Skip to main content

Electric Power Transmission (College Level )

The electrical power generated in a power station situated in a remote place is transmitted to different regions for domestic and industrial uses. Here we discuss the electric power grid, power generation, transmission, and distribution.

  • Power Grid

    What is a power grid?
    The power grid forms a bridge between electrical suppliers and consumers through interconnected networks.
    The electrical power grid consists of three main parts:
    1. Generating plant for electric power.
    2. Transmission of the electric power.
    3. Distribution of the electric power.
  • Electrical Power Generation in Power Stations

    Normally, electric power generating plants are located near the source of power generation like dams, coal mines, etc. They may be in remote locations, and the generated power has to be supplied to the consumer in the city.
    Sources for Power Generation:
    The following types of resources are available for generating electrical energy for distribution:
    Steam Power Plants
    Looking For Used Processing Plants? Find Them Here! 30 Years Experience
    Ads by Google
    • Conventional Methods
    Thermal energy or Nuclear Energy used for producing steam for turbines which will drive the alternators (rotating AC generators).
    2. Hydro-Electric:
    Potential of water stored at higher altitudes is utilized as it is passes through water turbines which drive the alternators.
    • Non- Conventional Methods:
    1. Wind Power:
    High velocities of wind are utilized in driving wind turbines coupled to alternators.
  • Sources of Power Generation

    Hydro-electric power stationNuclear Power PlantCoal power plant -Thermal Power StationWind Power
  • Transmission of Power

    Power DistributionHigh Voltage Transmission Lines
  • Transmission of Electric Power

    Once the power is generated from the alternator, it is send to the typical substation in the power plant where they step up the voltage by using the step-up transformers for transmission purposes.
    As the voltage is stepped up, it reduces the transmission losses. It is then sent to the power grid from where it is then transmitted to different cities. All the power generated in different places by different methods is stepped up and sent to a common place called the grid.
    Why do we need to step up the voltage for transmission?
    For long distance transmission, power lines are made of conducting material like aluminum. There is always some power loss associated with these lines.
    If I is the current through the wire and R is the resistance, a considerable amount of electric power (I2R) is dissipated as heat. Hence, the power at the receiving end will be much less than the actual power generated.
    However by transmitting the electrical energy at higher voltage, power loss can be controlled as is evident from the following cases:
    Case 1:
    Power Transmitted At Lower Voltage:
    A Power of 11,000 Watts is transmitted at 220 Volt.
    Formula for Power (P) = V × I
    Therefore, Current (I) =P / V
    Current (I) =11,000 / 220.
    Current (I) =50 Ampere.
    If R is the Resistance of the line wire,
    Then the power Loss:
    Formula, Power Loss = I2 × R
    Power Loss = 502 × R watts = (25000 × R) Watts.
    Case 2:
    Power Transmitted At Higher Voltage:
    If 11,000 Watts power is transmitted at 22,000 Volt
    Current (I) =P/V = 11,000/22,000 =0.5 Ampere.
    Power loss = I2 × R = (.5)2× R = (0.25 × R ) watts.
    From the case 1 and 2, we found that when the power is transmitted at higher voltage, the power losses are less. Hence it is evident that if power is transmitted at a higher voltage, the loss of energy in the form of heat can be considerably reduced.
    For transmitting electric power at 11,000W at 220 V the current capacity of line wire has to be 50 A and if transmission is done at 22,000V it is only 0.5 A.
    Thus for carrying larger current (50A), thick wires have to be used. This increases the cost of transmission to support these thick wires, and stronger poles have to be erected, which further adds on to the cost. On the other hand, if transmission is done at high voltages, the wires required are of lower current carrying capacity, so thicker wires can be replaced by thin wires, thus reducing the cost of transmission considerably.
    An example would be if 400MW power is produced at 15,000V in a power station, it could be stepped up to 230,000V before transmission. The power is then transmitted through the transmission lines or network to the power grid.
  • Power Grid

    Power DistributionSub-Station Before the City to Step Down Voltage
  • Distribution of Electric Power

    The electric power grid connects different parts of the country. And the grid distributes the power to the different parts of the country or state through the transmission lines or network connecting different cities.
    Outside the city, the transmitted power from the grid is stepped down in voltage to 110,000 Volt from 230,000 Volt by a step-down auto transformer. Again the power is stepped down to 11,000 Volt from 110,000 Volt by a Step Down power transformer located in the streets and it is distributed to the industrial uses.
    Finally before distribution to the domestic user, the power is stepped down to 230 V or 440 V depending upon the needs of the domestic user.

Popular posts from this blog



In  this  configuration  the  input  is  applied  between the  base  and  the  collector and  the  output  is  taken  from  the  collector  and  the  emitter.  Here  the  collector  is common to both the input and the output circuits as shown in Fig.

  Common Collector Transistor Circuit

In  common  collector  configuration  the  input  current  is  the  base current  IB  and  the output current is the emitter current IE. The ratio of change in emitter current to the  change in the base current is called current amplification factor.

It is represented by


A test  circuit  for determining the  static characteristic  of an NPN transistor is shown in Fig. In this circuit the collector is common to both the input and the output circuits.   To   measure   the   base   and   the   emitter   currents,   milli   ammeters   are connected in series with the base and the emitter circuits. Voltmeters are connected   across the input an…

XII - Ch# 12 : Electrostatics :Solved Numericals

Solution Manual : Mathematical methods for physicists 5th edition Arfken and Weber

DJ VU Reader
Book Description Now in its 7th edition, Mathematical Methods for Physicists continues to provide all the mathematical methods that aspiring scientists and engineers are likely to encounter as students and beginning researchers. This bestselling text provides mathematical relations and their proofs essential to the study of physics and related fields. While retaining the key features of the 6th edition, the new edition provides a more careful balance of explanation, theory, and examples. Taking a problem-solving-skills approach to incorporating theorems with applications, the book's improved focus will help students succeed throughout their academic careers and well into their professions. Some notable enhancements include more refined and focused content in important topics, improved organization, updated notations, extensive explanations and intuitive exercise sets, a wider range of problem solutions, improvement in the placement, and a wider ra…