* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Generation of electricity
Faraday paradox wikipedia , lookup
National Electrical Code wikipedia , lookup
Electromotive force wikipedia , lookup
Earthing system wikipedia , lookup
Superconducting magnet wikipedia , lookup
Scanning SQUID microscope wikipedia , lookup
High voltage wikipedia , lookup
Static electricity wikipedia , lookup
Induction heater wikipedia , lookup
Electric machine wikipedia , lookup
Electrical resistance and conductance wikipedia , lookup
History of electric power transmission wikipedia , lookup
Electric current wikipedia , lookup
History of electromagnetic theory wikipedia , lookup
Electricity wikipedia , lookup
Electrical injury wikipedia , lookup
Alternating current wikipedia , lookup
The discovery of electricity Generation of electricity If a single wire is passed through a <magnetic field>, a small pulse of electricity is produced. By this method, however, it is not possible to generate enough electricity to light the tiniest light bulb. MAGNET 1 The discovery of electricity fact sheets reviewed and updated with the assistance of STAV Publishing But if a magnet revolves inside a coil of wire, then the energy of motion is transformed (changed in form) into electrical energy, and an electric current flows in the wire. Electricity is generated whether the coil of wire or the magnet is moved relative to the other. <Michael Faraday> was the first person to discover this, and develop an elementary method of generating electricity by means of motion in a magnetic field. ROTATING MAGNET In our power stations, a powerful <electro-magnet> (rotor) is mounted on a shaft supported between bearings. This rotates inside a cylindrical iron shell (stator) containing slots through which the conductors are wound. print friendly Alternating current The current produced by this type of generator flows momentarily in one direction through the conductors and then it reverses and flows in the opposite direction and the cycle is repeated continuously. This is called <“alternating current”> (generally shortened to the letters AC). 2 The AC used throughout Victoria flows alternatively in each direction 50 times each second. This frequency gives some idea of the speed the coil must turn. In technical terms, the unit of frequency is the Hertz (i.e. 1 Hz = 1 cycle per second). A current which continuously flows in one direction is called a “direct current” (DC). For example, the electricity supplied by a battery flows in one direction. Direct current is used for electroplating processes, railway and tramway systems and other motor driven applications where a smooth and wide range of speed control is required. It is generally more economical to transmit and distribute electricity in alternating current (AC) form, therefore all electricity generated at <power stations> is AC. The exception is for very long transmission lines connecting two networks together where DC is often preferred, for example <Basslink>. When DC is to be used, the electricity is converted into direct current by means of devices called converters or rectifiers and back into AC by devices called inverters. STATOR ROTOR TURBINE STEAM FROM BOILER STEAM TO CONDENSORS print friendly 3 Why does electricity flow in a circuit? Electrical current flows from the generators to the point where it is used, and then it returns to the generator. Why is a return path to the generator needed? If you pump water into a pipe and place a secure plug in the other end of the pipe, the water will cease to flow. Regardless of the amount of pressure you build up, the water will not flow. However, if we construct a unit with a water pump forcing a current of water through a closed system of pipes to run a hydraulic motor we have made a path or circuit for the flow of water. A generator is like a pump. It is a machine which creates pressure (voltage) which makes electrons move or flow in the wire. If a return path is not available to make a complete circuit such as when a switch is opened, the flow is stopped. Regardless of the amount of pressure (or voltage) generated, the electrons cannot flow. In the case of electricity, the homeowner uses the energy produced by the movement of electrons, to do work such as running a mixer, cooking food or heating a room. HYDRAULIC MOTOR Further information WATER PUMP Electricity: general <http://www.school-for-champions.com/science.htm#Electricity> Circuits <http://www.energyquest.ca.gov/story/chapter04.html > Generation of electrical power <http://www.eia.doe.gov/cneaf/electricity/page/prim2/chapter3.html> Alternating current <http://www.school-for-champions.com/science/ac.htm> <http://www.school-for-champions.com/science/actransformers.htm> Generating electrical current <http://www.school-for-champions.com/science/electgeneration.htm> Electrical power <http://www.school-for-champions.com/science/electpower.htm> print friendly Generation of electricity If a single wire is passed through a <magnetic field>, a small pulse of electricity is produced. By this method, however, it is not possible to generate enough electricity to light the tiniest light bulb. But if a magnet revolves inside a coil of wire, then the energy of motion is transformed (changed in form) into electrical energy, and an electric current flows in the wire. Electricity is generated whether the coil of wire or the magnet is moved relative to the other. <Michael Faraday> was the first person to discover this, and develop an elementary method of generating electricity by means of motion in a magnetic field. In our power stations, a powerful <electro-magnet> (rotor) is mounted on a shaft supported between bearings. This rotates inside a cylindrical iron shell (stator) containing slots through which the conductors are wound. Alternating current The current produced by this type of generator flows momentarily in one direction through the conductors and then it reverses and flows in the opposite direction and the cycle is repeated continuously. This is called <“alternating current”> (generally shortened to the letters AC). The AC used throughout Victoria flows alternatively in each direction 50 times each second. This frequency gives some idea of the speed the coil must turn. In technical terms, the unit of frequency is the Hertz (i.e. 1 Hz = 1 cycle per second). A current which continuously flows in one direction is called a “direct current” (DC). For example, the electricity supplied by a battery flows in one direction. Direct current is used for electroplating processes, railway and tramway systems and other motor driven applications where a smooth and wide range of speed control is required. It is generally more economical to transmit and distribute electricity in alternating current (AC) form, therefore all electricity generated at <power stations> is AC. The exception is for very long transmission lines connecting two networks together where DC is often preferred, for example <Basslink>. When DC is to be used, the electricity is converted into direct current by means of devices called converters or rectifiers and back into AC by devices called inverters. Why does electricity flow in a circuit? Electrical current flows from the generators to the point where it is used, and then it returns to the generator. Why is a return path to the generator needed? If you pump water into a pipe and place a secure plug in the other end of the pipe, the water will cease to flow. Regardless of the amount of pressure you build up, the water will not flow. However, if we construct a unit with a water pump forcing a current of water through a closed system of pipes to run a hydraulic motor we have made a path or circuit for the flow of water. A generator is like a pump. It is a machine which creates pressure (voltage) which makes electrons move or flow in the wire. If a return path is not available to make a complete circuit such as when a switch is opened, the flow is stopped. Regardless of the amount of pressure (or voltage) generated, the electrons cannot flow. In the case of electricity, the homeowner uses the energy produced by the movement of electrons, to do work such as running a mixer, cooking food or heating a room. Further information Electricity: general <http://www.school-for-champions.com/ science.htm#Electricity> Circuits <http://www.energyquest.ca.gov/story/ chapter04.html > Generation of electrical power <http://www.eia.doe.gov/cneaf/electricity/ page/prim2/chapter3.html> Alternating current <http://www.school-for-champions.com/ science/ac.htm> <http://www.school-for-champions.com/ science/actransformers.htm> Generating electrical current <http://www.school-for-champions.com/ science/electgeneration.htm> Electrical power <http://www.school-for-champions.com/ science/electpower.htm> The discovery of electricity fact sheets reviewed and updated with the assistance of STAV Publishing