Electricity shared to the GRID

[jakiul094]

Want to produce electricity from a generator by using the motor driven by electricity suppose 10KW. It will be for only once. When the generator is able to provide suppose 60 KVA, among them I want to share 50KVA to Grid and other 10KVA I will use to run the starter motor. Is that logically ok?
Can anyone please help me give some suggestions?

 

[berkeman]

Welcome to the PF.

I'm not able to read the lower right corner of your paper. What is the original source of the electrical power? In general, you would just process that electrical power without using a motor/generator in order to merge some of the power with the Grid. Consult your local power utility for regulations and application forms for providing power into the Grid. There are certain requirements that you must meet, including harmonic content and "Anti-Islanding" safeguards.

In some cases a motor/generator could be used to provide cleaner AC to the Grid, if you are not able to build the appropriate power conversions inverter circuitry.

 

[russ_watters]

Want to produce electricity from a generator by using the motor driven by electricity suppose 10KW. It will be for only once. When the generator is able to provide suppose 60 KVA, among them I want to share 50KVA to Grid and other 10KVA I will use to run the starter motor. Is that logically ok?

You're saying you want a 10kW motor to drive a 60kVA (kW) generator? You don't see a problem with that sizing mismatch? This thread will probably need to be locked for a reason that should be obvious, but I'll give you an opportunity to figure it out and acknowledge the obvious error first...

 

[anorlunda]

You're saying you want a 10kW motor to drive a 60kVA (kW) generator?

I think he said he has a 60 kW generator, to drive a 10 kW motor, plus ship 50 kW to the grid.

Can anyone please help me give some suggestions?

This is AC correct? There are retail level grid interface units typically used for DC generated by solar panels. As @berkeman said, contact your local utility. Often, they insist on providing the interface themselves and doing the installation.

But power plants interface to the grid without such interface boxes, so why can't you? You could if you meet the connection requirements. But those requirements are typically written for voltages > 69 kV and powers >1 MW, and engineering budgets in the 5-6 figure dollar amounts. Small scale AC connections are typically not allowed.

You could rectify your 50 kW to DC, then use one of those solar power interface boxes.

 

[russ_watters]

I think he said he has a 60 kW generator, to drive a 10 kW motor, plus ship 50 kW to the grid.

...with the 10kW motor being the prime mover for the "generator" is what I'm seeing. The word "generator" can be ambiguous that way. But the OP can clarify.

 

[jakiul094]

I think there is some confusion you find in my question. let me say again...
"suppose I wat to run a 60KVA generator by a 10 KW motor. I will supply 10 KW from the local electricity line. The motor will provide mechanical power to the generator. Once electricity generation starts from the generator, I will disconnect the local line to the motor. And from the output of the generator let's say 60KVA, I will distribute 50KVA to the national GRID. and rest of the power I will use to run the starter motor which I used to start the generator.
Hope you guys understand now.
I want to know is that possible to do that? If yes then how can I di that?

 

[jakiul094]

Welcome to the PF.

I'm not able to read the lower right corner of your paper. What is the original source of the electrical power? In general, you would just process that electrical power without using a motor/generator in order to merge some of the power with the Grid. Consult your local power utility for regulations and application forms for providing power into the Grid. There are certain requirements that you must meet, including harmonic content and "Anti-Islanding" safeguards.

In some cases a motor/generator could be used to provide cleaner AC to the Grid, if you are not able to build the appropriate power conversions inverter circuitry.

I think there is some confusion you find in my question. let me say again...
"suppose I wat to run a 60KVA generator by a 10 KW motor. I will supply 10 KW from the local electricity line. The motor will provide mechanical power to the generator. Once electricity generation starts from the generator, I will disconnect the local line to the motor. And from the output of the generator let's say 60KVA, I will distribute 50KVA to the national GRID. and rest of the power I will use to run the starter motor which I used to start the generator.
Hope you guys understand now.
I want to know is that possible to do that? If yes then how can I di that?

 

[jakiul094]

I think he said he has a 60 kW generator, to drive a 10 kW motor, plus ship 50 kW to the grid.This is AC correct? There are retail level grid interface units typically used for DC generated by solar panels. As @berkeman said, contact your local utility. Often, they insist on providing the interface themselves and doing the installation.

