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Real Time Applications Using Linear State Estimation Technology

(RTA/LSE)

Ken Martin Electric Power Group

martin@electricpowergroup.com JSIS

May 30-31, 2019 Salt Lake City, UT

DOE/OE Transmission Reliability Program

Introduction

• Project: Real Time Applications Using Linear State Estimation Technology

– DOE Grant Award DE-OE0000849

• Primary recipient: Electric Power Group, LLC

• Project Partners (host site & cost share):

– Bonneville Power Administration

– New York Power Authority

• Added project host site

– Duke Energy

• Implement 3 applications to monitor power system

• Test with simulated and recorded data

• Demonstrate at host utilities

Project approach

Phasor

Data

Stream

Data:

Concentration,

Validation,

Alignment –

PDC and LSE

Real-time

Contingency

Analysis (RTCA)

Area angle stability

detection

Voltage corridor

stability detection

Operator

notification

REAL-TIME CONTINGENCY ANALYSIS (RTCA)

Methodology

• Uses a base case (power flow model) as input and updates the observable area using eLSE results

• Run all contingencies from a list using Power flow solution (FDLF/NR)

• Detect voltage & power flow limit violations

• Use full system model covering utility with surrounding connections

• Challenges – Base case may not match current system

– Obtaining accurate results with small number of PMU measurements

RTCA Results Visualization

Violations for Individual Contingencies

List of Contingencies Causing Violations

Trend of Historical RTCA Results

List of Recent

RTCA results

Menu – Options, Settings

Real-time Mode vs Manual Study Mode

VOLTAGE CORRIDOR STABILITY LIMIT MONITORING

Transmission Corridor VSI Index

• Uses PMU measurements of V & I at both ends of a transmission corridor to compute complex power

• Computes a stability index that is simply the voltage across the system divided by the load voltage

• Limits are set based on local limitations

• Technique will handle a transmission corridor with a network of lines and multiple input and output points

VSI configuration

Loading Malin Voltage VSI

1 Base Case (3807 MW) 514.8 kV 16.61

2 4353 MW 504.8 kV 19.11

3 4667 MW 493.7 kV 21.21

4 4917 MW 480.2 kV 23.38

5 5125 MW 472.5 kV 24.87

6 5150 MW 471.5 kV 25.03

7 5160 MW 466.6 kV 25.93

8 5205 MW NA Diverges

Alarm levels were determined: • Alert: 19

• Alarm: 23

• Establish VSI limits based on various severe contingencies

• For BPA, used maximum generator & DC intertie – Example - Loss of Two Palo Verde Units

VSI Visualization in Real-Time (Loss of 2 Palo Verde Units with 4667 MW initial loading on corridor)

VSI Plot

Alarm color-coded VSI

visualization on map

Corridor Bus Voltages Corridor Power Flows

Alarm Threshold

VSI Exceeds

Alarm Threshold

AREA ANGLE LIMIT MONITORING

Area Angle Monitoring (AAM) – Overview

• Power flow creates a phase angle. Higher angles result from – Higher power flow

– Higher impedance (fewer lines carrying flow)

• High Angle can indicate excessive stress or a lost transmission line

Power

flow into

an area

Power

flow out

of an area

Calculation of Area Angle

Area angle calculation

An area with border buses

Weights of border buses are

calculated with Kron

reduction

• Select an area with a through power flow & PMU measurement on boundary busses

• Determine a weighting for each boundary bus based on the network admittances

• Study outages to relate area angle to relate area angle to allowable power flow through the area

Visualization of AAM On RTDMS Client

• Monitor an area in BPA

• Contingency: Loss of John day–Grizzly #1 and #2 and the line Grizzly–Malin

Alarm color-coded AAM

visualization on map

Area angle curve

Emergency threshold

Warning threshold

23.50 degree

21.29 degree

Applications Benefits

• RTCA Improves Situational Awareness & provides Actionable Intelligence – Based on eLSE which always solves

• Provides Backup to Conventional RTCA • VSI covers transmission corridors rather than

specific lines – Covers less well defined transmission flows

• Area angle can detect weakness in the bulk grid – Does not depend on individual flow measurements – Other measurement techniques do not provide angle

• Both applications back up existing flow and stability indices

• Application developments are complete

• Prototype demonstration was made to DOE and project participants in Feb 2019

• BPA implementation complete in June 2019

– Factory tests (FAT) in May & installation in June

– Site tests (SAT) after on-site tuning

• Implementation for NYPA under way

– Implementation for Duke to follow

Project status

Looking Forward

• Activities through FY 2019

– Complete adaptation for NYPA and Duke

– Perform FAT tests for both

– Deploy at host sites & SAT tests

– Monitor operation & improve operation as needed

• FY 2020:

– Monitor and improve applications

– Final project report

– Produce commercialization plan

Thank You!

Reserve

• Delete at end

Advisors & observers

• Project Advisors – Anjan Bose – Washington State University – Ian Dobson – Iowa State University – Dejan Sobajic – Grid Engineering – Anurag Srivastava – Washington State University

• Project Observers – Dominion Virginia Power (Dominion) - Kyle Thomas – Peak Reliability - Hongming Zhang – PJM - Emanuel Bernabeu, Ryan Nice

Project Objective

• Develop Real Time Applications Using Phasor Data and Linear State Estimator Technology

– Provide operators with actionable intelligence on contingencies, voltage margins, & phase angle limits

• Applications include

– Real Time Contingency Analysis

– Voltage Stability Monitoring

– Area Angle Limit Monitoring

4-13-2017

Project Timeline Task Deliverable Completion Date Documentation & notes

1 Project Management Plan 4/12/2017 Project management plan document

2 Research, Design & Development of Prototype

2.1 RTA/LSE Design & enhanced

LSE implementation

7/28/2017 Design specification document

2.2 Offline study 9/6/2017 Offline study report

2.3 Real time applications

prototype, and development

and testing

1/29/2019 Test cases and test results

2.4 Prototype Demonstration for

DoE and all the participants

3/31/2019 Demonstration at EPG

3 Deployment, Testing & Acceptance

3.1 Factory Acceptance Tests 7/24/2019 Test cases and test results

3.2 Site Acceptance Tests 10/15/2019 Test cases and test results

4 Demonstration at utility host

site, training and a report

12/20/2019 Demonstration, training and report

5 Marketing and Outreach

5.1 Marketing Plan 2/1/2020 Marketing plan

5.2 Outreach 3/14/2020 Industry presentations and briefing documents

RTCA - Overview

• Real-time Contingency Analysis - Application performs Contingency Analysis using PMU Data and enhanced Linear State Estimation (eLSE)

• Study what-if Contingency Scenarios to assess System Violations

• Contingencies Include – Loss of Lines, Transformers, Generators (N-1, N-2, N-k) etc.

RTCA Benefits

• High-level view of risks and potential severe problems – Contingencies Causing Violations & List Violations by

Category

– Detailed Results for each contingency

• Offers Real-time and Manual study Modes

• Improves Situational Awareness & provides Actionable Intelligence

• Based on eLSE which always solves

• Provides Backup to Conventional RTCA