Voltages Generated from Power Plants

pure DC voltage have no skin effect..... but if the frequency increases skin effect will come also corona loss will also come to picture.. so optimum frequency for copper wire with steel conductor is 50 to 60 hz so only england standards always prefare 60 Hz and american standards follows 60Hz... if you want more please feel free to mail me at mahalingam_eee@yahoo.com

bye

I work in the Marine Industrial Electrical and field. We Generate alot of power. We defineatly dont have the diversity in production. My observations tells me that we are only allowed to generate what is allowed to run a plant because our safety technology limilts us. Safety is a great thing, but there is something beyond that as well. The technology allowed for the American people to plat with is very limited to what is allowed by laws and policies. Take a look at Hydrogen to electric power production. Unless you are a approved and supported company by state and sharing your profits to the dominent pwer supple company, you may get assisinated for discovering how to turn your petrol dependet car into hydrogen, or propane, or methane, or even just water.

Your Question is very valid. My anser would be were not allowed to. The technology allowed to the world is not allowd here. Even with internet its getting censored more and more each day, just like your country.

Peace and Respect. Tola Kong USA,

Of the voltages you mention above, almost NONE of them are what the power utilities generate. They all generate much higher voltages and use transformers to step it down into what are called "Utilization Voltages", which are the numbers you listed above.

Higher frequencies mean more losses. The frequencies used throughout the world represent a complex series of compromises and commercial considerations that resulted in 2 basic standards; 60Hz in North America, because of the dominance of Westinghouse in the early years, and 50Hz in the rest of the world, because of the dominance of AEG in Germany in the early years. The "best" frequency to be used depends on the application. For motors it was was discovered early on by Tesla that low frequencies work better when he developed the first AC generating system in Niagra Falls. It was 25Hz, and some of those are still in operation today. One of the first large public works projects to use AC power were the pumps used to maintain New Orleans, the infamous ones that flodded during hurricane Katrina, and they are 25Hz as well (although they are being changed out). The problem with 25Hz was that once AC power was applied to Edison's new light bulb (which he designed for DC), there was a detectable flicker in the light output. Edison's projector had already established that the human eye cannot detect anything faster than 40Hz, so when he succumbed to the practicality of AC over his DC systems, he wanted to use 40Hz! At one point in the US, there were power systems of many different frequencies, from 16.7Hz to 133.3Hz. But the problem was, as consumers began demanding electrical products, anything with a motor needed to be matched to the supply frequency. Since Westinghouse was making most of the motors at the time, 60Hz became the defacto standard and eventually the official one. A similar thing happened in Germany because of AEG and eventaully the rest of Europe, who through colonization ended up spreading 50Hz throughout the rest of the world.

Aircraft and marine systems often use 400Hz because the components can be smaller and efficiency isn't as important, but if we all used 400Hz, the efficiency losses would be enormous.

Great summary! Lots of interesting stuff. 25 Hz pumps still in use!! Incredible. Your post caused me to read up a little on the changeout efforts in New Orleans. It's a sad state of affairs.

Thank you all very much for your wonderful, humour but very practically reply. Very interesting and I learned very much from it, in fact, I dont know so many frequencies power produced in electric history in USA until now (#3post). I know only a fact, people define 50/60hz due to respondence of human eye. We also offer power supply of 400Hz for aircraft equipments, but I havnt learned why they use so particular power. occasionaly some poeple asked me such questions, I dont know how to answer them as well. Im intereting also to knwo these history story about them. I try to anwer the #1post as follow yesterday. I dont know if it right. suppose we rise the frequency only 10 times to 500hz, we would save lots of material of equipments and weight. as to power line, we can make it empty core or collect many lines together like cable to increase its effective area for long distance supply, in fact it implements in many other fields like broadcast to transmit higher frequency signal in the way. people even begin to tranmite the power by microwave last century.
The disadvantage will be in the audible range it will interfere audio facility like telephone.
I know this will be very difficult to implement. it refer to lots of presenting equipment and facilities to change.The charge will be huge. I do agree to #2post, they aer beyond our energy, ability and power.
I hope to know as well why people define the voltage at 220v or 110? rather than100v, 200v, 500v etc. As pointed out by #2 post they are not produced by plant but a utilization numbers. 10kv,20kv,35kv,60kv...up to 700kv are using in the world and 1100kv will be put into use in China, I ws told, most of these are porduced in transformer substation, I think. to be the aim at reducing energy losses on transmission line. I want to know how many kinds of voltages is there existing in the world?( supplying motor) because I met much curious requiement about the motors and theirs power supply. most of them are not exsiting in China.

cWhen I was a student, I remembered I had read a book about why defined 220v, its described if we act human body as a capacitor, he would charge 220v voltage under safe charges. but in practise, we use 36v as safety voltage a.c.)

My memory is not wonderfull on this point but I do believe that due to the mechanical difficulties in the late 19th Century of turning the then Generators at any high speed at all, the 50/60HZ examples were the best compromise between not seeing the Electrical lamps of the day pulsing and what was feasable......probaby working with reciprocating steam engines most of the time....(when were large steam turbines first available?)

Lets face it, except for specific areas of motor speed intolerant applications, and some old TVs and suchlike who used the frequency for time base applications, it really does not matter if its 50 or 50 HZ most of the time.....

Even a lot of motor applications will also work as the speed difference can be designed to have little or no effect on the application itself. (For example a small water pump running at 50 HZ will just pump with a theoretically 10% speed difference at 60HZ... for example. Using a single phase on 220 volt systems and across 2 phases on 110 Volt systems.....for a single phase motor of course!)

