Circuit Breakers , Switchgear & Power Transformers

• Introduction to Switchgear and Transformers
• Application of Switchgear
• Specification of Switchgear
• Safety Policies
• Operation of Modern Switchgear
• Diagnostics,Testing and Maintenance
• Transformers' Main Functions and Classifications
• Transformer Theory
• Power Transformer Protection
• Auto-Transformers, Generator Transformers, Unit Transformers and Station Transformers
• Oil Quality
• Power Transformer Electrical Tests

Topics covered are

• Single-line diagrams

• Active and passive network components

• Circuit breaker utilization

• Alternative forms of MV switchgear: ring main units and load-breaking/fault-making switches

• Fuse switches

• HV fuses in combination with and as alternatives to circuit breakers

• Auto-reclosers and auto-reclose operation

• Principles of current interruption

• Plain break circuit breakers

• Bulk and small oil volume circuit breakers

• Turbulator (explosion pot)

• Operating mechanisms

• Transfer earth circuit breakers

• Air break and air blast switchgear

• SF6 and vacuum

• Switchgear in association with isconnectors

• Fixed and withdraw-able designs

• Switchgear standards

• Factors affecting switchgear selection

• Switchgear ratings – highest system and impulse withstand voltages, load, and short circuit currents

• Simple and complex protection systems

• Switchgear ancillaries, measurement CTs, VTs and relays

• Cable terminations

• Indoor and outdoor operation

• Substation and switch room layouts and designs

• Short-circuit testing

• General safety precautions and the use of personal protective equipment

• Principles of safety rules

• Principles of personal authorization

• Operative training for the safe operation of switchgear

• Isolation in a circuit breaker context

• Safety documentation

• Operational and safety locking, caution and danger notices

• Work safety in a substation environment

• Safety interlocks

• Substation alarms

• Individual study tasks and presentation: safety policies in my company and how they might be  improved

• Case Studies

• Switchgear inspection methodologies

• Partial discharge measurement and survey

• Timing tests

• Thermovision

• Mechanisms of deterioration

• Principles of circuit breaker maintenance

• Maintaining oil circuit breakers

• Contact maintenance and contact wipe

• Oil testing

• Maintaining vacuum circuit breakers

• Maintaining SF6 circuit breakers

• SOPs and DINs

• Switchgear defects and defect control Systems

• Construction (shell type and core type)

• Classification and type in relation to insulation, windings, core, cooling systems, voltage level, sizing, tank and breathing action

• Transformer parts

• Power transformers and safety

• Electrical values and their definition in a power transformer: voltage, current, number of turns,  impedance and their interrelation

• Operation of power transformers in a power system

• Thermal performance, loading, paralleling, tap-changing, connections and vector groups

• Surge protection

• Protective relaying (differential, over-current and earth fault)

• Buchholz relay and pressure relief relay

• Thermal devices and instruments (oil temperature alarm and trip, winding temperature alarm and trip)

• Design criteria

• Specifications

• Oil contents: water, acidity and dissolved gas

• Oil tests: dielectric breakdown, moisture, resistivity, interfacial tension, specific gravity, power factor and furan analysis

• Recovery voltage measurement test

• AC Tests:

• Power factor tests (insulation, oil, and bushings)

• Single-phase excitation current test

• Transformer turn ratio test

• DC Tests

• Preventative maintenance on power transformers

• Techniques to improve life expectancy