ECE525: Power System Protection and Relaying

Lecture 1

• Fall 2024 Welcome
• Course Syllabus Fall 2024
• Lecture 1 handwritten notes
• Introduction to Protection Concepts (PDF)
• General UI information for students in fall courses

Lecture 2

• Lecture 2 handwritten notes

Lecture 3

• Lecture 3 handwritten notes
• Relay Device Numbers (PDF)

Additional References

• Link to IEEE Standard C37.2-2008 through IEEEXplore Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)

Lecture 4

• Lecture 4 handwritten notes
• Reflecting primary circuit impedances across CT and VT ratios (PDF)
• Reflecting primary circuit impedances across CT and VT ratios (Mathcad)
• Reflecting primary circuit impedances across CT and VT ratios (Mathcad Prime)

Lecture 5

• Lecture 5 handwritten notes
• CT modeling and response

Lecture 6

• Lecture 6 handwritten notes
• Mathcad CT Simulation (PDF)
• Mathcad CT Simulation (Mathcad)
• Mathcad CT Simulation (Mathcad Prime)
• CT characteristics (PDF)
• CT characteristics (Mathcad)
• CT characteristics (Mathcad Prime)

Reference Material

• Chapter 3 of Das
• Chapter 6 (especially Section 6.4 of the Areva Network Protection and Automation Guide


• Link to: S.E. Zocholl and D.W. Smaha, "Current Transformer Concepts" (this takes you to the SEL web site, free registration may be required)


• Document from Schneider Electric: "Current Transformers: How To Specify Them"


• Link to: R. W. Folkers, "Determine Current Transformer Suitability Using EMTP Models" from 1999 Western Protective Relay Conference (this takes you to the SEL web site, free registration may be required)


• The book Stanley Zocholl, "Analyzing and Applying Current Transformers" is also a good reference. This web page points to a link for ordering it.

Lecture 7

• Lecture 7 handwritten notes

Reference Material

• Link to paper: L. Lawhead, R. Hamilton, and J. Horak, "Three Phase Transformer Winding Configurations and Differential Relay Compensation" 60th Annual Georgia Tech Protective Relay Conference, May 2-5, 2016 (this takes you to Basler web site, free registration required)

Lecture 8

• Lecture 8 handwritten notes
• Determining time to saturation (PDF)
• Determining time to saturation (Mathcad)
• Determining time to saturation (Mathcad Prime)
• Mathcad CT Simulation for the example presented in class (PDF)
• Mathcad CT Simulation for the example presented in class (Mathcad)
• Mathcad CT Simulation for the example presented in class (Mathcad Prime)

Reference Material

• Link to: J. Holbach, "Modern Solutions to Stabilize Numerical Differential Relays for Current Transformer Saturation During External Faults" This is the paper that goes with the presentation. It was presented at the 2005 Western Protective Relay Conference and 2006 IEEE Power Systems Conference: Advanced Metering, Protection, Control, Communications and Distributed Resources.

  Link takes you to IEEEXplore. Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)

• Presentation to go with the paper
• Link to: R. W. Folkers, "Determine Current Transformer Suitability Using EMTP Models" from 1999 Western Protective Relay Conference (this takes you to the SEL web site, free registration may be required)
• CT saturation model and documentation from IEEE Power Systems Relaying and Control Committee

Lecture 9

• Lecture 9 handwritten notes
• Voltage Transformers and Capacitive Voltage Transformers (PDF)


• Update to homework 2 (PDF) due L11 (September 25) See below for Mathcad and Mathcad Prime versions

References on CVT

• Textbook by Das, starting with section 3.13
• Sections 6.2 and 6.3 in the Alstom Grid NPAG


• Trench (CCVT vendor) CVT web page


• Link to GE paper by B. Kasztenny, D. Sharples, V. Asara and M. Pozzuli, "Distance Relays and Capacitive Voltage Transformers-Balancing Speed and Transient Overreach," From 53rd Annual Conference for Protective Relay Engineers-free registration required


• Link to IEEE Xplore paper: A. Sweetana, "Transient Response Charactersitics of Capacitive Potential Devices," IEEE Trans. on Power Apparatus and Systems. Vol. PAS-90, No 5, pp. 1989-2001, June 1971. Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)


