Power System Protection: Protective Relay Logic

3 sections | 13 lectures | 2hr 15min

Learn how to implement digital logic in modern microprocessor-based protective relays with our Power System Protection: Protective Relay Logic online course. Earn 2 PDHs for professional engineers.


Course Description

This course is part of a multi-part course series about one of the main areas of power engineering: power system protection and control. Power system protection and control ensures the reliable continuous operation of power systems and is therefore an essential area of power engineering. In this course of the multi-part course series, you will learn how to implement digital logic in protective relays. The course is divided into the following sections:

1. Introduction to Protective Relay Logic: we will begin in section 2 of the course by introducing logic gates and how they work. We will also be discussing the order of operation of logic functions and how to develop truth tables to determine proper operation of logic schemes. We will finish the section by discussing some functions commonly used in protective relay logic: timers, latches, and edge triggers.

2. Applications of Logic in Protective Relays: having defined the fundamentals of relay logic, we will move into developing practical examples in section 3 of the course. We will be taking a look at how to build five different logic schemes: enable/disable switches, permissive tripping schemes, overcurrent blocking schemes, breaker failure schemes, and automatic reclosing schemes.

By learning how to use digital logic in protective relays, you will be able to continue your study of power system protection and control and power engineering.

Remember that we are also always available for questions while you go through the course to ensure everything is clear.

See you in the course!

What You'll Learn

  • How to use logic gates in protective relays
  • How protective relay functions, such as timers, latches, and edge triggers work
  • How to use truth tables to determine protective relay logic operation
  • How to implement different logic schemes, such as enable/disable functions, permissive tripping schemes, breaker failure schemes, and auto reclosing schemes

Preview Lectures

Check out the three lectures below from this course!


Pricing Options

We offer three different pricing options to meet your needs: annual and monthly subscriptions which include access to this and all of our other online courses, and a one-time purchase of this course. All of our courses and subscriptions offer a 30-day 100% money-back guarantee.




  • Includes access to all of our courses, including this one, with a recurring annual payment
  • Courses available on mobile devices
  • Contact the course instructor with questions
  • Save 20% over the monthly subscription plan




  • Includes access to all of our courses, including this one, with a recurring monthly payment
  • Courses available on mobile devices
  • Contact the course instructor with questions
  • Pay month-to-month



  • Includes lifetime access to this course, including any future updates
  • Course available on mobile devices
  • Contact the course instructor with questions

Course Outline

Not sure if this course covers what you want to learn? Download the full course outline to find out more.

Course Instructor

Ricardo Romero, PE is an Electrical Engineer with over ten years of experience in Power Systems, having worked as a Power Systems Protection Engineer at Schweitzer Engineering Laboratories, Inc. (SEL) and Power Relaying Solutions, PLLC (PRS). He started his own power engineering consulting and online learning business in 2020 – the Romero Engineering Company. He obtained his bachelor’s and master’s degrees in Electrical Engineering from The University of North Carolina at Charlotte, where he specialized in Power Systems, Power Electronics, and Power System Protection and Control. He is a licensed Professional Engineer in Power Systems in the states of Arizona, North Carolina, Pennsylvania, South Carolina, and Virginia.

Frequently Asked Questions

This course grants you 2 PDHs to meet your PE licensing requirements. Please note that the final course exam must be completed and you must obtain a minimum score of 70% to obtain the PDHs.

This course includes 13 lectures, totaling roughly 2.25 hours of video lectures.

Your subscription, whether the annual or monthly options, gives you access to all courses offered by Romero Engineering Co. This includes updates to existing courses as well as any new courses.

This course is designed with three types of students in mind: professional engineers looking to meet their licensing PDH requirements, practicing engineers looking to learn more about protection engineering, and engineering students looking to start learning about power system protection and control.

Start Learning Today

If you're ready to start learning about protective relay logic, let's get started.

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