Magnetic generator power rating

In summary, the document discusses a 2.5 kW generator that is rated at 250 rpm. To confirm, the generator supplies 2.5 kW per second, over 1 hour this is 2500 watts x 3600 seconds = 9,000,000 J or 9 MJ. Can I also relate this to 9,000,000 watts? No, you can't say kW per second. That would be redundant/wrong since the seconds are already contained in the definition of the unit. Your math is correct, though typically electrical energy is expressed in kilowatt-hours, not joules. And the way 9 MJ relates to 9 MW should be obvious from the calculation you did: 2.5 k
  • #1
barendfaber
54
0
Hi there,

I have recently downloaded this document on magnetic generators. I would just like to confirm a most probably very standard thing. One of the generators discussed is a 2.5 kW at approx 250 rpm. To confirm, is the 2.5 kW delivered per minute or per second at the rated speed?
 

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  • #2
KW is a unit of power, which is energy per unit time. In this case, kJ/sec.
 
  • #3
Thank you! So this means the generator supplies 2.5 kW per second, over 1 hour this is 2500 watts x 3600 seconds = 9,000,000 J or 9 MJ? Can I also relate this to 9,000,000 watts?
 
  • #4
No, you can't say kW per second. That would be redundant/wrong since the seconds are already contained in the definition of the unit.

Your math is correct, though typically electrical energy is expressed in kilowatt-hours, not joules.

And the way 9 MJ relates to 9 MW should be obvious from the calculation you did: 2.5 kw for an hour = 9MW for a second.
 
  • #5
Thanks for this, and sorry for all the questions. I appreciate your help.

I am a bit confused here with the last comment. If I run the generator for 1 hour (3600 seconds), should it not be 9MW for the 1 hour in total, instead of 9 MW for a second? Or am I missing something here? I am trying to learn this on my own, so if I sound stupid, could you point me in the right direction?

Lets say I run my generator for just 1 second, that gives me 2.5 kW. Now I want to use this power to lift a 10 kg object 1 meter into the air over 1 second. If my lift cost me (10 kg x 1 meter x 9.8 ms2 gravity) 98 J or W, am I correct in assuming that I will have 2.402 kW left?
 
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  • #6
You are continuing to make the same mistake of confusing power and energy by inventing the nonexistent unit of kw/s. Kw is just kw. 2.5 kw for a second? 2.5 kw. For an hour? Still 2.5 kw. You need to pay very close attention to what the units are telling you.

Perhaps until you get it straight, you should do all the calculations in terms of joules.
 
  • #7
Do apologise, can see how I am getting confused. So to confirm, the generator is rated at 2.5 kW, this is power. If this generator runs for 1 hour, I will have 2.5 kWh, or 2.5 kW x 3600 seconds as calculated above, this is energy? This gives me energy over an hour. What happens if I run my generator for only 15 seconds, how much energy will I get?
 
  • #8
barendfaber said:
Do apologise, can see how I am getting confused. So to confirm, the generator is rated at 2.5 kW, this is power. If this generator runs for 1 hour, I will have 2.5 kWh, or 2.5 kW x 3600 seconds as calculated above, this is energy? This gives me energy over an hour.
Correct.
What happens if I run my generator for only 15 seconds, how much energy will I get?
2.5 kJ/sec * 15 sec = ...?
 
  • #9
So energy over 15 seconds is 22.5 kJ. If I use some of that energy to lift the 10 kg object 1 meter in the air over 1 second (98 J), I will have 22.402 kJ left to use for something else.

I can start a new thread, but wanted to ask if you are good with magnetic generators? I now have the basics ready, and would like to find out the strength of the magnets and the gauge of wire used in the generator described in the pdf document. Can you help with that?
 

What is a magnetic generator power rating?

A magnetic generator power rating is a measurement of the amount of electricity that can be produced by a magnetic generator. It is typically expressed in watts or kilowatts.

How is the power rating of a magnetic generator determined?

The power rating of a magnetic generator is determined by the strength of the magnetic field, the speed at which the magnetic field is moving, and the number of turns in the generator's coil. These factors directly impact the amount of electrical current that can be generated.

What is the difference between the power ratings of different magnetic generators?

The power ratings of different magnetic generators can vary greatly depending on their design, materials used, and efficiency. Generally, larger and more advanced generators will have higher power ratings than smaller or simpler ones.

Can the power rating of a magnetic generator be increased?

Yes, the power rating of a magnetic generator can be increased by increasing the strength of the magnetic field, increasing the speed of the magnetic field, or adding more turns to the generator's coil. However, there may be limitations based on the design and materials used in the generator.

What factors can affect the power rating of a magnetic generator?

The power rating of a magnetic generator can be affected by various factors such as temperature, humidity, friction, and the quality of the materials used. These factors can impact the efficiency of the generator and ultimately affect its power rating.

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