30/03/2015
Level-5(Electrical) syallbus for nea exam
1. FUNDAMENTALS
Concept of resistance, inductance, capacitance and their role in electric circuits.
Series and parallel connection of resistance, inductance and capacitance.
Ohm’s law and Kirchhoff’s law.
Alternating current fundamentals: Faraday’s laws of electromagnetic induction, generation of alternating voltages and currents and their equations and waveforms, amplitude, frequency, phase, phase difference, average and rms values, A.C. through resistance, inductance, capacitance and through their combinations, single phase and three phase AC systems.
Heating effect of electric current
General norms of system voltage regulation and frequency regulation.
2. POWER PLANTS
Hydroelectric power plants: Merits and demerits, classifications and respective layouts, selection of sites, types of water turbines, their working principles and applications.
Diesel electric power plants: Merits and demerits, selection of sites, elements of a diesel plant and its layout.
Non conventional power generation: Photo voltaic or solar cells, solar power generation, wind power generation.
3. ELECTRICAL MACHINES
D.C. generators: Working principle, types of D.C. generators, external, internal and no load characteristics, losses and efficiency.
D.C. motors: Working principle, types of D.C. motors, characteristics of D.C. series and shunt motors, losses and efficiency
Synchronous generator: Working principle, equation of induced E.M.F., short circuit and open circuit characteristics, voltage regulation, losses and efficiency, parallel operation and synchronizing, Alternators connected to infinite bus bars, different types of excitation systems, drying of alternators.
Three phase induction motors: Working principle, squirrel cage and slip ring motors, characteristic of induction motors, starting torque ant torque under running condition, starting of induction motors.
Transformers: Working principle, E.M.F. equation, transformer at no load and at loaded condition, losses and efficiency, parallel operation, different components of transformers, transformer oil and its role, cooling of transformers, Bucholtz protection.
Prerequisites for starting of generators in hydro and diesel station.
Necessity of cooling in power stations
Role of auxiliary equipments in power stations, storage batteries, their capacities, charging and maintenance.
Concept of black start units in power stations.
4. CONTROL AND PROTECTION
Necessity of D.C. system in power stations.
Working principle of bulk oil, vacuum, minimum oil and gas filled circuit breakers.
Working principle of over current, earth fault and under voltage relays and their importance for protection of the system.
Instrument transformers and their role in system protection.
Power line carrier communication and its importance.
Surge arrestor and its importance in protection against lightening.
5. SUB-STATION AND TRANSMISSION LINE
Substations: Substation equipments and their functions, general layout of substation, types of bus bar arrangements, earthing of equipments in a substation.
Transmission lines: General concept of overhead transmission line and under ground cabling, necessity of high voltage transmission, line parameter, resistance, inductance and capacitance, choice of voltage level, conductor spacing, voltage regulation and efficiency of short and medium transmission lines, sag, tension and clearances, supports and cross arms, insulating materials and their classification, conducting materials, vibrations and dampers in transmission lines..
Lightening phenomenon, types and functions of lightening arrestor, over head earth wire.
Corona and its effects, advantages and disadvantages.
6. DISTRIBUTION AND CONSUMER SERVICES
Primary distribution system: Radial system, ring main system and interconnected network system
Secondary distribution system: Three phase four wire distribution, single phase two wire distribution
Voltage regulation
Selection of supports and conductors in secondary distribution system
Earthing of electrical system and equipment
Consumer supply connection
General idea of fuse, MCB and MCCB protection
Consumer supply energy meters: Construction and principle of operation, creeping errors and their compensation, testing of energy meters
7. POWER SYSTEM OPERATION AND MAINTENANCE
Concept of maximum demand, diversity factor, load factor and load curves, load duration curves, power factor correction and improvement
Operation of substation during normal and abnormal condition
Synchronizing and system restoration
Preventive maintenance in electrical system for transmission lines and its equipment, distribution lines and its equipments, transformers, switchgears, motors, generators, turbines excitation system, and communication system used in power system
Maintenance of D.C. system
Safety and precautions, safety rules and regulation, safety tools and devices.
8. INSTITUTIONAL KNOW-HOW
General knowledge of Nepal Electricity Authority, its organizational structure and function of various business groups
General knowledge of various power plants of Nepal, their types, salient features, and their geographical locations
Level-5(Electrical)400/64/11/24
General knowledge on Nepalese power transmission system, voltage levels and lengths, export-import links for power exchange with India.