But power plants interface to the grid without such interface boxes, so why can't you? You could if you meet the connection requirements. But those requirements are typically written for voltages > 69 kV and powers >1 MW, and engineering budgets in the 5-6 figure dollar amounts. Small scale AC connections are typically not allowed.

You could rectify your 50 kW to DC, then use one of those solar power interface boxes.

I think there is some confusion you find in my question. let me say again...
"suppose I wat to run a 60KVA generator by a 10 KW motor. I will supply 10 KW from the local electricity line. The motor will provide mechanical power to the generator. Once electricity generation starts from the generator, I will disconnect the local line to the motor. And from the output of the generator let's say 60KVA, I will distribute 50KVA to the national GRID. and rest of the power I will use to run the starter motor which I used to start the generator.
Hope you guys understand now.
I want to know is that possible to do that? If yes then how can I di that?

 

[jakiul094]

Welcome to the PF.

I'm not able to read the lower right corner of your paper. What is the original source of the electrical power? In general, you would just process that electrical power without using a motor/generator in order to merge some of the power with the Grid. Consult your local power utility for regulations and application forms for providing power into the Grid. There are certain requirements that you must meet, including harmonic content and "Anti-Islanding" safeguards.

In some cases a motor/generator could be used to provide cleaner AC to the Grid, if you are not able to build the appropriate power conversions inverter circuitry.

I think there is some confusion you find in my question. let me say again...
"suppose I wat to run a 60KVA generator by a 10 KW motor. I will supply 10 KW from the local electricity line. The motor will provide mechanical power to the generator. Once electricity generation starts from the generator, I will disconnect the local line to the motor. And from the output of the generator let's say 60KVA, I will distribute 50KVA to the national GRID. and rest of the power I will use to run the starter motor which I used to start the generator.
Hope you guys understand now.
I want to know is that possible to do that? If yes then how can I di that?

 

[Tom.G]

I want to know is that possible to do that?

Sorry, no.

There are a few things working against you.

1. Both the motor and the generator have about 90% efficiency. You can detect that by noticing that a running motor gets hot. That heat is the lost 10% of the input energy.
2. The generator can not put out more energy than you put into it with the motor. The more load you put on the generator the harder it is to turn.
3. With 10kW motor input there will be about 9kW available to drive the generator.
4. With 9kW to the 90% efficient generator, it can put out about 8.1kW to drive the motor.

So you see, you will be converting some of that electrical energy to heat every time it goes around the loop from motor to generator to motor.

Cheers,
Tom

 

[jakiul094]

Sorry, no.

There are a few things working against you.

1. Both the motor and the generator have about 90% efficiency. You can detect that by noticing that a running motor gets hot. That heat is the lost 10% of the input energy.
2. The generator can not put out more energy than you put into it with the motor. The more load you put on the generator the harder it is to turn.
3. With 10kW motor input there will be about 9kW available to drive the generator.
4. With 9kW to the 90% efficient generator, it can put out about 8.1kW to drive the motor.

So you see, you will be converting some of that electrical energy to heat every time it goes around the loop from motor to generator to motor.

Cheers,
Tom

If I use gear box to increasegenerator side speed. I will use gearbox in between motor and generator. then ?

 

[Tom.G]

Then you will have a few percent more losses in the gearbox.

 

[russ_watters]

"suppose I wat to run a 60KVA generator by a 10 KW motor.

A 10 kW motor produces 10 kW of mechanical power. A 60 kW/kVA generator requires a little more than 60 kW of mechanical input power. So obviously, no, it won't work. It's a simple application of conservation of energy. I tried to push you toward recognizing this in my first post. There's nothing left to discuss and it's up to you to choose to believe it or not, so the thread is locked. (and we don't discuss perpetual motion machines here.)

 

[anorlunda]

The OP asked for an explanation of why this thread was closed. Member TomG provided a nice explanation, that i think is worth appending.

Rotational Mechanical Power is the product of speed and torque. A gearbox can increase either one, but the other will be decreased by the same ratio.

For instance, if you use the same motor and add a gearbox, you can multiply the speed by three but then the torque will be divided by three. The product (the power) will remain the same...(minus the losses in the gearbox such as friction and the work used to move around the oil or grease lubricant.)

Unfortunately that is just the way the world works. You may have heard the expression "Their is no free lunch." In this case it is "You can't get something for nothing", or you can't get more power out than you put in.

In Physics this is known as "Conservation of Energy." Try this Google search:
conservation of energy definition - Google Search