PRESENTED TO:

ENGR. ASIM NOONSUBJECT:

ELECTRIC MACHINES

Group Members:Name Reg #

Umaiz Ahmad FA14-BEE-003

Yasir Zulfiqar FA14-BEE-015

Tayyab Bilal FA14-BEE-021

TOPIC:

ElectricityGenerationTransmition

&Distribution

Power System

Generation of Electric Power:

Electricity generation is the process of generating electric power from other sources of primary energy. The fundamental principles of electricity generation were discovered during the 1820s and early 1830s by the British scientist Michael Faraday. This basic method is still used today: Electricity is generated by the movement of a loop of wire, or disc of copper between the poles of a magnet. For electric utilities, it is the first process in the delivery of electricity to consumers.Electricity is most often generated at a power station by electromechanical generators, primarily driven by heat engines fueled by chemical combustion or nuclear fission but also by other means such as the kinetic energy of flowing water and wind. Other energy sources include solar photovoltaic's and geothermal power and electrochemical batteries.

Conventional Sources of Electric Power Generation:There are mainly three conventional source of electric power generation, and they are thermal hydal, and nuclearenergy.1-Thermal Power Generation:In thermal power plant coal or diesel is burnt to produce sufficient heat. This heat energy is utilized to produce high temperature and high pressure steam in the boiler.This steam is then passed through the turbine blades and the turbine shaft rotates due to this steam pressure. The rotor of an alternator is mechanically coupled with the turbine shaft and hence it also rotates. This rotationproduces electric power.

A View of Thermal Power Plant Kabirwala (Punjab):

Capacity: 412 MW-450 MW,,, Furnace Oil Operated

2-Hydal Power Generation:Here the water head is used to rotate the rotor shaft of an alternator. Water head can be naturally available or it can be created. In hilly region water head can be naturally available in the hill top natural lakes. In plain land, it can be created by constructing dams across suitable rivers. In comparing to a thermal power plant, hydal plants are more echo-friendly as they are free from fuel combustion. Also the running cost of hydal plant is much cheaper than that of thermal plants as there is no need of fuel to be burnt.

A View of Terbela DAM:

Capacity: 3478 MW

3-Nuclear Power Generation:It is estimated that, the coal reserve of our country will be exhausted within next 40 years if the coal is continued to be consumed in present rate. The solution of this situation is a nuclear power plant as thought. In a nuclear power station, Uranium 235 is subjected to nuclear fission. In fission process, U 235 is bombarded by a beam of neutrons. The collision of neutrons with the nucleus of U 235 creates huge heat energy along with other neutrons. These newly created neutrons are called fission neutrons which again hit by other U 235 nuclear and create mare heat energy and other fission neutrons. During fission process the nucleus of U 235 is divided into two parts. The fission process is commutative in nature. That is why, a nuclear reaction is a chain reaction and hence it should be allowed to be occurred in a controlled manner. The moderates and control rods are used to control this chain reaction.

A View of ChashNUPP:

Capacity: 2800 MW (Total 5 Reactors)

Non Conventional Source of Electrical Power Generation:Although the main sources of electric power generation are thermal, hydal, and nuclear power plants, but still there are many other non conventional sources of power available. These non conventional sources, like wind power, solar power, MHD generation, fuel cell, etc. are becoming the promising alternative sources for electric power generation.

Transmission of Electric Power:

Unit Transformer:Unit transformer are step up transformer which is connected to generating house & step up voltage from 11/15kV voltage to 220/400kV voltage level as requirement or line design parameter. It is just like transformer but connected to unit of the generating house that's why we called it unit transformers.

Overhead Transmission Lines:An overhead power line is a structure used in electric power transmission and distribution to transmit electrical energy along large distances. It consists of three conductors suspended by towers or poles.These are the high voltages (220kV-750kV) lines which transmit electric power from generation plants to substations.

Substation:A substation is a part of an electrical power system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions.A distribution substation transfers power from the transmission system to the distribution system of an area. It is uneconomical to directly connect electricity consumers to the main transmission network, unless they use large amounts of power, so the distribution station reduces voltage to a level suitable for local distribution.The input for a distribution substation is typically at least two transmission or sub transmission lines. Input voltage may be, for example, 115 kV, or whatever is common in the area. The output is a number of feeders.

Distribution voltages are typically medium voltage, between 2.4 kV and 33 kV depending on the size of the area served and the practices of the local utility. The feeders run along streets overhead (or underground, in some cases) and power the distribution transformers at or near the customer premises.In addition to transforming voltage, distribution substations also isolate faults in either the transmission or distribution systems. Distribution substations are typically the points of voltage regulation, although on long distribution circuits (of several miles/kilometers), voltage regulation equipment may also be installed along the line.

Substation Transformer:Substation transformer is step down transformer which step down voltage from 220/400kV voltage to 11/15kV voltage level as requirement or line design parameter. 

Substation:

Feeder in Power System:These are the distribution lines which transmit electric power from substation to the distribution transformer. These are the 3-phase 3-wire lines. These lines contains 11kV commonly.

The transmission system from generation end to the distribution transformer contains 3- Phase wires, because we do not require 4th wire (neutral) in the transmission of electricity, so we can save the cost of 4th wire. But in the utilization of energy the neutral wire is also required to provide the return path to electric current. So from the distribution transformer to the consumer end, electricity transmit 3-Phase 4-Wire system.

Distribution Transformer:A distribution transformer or service transformer is a transformer that provides the final voltage transformation in the electric power distribution system, stepping down the voltage used in the distribution lines to the level used by the customer. It transform 11kV to 220V/440V as requirement.