1

System Requirements of Visualization Platform

for Wide Area Situation Awareness System
Jia Wang, Member, IEEE, Yi Hu, Senior Member, IEEE, Anthony Johnson, Member, IEEE,
Hahn Tram, Senior Member, IEEE, Reza Nasri, Member, IEEE,

without risking system performance. In recent years, a number

Abstract—With the advancement of sensor, communication of large-scale WAMPAC deployment pilot projects have been
and information technologies, Wide Area Monitoring, Protection initiated in different parts of the world (e.g. US, Brazil, China,
and Control (WAMPAC) systems have been identified as the new and Europe) and the requirements of large-scale WAMPAC
generation of solutions to improve power system planning,
system have also been defined [4]. In US, a number of large-
operation, and maintenance. With huge amount of real-time data
collected through distributed sensors deployed in a wide area, scale Wide Area Monitoring (WAM) systems based on the
effective information presentation has become a key component synchrophasor technology will be deployed in the next three
for such systems. Effective information presentation will enable years with matching Smart Grid Investment Grant funding
power system operators to be aware of the critical system status, from the US Department of Energy.
quickly pinpoint the problems, make correct decisions, and take
appropriate actions. This paper discusses the requirements of a
visualization platform (VP) for a Wide Area Situation Awareness
System (WASAS) to be deployed in Southern California Edison
Grid Control Center. Major features of such VP, including
effective geospatial information presentation, situation awareness
with both electrical and non-electrical information, etc., are
identified. Corresponding functional requirements are outlined
as well. Additionally, this paper discusses the importance of an
open VP interface that will be the key for the VP to integrate
with many future WAMPAC applications and to be used by
other SCE business areas.

Index Terms—Geographic Information Systems (GIS), Phasor

Measurement Unit (PMU), Situation Awareness, Synchronized Fig. 1. Technology maturity curve for WAMPAC technologies
Measurements, Visualization, Wide Area Monitoring, Protection
and Control (WAMPAC) Fig.1 shows various maturity stages for key WAMPAC
system deployment factors. Hardware and data collection are
I. INTRODUCTION ahead of other factors and are commercially available.

W ITH the advancement of sensor, communication and

information technologies, the electric power grid is in
an evolution of transforming into a more reliable, secure, and
Different applications, like monitoring, protection and control,
need to be enhanced to provide quick and actionable support.
More effort is required in setting up operational and business
efficient network that enables renewable resources integration, processes in the future. According to this maturity curve, D.
advanced grid control, and smart customer solutions. In Novosel, et al. proposed a WAMPAC deployment roadmap
various Smart Grid strategic planning and roadmap studies, [5] that WAM applications, such as angle/frequency
Wide Area Monitoring, Protection and Control (WAMPAC) monitoring, voltage stability monitoring, etc. are the first step
technologies have been identified as one of the most critical to deploy a WAMPAC system, named WAM system.
components [1]-[3]. Several WAM systems have been tested and evaluated [6]-
WAMPAC systems can take highly accurate system [8]. One of the major challenges in developing a WAM
snapshots at high resolution (30 or 60 samples per second) of system is to display the PMU measurements as well as other
currents, voltages, phase angles, etc., of a power system. Such wide area information in an effective way for situation
information can be used to assist real-time decision making awareness. In a large-scale system with more than 1000 PMUs
for system operators. The ultimate goal of WAMPAC is to and up to 120 sample/second sampling rate, traditional point-
maximize the transfer capability on transmission networks by-point presentation methods do not work with such a high
rate of data. Some commercially available visualization
J. Wang (email: jwang@quanta-technology.com), Y. Hu, H. Tram, R. system, such as GIS, EMS, DMS, etc. can effectively present
Nasri are with Quanta Technology, 4020, Westchase Blvd. Suite 300, Raleigh, the large amount of data at slow speed. However, how to
NC, 27607.
A. Johnson is with the Southern California Edison, 2131 Walnut Grove
handle real-time phasor data streams and refresh display in
Ave., Rosemead, CA 91770. real-time or near real-time is still a challenge. Meanwhile, to

978-1-4244-6551-4/10/$26.00 ©2010 IEEE

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support system operational requirements, the VP shall enable

users to recognize the status of the entire system at a glance, to
have quick access to detailed data if needed, and to make
correct decisions with available information. The other

output Reg. info

request/ Apps
challenge is to develop an expandable, scalable and

Phasor data

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ata
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stream

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upgradable system. Most presentation software today is tightly

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coupled with various applications that do not support open

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interfaces. For such systems, it is very difficult to add and

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integrate new applications to the system, particularly for third

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party applications. As many WAMPAC applications are yet to

