balance between electrical power production and consumption

Hello to all, I have one question and hope you'll help me to answer it. Recently I have visited one power plant. There I learned basics of el.
energy production and also fact that in every moment production consumption because el. energy cannot be conserved. I also learn that by allowing more steam to turbine, more power of turbine and generator will be. So basicaly operator control valves and flow of steam to turbine so he controls power. However I know that in one simple circuit power is determined by consumer, if if reciver needs more current for same voltage, there will be more power. So basically my question is how is possible to control how much power is producted with just allowing more or less steam to turbine when real need is determined by consumer. Whr if more steam is sent to turbine that will enable more power on turbine, but system (consumers) does not need more power? I hope there are some guys here who will know to answer my question. Thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Better to say that electrical energy can't easily be "stored", not conserved.

will
more
The fundamental idea that allows this to work is that there is some energy stored in the rotating mass of the generator (and turbine). If the customer load increases, this additional energy is supplied to the load by the inertia of the generator - the stored energy decreases, and the generator slows down a small amount. The control system for the turbine responds to this decrease in speed by opening up the steam valves (or wicket gates or whatever) to put more energy back into the generator and restore the speed. If the load drops, the generator speeds up and the steam valve is moved to reduce steam flow. So, to regulate the generators, the speed is very closely controlled.
Bill
( who likes to imagine all the thousands of generators in the MAPP area swinging just a micron or so, every time he pushes down the lever on the toaster)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bill Shymanski wrote:
Thank you Bill for your answer, just to be sure to understand... Turbine is rotating at constant speed of 3000 rpm since net frequency is 50Hz. If there is more need for power from consumer, does that mean that more power will try to change this speed so that turbine regulator must open steam valve to allow more steam on turbine and therefore more power to bring speed backto 3000 rpm? I always wonder how more steam wouldn't cause turbine to rotate faster, but my answer is that net is very strong and robust so when generator is connected to the net and beacuse of net frequency of 50 Hz, turbine will rotate at 3000 rpm and more steam would cause more power.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The speed of the turbine is constant, but the current in the generator field windings is varied to produce varying power output. If you want to look on this a different way, increasing the field winding current increases the rotational resistance of the armature due to increased magnetic field strengths, for which more steam is required to maintain the intended speed (and more output current is produced).
So yes, more steam is needed, but the turbine/rotor doesn't go any faster (providing there's adiquate matching demand for the increased output).
--
Andrew Gabriel

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
writes:

Before a generator is brought on line and connected to the power grid, it's frequency and the phase angle of its output is aligned until it matches that of the power grid to which it connects perfectly. The power grid also serves to keep a generator at the proper frequency and phase once it is connected.
The steam generators (better term than a boiler, because not all such units actually turn water to steam by boiling) which produces the steam also has elaborate controls to regulate steam flow and pressure. Depending upon the type of steam generating unit, this can be rather tricky, because while it easy to adjust turbine control valves to quickly adjust steam input to a turbine, doing so will upset the design conditions for steam temperature and pressure at the turbine inlet. Also, it's tricky to maintain the proper balance between steam flow and fuel input; the response of a steam generator to changes in fuel input is slow.
M.H.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
writes:

frequency
mean
regulator
more
faster,
generator
turbine
That turns out not to be the case. Adjusting the field current will change the terminal voltage of the generator and the reactive power flow, but this is NOT how the real power output of the machine is controlled. The chain of events is more like: - generator load changes - generator rotor changes speed to supply/absorb energy - unit governor system detects change of speed - steam valve is adjusted to supply more/less energy to turbine/generator and restore speed to initial value.
Bill ( who got to see the knobs marked "Megawatts" and "Megavars" at more than one generating station)
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Do you mean that rotor change it rotation speed (3000 rpm +- a couple of rpm) or what? Foe example, if load increase does that mean that rortation speed tries to decrease? Since net is robust I expect that speed change is only about +-50 rpm ot less.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

tries
Exactly. The amount of speed change depends on the load change and the capacity of the network; large networks may have a 100 MVA change of load only affect the frequency by a few hundredths of a Hz - on the other hand, I could hear the little 4kW generator in my back yard slow down quite a lot when I plugged in an electric kettle.
Bill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 3 Jul 2006 12:57:22 -0700, v snipped-for-privacy@yahoo.com Gave us:

Think exactly the opposite of a motor being shaft loaded.
I had an old car DC generator that I put a car battery on the field, and rotor, and I used it on a go cart, back in '72 to drive the thing.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Gave us:

How VARtuous of you.
Every small scale, motor driven gen set I ever heard in operation slowed as it was loaded, and was immediately revved back up to the desired operating speed by the load monitoring/shaft speed governing system, while supplying said demand. If the demand increased, the process occurred again. When the load was removed, one could hear the throttle being backed off to match whatever remaining load there was still on the line, when all loads were taken offline, the thing went back to matching the speed with much ease.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Gave us:

What happens when I throw a pipe up into the high tension lines?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
You stop posting to any newsgroups forever??

-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Gave us:

Top posting retard. If thrown, I would not be touching it, dipshit.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Sun, 02 Jul 2006 22:14:47 GMT, Roy L. Fuchs

Doesn't matter if you are not touching it. It you are close enough to the direct short you are causing you will receive serious if not fatal injuries from the blast and arc flash effects.
Beachcomber
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I think he ought to try and prove us wrong.

-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thank you for this valueable informations. Do you know any good links with articleas about this issue? I'm very interested to learn more about this.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Gave us:

The idiots are coming out of the woodwork, and your retarded, top posting ass tops the list.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Now thats original.

-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Gave us:

Top posting, know nothing Usenet retard! FOAD!
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
What is your problem with the mentally challenged? I know a lot of them, and they are each smarter than you.

-
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.