powersystemsppt.docx

1、powersystemspptPAPER PRESENTATION ON “POWER SYSTEMS”ABSTRACT This paper now consists over all view of power systems. This paper contains introduction about power system, superiority of electrical energy, Generating of electrical power using by different natural sources i.e (Hydro electrical plant, t

2、hermal power plant, nuclear power plants); Transfer the electrical power by using transmission and distribution lanes. And what are the main parts in transmission lines. i.e(conductors, insulators, poles) etc., define grid input and grid out put. And also it consist of history about transmission lin

3、es distribution lines, transmission lines and distribution line figures, are what are the main protective equipments in power system. POWER SYSTEMSIntroduction - Superiority of Electrical Energy - Generation of Electrical Energy - About Transmission and Distribution Grid - Protection - Utilization.I

4、NTRODUCTION Power is the basic need for the economic development of any country. Availability of electricity has been the most powerful vehicle of introducing economic development and social change throughout the world. The process of modernization, increase in productively in industry and agricultu

5、re and the improvement in the standard of living of the people basically depend upon the adequate supply of electrical energy. Electrical energy has been the highest priority in the national planning process. In Electrical power system “Generation” is the first process in the delivery of electricity

6、 to consumers. The other processes are electrical power “Transmission” and “Distribution”. Electricity has been generated for the purpose of powering human technologies for at least 120 years from various sources of potential energy. The first power plants were run on wood, while today we rely mainl

7、y on petroleum, natural gas, coal, hydroelectric and nuclear power and a small amount from hydrogen, solar energy, tidal harnesses, wind generators, and geothermal sources. Generally electrical power is generated at the generating stations located at far away from load centres, in view of economic c

8、onsiderations this power has to be conveyed to the consumers residing at various places. Therefore there is need to transmit power from generating stations to the areas to be served by conductor system known as transmmition lines and distribution lines. In power system consisting of generators, trsn

9、sformers, transmission and distribution circuits, it is invetable that soon or later some failure will occur somewhere in system, it must be quickly detected and disconnected from the system by using protecting equipments.SUPERIORITY OF ELECTRICAL ENERGYElectrical energy is considered superior to al

10、l other forms (chemical, heat, light, sound, or mechanical) of energy due to the following reasons:-i. cheapness: it is much cheaper than that in other forms and therefore, it is economical to use energy in this form for domestic, commercial, industrial and agricultural purposes.ii. Convenient and e

11、fficient Transmission: the electrical energy can be transmitted conveniently and efficiently from the generating stations, usually located quite away from the centres of usage, through consuctors of suitable size.iii. Easy control: electrically oprated machines have simple and convenient starting, c

12、ontrol and operation. iv. Cleanliness: use of electricity (electric drive or electric heating) does not produce smoke, fumes, dust or poisonous gases and therefore, its use ensure cleanliness and polution free conditions. v. Greater Flexibility: Electrical energy offers greater flexibility as it can

13、 be taken to any corner fo the house, factory, street, hospital, farm, mine etc. through solid, stranded or flexible conductors.vi. Versatile Form: Electrical energy is a very convenient form of energy and it can be easily converted into other forms of energy-heat, light, mechanical, sound or chemic

14、al. Though at present about three-fourth of the total energy is still used in non-electrical form (transport, residential heating and industrial heating use energy mostly in non-electrical form) but because of numerous advantages, mentioned above, electricity will accont for a greater and greater po

15、rtion of total energy consumption in the coming years. It is expected that the electricity demand will continue to go up for many more years to come, even in developed countries.Power system = Generation Transmission Distribution UtilizationGENERATIONElectricity generation is the first process in th

16、e delivery of electricity to consumers. Electrical energy is generated by conversion of energy available in different forms form different natural sources such as kinetic energy of blowing winds, pressure head of water, chemical energy of fuels and nuclear energy of radio active substances in to ele