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be developed and deployed, tightly coupled presentation and
application system design will become a major expansion
roadblock for many WAM systems.
In this paper, we discuss the system requirements of an
open VP for a Wide Area Situation Awareness System
(WASAS) to address the aforementioned challenges. WASAS
is a WAM system that will be deployed within the next few
years in Southern California Edison (SCE) Grid Control Fig. 2. Data flow for VP in WASAS
Center (GCC). The WASAS is expected to become a
WAMPAC system with other measurements in addition to 1. Effective geospatial information presentation –
synchrophasor data, such as more measurement points, and many situation awareness applications with large
many advanced WAMPAC applications. amount of PMU data and environmental data require
The data flow between the VP and other WASAS effective geographic-based information presentation
subsystems according to its system design will be illustrated and display. Effective display can enhance the value
first, and the major features of VP will be identified in section of these situation awareness applications.
II. The corresponding functional requirements are discussed in 2. Decoupled visualization platform – since many
section III. An open interface between VP and applications is PMU-related WAMPAC applications are still in the
discussed in section IV. It will allow VP to be a stand-alone developing phase, the VP shall be able to provide an
module and be flexible to integrate with new WAMPAC open and decoupled platform for easy integration of
applications as well as for use by other business areas. future applications.
3. Environmental information assisted situation
II. SYSTEM OVERVIEW awareness – it is envisioned that wide-area non-
WASAS is designed to provide wide area system dynamics electrical environmental data will be important for
information primarily based on the synchronized phasor WASAS in situation awareness. For example, weather
measurement technology. It will also incorporate other wide information could help forecast upcoming changes in
area information input, such as EMS/SCADA information the wind and solar generation more accurately. Such
(RTU data, meter, event message, meta data, etc.) and non- forecast can be used to coordinate these renewable
electrical information (weather, traffic, fire, earthquake, etc.), generation sources with energy storage and other
to provide additional situation awareness support for system generation sources to improve their dispatchability.
operators and engineers. The system consists of the Digital 4. Combination of traditional and wide area display –
Fault Recorder combined with the Phasor Measurement Unit it is important to include both traditional displays in
(DFR/PMUs), the Phasor Data Concentrator (PDC), System the VP, such as trending, that have proven to be useful
and Data Management (SDM), VP, data storage, and other to users, and also new features for effectively present
analytical applications. the wide area synchronized data in the form of
The VP interacts with multiple data sources, including real- actionable intelligence, such as multi-layer
time data streams from PDC and analytical application geographical display, global warnings/alarms display,
outputs, stored data from WASAS real-time operational and animated contour display, streamed video, etc.
non-operational (WASAS historian) databases, EMS/SCADA
databases, engineering databases, etc. The data flow with III. VISUALIZATION PLATFORM FUNCTIONAL REQUIREMENTS
respect to VP in WASAS is shown in Fig. 2. The WASAS VP will include geospatial information
WASAS will be used in both real-time operations mainly presentation capability that supports multi-layer, multi-view,
by grid operators and non-real-time analysis for post event and dynamic displays of real-time and historical data. It shall
analysis and engineering analysis by various users in grid be able to handle real-time phasor data stream. It shall support
operation, engineering, planning, and other departments. both wall display for system overview and multiple desktop
Considering the user groups and needs, the major features for displays for detailed information of selected areas/items, as
VP are identified as following: shown in Fig. 3. Simple, fast and unambiguous operating and
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navigating procedures are the general requirements. awareness. The power system operators and engineers shall be
able to get the visualized system status by just a glance of the
display. The layers are listed but not limited to those shown in
table I. Each individual layer shall be able to hide/unhide.
TABLE I
MULTIPLE LAYERS IN WASAS FOR VISUALIZATION

