APP 787: SEL-787 Transformer Protection Relay

This two-day course provides hands-on application and step-by-step settings guidance for the SEL‑787 Transformer Protection Relay. APP 787 includes applying simplified calculation methods and recommendations and using data from real-world transformers to develop protection settings. Students (in groups of two) will work directly with an SEL-787 Relay to configure system data and determine protection settings.

Audience

APP 787 is intended for utility and industrial protection engineers and power system consultants.

Agenda

Day 1

• Product Overview
• Differential (87) Element Settings
• Commissioning Assistant
• Relay Logic Settings
• Through-Fault Event Monitor

Day 2

• Restricted Earth Fault (REF) Element Settings
• Overcurrent Elements
• Overexcitation Volts/Hertz (24C) Element Settings
• Over- and Undervoltage (59, 27) Protection
• Frequency (81) Protection Settings
• Event Report Retrieval and Analysis

Course Objectives

At the conclusion of this course, students can:

• Use acSELerator QuickSet SEL-5030 Software to read and send settings to the relay.
• Determine system and transformer winding data and configuration settings.
• Calculate CT compensation, operate and restraint, and harmonic blocking settings.
• Test high- and low-voltage CT configuration settings using Commissioning Assistant.
• Determine settings for through-fault element protection and monitoring.
• Apply effective protection for REF, overexcitation, undervoltage, and underfrequency.
• Test settings by observing relay operation after current/voltage is applied.

Student Background and Knowledge

Before you attend this class, we recommend that you:

• Complete CBT 101: Introduction to SEL Relays OR be familiar with SEL relays.
• Have a basic understanding of power systems and transformer protection theory.