Duration: 5-8 Hours | |
Schedule: Online | |
Level: Beginner | |
Rs: 64,000 |
Objectives
Electrical distribution system
Reading single line diagrams
LV, MV AND HV equipment
Function and types of electrical switchgear
Basic circuit breaker design
Need for protective apparatus
Basic requirements and components
The development of simple distribution systems
Faults-types, effects, and calculations
Equivalent diagrams for reduction of system impedance
Calculation of short circuit MVA
Unbalanced faults and earth faults
Symmetrical components
Phase and earth faults
Comparison of earthing methods
Protective earthing
Effect of electric shock on human beings
Sensitive earth leakage protection
System classification
Fuse operating characteristics, ratings and selection
Energy ‘let through’
General rules of thumb
IS-limiter
Circuit breakers – types, purpose and arc quenching
Behavior under fault conditions
Protective relay-circuit breaker combination
Circuit breakers with in-built protection
Conventional and electronic releases
‘Class’ of instrument transformers
Voltage and current transformers
Applications
Principle of construction and operation of protective relays
Special focus on IDMTL relays
Factors influencing the choice of plug setting
The new era in protection – microprocessor, static and traditional
Universal microprocessor overcurrent relay
Technical features of a modern microprocessor relay
Future of protection for distribution systems
The era of the IED
Substation automation
Communication capability
Need for reliable auxiliary power for protection systems
Batteries and battery chargers
Trip circuit supervision
Why breakers and contactors fail to trip
Capacity storage trip units
Protection design parameters on MV and LV networks
Coordination – the basis of selectivity
Current, time and earth fault grading
Time-current grading
Grading through IDMT protection relay
Coordination between secondary and primary circuits of transformers
Current transformers – coordination
Importance of settings and coordination curves
Protective relay systems
Main, unit and back-up protection
Methods of obtaining selectivity
Differential protection
Machine, transformer and switchgear differential protection
Feeder pilot-wire protection
Time taken to clear faults
Unit protection systems – recommendations and advantages
Over-current and earth fault protection
Application of DMT/IDMT protection for radial feeders
Directional overcurrent relays in line protection
DMT and IDMT schemes applied to large systems
Unit and impedance protection of lines
Use of carrier signals in line protections
Transient faults and use of auto reclosing as a means of reducing outage time
Auto-reclosing in circuits with customer-owned generation
Auto-reclosing relays for transmission and distribution lines
Winding polarity
Transformer connections and magnetizing characteristics
In-rush current
Neutral earthing
On-load tap changers
Mismatch of current transformers
Types of faults
Differential protection
Restricted earth fault
HV overcurrent
Protection by gas sensing and pressure detection
Overloading
Motor protection basics
Transient and steady-state temperature rise
Thermal time constant
Motor current during start and stall conditions
Stalling of motors
Unbalanced supply voltages and rotor failures
Electrical faults in stator windings earth fault phase-phase faults
Typical protective settings for motors
An introduction to generator protection