N th A iNorth American SynchroPhasor InitiativeSynchroPhasor Initiative

Working Group MeetingMarch 6 & 7, 2008March 6 & 7, 2008

The role of Phasor Data Concentrators(PDC requirements for Large Scale(PDC requirements for Large Scale

Applications)

Presentation outlinePresentation outline

• IntroductionIntroduction• The information produced by C37.118

Diff t l l f t ti– Different levels of concentration– The impact of the volume of information

• Typical on-going projects for PDC’s– Data storage and off-line analysis– Data concentration– Data concentration with decision capabilities

Presentation outline (cont’d)

• Where is the best breakpoint for a PDC to

Presentation outline (cont d)

Where is the best breakpoint for a PDC to a « Super PDC »

• Is the ultimate goal control with this• Is the ultimate goal control with this information?

If f h ld b th b t l l f– If yes, from where would be the best level for the control or is it at multiple levels?

IntroductionIntroduction

• For the purpose of this discussion allFor the purpose of this discussion all sampling is performed at 60 times per second (that has been a request from asecond (that has been a request from a number of utilities in the past year)!

• Question: Is this a new trend seen by NASPI i f 30 t 60 lNASPI going from 30 to 60 samples per second?

The information by C37 118The information by C37.118

The following slides provide a quick review of C37 118 data structuresof C37.118 data structures.

IEEE C37 118 StandardIEEE C37.118 Standard• Data from a PMU to a PDCNo. Field Size Description

1 SYNC 2 Synch byte2 FRAMESIZE 2 # of bytes in frame3 IDCODE 2 ID3 IDCODE 2 ID4 SOC 4 SOC time stamp (of the PMU)5 FRACSEC 4 Fraction of second (of the PMU) and quality6 STAT 2 Bitmapped flagsg7 PHASORS 4x6 6 substation direct sequence voltage phasors8 FREQ 2 Substation frequency9 DFREQ 2 Rate of change of frequency

10 ANALOG 0 Not used11 DIGITAL 0 Not used12+ CHK 2 CRC-CCITT

Bandwidth Requirements per PMUBandwidth Requirements per PMU

• At 60 frames/secondAt 60 frames/second– 48 bytes * 60 = 2,880 bytes/second or

approximately 30 000 bits per second (not toapproximately 30,000 bits per second (not to much for a one connection)

• Or with 50 PMUs sending data to a PDCOr with 50 PMUs sending data to a PDC– Combined data rate of 144,000 bytes per

second or approximately 1 440 000 bits persecond or approximately 1,440,000 bits per second (starting to be interesting for a connection)

IEEE C37 118 StandardIEEE C37.118 Standard• Data from a PDC to a Higher Level SystemNo Field Size DescriptionNo. Field Size Description

1 SYNC 2 Synch byte2 FRAMESIZE 2 # of bytes in frame3 IDCODE 2 ID3 CO4 SOC 4 SOC time stamp (of the PMU)5 FRACSEC 4 Fraction of second (of the PMU) and quality6 STAT 2 Bitmapped flags7 PHASORS 4x50 Direct sequence voltage phasors of 50 PMUs8 FREQ 2 Not used9 DFREQ 2 Not used

10 ANALOG 4x50 Load Voltage Deltaθ Delta f10 ANALOG 4x50 Load Voltage, Deltaθ, Delta f 4x2 Packet transmission time: SOC+FRACSEC

11 DIGITAL 2x1 PMUs used for Deltaθ, Delta f computations12+ CHK 2 CRC-CCITT

Bandwidth Requirements per PDC hi h l lto higher level system

• At 60 frames/secondAt 60 frames/second– 424 bytes * 60 = 25,440 bytes/second or

254 400 bits per second)254,400 bits per second)• With 10 PDC’s sending information at 60

frames/secondframes/second– 25,440 bytes * 10 = 2,544,000 bytes/second

In a wide area environment

IEEE C37 118 StandardIEEE C37.118 Standard• What would be the requirements of a “Super”

PDCPDC– The « Super PDC » can be thought of an

enterprise level system capable of receivingenterprise level system capable of receiving massive amounts of data (many hundreds of PMU’s or maybe thousands, what should it be?).

– Store this vast amount of information produced by all these PDC’s or maybe PMU’s.

– Allow multiple distributed systems to access theAllow multiple distributed systems to access the current information plus the older data for analysis.

Typical on-going projectsTypical on going projects

The following slides will present work we are doing with different utilities in the areaare doing with different utilities in the area of Phasor data concentrators.

Low level PDC’sLow level PDC s

• Used for local storage and off-line analysis ofUsed for local storage and off line analysis of small amount of PMU’s.

• Normally with limited amount of storage ( 6 to 12 y g (months)

• Normally provides local visualization in real-time y pwith viewing screens for the historical information.

• Quite often the first step for a utility who is looking at how to use this type of information.

PMU Data ConcentrationPMU Data Concentration

• Normally the next step for a utility inNormally the next step for a utility in working with Phasor data.

Concentrate the data in this case from many– Concentrate the data, in this case from many PMU’s and/or PDC’s together.

– Store the information for a longer period ofStore the information for a longer period of time to allow more in-depth analysis in the interaction of the overall data.

PDC with Decision capabilityPDC with Decision capability

• When utilities feel they have reached aWhen utilities feel they have reached a level of confidence and understanding of the capabilities of this technology seniorthe capabilities of this technology, senior management will normally go to the next step and allow control functions to bestep and allow control functions to be activated by PDC’s.

Control Aspects with a PDCControl Aspects with a PDC

The next slide provides a diagram of a system whose goal is to control equipmentsystem whose goal is to control equipment to stabilize the grid for a large metropolitan areaarea.

Control Aspects of a PDC

The Control Action by the PDCThe Control Action by the PDC

• Once a decision is taken by the logic theOnce a decision is taken by the logic, the control objective is simple!

• What would be the best way to document• What would be the best way to document the overall control trigger process?

G l l f diff t t– General log of different events– A configurable time before and after the event

to record the principal information (and storeto record the principal information (and store in Comtrade format or other format)?

The Ultimate Goal (discussion)The Ultimate Goal (discussion)

• The goal in reading all this information isThe goal in reading all this information is for control?

• But what kind of responses are we looking• But what kind of responses are we looking at going through all these systems, will the control be timely (this discussions to becontrol be timely (this discussions to be based on having PDC’s in the Sub, and at an intermediate level and at a Superan intermediate level and at a Super level)?

The Ultimate Goal (discussion) ’dcont’d

• Using the capabilities of advancedUsing the capabilities of advanced intelligent PDC’s to work in a distributed decision making environment can wedecision making environment, can we achieve acceptable control?

This context is based on having level 2 PDC’s– This context is based on having level 2 PDC s capable of making decisions but also talk (61850 or other protocols) to a number of ( p )other PDC’s at its level or receiving new settings from a higher level system.

Discussion – Question PeriodDiscussion Question Period

The goal of this presentation is to create aThe goal of this presentation is to create a discussion of where we are going.

What are the next requirements in making thi d h i h i t blthis dream happen – i.e. having a stable electrical grid by using the Phasor i f ti i bl f hiinformation in a manageable fashion.

Thank You!Thank You!

R b t O’ R illRobert O’ ReillySenior Application EngineerCooper Power Systems –

Energy Automation SolutionsEnergy Automation Solutions