History of Power Systems Prof. Ramzy R. Obaid 1
With many thanks and appreciation to Prof. Mohamed A. El-Sharkawi 2
Road to Power Systems Greek philosopher Thales of Miletus (around 600 BC) When rubbing fur on amber, electric charge is built up on the amber. The charge attracts light objects such as hair. 3
Road to Power Systems English physician William Gilbert (1544-1603) Was the first to use the term electric Derivation from the Greek word for amber (ηλεκτρον). The word amber itself was derived from the Arabic word Anbar. 4
Road to Power Systems Italian scientist Alessandro Guiseppe Antonio Anastasio Volta (1745-1827) Galvanism occurred whenever moist is placed between two different metals. The first battery was invented in 1800. Today we use the unit Volt for the electric potential in honor of this great Italian inventor. 5
A Model of Volta s Battery 6
Road to Power Systems French mathematician and physicist André-Marie Ampère (1775-1836). Explain the link between magnetism and electric currents. The basis of electromagnetic devices: motors, generators, transformers, etc. Today we use Ampere as a unit for electric current in honor of this French scientist. 7
Road to Power Systems German scientist George Simon Ohm (1789-1854) Related electric current to the electromotive force. His work is known as Ohm's law. The theory opened the door wide for circuit anaysis and designs. We now use Ohm as the unit for resistance (or impedance) in his honor. 8
Road to Power Systems English chemist and physicist Michael Faraday (1791-1867). Developed the foundations of all electromechanical theories. In his memory, the unit of capacitance (farad) is name after him. 9
Road to Power Systems French instrument maker Hippolyte Pixii (1808-1835) Not widely known inventor Built the first generator (or dynamo). His machine, named magnetoelectric, was later developed into the electrical generators. 10
Pixii s Generator 11
Road to Power Systems Italian Antonio Pacinotti (1841-1912) invented a device that had two sets of windings wrapped around a common core. This was the basis for the transformers we use today. Westinghouse further developed the transformer and had several early models Gaulard and Gibbs transformer developed in 1883 Stanley transformer developed in 1886. 12
Stanley s Transformer 13
Thomas Edison and Nicholai Tesla 14
Thomas Edison Born on February 11, 1847, in Milan, Ohio, and died on 1931 at age 84. Had 1093 patents. his first patent was granted at age 21 his last one was at age 83. an average of about 1.5 patent per month. 15
Thomas Edison In 1874 at age 27, Edison opened his first research and development laboratory in Newark, New Jersey. In 1876, he moved the facilities to a bigger laboratory at Menlo Park, New Jersey. The finest research and development laboratories in the world at that time. 16
Thomas Edison The electric light bulb is one of Edison s most important inventions (1878). 17
Thomas Edison Edison received the U.S. congressional gold medal for career achievements in 1928. When Edison died on 1931, people world wide dimmed their lights in honor of his man s achievements. 18
Nikola Tesla Nikola Tesla was born in Smiljan, Croatia on July 9, 1856. During his career, Tesla had over 800 patents. Tesla moved from Europe to the United States in 1884. He worked for Thomas Edison in his lab as a research assistant. 19
Tesla s ac motor 20
Nikola Tesla Tesla received the IEEE Edison Medal in 1917, the most coveted electrical prize in the United States. Tesla was inducted into the Inventor's Hall of Fame in 1975. In 1956, the term "tesla" was adopted as the unit of magnetic flux density in the MKSA system in his honor. In 1975, the IEEE Power Engineering Society established the Nikola Tesla Award in his honor. Tesla died on January 7, 1943. 21
The Battle of ac versus dc Voltage or Current Voltage or Current Time Time 22
The Battle of DC versus AC Edison system was 100V Direct Current In September 1882, his Pearl Street plant in lower Manhattan starts operation the world's first commercial electric lighting power station. City of Brockton, Massachusetts is the first city to be electrified (1883). 23
Problems With Low Voltage For the same power, the lower the voltage, the higher is the current. P V I P: Power V: Voltage I: Current 24
Problems With Low Voltage High currents require large cross section wires Expensive copper wires Heavy wires that cannot be easily mounted on transmission towers Customers voltage is substantially reduced at heavy loading conditions 25
Source Line Voltage Drop R wire I V S V load R Load V load I R R V S R wire R 26
Wire Resistance R wire l A To reduce the wire resistance A should be increased. However, bigger cross section wires are more expensive heavier and would require poles to be placed at shorter spans. 27
Edison s Options To have several small cross-section wires feeding areas with high demands. Expensive solution; more wires for long miles. To place electrical generators at every neighborhood. Impractical and expensive solution. To increase the voltage Best solution, but the technology to increase the voltage of the dc system was not available then. 28
Tesla s Solution P V I Tesla knew the problem was related to the low voltage (100 V) Edison was using in his dc system. For same power, increasing the supply voltage reduces the current. Hence the voltage drop across the wire could be reduced. However, adjusting the voltage of dc systems was beyond the technology at that time. 29
Here Comes the AC! Main Advantage of AC: The voltage of AC systems can be changed by transformers. How about DC? The transformers cannot change the DC voltage. 30
Tesla s Solution (AC system) Low Voltage High Voltage Transformer 2 Transmission line Power plant Transformer 1 Low Voltage 31
Source Tesla s Solution (ac system) R wire I V S V 1 V 2 V load R Transformer 1 Transformer 2 Load 32
Example V S = 100 V, R = 1, Rwire = 0.5 Compute the following: 1. The voltage at the load side 2. The percentage of the load voltage with respect to the source voltage 3. The energy consumed by the load during a 10 hour period 4. The maximum load (minimum resistance) if the load voltage cannot be reduced by less than 10% of the source voltage. 5. The energy consumed by the new load during a 10 hour period. 33
Solution Vs 100 Vload 66. 67 Rwire 0. 5 1 1 R 1 Vload 66. 67% V s V 2 2 Vload 66. 67 E P t t 10 44. 444 R 1 kwh 34
Solution V V load s 0. 9 1 1 1 R 1 0. 5 R wire R 2 Vload 0. 9* 100 E P t t 10 18. 0 R 4. 5 2 kwh 35
Edison s Reaction to Tesla s Idea Edison was not impressed by Tesla s AC system because of its unsafe high voltage wires that would pass through residential areas. Most historians believe that Edison s rejection to the AC system was because he had too much money invested in the DC infrastructure. 36
Edison s Reaction to Tesla s Idea Edison used unconventional methods to convince the public that Tesla s high voltage ac system was too dangerous. Live demonstrations where he deliberately electrocuted animals such as puppies, cats, horses and even elephants. Edison went so far as to convince the state of New York to use an electric chair powered by high voltage ac system to execute condemned inmates on the death row. Most historians believe that his real motive was to further tarnish the safety of the ac system. 37
Edison high voltage test 38
And the Winner is 39
Today s World at Night 40
Power System of the Future Less Polluting Power Plants new industrial processes. The use of less polluting material (natural gas instead of coal). Preprocessing the material to remove the polluting agents such as reducing the sulfur in coal. Develop effective filters at every stage of the production. Develop creative ideas to reduce the negative impact on the environment; for example hydro power plants with fish ladders facilitate fish migration. 41
Power System of the Future Alternative Resources Sun, wind, tide, geothermal, biomass, hydrogen, and others Distributed Generation Personal utility Power Electronics Enhance the efficiency Improve performance 42
Power System of the Future Enhanced Reliability. Redundancy of system components Public concerns regarding new constructions Space power plant. Intelligent Operation, Maintenance and Training. 43
Space Power System 44
Smart Grid 45