• Review: Link to SEL paper "Capacitive Voltage Transformers: Transient Overreach Concerns and Solutions for Distance Relaying" (this takes you to SEL web site, free registration required)

Lecture 10

• Lecture 10 handwritten notes
• CVT analysis example (PDF)
• CVT analysis example (Mathcad)
• CVT analysis example (Mathcad Prime)

Reference Material

• S. Meier, "Sharing IEC 61850 Sampled Values," PAC World Magazine, August 2014
• V. Skendzic, I. Ender, G. Zweigle, "IEC 61850-9-2 Process Bus and Its Impact on Power System Protection and Control Reliability," Presented at 2007 Western Protective Delivery Automation Conference

Lecture 11

• Lecture 11 handwritten notes
• Intro to time overcurrent protection (PDF)
• Digital filter examples (discussed next lecture (PDF)
• Digital filter examples (discussed next lecture (Mathcad)
• Digital filter examples (discussed next lecture (Mathcad Prime)


• Link to Western Protective Relay Conference home page

Reference Material

• R.W. Wall and B.K.Johnson, "Using TACS functions within EMTP to teach protective relaying fundamentals," IEEE Transactions on Power Systems. Vol 12, No. 1, pp. 3-10, February 1997
• R. Wall, Introduction to digital cosine filters (PDF)

Lecture 12

• Lecture 12 handwritten notes

Lecture 13

• Lecture 13 handwritten notes
• Introduction to ATP
• Introduction to PSCAD/EMTDC

Reference Material

• Introductory tutorial videos on EMTP-RV, at EMTP-RV web site
• Tutorial video for getting started with PSCAD/EMTDC (at Manitoba HVDC Centre web site

Lecture 14

• Lecture 14 handwritten notes
• ATPDraw example with CTs and CVTs (PDF)
• ATPDraw example with CTs and CVTs (Mathcad)
• ATPDraw example with CTs and CVTs (Mathcad Prime)
• ATPDraw file from example (zip) PSCAD/EMTDC example to be added
• Inverse time overcurrent element coordination example (PDF)
• Inverse time overcurrent element coordination example (Mathcad)
• Inverse time overcurrent element coordination example (Mathcad Prime)

Lecture 15

• Review of symmetrical components (PDF)

Lecture 16

• Power apparatus models in sequence domain (PDF)
• Fault example (to be discussed in Lecture 17 (PDF)
• Fault example (to be discussed in Lecture 17 (Mathcad)
• Fault example (to be discussed in Lecture 17 (Mathcad Prime)
• Powerworld files to go with fault example (to be discussed in Lecture 17 (zip)

Lecture 17

Reference material

• See section 13.3 in the textbook

Lecture 18

• Directional Element Examples
• Load Comtrade to MathCAD (PDF)
• Mathcad direction element relay models (PDF)
• Mathcad direction element relay models (Mathcad)
• Mathcad direction element relay models (Mathcad Prime)
• COMTRADE files from examples (zip)

Reference Material on COMTRADE standard

• Link to C37.111-2013 - IEEE/IEC Measururing relays and protection equipment Part 24: Common format for transient data exchange (COMTRADE) ( via IEEEXplore Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)
• Link to IEEE Standard C37.111-1999: IEEE Standard Common Format for Transient Data Exchange (COMTRADE) for Power Systems--older revision of standard ( via IEEEXplore Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)

Lecture 19

• Classifications of grounding and impacts of different types of grounding on protecetion (PDF)
• SLG fault examples with different grounding schemes, to be discussed lecture 21 (PDF)
• SLG fault examples with different grounding schemes, to be discussed lecture 21 (Mathcad)
• SLG fault examples with different grounding schemes, to be discussed lecture 21 (Mathcad Prime)

Reference Material

• Das Textbook: Chapters 7 and 8
• NPAG Sections 9.18-9.21
• IEEE Standard 142-2007 (also known as the "Green Book"
• National Electrical Code

Lecture 20

• Arc Flash lecture notes

Reference Material

• Link to IEEE Standard 1584:IEEE Guide for Performing Arc-Flash Hazard Calculations via IEEEXplore Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)
• Link to paper: R.H. Lee, "The Other Electrical Hazard: Electric Arc Blast Burns" from IEEE Trans on Industry Applications, May 1982 Via IEEEExplore. Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)
• Arc flash videos and material from Westex Milliken
• EasyPower arc flash resource center
• Arc flash testing videos from SEL web site

