Power Systems Protection-Control and Stability

• The need for protection
• An overview of power system fault analysis
• Protection fundamentals
• Relay transducers, both current and future
• System grounding principles
• Overcurrent earth fault protection
• Coordination principles
• Transformer protection
• Generator protection
• Bus protection
• Motor protection
• Line and feeder protection
• Principles of relay application

COURSE CONTENT

Need for Protection

• Selectivity, stability, sensitivity, speed, reliability, dependability, security

Fault Types & Their Effects

• Active, incipient, passive, transient, asymmetrical
• Phase & earth faults

Simple Calculation of Short Circuit Currents

• Revision of simple formulae
• Calculation of short circuit MVA & fault currents
• Worked examples

System Earthing

• Solid, impedance, touch potentials
• Effect of electric shock
• Earth leakage protection

Protection System Components Including Fuses

• History, construction & characteristics
• Energy let through & applications

Instrument Transformers

• Current transformers: construction, performance, specification, magnetization curves
• Voltage transformers: types, accuracy, connections

Circuit Breakers

• Purpose & duty, clearance times, types

Tripping Batteries

• Battery types, chargers, maintenance, D.C. circuitry

Relays

• Inverse definite minimum time (IDMT) relay
• Construction principles and setting
• Calculation of settings - practical examples
• New Era - modern numerical relays & future trends

Practical Demonstrations and Sessions

• Including simple fault calculations and relay settings

Co-Ordination by time Grading

• Problems in applying IDMT relays

Low Voltage Networks

• Air & molded circuit breakers
• Construction and installation
• Protection tripping characteristics
• Selective co-ordination (current limiting, earth leakage protection, cascading)

Principles of Unit Protection

• Differential protection - basic principles

Feeder Protection

• Cables
• Pilot wire differential
• Overhead lines
• Distance protection (basic principles, characteristics, various schemes)

Transformer Protection

• Phase shift, magnetising in-rush, inter-turn, core & tank faults
• Differential & restricted earth fault schemes
• Bucholz relay, oil & winding temperature
• Oil - testing & gas analysis

Switchgear (Busbar) Protection

• Requirements, zones, types
• Frame leakage
• Reverse blocking
• High, medium & low impedance schemes

Motor Protection

• Thermal overload, time constraints, early relays, starting & stalling conditions
• Unbalanced supply voltages, negative sequence currents, de-rating factors
• Phase faults protection
• Earth faults - core balance, residual stabilizing resistors

Generator Protection

• Stator & rotor faults
• Overload & over-voltage
• Reverse power, unbalanced loading
• Loss of excitation and synchronism
• Typical protection scheme for industrial generators

FOR WHOM:

Works, Services and Maintenance Personnel

TRAINING METHODOLOGY

The training methodology combines lectures, discussions, group exercises and illustrations. Participants will gain both theoretical and practical knowledge of the topics. The emphasis is on the practical application of the topics and as a result participant will go back to the workplace with both the ability and the confidence to apply the techniques learned to their duties.