Layers Components Features

Geographic - Street map - Static data
world map - Satellite map
Electric circuits - Schematic one-line - Static data, and adjustable
diagram by users
- Geo-positioned circuits - Dynamic coloring for
Fig. 3. Multi-view display illustration - EMS/SCADA circuit connectivity and
energization
Environment & - Traffic - Dynamic data with various
A. Basic Graphical User Interface (GUI) Features weather - Fire sample rate by different
- Earthquake sources
As illustrated in Fig. 4, basic GUI features are listed but not - Weather - External data
limited to: windows, permanent indicators, geographical view, - Lightning
toolbars, and help functions. The main view shall be - Etc.
geographic-based presentation. It shall be possible to define Synchronized - Voltage, current, active - Dynamic data with rate of
phasor and reactive power, 60 samples per sec.
related windows as hierarchical set so that this set of windows phase angle, and df/dt - PMU could increase
can be navigated up and down. On each monitor, several Analytical - Voltage/Current - Need to define interface
indicators, such as data and time, power system status, alarm Applications magnitude monitoring and layer for new
acknowledgement, shall be displayed all the time. Toolbars Output - Phase angle difference applications
monitoring
shall support fast navigation to functions and displays, such as
- Etc.
hide/unhide map layers, call up applications and functions,
etc. The WASAS users shall also be able to customize
For PMU data, contouring technology, color formatting,
toolbars and save it for future use. The help functions shall be
text label, dynamic formatting, etc. shall be used to optimize
similar to standard Microsoft Windows applications, and can
the display. It is important to effectively show as much
be called from any display.
information as possible simultaneously without rendering the
The GUI shall provide the following traditional graphical
display too cluttered to be readable. For example, to display
data representation methods: bar chart, dial chart, pie chart,
the voltage, current, phase angle, and active power at the same
and X-Y plots.
time in one map, the voltage could be shown by color, current
could be show as text label above lines, phase angle could be
shown by dial chart around PMU, and active power could be
shown by line width.
For environmental data, the standard display and
symbolization method shall be adopted for each individual
type. The transparency of the environmental layers shall be
adjustable so that they will not overlay the circuit data layers.
Besides data layers and symbols, there are other important
functional requirements for multi-layer displays. A
decluttering mechanism shall be provided to display different
level of symbols and details as the window magnification is
changed by zooming. It shall be possible to import pictures
and videos. It shall support display of multiple real-time feeds
from multiple sources with varied data rates depending on the
external sources and their communication links to the
visualization server. Individual users shall be able to turn on
and turn off the real-time feeds and the automatic update
Fig. 4. Basic GUI features illustration in WASAS feature.
C. Trend Displays
B. Multi-Layer Displays
As a major traditional display, trend displays provide the
Multi-layer display, which enables effective presentation of capability to view telemetered and calculated data plotted
the large amount of information from various sources and against time in a horizontally or vertically oriented graph.
applications, is the most important part for situation
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Both real-time update with configurable refresh rates and support information protection and data management
historical data trending shall be provided. The real-time and functions. It shall be able to collaborate and communicate
historical data combined trending shall also be supported, across multiple organizations and support different groups of
which display historical curve immediately and update plots users. Each group has their own roles, capabilities and data
as new values are received with configurable refresh rates. access authorities. An individual user shall be assigned to one
Sometimes, the user requires a revision of a particular group and associated permissions. This function shall be
situation detected on the power system, and freezing the plot consistent with utility enterprise security strategy and shall be
becomes very useful. It shall be possible to freeze the trending developed in consultation with individual utility.
that allows the user to have a snapshot of the graph. The
G. Authoring Tools
precise reading of curve values shall be displayed by placing a
cursor at the desired point. It shall be possible to align the WASAS VP is expected to support future expansions on
time scale of several selected trending plots. type and amount of the data and new applications. As such, it
shall be highly flexible and configurable. It shall provide a set
D. Playback Functions of authoring tools to allow its users to easily author and
Playback function is an effective method to perform post- publish the visualized information. It shall also provide
event analysis on stored wide area information for power flexibility and configurability for information presentation
system operator and operational analysts in GCC. In addition under various physical display environments, from single user
to traditional trending type of playback displays, it shall also station for many users to more versatile setup at GCC.
be able to replay user selected historical records and events on It shall be possible for users to define and save their
the geospatial map so that user can review the system individual screen layouts for the user station monitors,
dynamics and trend in a wide area level as was in real-time including the preferred number of windows on each monitor
operation conditions. This will be very useful in system of the user station, their size, position, color, text, contents,
operator training and post-event analysis. It shall provide etc. When a user logs on to a user station, the user's pre-
capabilities to view historical data within a time period at defined screen layouts shall appear. A simple one-step method
configurable playback rate, and to have all the video control shall also be provided to restore user customized screen layout
options, such as play, stop, pause, start time, end time, after having manipulated the initial layout of the windows.
slidebar to adjust current time, etc. There shall be a record The user shall be able to modify the display properties of map
statistics graph in the progress bar so that user shall be able to layers so that the data can be shown with different symbols,
view the playback more effectively. It shall be possible to color schemes, etc. The display property shall be able to be
generate animation video from the playback records and saved for future use. The WASAS shall provide tools for user
export it in popular video format. to build the electrical T&D lines, substations, PMUs, etc. The
objects displayed shall be able to link to the values and
E. Alarms & Events (A&E)
attributes in the database.
Alarms and events may be defined differently in different
system. The sample definitions of A&E in SCE WASAS are IV. SYSTEM INTERFACE
as following:
To ensure that VP provides a flexible and open platform
• Alarms: equipment failures, values transgressing their
that can be used to integrate many planned and future
limits/boundaries set by corresponding applications,
applications, and in other business areas, it shall be an
etc.
independent function module not coupled with other
• Events: data entry in database, alarm acknowledge,
applications, such as WAMPAC applications. An open system
alarm deletion, logon information, etc.
interface is needed for VP to meet this requirement.
There shall be an alarm list as in many EMS systems to
show all alarms which can be sorted, filtered and searched. A. Enterprise Service Bus (ESB) based Interface
The alarm indicator shall change to proper alarm status as Many enterprises are implementing Enterprise Service Bus
soon as a new alarm is generated. It shall also be able to as part of its Service Oriented Architecture in their enterprise
present alarms in the geographical map to extend to wide area systems. As illustrated in Fig. 5, the ESB will facilitate data
level. interfaces between the VP and other WASAS subsystems. The
It shall be possible to assign alarms to different priorities, VP will receive data via the Application Programming
and change of priority shall be recorded as an event. The Interfaces (API) that the visualization software supplier will
authorized user shall have the capability to inhibit alarm provide, receive real-time data feeds from SDM or PDC in the
processing for any circuit point. This capability will prevent form of C37.118 data streams, and receive/output
nuisance alarms from points which are under maintenance or configuration settings and parametric data with applications
intermittent. The reporting and summary functions shall be and historical data using the APIs provided by the respective
also included for A&E. application and historical data server (HDS) suppliers. The
F. System Administration System Integrator will develop adapters for data
transformation and manage data transport through the ESB as
WASAS VP shall provide the administration tool to
required.
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interface is critical for integrating SCE currently planned and

