PROT 300: Symmetrical Components Theory and Application

PROT 300 is designed to help engineers and technicians analyze faults using symmetrical components. Symmetrical components and the per-unit system are two of the most fundamental and necessary types of mathematics for relay engineers and technicians. PROT 300 provides both theoretical and real-world examples to help the student gain experience calculating and using symmetrical components for various types of faults. Students will gain a fundamental understanding of symmetrical components and hands-on experience comparing calculated values to real-world event reports using SEL-5601-2 synchroWAVe Event Software or the event viewer of their choice.

Audience

Utility and industrial protection engineers, consultants, and technicians should attend this course.

Agenda

Day 1

• Phasors
• Per Unit
• Balanced Faults
• Introduction to Symmetrical Components
• Sequence Networks
• Fault Calculations Using Sequence Networks

Day 2

• Single-Phase Vs. Three-Phase Fault Current
• Faults on a Radial System
• Faults on a Nonradial System
• Changing Bases
• Phase Rotation
• Fault Locator

Day 3

• Transformer Phase-to-Ground Fault
• Transformer Phase-to-Phase Fault
• Fault Identification Selection (FIDS) Logic
• High-Impedance Fault
• Open Phase
• Zero-Sequence Currents in an Autotransformer

Note: This course teaches fundamental knowledge but does not provide hands-on experience with SEL relays.

Course Objectives

At the conclusion of this course, students can:

• Define phasors and perform phasor operations.
• Define and identify advantages of the per-unit system.
• Convert systems into per-unit quantities.
• Define short-circuit (fault) types.
• Simplify complex circuits using a Thévenin equivalent circuit.
• Identify the zero-, positive-, and negative-sequence components.
• Convert between phase and symmetrical component values.
• Calculate symmetrical components for nontraditional fault types and phase rotations.
• Determine sequence impedances for transformers, generators, and transmission lines.
• Connect sequence networks and calculate fault currents for various shunt and series fault types.
• Analyze various types of faults using symmetrical components and real event reports.
• Learn how a delta-wye transformer’s phase shift is represented in the symmetrical component networks.
• Learn how relays use symmetrical components to determine the fault type and location.

Student Background and Knowledge

Before you attend this class, we recommend that you:

• Have a basic knowledge of power systems.
• Have a working knowledge of phasor math and trigonometry, per-unit calculations, and synchroWAVe Event Software.