Transformer Differential Protection Course: Understanding Schematics, Relay Settings and Testing

Learn how to analyse and troubleshoot transformer differential protection schematics, relay setting calculations and trip characteristics. Study transformer winding connections from vector diagram and drawing relay settings calculations curve. 22 lessons in 3h 53m total course length.
Course
Materials

Course Description

This course deals with transformer differential protection, analyzing schemes, various relay settings and protection testing. We will analyze the transformer differential schematics and talk about current transformers (CTs), their errors and errors due to the tap changer in the transformers.

Special attention is paid to biased differential protection of transformer and modification of standard scheme by providing a restraining winding which is energized by the through current. We will also discuss relay protection setting calculations, MS Excel calculation sheet & plotting of slope, relay characteristics and trip characteristics.

The last lessons are dedicated to drawing the relay settings calculations curve and finding a point of intersection and drawing protection characteristics.

Power Transformers generally develop rare faults as it is static, totally enclosed and oil immersed but if these faults sustain the results may be serious unless the transformer is disconnected.

The best way of protecting power transformers against an internal fault is by the method of differential protection scheme since it covers the transformer’ zone of protection. So for a transformer having ratings of 5 MVA and above, the differential scheme serves as an important protection against internal phase-to-phase and phase-to-earth faults.

Course Summary

1. Transformer Differential Protection
2. Biased Differential Protection
3. Phase angle and ratio compensation
4. Differential Relay settings Calculations

Requirements

• Basics of electrical concepts

Who Is This Course For

• Practicing power system engineers
• Substation engineers
• Maintenance staff
• Electrical engineering students planning on pursuing a career in power engineering
• Power System Protection Engineers

After purchasing the course, students can download the following documents:

1. Course Documents (PDF, XLSX, DOCX):

1. 7UT612_Manual_V40R01_76 (PDF)
2. 7UT613_63x_Manual_A1_V040005_en (PDF)
3. Diff Operating Characteristic (OTF)
4. Differential Relay 7UT612 +R03.1 (DOCX)
5. FA-17P003P-E02+RP4-R1 (PDF)
6. LVOC- +R09.1 (DOC)
7. RELAY SETTING (PDF)
8. Time calculator (XLSX)

2. Guides, Papers, and Tools (PDF, XLSX):

1. Advanced protection scheme for power transformers based on IEC 61850 standard (PDF)
2. Guide through applications for SIPROTEC protection relays (PDF)
3. Instrument Transformer Calculations and Dimensioning For Substation Protection (PDF)
4. Lecture notes in relay protection for students: Generator, motor and transformer (PDF)
5. Primary-side protection of distribution substation transformers (PDF)
6. Principles and protection applications of low-impedance bus differential relay (PDF)
7. Secondary injection testing for transformer differential protection relay (PDF)
8. Testing Procedures for Power Transformer: MS Excel Spreadsheet (XLSX)
9. Transformer Differential Protection Scheme (PDF)
10. Voltage and current measurement in modern digital high voltage substations (PDF)