Course Outline for Power System Protection for Non-Protection Electrical Workers
- Introduction
Electrical 'Faults' occur in electrical power system as a result of insulation failure between phases and between phase to ground and sometimes due to external causes. The high value of the short circuit current that results from a fault stresses the electrical equipment thermally and mechanically. Ground faults give rise to high value of 'touch' and 'step' potentials posing danger of shock or even electrocution to personnel working nearby. Thermal energies released from the arcs at the fault point can cause dangerous or even fatal burn injuries to operating and maintenance workers in the vicinity. It is therefore necessary to detect and clear any electrical fault quickly using fuse, circuit breaker with in-built releases or switchgear. Relays were initially electromechanical devices but static relays and more recently digital relays have become the norm together using high end communication protocol. Requirement for minimization of fault clearing time is necessary to reduce equipment damage and also the danger to operating personnel. Equipment such as transformers, feeders and capacitor banks need special forms of protection schemes characterized by their design and operating principles. This course will explain all of the above points in detail and provide the non-protection electrical workers with the necessary knowledge on the type of faults, various protection system components and their testing and protection schemes for transformers, feeders, bus-bar and capacitor banks employed in Utilities and Industries.
- Objective
This course is designed to enable non-protection engineers to:
- Understand the protection philosophies employed by Utility and Industrial Distribution Systems.
- Understand different types of power system faults.
- Understand types and testing of protection system components e.g. CTs, VTs and Relays.
- Understand various protection philosophies e.g. differential, over-current and earth fault.
- Understand grading margin and relay co-ordination.
- Understand the protection schemes for transformers, feeders, bus-bar and capacitor banks.
- Course Benefits
At the end of this course, the non-protection engineers will be equipped with a better understanding of the various faults and protection schemes associated with transformers, feeders, bus-bar and capacitor banks. In effect, utilities may avoid expensive equipment failures and unscheduled outages, and most importantly, personal injury.
- Who Should Attend?
This course is specially designed for Engineers, Supervisors and Technicians dealing with Operation, Maintenance & Planners of Electrical Distribution System.
COURSE OUTLINE
DAY 1
Introduction 9.00 am – 10.00 am
- Philosophy
- Terminology and Symbols
- Reading single line diagrams
- Basic circuit breaker design
- Balanced and Unbalanced Faults – types and effects
- System Earthing and Earth Fault Current
- Protection Zones
Break for refreshment 10.00 am – 10.15 am
Protection System Components 10.15 am – 11.00 am
- Current Transformers
Burden & Specification
Accuracy
Application
- Voltage Transformers
Types
Accuracy
Application
Protective Relays 11.00 am – 1.00 pm
- Construction and Operating Principles
- Types of Electro-mechanical Relays
- IDMT Characteristics
- Factors influencing choice of plug setting
- Technical features of modern Microprocessor Relays
- Substation automation – communication capability
- Reliable Auxiliary Power – Battery and Battery Chargers
- Trip Circuit Supervision
- Smart Electrical Distribution (SED)
Break for lunch 1.00 pm – 2.00 pm
Hands-on Session 2.00 pm – 5.15 pm
- Hands on session - CT Testing
- Hands on session - VT Testing
- Hands on session - Relay Testing
Break for refreshment 3.30 pm – 3.45 pm
Several utility based case studies will be presented. Hands-on session will be conducted.
DAY 2
Grading Margin and Relay Co-ordination 8.30 am – 10.00 am
- Grading Margin
- Coordination - basis of selectivity
- Current, time and earth fault grading
- Time-current grading
- Grading through IDMT protection relay
- Importance of settings and coordination curves
Break for refreshment 10.00 am – 10.15 am
Feeder Protection 10.15 am – 11.00 am
- Feeder Faults
- Protection
- Over-current & Earth Fault schemes
- Directional Over-current
- Differential - Pilot Wire Relaying
- Phase- Comparison Relaying
- Carrier-current Relaying
Transformer Protection 11.00 am – 12.30 pm
- Transformer Faults
- Protection
- Over-current
- Differential
- Restricted Earth
- Stand-by
- Oil and Gas devices
Capacitor Bank Protection 12.30 pm – 1.00 pm
- Faults
- Protection
- Fused
- Over-current and earth
- Unbalance
- Overload
- Voltage Differential
Break for lunch 1.00 pm – 2.00 pm
Hands-on Session 2.00 pm – 5.15 pm
- Hands on session - Transformer Differential Protection
- Hands on session - Feeder Differential Protection
- Hands on session - Capacitor Bank Protection
Break for refreshment 3.30 pm – 3.45 pm
Several utility based case studies will be presented. Hands-on session will be conducted.
DAY 3
Hands-on Session 8.30 am – 1.00 pm
- Hands on session - Transformer Differential Protection
- Hands on session - Feeder Differential Protection
- Hands on session on Capacitor Bank Protection
Break for refreshment 10.15 am – 10.30 am
Break for lunch 1.00 pm – 2.00 pm
Bus-Bar Protection 2.00 pm – 3.15 pm
- Bus-bar Faults
- Protection Schemes
- Arc Protection Scheme
Break for refreshment 3.15 pm – 3.30 pm
Auto-Reclosing Relay Scheme 3.30 pm – 4.15 pm
- Definition
- Application on MV System
- High/Low Speed Auto-Reclosing
- 3-ph vs. 1-ph
- Operating Features
Test 4.15 pm – 5.00 pm
Several utility based case studies will be presented. Hands-on session will be conducted. |
