
2. Application GUID-CF75762E-73C1-40AF-8D6F-6EC3D8395982 v4
RES670 is a Phasor Measurement Unit (PMU) that
provides power system AC voltages and currents as
phasors for all voltage levels in power system networks.
Phasors are provided as real and imaginary or as
magnitude and phase angle. The reference for the phase
angle may be either a PTP time synchronization source
or the NavStar Global Positioning System - GPS, both
supplying highly accurate time and date. The measured
data in each PMU is time synchronized via one of the
mentioned time synchronization sources - with an
accuracy of one microsecond - and transmitted to
Phasor Data Concentrators (every 100 milliseconds, for
example). The accurate time tagging of measurements
taken at different geographical locations makes it
possible to derive the synchronized phasor quantities
(synchrophasors). Based on synchrophasors, a number
of power system applications are available.
The PMUs are installed at substation level, and can be
connected directly to the current and voltage
transformers within the substations. Each RES670 may
be fitted with different options for time
synchronization: PTP via the Ethernet network, via the
GPS system with an own antenna for the RES670, or via
the IRIG-B signal received from an external GPS-based
clock. It is also possible to have a combination of the
three to provide time synchronization redundancy for
the PMU. RES670 streams out its synchrophasor data
according to IEEE C37.118 and/or IEEE 1344 standards
for synchrophasor data streaming and with user-
selectable reporting rates. RES670 supports reporting
rates of 10, 25, 50, 100, and 200 frames per second for
50Hz system (or 10, 12, 15, 30, 60, 120, and 240 frames
per second for 60Hz system). Each RES670 can
communicate its synchrophasor data to up to eight
independent clients over TCP and/or six independent
UDP channels (unicast/multicast), simultaneously. More
information is available in RES670 Application Manual
under Wide Area Measurement System. section.
In addition to the synchrophasor communication
standard (IEEE 1344, IEEE C37.118), RES670 is also
compliant to IEC 61850-8-1 standard for integration to
substation automation systems and exchange of GOOSE
messages, when necessary. RES670 is able to
communicate over IEC 62439-3 PRP for redundant
station bus communication for both IEEE C37.118 and
IEC 61850-8-1, simultaneously.
Figure 1 shows an example of a system architecture for a
Wide Area Monitoring System (WAMS). PMUs are the
building blocks for a WAMS. The architecture of a WAMS
consists of the following main components:
•PMU Phasor Measurement Unit, including all
accessories for time synchronization
•TCP/IP and/or UDP/IP communication network infra-
structure
•PDC Phasor Data Concentrator, including wide area
applications
Substation 1
Visualization
(Applications)
Interface to
SCADA / EMS
Data Storage and Event
Driven Archiving
Gateway to other Utilities
Phasor Data Concentrator
PDC
Substation 2 Substation 3 Substation N
Router Router Router Router
TCP/IP communication network
PMU protocol IEEE C37.118
PMU PMU PMU PMUPMU PMU
PTP or
GPS/IRIG-B
IEC140000114-2-en.vsd
PTP or
GPS/IRIG-B
PTP or
GPS/IRIG-B
PTP or
GPS/IRIG-B
PTP or
GPS/IRIG-B
PTP or
GPS/IRIG-B
IEC140000114 V2 EN-US
Figure 1. Wide Area Monitoring System architecture — overview
A Wide Area Monitoring System collects, stores,
transmits and provides ways to analyze critical data
from key points across the power networks and over
large geographical areas. The architecture of the WAMS
can provide a scalable solution, from small installations
for data collection and basic visualization (PDC) to
larger systems with intelligent monitoring using wide
area applications. The Wide Area Monitoring
applications are designed to detect abnormal system
conditions and evaluate large area disturbances in order
to preserve system integrity and maintain acceptable
power system performance.
The WAMS is configured in a way to acquire
synchrophasor data from several PMUs. Based on the
data collected in the PDCs, WAMS is able to present the
state of the grid to the power system operator, and to
provide monitoring of the power system based on real-
time measurements and the results of on-line
applications. In addition, the data available from PDCs
enables off-line analysis of the power system for post-
disturbance assessments. It is possible to communicate
the PMU measurements and the results of the advanced
applications to SCADA/EMS systems as a way to
improve the supervision of the system, providing the
operator with a clear indication how likely the system is
to collapse, thus giving the possibility to react in time.
Forcing of binary inputs and outputs is a convenient way
to test wiring in substations as well as testing
configuration logic in the IEDs. Basically it means that all
Phasor measurement unit RES670
1MRK 511 410-BEN L
4 Hitachi Power Grids
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