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Author Topic: How many mA in an Ampere?  (Read 22963 times)

Rob Spence

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Re: How many mA in an Ampere?
« Reply #60 on: April 07, 2016, 07:51:50 PM »

I think 1MV or 1.2 MV... 1,000 kV is easier to visualize compared to 500kV systems.

JR

We got a 1000kv DC system in our area. One fewer wire and supports for it. Real big inverter too (though it is in a building... Sure would like to see it).


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Mike Sokol

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Re: How many mA in an Ampere?
« Reply #61 on: April 07, 2016, 09:54:20 PM »

We got a 1000kv DC system in our area. One fewer wire and supports for it. Real big inverter too (though it is in a building... Sure would like to see it).


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A 1 million volt DC inverter would be really cool to see. But please don't sneak into the building to get a picture.
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Bill Harvey

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Curt Sorensen

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Re: How many mA in an Ampere?
« Reply #63 on: April 07, 2016, 11:21:34 PM »

Hi,
This audience might appreciate this story. I was reminded by the plumbing analogy. My dad worked for Laurens Hammond, inventor of the Hammond Organ. While in college, Mr Hammond walked into the wrong final exam and took a test for a class which should have been a year or two later in his electrical engineering studies. He was called in and accused of cheating as he couldn't have known how to answer the questions. He explained that he converted the problems to hydraulics, solved them and re-converted the results. Apparently the professors realized they had someone special in him.
Best,
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David Buckley

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Re: How many mA in an Ampere?
« Reply #64 on: April 07, 2016, 11:54:30 PM »

Something I've noticed in my recent China travels and wondered about.  Almost all of the transmission lines I see there have 4 conductors in parallel.  Where in the states you typically see singles and I occasionally see doubled conductors.
Its just to get more current capacity.

HV AC transmission is interesting, You've got competing forces.  One set of losses is I2R, so you naturally want to put the voltage up do reduce the current, and thus reduce the losses by the square.  But, as the voltage goes up, and the I2R losses go down, the capacitive losses go up.  Essentially, the overhead line is a big capacitor to ground, and a reactance calc for a given length will give the impedance of the short to ground.

So its a balancing act.  Otherwise all HVAC lines would be 1MV+ :)

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David Buckley

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Re: How many mA in an Ampere?
« Reply #65 on: April 08, 2016, 12:02:11 AM »

A 1 million volt DC inverter would be really cool to see.

Never been near a 1MV converter station, but we've got a 350KV bipole here in NZ.  The sound of a converter station is far more impressive than the visuals.
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Tim McCulloch

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Mike Sokol

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Re: How many mA in an Ampere?
« Reply #67 on: April 08, 2016, 09:28:30 AM »

I grew up near this:  https://en.wikipedia.org/wiki/Sylmar_Converter_Station

Interesting....

The Sylmar Converter Station is the southern converter station of the Pacific DC Intertie, an electric power transmission line which transmits electricity from the Celilo Converter Station outside The Dalles, Oregon to Sylmar, a neighborhood in the northeastern San Fernando Valley region of Los Angeles, California. The station converts the 500 kV direct current coming from the northern converter station Celilo to alternating current at 60 Hz and 230 kV synchronized with the Los Angeles power grid. The station capacity is 3,100 megawatts.

So how many watts are 3,100 megawatts? Yes, I know the answer is 3,100,000,000 watts or three billion, one hundred million watts. But I really don't think the general public has any idea of what that means when they hear those numbers rattled off on television. That's a lotta watts...
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Tim McCulloch

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Re: How many mA in an Ampere?
« Reply #68 on: April 08, 2016, 10:55:06 AM »

Interesting....

The Sylmar Converter Station is the southern converter station of the Pacific DC Intertie, an electric power transmission line which transmits electricity from the Celilo Converter Station outside The Dalles, Oregon to Sylmar, a neighborhood in the northeastern San Fernando Valley region of Los Angeles, California. The station converts the 500 kV direct current coming from the northern converter station Celilo to alternating current at 60 Hz and 230 kV synchronized with the Los Angeles power grid. The station capacity is 3,100 megawatts.

So how many watts are 3,100 megawatts? Yes, I know the answer is 3,100,000,000 watts or three billion, one hundred million watts. But I really don't think the general public has any idea of what that means when they hear those numbers rattled off on television. That's a lotta watts...

I think it started out using mercury tubes, too.  PGE shut it down after the 1971 Sylmar earthquake (what a ride that was!).  Not sure if the station was converted to solid state then, but they repaired quake damage and beefed up a lot of the infrastructure.
« Last Edit: April 08, 2016, 12:27:46 PM by Tim McCulloch »
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"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

Stephen Kirby

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Re: How many mA in an Ampere?
« Reply #69 on: April 08, 2016, 12:34:44 PM »

Interesting....

The Sylmar Converter Station is the southern converter station of the Pacific DC Intertie, an electric power transmission line which transmits electricity from the Celilo Converter Station outside The Dalles, Oregon to Sylmar, a neighborhood in the northeastern San Fernando Valley region of Los Angeles, California. The station converts the 500 kV direct current coming from the northern converter station Celilo to alternating current at 60 Hz and 230 kV synchronized with the Los Angeles power grid. The station capacity is 3,100 megawatts.

So how many watts are 3,100 megawatts? Yes, I know the answer is 3,100,000,000 watts or three billion, one hundred million watts. But I really don't think the general public has any idea of what that means when they hear those numbers rattled off on television. That's a lotta watts...
Interesting, they transmit DC the length of California?

But with 1.21 gigawatts you can go back in time.   ;D
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ProSoundWeb Community

Re: How many mA in an Ampere?
« Reply #69 on: April 08, 2016, 12:34:44 PM »


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