PMUs for Smart Grid Will the current set of ... - Mehta Tech, Inc.

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Nov 21, 2013 (3 years and 7 months ago)

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PMUs for Smart Grid


Will the current set of “standards”

assure measurement subsystem
interoperability?


A discussion to revisit


Standards Framework for

Smart Grid Measurement Devices


NASPI PSTT October 12, 2011 Meeting



©
Harish Mehta, Mehta Tech, Inc.

www.mehtatech.com

Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

2

SG* Information Systems and PMUs*


Smart Grid Information Systems



Integrated automation/information systems


Systems to service applications and for compliance data


End
-
to
-
end predictable system
-
level performance is targeted



PMUs will be SG’s primary source of measurements and
operational data for network automation and information
systems at transmission level


* SG


Smart Grid

* PMUs


Phasor Measurement Units

Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

3

SG Information Systems and PMUs
(continued)



PMUs


Measurement subsystem capabilities and features needed to
satisfy system
-
level performance/support requirements



Synchronized measurements


Predictable performance in a multifunction environment


Interoperability for data and information exchange


Configurability for energy sources
-

dynamic operation


Upgradability for continuous enhancements


Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

4

PMU’s Standards
-
driven Capabilities


Measurement and Data Management



Precise UTC Time for Measurements



Standard for Measurements


UTC synchronized measurements


Phasors, frequency and rate of change of frequency


Requirements for analog values, event data, computed
quantities, etc. are implied but not explicitly defined




Standards for data Communications Protocol/Local Storage


Communication protocols with “richer” information content
than SCADA/EMS and ICCP practices in use today


Standards do not define local data storage/access

Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

5

Scope of PMU
-
related

SG Standards, Guides and Regulations



IEEE and IEC Standards
(IEEE C37.118, C37.238, IEC 90
-
5, etc.)


Precise time of measurement


Measurement accuracies


Data formats and communication protocols



IEEE Guides
(IEEE C37.242, C37.244, etc.)


PMU installation, test and calibration


Functional requirements for “real
-
time data/information
processing devices” such as ssPDCs, PDCs and Gateways



NERC Regulations
(PRC and other Standards)


PMU Registry and naming conventions


Monitoring/reporting compliance regulations such as PRC
-
002


CIP


Critical Infrastructure Protection requirements

Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

6

Defining Interoperability Parameters for

SG Measurement Devices



SG Information Systems include measurement devices
that perform “information processing” functions in a
“distributed computing environment”


Interoperability requirements should be defined within
the context of all application processing performed by
SG automation
-
information system




Software for application functions may be executed in PMUs
and/or in downstream devices



Breadth of applications should include all real
-
time, near real
-
time and off
-
line uses of measurements (data and results)

Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

7

Interoperability



A Suggested Definition



Software capability to automatically exchange
measurements, data and information in a distributed
processing environment



To satisfy end
-
application requirements reliably with
predictable and optimized system
-
level performance using
compliant devices



To assure long
-
term supportability in a multi
-
vendor
competitive market space and evolving information and
automation technologies and practices



Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

8

SGIP and Harmonization



Role of SGIP


Smart Grid Interoperability Panel


Harmonization of industry standards to support interoperability



PAP
-
13


Harmonization of IEEE C37.238
-
2011, C37.118.1
-
2011, C37.1182
and IEC 61850 90
-
5


Scope does not include harmonization of NERC regulations



“Harmonization” of all applicable standards and guides
including regulations is needed to assure “interoperability”

Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

9

Interoperability Issues for PMU Installations


Development of “consistent standards framework”



IEEE, IEC and NERC standards, guides and regulations need to
clearly delineate among mandatory requirements and good
practices for voluntary adoption


Standards also need to explicitly identify and exclude those
requirements that hinder interoperability



Recognition of “additional requirements”


Fulfillment of flow
-
down requirements for multifunction devices
exchanging information in a distributed processing environment



Explicit attention to “legacy issues”



to assure usability of data collected by them and upgrade path to
meet newly added requirements

Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

10

Example of Interoperability Issues

PMU


Time of Measurement


Time of Measurements*


Descriptors for accuracy of time reference (for determination of
time of measurement) delivered to PMUs in the following
standards appear to be inconsistent and inadequate under
certain conditions



IEEE C37.118.1
-
2011


IEEE C37.118.2
-
2011


IEEE C37.238
-
2011


IEEE 1588


IEC 61850 90
-
5


*
PAP
-
13 is addressing this issue. Recent changes during October
2011 to these standards may resolve some of these issues

Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

11

Example of Interoperability Issues

PMU
-

Test and Calibration


Test and Calibration



IEEE Guide C37.242 and NERC’s regulation such as PRC
-
018
will apply to multifunction DFR/PMU



In future the same NERC test and calibrations requirements that
are currently applied to relays may be applied to DFR/PMUs



IEEE Guide C37.242 as written appears to be a tutorial



NERC standards require mandatory compliance requirement





Reference to IEEE Standards and Guides in NERC’s compliance
regulations will necessitate changes to their current versions


Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

12

Example of Interoperability Issues

PMU/PDC and Information System Architecture


SG Information System architecture, configuration
provisions and performance will vary significantly



A line
-
centric PMU
-
based automation/information system will
require substation PDC whereas a substation
-
centric PMUs
does not



Scope of PDCs and other auxiliary devices will vary depending
on information processing in PMUs and in devices that execute
end
-
applications



To be useful, standards and guides need to address these variations
and provide definitive insightful direction for each


Mehta Tech 10
-
2011

NASPI/PSTT PMU Interoperability

13

Summary
-

Question and Answer


Question

PMUs for Smart Grid


Will the current set of “standards”

assure interoperability?


--------------------------------------------------------------------------


Answer

???


There is an urgent need for careful review of

lessons learned in executing SGIG
-
funded projects and

NIST’s recent Interoperability Roadmap Release 2.0

Greater attention to standards to assure interoperability is needed