Experiences with Automated Relay Settings Process to Improve Productivity and Reduce Misoperations

Entergy Tom Field

Mississippi State University Michael Mazzola

RSA Team

• Dan Glaser (Entergy)

• Simon Bian (Entergy)

• Shelbi Martin (Entergy)

• Chintu Beeravolu (Entergy)

• Angela Card (MSU)

• Greg Henley (MSU)

• Tommy Morris (UAH)

Traditional relay setting philosophy

• The Art and Science of Protective Relay Setting

– The Art is a flexibility between engineers that does not ensure consistency

– The Science is a fixed methodology

• The issue of Consistency can only be resolved if:

– The Art is converted to a Science

– The rules of the Science are defined

Convert to “the Science of Relay setting”

• Step 1: Define Your Relay Setting Philosophy (the Science)

• Step 2: Develop Specific Rules from Philosophy

• Step 3: Determine the Majority of Special Cases (the Art)

• Step 4: Define Rules for the Special Cases

Relay Setting consistency

• Specific Rules Required for Consistency

• Specific Rules can be implemented manually or automatically

Entergy Philosophy

Entergy Defined Rules

Sources of Human error

• Not understanding Philosophy

• Undefined Rules for Special Cases

• Mathematical errors

• Typing errors

Elimination of human error

• Not understanding Philosophy – Define the Rules for the Philosophy

• Undefined Rules for Special Cases – Define the Rules for the Majority of the Special Cases

• Mathematical errors – Automate the Calculations with a spreadsheet or a

program

• Typing errors – Automate all steps that require typing of numbers

To ensure consistency and eliminate human performance error

• 1) Define the rules

• 2) Implement the rules in a Program

• 3) Automate all Number Transfers

Benefits of Relay Setting Automation

• Eliminate Human Error from Number Copying

• Standardize how and what data is obtained (consistency)

• Reduce time to set relays

• Documentation of what was performed

Statistics on human error and inconsistency

• Several benchmark cases were initially setup by relatively new setting engineers

• Initial comparison of hand calcs to RSA showed errors

• 48% of the errors were due to human error in the

benchmark cases

• 28% of misoperations due to the relay setting process according to NERC

NERC Misoperation Statistics

Human Errors Found

• Sources of Human Error found to be:

– Misunderstanding Philosophy

– Using an incorrect Value

– Typing mistake

Examples of Errors found

• selected incorrect strongest source

• outage source too many tiers back

• did not do infeed simulation on fictitious short line

• captured wrong transformer rating

• forgot to multiply impedance by 100

• recorded wrong infeed angles from simulation

• wrong per unit impedance based on transformer

• incorrectly read 3x zero sequence current

• omitted transformer on remote bus

• typo

MSU/Entergy Relay Setting Automation Program

• Relay Setting Automation (RSA) Program

MSU/ENTERGY RSA Program Intended Work Flow

• Program takes input in calc sheet or menu

• Program runs faults in Short Circuit Program and places information in calc sheet

• Program takes settings from calc sheet and places relays in Short Circuit Program

• Program checks coordination in Short Circuit Program and adjusts reaches and timers

• Program places adjusted values in calc sheet

• Program writes final settings into RDB file

Program outputs

• Calc Sheet with input, values from the Short Circuit Program, calculated settings, and adjusted settings

• Document file with all steps performed and values selected during contingencies

• RDB File ready to load into relay

Running RSA from within ASPEN OneLiner

Selected Relay

Samples of Calc Sheet after RSA Run

Samples of Calc Sheet after RSA Run (cont.)

Infeed Calculation Results

Breaker Failure Calculation Results

Folder After RSA Run

Updated OneLiner file with relay information added

Updated RDB File with Settings from Calc Sheet

Results file that contains Documentation for all faults during RSA run

Updated Calc Sheet with Outage Method Appended

Other Outcomes of RSA Program

• Modeling Rules Developed

• Data Requirements from Short Program significantly increased – Created Worksheet in the Calc Sheet that was significantly

increased from proof of concept’s 589 rows to production version of 8,133 rows

• Many new setting calculations added

• New Regulatory requirements added

Understanding How to Use RSA

• Developed Modeling Rules – Many production use issues due to modeling rules

(line naming) not being followed

– Program Developed to automate line naming

• Defined Limitations – Some production issues due to cases outside of

limitations being used

– Updated documentation on limitations developed

– Of 500 actual cases checked for topology, only 12 required attention from a relay settings engineer

Philosophy and Rules Defined During Process

• Special cases required new rules

• Philosophy and rules not previously defined by utility for special cases

• Little or no formal standardization of philosophies or rules in Industry

Next Steps

• More standardization in the industry will allow more sharing of automation methods

• Commercialization being explored