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BASIC ELECTRICAL SYSTEM GUIDE PDF DOWNLOAD

BASIC ELECTRICAL SYSTEM GUIDE PDF DOWNLOAD
Know the basics of electrical system from generation to customer billing

Introduction to Electric Power Supply Systems

Electric power supply system in a country  comprises of generating units that produce electricity; high voltage transmission lines that transport electricity over long distances; distribution lines that deliver the electricity  to consumers; substations that connect the pieces to each other; and energy control centers to coordinate the operation of the components.  

The  Figure  1.1  shows  a  simple  electric supply system with transmission and distribution network and linkages from electricity sources to end-user.

Power Generation Plant

The fossil fuels such as coal, oil and natural gas, nuclear energy, and falling water (hydel) are commonly used energy sources in the power generating plant. A wide and growing variety of unconventional generation technologies and fuels have also been developed including cogeneration, solar energy, wind generators, and waste materials.

About 70 % of power generating capacity in  India is from coal based thermal power plants. The principle  of   coal-fired   power   generation plant is shown in  Figure 1.2. Energy stored in the coal is converted in to  electricity in thermal power plant. Coal is pulverized to the consistency of talcum powder. Then powdered coal is blown into the water wall boiler where it is burned at temperature higher than 1300degreesC.

The heat in the combustion gas is transferred into steam. This high-pressure steam is used to run the steam turbine to spin. Finally turbine rotates the generator to produce electricity.In India, for the coal based power plants, the overall efficiency ranges from 28% to 35% depending upon the size, operational practices, fuel quality and capacity utilization.

Where fuels are the source of generation,  a common term used is the “HEAT RATE” which reflects the efficiency of generation.  “HEAT RATE” is the heat input in kilo Calories or kilo Joules, for generating ‘one’ kilo Watt-hour of electrical output.  One kilo Watt hour of electrical energy being equivalent to 860 kilo Calories of thermal energy or 3600 kilo Joules of thermal energy. The  “HEAT RATE” expresses in inverse the efficiency of power generation.

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