Lecture 21

• Pictures of ground resistor and CTs for a generator (PDF)
• Description of relay model examples for lab 1 in ATPdraw and PSCAD/EMTDC (PDF)
• ATPDraw and PSCAD/EMTDC files for lab 1 (zipped) (optional for lab)

Lecture 22

Reference Material

• Link to paper J. Roberts, H.J. Altuve, D. How, "Review of Ground Fault Protection for Grounded, Ungrounded and Compensated Distribution Systems" (this takes you to the SEL web site, free registration may be required)
• Link to paper: D. How and N. Fischer, "Deterministic High-Impedance Fault Detection and Phase Selection on Ungrounded Distribution," Presented at 43rd Annual Industrial & Commercial Power Systems Technical Conference Edmonton, Canada May 6-11, 2007. (this takes you to the SEL web site, free registration may be required)
• Link to paper: D. Whitehead and N. Fischer, "Advanced Commercial Power System Protection Practices Applied to Naval Medium Voltage Power Systems," IEEE Electric Ship Technologies Symposium, July 2005 (this takes you to the SEL web site, free registration may be required)
• Link to paper: R. Lavorin, D. How, H.J. Altuve, N. Fischer, F. Calero, "Selecting Directional Elements for Impedance-Grounded Distribution Systems," Presented at the 34th Annual Western Protective Relay Conference Spokane, Washington October 16-18, 2007 (this takes you to the SEL web site, free registration may be required)

Lecture 23

Lecture 24

• Mathcad Bus Relay (PDF)
• Mathcad Bus Relay (Mathcad)
• Mathcad Bus Relay (Mathcad Prime)
• COMTRADE files for bus relay example (zip)

Reference Material

• Chapter 9 of Das textbook (includes typical bus arrangements)
• Chapter 15 of Numerical Protection and Automation Guide
• Link to paper "Reliable Busbar and Breaker Failure Protection With Advanced Zone Selection" (this takes you to the SEL web site, free registration may be required)
• Link to paper: J.G. Andrichak and J. Cardenas, "Bus Differential Protection," 22nd Annual Western Protective Relaying Conference.
• Link to paper: "Bus Protective Relaying, Methods and Applications," Note that you will need to create a free account to access paper
• Link to paper: Ken Behrendt, David Costello and Stanley E. Zocholl: "Considerations for Using High-Impedance or Low-Impedance Relays for Bus Differential Protection" Presented at 35th Annual Western Protective Relay Conference, October 2008

Lecture 25

Reference Material

• Breaker Failure protection in textbook by Das: Section 2.7, Section 11.15
• IEEE Power Systems Relaying and Control Committee: Summary of Revision, IEEE C37.119-2016, Guide for Breaker Failure Protection of Power Circuit Breakers
• Motor bus transfer in textbook by Das, Section 9.9
• IEEE PSRC Report: Motor Bus Transfer Applications Issues and Considerations
• Reading ahead on transformer protection next lecture: 12.1, 12.3 12.13

Lecture 26

• Transformer connection compensation matrices for common connections (PDF)
• Transformer connection compensation matrices for common connections (Mathcad)
• Transformer connection compensation matrices for common connections (Mathcad Prime)
• Transformer protection examaple for lecture 27 (PDF)
• Transformer protection example for lecture 27 (Mathcad)
• Transformer protection example for lecture 27 (Mathcad Prime)

Reference Material

• Link to paper: L. Lawhead, R. Hamilton, and J. Horak, "Three Phase Transformer Winding Configurations and Differential Relay Compensation" 60th Annual Georgia Tech Protective Relay Conference, May 2-5, 2016 (this takes you to Basler web site, free registration required)
• Link to: D.I. Taylor, J.D. Law, B.K. Johnson, and N. Fischer, "Single-Phase Transformer Inrush Current Reduction Using Prefluxing," IEEE Transactions on Power Delivery. Vol. 27, No. 1, 2012, pp. 245-252 Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)
• Link to IEEE Standard C37.91: IEEE Guide for Protecting Power Transformers through IEEEXplore Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)
• Link to IEEE Standard C57.12.00: IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers through IEEEXplore Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)
• Link to paper: B. Kasztenny, M. Thompson, and N. Fischer, "Fundamentals of Short-Circuit Protection for Transformers" (this takes you to SEL web site, free registration required)