emerging future WAMPAC applications, and for enabling its
use by other business areas. This is be realized by an ESB
based open system design for this project.

RT Stream C37.118
RT Stream C37.118

RT Stream C37.118

SCE WASAS VP will be procured and deployed based on

the system design to meet its functional requirements

System Integrator
described above. The authors intend to report the experience
and the performance of the deployed system in a future paper.
RT Stream C37.118

RT Stream C37.118
VI. REFERENCES
[1] BC Transmission Corporation, “Transmission technology roadmap
pathways to BC’s future grid”, Sep. 2008. [online] available
http://www.bctc.com/transmission_planning/innovation/technology_roa
dmap.htm
[2] US Department of Energy, “Smart grid system report”, Jul. 2009.
[online] available http://www.oe.energy.gov/DocumentsandMedia/
Fig. 5. System interface diagram SGSRMain_090707_lowres.pdf
[3] Univeristy of San Diego, “San Diego smart grid study final report” Oct.
2006. [online] available http://www.sandiego.edu/epic/publications/
This design utilizes ESB as an open platform and enables
documents/061017_SDSGStudyES_FINAL.pdf
integration of different subsystems from various vendors. Any [4] Y. Hu, V. Madani, R.M. Moraes, and D. Novosel, “Requirements of
emerging applications can be seamlessly integrated into large-scale wide area monitoring, protection and control systems,” in
WASAS VP and be displayed accordingly. Proc. Fault and Disturbance Analysis Conference, Atlanta, GA, Apr.
2007.
B. Visualization APIs [5] D. Novosel, V. Madani, B. Bhargava, V. Khoi, J. Cole, “Dawn of the
grid synchronization,” IEEE Trans. Power and Energy Magazine, vol. 6,
VP shall include a set of standard APIs for WASAS pp. 49-60, Jan-Feb 2008.
applications and other subsystems to provide data to display in [6] J. Bertsch, C. Carnal, P. Korba, L. Broski, W. Sattinger, M. Ingram,
“Experiences and benefits of systems for wide Area monitoring” Proc.
VP. The APIs shall include the following functionalities as a 6th Annual Western Power Delivery Automation, Apr. 2004
minimum: [7] M. Parashar, J. Mo, "Real Time Dynamics Monitoring System
1. Requested display type (event/alarm, trending, pie (RTDMS): Phasor Applications for the Control Room," Proc. 42nd
chart, etc.) Hawaii International Conference on System Sciences, pp.1-11, 2009
[8] T. Babnik, U. Gabrijel; B. Mahkovec; M. Perko; G. Sitar, “Wide Area
2. List data (dimension and values) Measurement System in Action” Proc. IEEE Power Tech, Lausanne,
3. Time series (dimension, time tags and values) pp:1646 – 1651, Jul. 2007
4. A&E data (event type, priority/severity, event
message, etc.)
5. Real-time data stream (DFR/PMU data ID)
6. Picture/Movie file (location, jpeg/bitmap/mv file)

V. CONCLUSION
As a capital investment project, SCE WASAS will be
deployed in its GCCs within the next few years. Effective
information presentation is the key subsystem to realize wide
area situation awareness benefits in this deployment project.
The main considerations and requirements for WASAS VP
has been discussed in this paper based on the its user groups
and applications needs.
The major features to enable effective situation awareness
in WASAS VP include:
1. Inclusion of effective geospatial information
presentation functionalities
2. Decouple visualization platform from other
application modules
3. Non-electrical environmental information assisted
situation awareness
4. Combination of traditional and wide area display
These features should be supported by corresponding basic
visualization functions, such as multi-layer displays, trend
displays, playback function, etc..
A separate VP functional module with a flexible and open