17、ctrical energy. The electrical power generated by some major available energy sources. These areHydroelectric Power Plant: Hydroelectricity is a renewable energy source. Hydroelectric power is the power obtained from the energy of falling water where as hydroelectric power plant is the power plant u

18、tilising the potential energy of water at a high level for the generation of electrical energy. In hydroelectric power station, water head is created by constructing a dam across a reiver or lake. The pressure head of water or kinetic energy of water is utilized to drive the water turbines coupled t

19、o alternators and, therefore, generation of electrical power. Hydro electric powr stations are usually located in high hilly areas, where the dam can be built easily and largereservoirs can be obtained. Hydroelectric power supplies 20% of world electricity. Norway produces virtually all of its elect

20、ricity from hydro, while Iceland produces 83% of its requirements (2004), Austria produces 67% of all electricity generated in the country from hydro (over 70% of its requirements). Canada is the worlds largest producer of hydro power and produces over 70% of its electricity from hydroelectric sourc

21、es.Thermal power station: It is also called as steam power plant. Coal is the fuel. The fact that thermal energy is the major source of powr generation itself shows the importance of thermal power generation in india more than 60% of electric power is produced by steam plants in india. Fig: Vijayawa

22、da thermal power station A generating station, which converts heat energy of coal combution into electrical energy, is known as a steam (thermal) power station. In steam power station coal is burnt in a boiler, which converts water into steam. The steam is expanded in a turbine, which produces mecha

23、nical power driving the alternator coupled to the turbine. In alternator the mechanical power convert into electrical power. The steam after expansion in prime mover is usually condensed in a condenser to be fed into the boiler again. In practice, however, a large number of modifications and improve

24、ments have been made so as to affect economy and improve the thermal efficiency of the palnt.Nuclear power plant: the fuels mainly used in Nuclear power plants are natural Uranium, thorium. A generating station in which nuclear energy is converted into electrical energy is known as a Nuclear Station

25、. The nuclear power station mainly consists of the following:1. Nucelar reactor2. Heat exchanger or steam generator3. Steam or gas turbine4. A.C generator and exciter 5. Condenser. The reactor of a nuclear power plant is similer to the furnace in a steam power plant. The heat liberated in the reacto

26、r due to the nuclear fission of the fuel is taken up by the coolant circulating in the reactor. Hot coolant leaves the reactor at top and then flows through the tubes of heat exchanger and tranasfer its heat to the feed water on its way. The steam produced in the heat exchanger is passed through the

27、 turbine and after the work has done by the expansion of steam in the turbine, steam leaves the turbine and flows to the condenser. The mechanical energy developed by the trubine is transferred to the generator which in turn generates the electrical energy and supplies to the bus through a step-up t

28、ransformer, circuit breaker and isolator.TRANSMISSION AND DISTRIBUTIONElectric power transmission is one process in the transmitting of electricity to consumers. The term refers to the bulk transfer of electrical power from place to place. Typically, power transmission is between the power plant and

29、 a substation near a populated area. This is distinct from electricity distribution, which is concerned with the delivery from the substation to the consumers. Due to the large amount of power involved, transmission normally takes place at high voltage (110 kV or above). Electricity is usually trans

30、mitted over long distance through overhead power transmission lines.Underground power transmission is used only in densely populated areas (such as large cities) because of the high cost of installation and maintenance.Engineers design transmission networks to transport the energy as efficiently as

31、feasible, while at the same time taking into account economic factors, network safety and redundancy. These networks use components such as power lines, cables, circuit breakers, switches and transformers.* Efficiency is improved by increasing the transmission voltage using a step-up transformer, wh

32、ich has the effect of reducing the current in the conductors, whilst keeping the power transmitted nearly equal to the power input. The reduced current flowing through the conductor reduces the losses in the conductor and since, according to Ohms Law, the losses are proportional to the square of the current, having the current results in a four-fold decrease in transmission losses.Electrical power Generating Station(up to 11 kV) Transmission lines Substation and increase voltage (up to 220 kv) or Grid.A transmission grid is a