What can hold back a large amount of electricity and only let a smaller amount thrgh

[Leo17]

Im needing to find out if there is a way to hold back a large amount of electricity and only allow a certain amount of watts to pass at a time.

Ex: i have a generator that creates 1 million watts at any given time, but i can only have 3000 watts come through at a time. So say i watt is to take out 3000kwh from the 1,000,000 kwh being produced.

Dose anyone know of a device that can do this? Thanks i really need this information

 

[PaulHolland]

Your asking yourself the wrong question. A Generator is creating a maximum 1 Mw this means you also need to consume it otherwise it will not generate it. Look at a bicycle dynamo on your bike. If you put it on and your light is broken your dynamo is still running but does not produce any output power, only some friction losses you will have. Now if you switch on the light again you will notice that the bicycle is dragging more since the dynamo is stealing power for the light.

So, if you have a 1Mw generator and you only consume 3Kw its not a problem unless your dynamo/generator is not allowed to operate at this low power. Hope its clear.

 

[alexan_e]

This doesn't make sense, a generator will provide power up to a specified limit,
it is the load that specifies how much of the energy will be used according to the resistance.

It is like having a 12v 10A transformer, it can provide up to 120W but if you connect a resistor of 12 ohm you will only use 1A and 12W.

It would make sense to have a circuit to limit the max load consumption to 3KW but not keep a minimum of 3KW

Alex

 

[vinayakbhat82]

I'm not sure if there's a device to reduce power output. May be you connect some storage element analogous to inverter batteries to store the unused power, but I guess that is not a feasible solution and storage element may become very very huge. Normally in power stations, they have multiple generators, some of which remain off unless the load increases.

 

[PaulHolland]

Seems that no body here understands how a generator works. It only generates the energy requested by the load !. !!!!!!!

 

[vinayakbhat82]

Seems that no body here understands how a generator works. It only generates the energy requested by the load !. !!!!!!!

It would be great to learn this, with your help. As I understand, generator would consume almost constant input power (mechanical) for generating the voltage at its terminals irrespective of its loading. So with a lower load, we could say that the input power is being wasted. Please let me know if you concur. Is it possible to utilise this and make use of the expended input power?

 

[PaulHolland]

OK. its very simple. See a generator as a transformer. What happens if a mains transformer is connected to the grid ?. and no load is connected ?. Correct, you almost consume NO power on the mains side since the transformers secundary windings do not generate a magnetic field counter acting the pimary magnetic field.

Now. If you now have a generator connected to a diesel-motor or something like that and no load is connected to the generator than it will produce a stable rated voltage on its output but no current is flowing so no magnetic field in the windings and also no counter field in the main windings. The only thing the diesel motor is driving is a shaft of a generator with some friction losses that is all. Until you connect a load to the generator, let say a lamp of 10Kw than you will have a current flowing through the windings and a counter field in the main windings which will result in a resistance that the diesel motor needs to counter act and this is the energy that we consume (10Kw) with friction some losses and efficiency.

\if you know that a small DC motor that you find in any toy can act like a generator, you will not be surprised if you feed the DC toy motor with voltage and you have no friction on the shaft. Now if you increase the friction on the shaft you will see the current increase. This you find normal but if it is the opposite you find it strange .. hope its clear now.

---------- Post added at 18:34 ---------- Previous post was at 17:23 ----------

It would be great to learn this, with your help. As I understand, generator would consume almost constant input power (mechanical) for generating the voltage at its terminals irrespective of its loading.

Wrong, input power is a function of output power !.

So with a lower load, we could say that the input power is being wasted.

Wrong. Depending on the type of drive, diesel engine or Coal. If you have a diesel driven generator the consumption of diesel will simply go down but if your system is driven with coal your wasting energy into the air.