Training Courses

Determining the Health of a Transformer

(with a focus on Oil Analysis and Electrical Testing)

Course Overview

Course Outline

• Basic Theory
  • Physics of electromagnetism
  • RLC Circuit
  • Insulation System
  • Stress Models
• Transformer Failure Mode Analysis
• The Engineer and Oil Analysis
• Oil Quality Essentials
  • Degraded by contaminants
  • Acidity
  • Moisture and Relative Saturation
  • Interfacial Tension
  • Dielectric Strength
• Dissolved Gas Analysis (DGA)
  • DGA explained from an Engineer’s perspective
  • Interpretation using DGA Signatures
  • Detection of dielectric and thermal faults
  • Chaos (false positives)
  • Stray Gassing
  • Practical Case Studies of South African Transformers
  • Analytics (IEC, Duval, etc)
• Furanic Analysis
  • Introduction into Cellulose Insulation
  • Furanic Compounds
  • Cellulose degradation principals
  • Conversion from 2FAL to DP
  • Degree of Polymerisation (DP)
• Practical Case Studies of South African Transformer
• Onsite Electrical Testing
  • Power Factor/Tan Delta
  • Insulation Resistance
  • Turns Ratio
  • Sweep Frequency Response Analysis (SFRA)
  • Exciting Current
  • Leakage Reactance
  • DC Winding Resistance
  • Partial Discharge (PD)
• Continuous Online Monitoring

Learning Outputs

• Understand the fundamental theory of transformers that pertains to diagnostic tests
• Understand the use of oil analysis as a tool to detect incipient faults
• Learn the principal of assessing the condition of the paper insulation
• Understand the basics of PD, its detection, and consequences
• Gain a greater insight into onsite electrical testing, its applicability to detect a fault and its correlation to oil analysis
• Improve asset management decisions by understanding the dielectric, thermal and mechanical condition of your transformer

Target Audience

Electrical Engineers, Technicians, Technologists, Maintenance Electricians, Managers, Supervisors, and other technical staff involved in testing and condition assessment of transformers.

Duration:

Two Days  

Venue:     

Pretoria and Durban

Presenters:

Luwendran Moodley (BSc Eng) Pr Eng and Kamendren Govender (BSc Eng) Pr Eng

The presenters have been involved in diagnostics testing and analysis of transformers for more than 25 years. They have been involved in transformer diagnostics across the energy sector which includes generation, transmission, wind turbines, dry type, furnace, rectifier transformers etc. They have pioneered advanced onsite diagnostic test techniques and have developed methods to seamlessly merge oil and electrical testing to ascertain the severity and location of faults.

Assessing the Mechanical Integrity of Transformers

Course Overview

This course equips the attendee with the vital knowledge of Sweep Frequency Response Analysis (SFRA) and Leakage Reactance (LR) tests. These diagnostic tests are essential when assessing the transformers ability to withstand mechanical stress. These stresses typically arise from electromagnetic forces during short circuit events or stresses that arise from careless transportation of the power transformer. SFRA and LR testing has become mandatory tests both at the factory and onsite and the ability to interpret these test results is paramount for asset managers to make informed decisions. The Congru Solutions specialist will train you to make sense of the traces and numbers, so it is clear and easy to understand.

Course Outline

• Mechanical Stresses
• Mechanical Failure Modes
• Condition indicators and diagnostic tests
• Sweep Frequency Response Analysis (SFRA)
  • The physics of electromagnetic forces
  • IEC and mechanical Stress
  • Mechanical structural components
  • Frequency Response and Transfer Function
  • Test setup and measurements
  • Interpretation in the absence and presence of baseline responses
  • Practical case studies of South African transformers
• Leakage Reactance (LR)
  • The physics of transformer fluxes
  • LR with respect to the geometry of the windings
  • Test setup and measurements
  • Interpretation
  • Practical case studies of South African transformers
• Developing Health Indices that incorporates mechanical condition

Learning Outputs

• Understand mechanical stresses and their failure modes on transformers
• Understand the principles of both Frequency Response and Leakage Reactance
• Understand the onsite measurement method
• Ability to assess SFRA responses and make sense of the Leakage Reactance numbers
• Improve asset management decisions by understanding the mechanical condition of your transformer

Target Audience

Electrical Engineers, Technicians, Technologists, Maintenance Electricians, Managers, Supervisors, and other technical staff involved in testing and condition assessment of transformers.

