22-Mar-17 Power System Operation Corporation Limited, India

Selection of Reference Node and Angular Baselining using Synchrophasors Measurement

for Real Time Operation

Pradeep Kumar SanodiyaVivek Pandey

Rajkumar Anumasula Chandan Kumar

Sunil PatilSrinivas Chitturi

NASPI Work Group Meeting-March 2017

22-Mar-17 Power System Operation Corporation Limited, India

Power System Operation Corporation Limited is an Independent Company w.e.f.

3rd January 2017

Reference Node Selection

• Need for Selection of Reference Node

• Case Studies with different Reference Node

• Summary

Angular Baselining

• Angular Baselining Need & Case Studies

• Summary

Power System Operation Corporation Limited, India22-Mar-17

Outline

Power System Operation Corporation Limited, India22-Mar-17

Need for Reference Node Selection

• Required for Offline Power System Simulations

• Required for EMS/SCADA

• Similarly required for Synchrophasors based analysis

Power System Operation Corporation Limited, India22-Mar-17

Angular separation is vital in Wide Area Monitoring

System

• Assessing the stress in the grid

• Oscillation Monitoring

• Event Detection and localization

• Visualizing power flow pattern

Power System Operation Corporation Limited, India22-Mar-17

Case Studies with different Reference Nodes

➡ Case-1- Weak Vs Strong Bus as Reference Node

➡ Case-2- Bus with Unreliable Vs Reliable Communication as Reference Node

➡ Case-3- Reference Node Near Vs Far from Event Location

➡ Case-4- Reference Node away from HVDC

➡ Case-5- Reference Node near to Varying Generation Complex

Power System Operation Corporation Limited, India22-Mar-17

Case-1 : Weak vs Strong Bus as Reference Node

Grid 1110 GW

Grid 240 GW

B

D

A

PMU Locations

Weak Bus as Reference

Strong Bus as Reference

Power System Operation Corporation Limited, India22-Mar-17

Case-2 : Bus with Unreliable vs Reliable Communication as Reference Node

Data from one of the node is non current

Reliable Communication

When PMU has taken as reference whose data is not updating , Rest of Angular Separation can not be visualized

Unreliable Communication

22-Mar-17 Power System Operation Corporation Limited, India

Case-3 : Reference Node Near vs Far from Event Location

B

AC

D

E

F

G

H

JI

KL

PMU Locations

Event Occurred at Node Cwhich is near to Node A

Reference node distant from Event node Helps inidentifying the event location

Near Reference Node is A

Reference Node is BFar

B

AC

D

E

F

G

H

JI

KL

Power System Operation Corporation Limited, India22-Mar-17

Case-4 : Reference Node away from HVDC

Ref

HVDC Link

HVDC Pole Blocking & De-blocking

M

PMU Locations

B

AC

D

E

F

G

H

JI

KL

Power System Operation Corporation Limited, India22-Mar-17

Case-5 : Reference node near to Varying Generation Complex

Ref

M

PMU Locations

High Hydro Generation

Hydro generation varying and

Reference Node H is near to the

Varying generation Complex

Power System Operation Corporation Limited, India22-Mar-17

Summary• Preferred locations for reference node

• Node with strong Interconnections

• Nodes with reliable communication

• Node close to base load Generation Complex

• Node with High fault level

• Nodes consistent with offline simulation/EMS studies

• Should be system-wide available and reliable

• Nodes to be avoided

• Nodes with Low inertia, Weak tie lines, Low fault level,

• Nodes located in Oscillation prone area,

• Nodes near to HVDC Bus,

• Nodes near to Varying Generation Complex

Power System Operation Corporation Limited, India22-Mar-17

Summary Contd…

• Reference node selection lookup table to be prepared

• Priority list for reference node selection based on above experiences.

• To be reviewed depending on Visualization and Application

Requirement and

• To be reviewed periodically

22-Mar-17 Power System Operation Corporation Limited, India

Angular Baselining

22-Mar-17 Power System Operation Corporation Limited, India

Need for Angular Baselining

• Validation of the data/Plausibility check

• To compare and validate angle limits with the state estimator

and offline load flow studies

• To distinguish between normal and abnormal grid

conditions-

• Discriminate seasonal off peak and peak stressed conditions

• For alarm generation to alert the operator

22-Mar-17 Power System Operation Corporation Limited, India

Validation of the data/Plausibility check

Wide Variation in Angular Separation due to Leap Second

System Islanding orLoss of time synchronization

22-Mar-17 Power System Operation Corporation Limited, India

Normal and Alert Grid Operation

FA

C

E

Bus-B

400kV Line765kV Line Line Open

PMU Locations

Bus E

B

Bus D

Bus F

GH

Bus G

Bus C

D

22-Mar-17 Power System Operation Corporation Limited, India

Criteria for Selection of Angle Node Pairs

• Wide Area Node Angle Pair

• Generation complex to load complex

• Power Corridors/Flow Gates

• Power Corridors from One Region to Other.

• Maximum Angular Separation in the Grid(wide distant node).

• Adjacent Node Angle Pair

• Both ends angle should be available

Power System Operation Corporation Limited, India22-Mar-17

Typical wide angle pair for baselining

BA

C

D

E

F

G

H

JI

KL

NM

Node O : Generation ComplexNode N : Load Centre

O

22-Mar-17 Power System Operation Corporation Limited, India

Typical wide angle pair for baselining Contd……

B

AC

D

E

F

G

H

JI

KL

NM

Flow Gate between Node M and I

Max Angle-39

Min Angle-14

22-Mar-17 Power System Operation Corporation Limited, India

Typical wide angle pair for baselining Contd……

B

AC

D

E

F

G

H

JI

KL

NM

Node B : Generation ComplexNode C: Load Centre

22-Mar-17 Power System Operation Corporation Limited, India

Maximum Angular Separation Monitoring in the Grid

Angular Separation going Out of 90 Degree Range : High Over drawal by One of the Region causing high angular separation and stress in the Grid

During Normal Operation maximum angle was 77degrees all grid parameters were with in limits

Power System Operation Corporation Limited, India22-Mar-17

Summary

• Angular Baselining helps in understanding the grid

condition during operational horizon.

• It helps in finding the various threshold for angle pairs for

monitoring and alarm generation.

22-Mar-17 Power System Operation Corporation Limited, India

References

• https://posoco.in/download/synchrophasors-initiatives-in-india-decmber-2013-

web/?wpdmdl=713

• http://wrldc.org/Docs/Angular_separation_report/

• EIPP Performance Requirements Task Team, “Definition and Implementation of aSystem-Wide Phase Angle Reference for Real-Time Visualization Applications”,October 13, 2005.

• https://posoco.in/reports/system-reliability-indices/daily-angular-difference/daily-angular-difference-2016-17/

• Eastern Interconnection Wide Area. SynchroPhasor Angles Baselining Study.Mahendra Patel, PJM. Co-chair: NASPI PITT. (Planning Implementation Task Team)

• https://www.wecc.biz/Reliability/JSIS_AZ_PhaseAngleBaselining_BB-FA_011413-D_FA%20Rev_aEPG.pdf

Email : psanodiya@posoco.inWRLDC,POSOCO, Mumbai

Thank You

22-Mar-17 Power System Operation Corporation Limited, India