For universal motors (DC motors with wound fields and a brushed comutator as in power tools and suchlike) the frequency has no bearing on the speed as far as I am aware, as both the field and the comutator reverse vptage at the same time, causing the motor to always run in the same direction, unless you need to reverse the motor, then reverse one (either field or the comutator) against the other....simple!

Some light sparking and wear at the brushes is probably the only effect of the AC voltage.......

In Brazil, frequency of electrical supply is 60 Hz.

Some material of voltage standard in the world for your reference.

Algeria 阿爾及利亞50 127,220 EP,EP3,BP Korca 韓 國 60 100 EP
Argentina 阿 根 廷 50 220 EP2,BP Kuwait科 威 特50 240 CP2
Australia 澳 洲50 240 AP3 Lebanon 黎 巴 嫩50 110 CP2
Austria 奧 地 利50 220 CP2 Libya利 比 亞50 125 BP3
Belgium 比 利 時50 127,220 BP3 Luxembourg盧 森 堡50 110,220 CP2
Bolivia 波利維亞50,60 220 EP,EP3 Mataya馬 來 亞50 230,240 BP3,BP
Brazil 巴 西60 220 CP2 Mexico 墨 西 哥60,50 120 EP
Bulgaria 保加利亞50 220 CP2 Monaco摩 納 哥50 127,220 CP2
Burma 緬 甸50 230 CP2 Netherrland荷 蘭50 220 GP
Canada 加 拿 大60 120 EP,BP New Zealand新 西 蘭50 230 AP3
Chile 智 利50 220 CP2 Nicaragua尼 加 拉 瓜60 120 EP
China 中国 50 220 cp。。EP

Colombia 哥倫比亞60 115 EP Nigeria奈 及 利 亞50 230 BP3,BP2
Congo 剛 果50 220 CP2 Norway挪 威50 230 CP2
Costa Rica 哥斯大黎加60 110 EP Okinawa那 霸60 100 EP
Cuba 古 巴60 115,120 CP2 Pakistan巴 基 斯 坦50 220 BP2,BP3
Czech 捷 克50 110,220 BP3 Panama巴 拿 馬60 120 EP
Denmark 丹 麥50 220 CP2 Peru秘 魯60 110,220 EP,CP2
Dominica 多明尼加60 115 EP Philippines菲 律 賓60 220 BP3,EP
Dubai 杜 拜50 220 BP2 Poland波 蘭50 220 CP2
Ecuador 厄瓜多爾60 110,120,127 EP Portugal葡 萄 牙50 220 CP2,BP3
EI Salvador 隆爾瓦多60 110 EP Romania羅 馬 尼 亞42,50 220 CP2
England 英 國50 240 BP3,BP Salpan塞 班 島60 110 EP
Finland 芬 蘭50 220 CP2 Saudi Arabia沙地阿拉伯50,60 120,220 CP2,EP
France 法 國50 220 CP2 Sierra Leone 塞拉利昂50 230 CP2,BP3
Germany德 國50 220 GP South Afria南 菲50 230 BP3
Ghana迦 納50 220 BP2 Spain西 班 牙50 220 CP2,EP
Greece希 臘50 220 BP3 Sudan蘇 丹50 240 BP3,BP2
Guam關 島60 110 EP Surinum蘇 利 南60 127 CP2
Guatcmata瓜地馬拉60 220 EP Sweden瑞 典50 120,127,220 CP2
Haiti海 地60,50 115 EP zerland瑞 士50 220 CP2
Hawaii夏 威 夷60 120 EP Syria敘 利 亞50 110 CP2
Honduras宏都拉斯60 110,220 EP Tanzania坦 桑 尼 亞50 230 BP3,BP
Hong kong香 港50 220 BP3 Thailand泰 國50 220 BP2
Hungary 匈 牙 利40,50 220 CP2 Tunisia突 尼 西 亞60 230 CP2
India印 度50 230 BP2,BP3 Turkey土 耳 其50 110,220 CP2
Indonesia印 尼50 110 BP3 Uganda烏 幹 達50 230 BP2
Iran伊 朗50 220 CP2 Unted Areb阿拉伯聯邦50 110,220 EP
Iraq伊 拉 克 50 220 CP2 U.S.A美 國60 115,120 EP
Jamaica牙 買 加50,60 110 EP, CP2 U.S.S.R俄国50 110,220 CP2
Jordan約 旦50 220 CP2 Viet-Nam越 南60,50 120 EP
Japan日 本50,60 100 EP Yugoalavia南斯拉夫50 220 CP2
Israel以 色 列50 230 CP2 Egypt埃 及50 220 BP2
Morocco摩 洛 哥50 110,220 CP2 Cyprus塞 普 路 斯50 220 BP2
Kenya肯 亞50 230 BP3,BP Paraguay巴 拉 圭50 220 CP2
CP.: Continental plug (插頭說明) EP:兩腳扁插頭（目前國內用） AP3：三腳扁插頭
E.P.: Edison plug CP2:兩腳圓插頭（4mm） BP:三腳扁鈍插頭
A.P.: Australia plug BP2：兩腳圓插頭（5mm） GP:兩腳圓插頭（4.8mm）
G.P.: German plug EP3:三腳圓插頭 EP3:一圓二扁插頭
B.P.: British Standard plug

it should be noted that those are only the residential voltages. That has nothing to do with what the utilities are generating.

Stumbled across this forum and thought I'd chime in here. Currently employed in power plant operations. Our generators produce power at 20kv and that is immediately stepped up to 500kv for transmission.

I m still here for new reply and new idea.