Duration:

One Day 

Venue:     

Pretoria and Durban

Presenters:

Developing a Condition Monitoring Strategy for Transformers

Course Overview

This is a unique course that navigates attendees through the daunting task of establishing an assessment Indices and the ranking of individual transformers in a fleet.  This strategy of using health indices allows asset managers to easily identify transformers which most urgently need attention or intervention. The course follows a basic model that includes goals setting, data gathering, diagnostics and finally arriving at the condition. These are the fundamental building blocks for a successful strategy. Data gathering and handling is essential and is made up of In-service Survey Techniques, Offline Electrical Testing and Continuous Online Monitoring.  The strategy is to perform the transformer assessment online which prevents unnecessary outage of the transformer. This online assessment will identify transformers with poor health indices and these units may require onsite interventions and/or offline testing to assess the severity and location of the fault. Finally, the focus is on the culmination of these diagnostic tests to development Health Indices to ensure effective transformer fleet management.

Course Outline

• Fundamentals of Condition Assessment
  • Condition vs Time Model
  • Building blocks of condition assessment
  • Transformer stress models
  • Transformer failure mode evaluation
  • Deriving condition indicators
  • Goals and Data Gathering
  • Creating realistic goals
  • Transformer’s life management data
• Diagnostics
  • In-service Survey testing
  • Offline Testing
  • Continuous Online Monitoring
• Condition Assessment
  • Understanding assessment indices
  • Scoring matrix
  • Application of Health Indices for transformers fleet management
  • Limitations of Health Indices

Learning Outputs

• Understand the building blocks in developing a condition assessment strategy
• Understand the important of handling and managing transformer life data
• Learn the essential role that diagnostics and analysis plays in a condition assessment strategy
• Gain insight into developing a scoring matrix to ensure consistency in asset scoring
• Understand the use of health indices in the effective management of a transformers fleet
• Understanding the shortcomings in Health Indices

Target Audience

Electrical Engineers, Technicians, Technologists, Maintenance Electricians, Managers, Supervisors, and other technical staff involved in testing and condition assessment of transformers.

Duration:

One Day 

Venue:     

Pretoria and Durban

Presenters:

Partial Discharge Analysis of Substation Plant

Course Overview

This course equips the attendee with the knowledge of Partial Discharge (PD) theory, testing and analysis. PD tests have become essential in assessing the insulation of substation plant. As such it is of paramount importance to understand PD Testing at the factory (as per IEC60270) and onsite. PD testing is a versatile tool that can be used in most substation plant such as power transformers, current and voltage transformers, switchgear (metal enclosed and GIS) and cables. Its effectiveness however is greater dependent on the detection sensor used and the interpretation of the results. Hence the Congru specialist will train you to differentiate between the different sensor technologies and the interpretation of their results. The course gives a practical appreciation of PD testing using local case studies.

Course Outline

• What is Partial Discharge and why do is it so important to detect
• History of PD Testing and Recognition
• High Voltage Insulation Materials
• Electric Fields Essentials
• Partial Discharge Theory
• IEC 60270 test methods
• Detection Technology
  • High Frequency Currents
  • Transient Earth Voltage
  • Ultra-High Frequency
  • Acoustic and Ultrasonic
• Case Studies on the Detection and Interpretation of PD in:
  • Transformers
  • Switchgear
  • Cables
  • Current and Voltage Transformers
  • Survey vs Permanent Online Monitoring

Learning Outputs

• Understand the fundamental concepts of PD origins and its effect on insulation
• Gain insight into IEC 60270 Factory Tests Method
• Learn the technology behind detection sensors and their appropriate application
• Understand the interpretation of PD results on various substation plant

Target Audience

Electrical Engineers, Technicians, Technologists, Maintenance Electricians, Managers, Supervisors, and other technical staff involved in testing and condition assessment of transformers.

Duration:

One Day 

Venue:     

Pretoria and Durban

Presenters: