferation in this capability in the distribution network in the future.
For further information regarding NOJA Powers OSM Recloser system and
their IEC 61850, go to http://www.nojapower.com.au
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