DAY ONE
Part 1. Transformer Design and Construction
Students will be introduced to the different types of single- and three-phase transformer construction, various types of core material, windings layout, connection, tap changers, voltage classifications and transformer applications, with an emphasis on explaining recent innovations in transformer design.
Transformer Construction and Main Parts
- Sealed Transformer
- Breathing Transformers
- Nitrogen Blanket Transformer
- Dry Transformers
Transformer Core
- Transformer core
- Core form and shell form
- Core loss
- Exciting current
- Noise level
- Structure
- Core Mechanical Assembly Requirements
- Special Requirements for Magnetic Core
Transformer Windings
- Transformer core
- Core form and shell form
- Core loss
- Exciting current
- Noise level
- Structure
- Core Mechanical Assembly Requirements
- Special Requirements for Magnetic Core
Transformer Insulation
- Winding conductors
- Load loss
- Impedance and voltage drop
- Winding insulation
- Cooling structure
- Short circuit withstand capability
- Core and coil assembly
Transformer Tank
- Oil paper insulation system
- Two functions of insulation fluid
- Various insulation fluids
- Factors affecting quality
- Factors accelerating degradation
- Paper and pressboard insulation
- Two functions of solid insulation
- Factors affecting quality
- Factors accelerating aging
- Aging cycle
Oil Preservation Systems
- Main tank
- Main tank components
- Seals, gaskets and valves, bushings
Transformer Bushings
- Air cell systems
- Breathing systems
- Auto-recharging dehydrating breather
- Oil cooling systems
Tap Changers
- Voltage class
- Current ratings
- Top and bottom terminal connections
- Mounting flange
- Test and voltage taps
- Air side dimensions
- Oil side dimensions
- CT pocket length
- Oil reservoir
- Many styles and types in use
Components and Accessories
- LTC
- DETC (OCTC)
- ULTC
- Headboard links
Part 2. Transformer Operation and Application
Transformer Applications and Types
- Top oil temperature monitoring
- Devices/Indicators
- Winding temperature monitoring
- Liquid level Gauges/Indicators
- Pressure and vacuum Gauges/Indicators
- Pressure relief device
- Gas Detection Relays
- Alarm and trip functions are equipped and preset
Transformer Operation and Theory
- Dry type
- Liquid filled
- Industrial vs public distribution
- Potential transformers (PTs)
- Current transformers (CTs)
- Control and power supply transformers
- Auto transformers
Transformer Cooling
- Load vs no load
- Transformer losses
- Hysteresis losses
- Eddy current losses
- Copper losses
- Stray losses
- Relationship between primary and secondary values
- Transformer polarity
- Single phase transformer connections
- Transformer impedance
- Transformer ratings
- Optimum transformer rating
Three-Phase Theory/Transformer Types
- Transformer cooling techniques and devices
Resistive Loads
- Transformer configuration
- Three phase transformer connections
- Delta connection
- Wye 'star' (Y) connection
- Voltage and current in various combinations
- Transformer terminal markings and identifications
Transformer Failures
- Inductive loads
- Capacitive loads
- Misapplication
- Vibration
- High operating temperature
- Lightning or line surges
- Overloading
- Care of control equipment
- Lack of cleanliness
- Care of idle or spare equipment
- Improper lubrication
- Careless or negligent operation
DAY TWO
Installation, Testing and Maintenance
Installation and safety operation
- Standards for Transformers
- Installation & Relocation
- Transformer Type Tests
- Transformer Routine Tests
- Transformer Commissioning Tests
- Transformer Maintenance: Concepts of preventive & condition based maintenance
- Case studies
- Discussion
Transformer failure statistics
- Connections and Vector groups
- Safe procedures relating to transformer operation in a utility or industry environment
- Thermal performance and Loading of Transformers
- Practical solutions for operating and maintaining power transformers
- Voltage Adjustment using Off-Load & On-Load Tap Changing
- Earthing of HV Transformers
- Transformer failure modes
- Lightening
- Internal Faults
- External Faults
- Insulation Damage
- Component Failures
- Transformer failure statistics
- How to categorize transformer failure modes
Protection methods
- Oil temperature Alarm and Trip
- Winding temperature Alarm and Trip
- Buchholz relay, Oil Surge relay & Pressure relief relay
- Surge protection
- Fuse protection
- Protective relaying ?V Overcurrent, Earth fault, Differential & Overflux
- Example of a Power Transformer System Selection and Installation
COURSE TIMETABLE
Both days:
Start: 8:00 a.m.
Coffee Break: 10:00 a.m.
Lunch: 12:00 noon
Restart: 1:15 p.m.
Finish: 4:30 p.m.