Lecture 27

Reference Material

• Link to paper: S.E. Zocholl, A. Guzman, and D. Hou "Transformer Modeling as Applied to Differential Protection." (free registration required)
• Link to paper N.T. Stringer, L. Lawhead, T. Wilkerson, J. Biggs and G. D. Rockefeller, "Testing and Performance of Transformer Differential Relays" through IEEEXplore. Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)
• Link to paper A. Guzman, N. Fischer, and C. Labuschagne, "Improvements in Transformer Protection and Control" (this takes you to SEL web site, free registration required)
• Link to paper M. Thompson and R. Folkers "Secure Application of Transformer Differential Relays for Bus Protection" (this takes you to SEL web site, free registration required) The paper is also free on IEEEXplore at: Note, you either need an IEEE/PES Digital Library subscription or else use the UI subscription (either connect from a UI IP-address or set up remote access through the UI Library)See equation (7) for the discussion in class on setting breakpoint for dual slope element

Lecture 28

Reference Material

• Link to paper: S. Hodder, B. Kaszdenny, N. Fischer, and Y. Xia, "Low Second-Harmonic Content in Transformer Inrush Currents - Analysis and Practical Solutions for Proteection Security" Presented at 67th Annual Conference for Protection Engineers, 2014

Lecture 29

• Restricted Earth Fault Example (PDF)
• Restricted Earth Fault Example (Mathcad)
• Restricted Earth Fault Example (Mathcad Prime)
• PSCAD/EMTDC file used for example (note, will not run on free student version)

Reference Material

• Linke to Siemens Technical Guidance Notes: High Impedance Restricted Earth Fault Protection Note: Link doesn't appear to work on Firefox, but does work on other browsers. If you use Firefox, add a .PDF extension to the file that is downloaded

Lecture 30

Homework 1

• Hw #1, due (September 9) (PDF)
• Hw #1, due (September 9) (Mathcad)
• Hw #1, due (September 9) (Mathcad Prime)
• Brief illustration

Homework 2

• Update to homework 2 (PDF) due (September 23)
• Update to homework 2 (Mathcad) due (September 23)
• Update to homework 2 (Mathcad Prime) due (September 23)

Homework 3

• Hw #3, due (October 7) (PDF)
• Hw #3, due (October 7) (Mathcad)
• Hw #3, due (October 7) (Mathcad Prime)

Lab 1

• Lab 1 Assignment-Engineering Outreach lab reports due (October 23) (PDF)
• Lab 1 Assignment-Engineering Outreach lab reports due (October 23) (Mathcad)
• Lab 1 Assignment-Engineering Outreach lab reports due (October 23) (Mathcad Prime)
• Lab 1 Relay Model (Mathcad)
• Lab 1 Relay Model (Mathcad Prime)
• Lab 1 Relay Model (PDF copy)
• COMTRADE files for lab 1 (zip)
• Description of relay model examples for lab 1 in ATPdraw and PSCAD/EMTDC (PDF)
• ATPDraw and PSCAD/EMTDC files for lab 1 (zipped) (optional for lab)

Lab 2

• Lab 2, part A Engineering Outreach lab reports due (Nov 15)
• Lab 2A Relay Model (PDF)
• Lab 2A Relay Model (Mathcad)
• Lab 2A Relay Model (Mathcad Prime)
• COMTRADE file for lab 2A (zip)

• Lab 2, part B Engineering Outreach lab reports due (Nov 15)
• Lab 2B Relay Model (PDF)
• Lab 2B Relay Model (Mathcad)
• Lab 2B Relay Model (Mathcad Prime)
• COMTRADE file for lab 2B (zip)

Lab 3

• Lab 3 Assignment- Engineering Outreach lab reports due (Dec. 3) (PDF)
• Lab 3: Mathcad Busrelay (PDF)
• Lab 3: Mathcad Busrelay (Mathcad)
• Lab 3: Mathcad Busrelay (Mathcad Prime)
• Lab 3 COMTRADE files (zipped)