Using Induction for Power Storage

http://en.wikipedia.org/wiki/Magneto_(electrical)

There was a proposal to use superconducting rings in a similar way.

While not induction, the energy could be extracted that way.

I always wondered why the cost of keeping the ring at the required temperature wouldn't kill the idea.

Choke of tube Lights.

The problem is (mechanically speaking) inductor stores Kinetic energy whereas the capacitor is potential energy.

As you are aware storage of KE is much more difficult and inefficient (since during the storage time itself the losses take place) whereas PE losses take place only when it is converted to KE.

Actually, inductors store energy in a magnetic field.

Hello stevem,

Very good point! Electrical Inductors produce ENERGY in a Magnetic Field.

I suppose you can call 'springs' inductors as well but, in this thread "inductors" is with ref' to Electrical Energy". Well said.

No, springs are like capacitors. Flywheels are like inductors.

Hello SB,

The choke in the tube light dosen't store any significant energy. It mearly accts as a depository for the difference between lamp voltage and source voltage. After Kirchhoff's voltage law must always be satisified.

Any reasonable form of magnetic energy storage requires superconductors to prevent rapid loss due to electrical resistance (conversion to heat). In general they have to be quite large (compared to capacitors) joule for joule.

Capacitor stores electron and discharges as electrical energy. This is not potential energy. The very design is based on higher the dielectric constant ( ability to polarize oxide higher the storage of electron will be and has nothing to do with potential energy.

On the other hand Induction is Magnestic energy. Melting metal in Induction furnace is very common. I have used Induction furnace to melt glass but I have to make sure my crucible is metallic in nature which will heat up with induction power

I have always related capacitors energy storage to that of a spring and inductor energy storage to that of a flywheel. A compressed spring can hold that stored energy for incredible amounts of time while a flywheel no matter how frictionless the bearings are or how low the windage losses are, it still always has a measurable rate of energy loss.

The earth is a massive fly wheel on frictionless bearings and is in the vacuum of space but yet its known that its still slowing down any way. Minute forces are still interacting with it to cause this slowing down.

Efficiency makes things expensive, hard to maintain and over all costlier to operate. Trading off some efficiency for solid gains in operating cost and workability is often a more practical approach. By using very cheap energy sources the efficiency losses can be factored out with far less concerns.

You are correct. Polarization is dielectic is very similar to that of spring analogy and discharge of capacitor is same as taking load out from pring and let spring go to it normal position.

Analogy is very close to correct statement but not 100 percent

Inductors work in a different way to capacitors but both are commonly used as energy storage devices.

Inductor energy storage is commonly employed in switch mode power supplies and in power filters due to its natural ability to store energy in a magnetic field and release it to appose a change in output voltage reduction. Problem is by their very nature the storage capacity isn't that great (which is why they are used as power filtering elements).

I can think of plenty of large scale inductive filtering applications (such as in HV substations, motor EMI filter chokes, etc) but none specifically for inductive energy storage (the equivalent of a capacitor bank), except for superconducting energy storage inductors.

Can anyone think of any?

Thanks Jack,

The reason I ask this question is that I was given a box full of very large and heavy inductors and a bunch of oil-filled capacitors... The old-guy that gave them to me said I would be able to levitate my house with the combination and slip the surly bonds of Earth - in a big way.

Not sure what he had in mind.

I have a couple of BIG inductors too. Not easy to lift.

No info on them.

Jon

Energy storage in the magnetic field of an inductor becomes "almost" sustainable when superconductors are used. The state-of-the-art is improving, but some difficulties still prohibit cost effective application in most cases. There was quite a bit of work done in the late 80's through early 90's using magnetic fields to store and release the energy needed for railguns. These were very interesting experiments, but not really practical outside the R&D world. Try...

http://en.wikipedia.org/wiki/Superconducting_magnetic_energy_storage

There are also one-shot devices that convert a magnetic field into a pulsed EM output...

http://en.wikipedia.org/wiki/Explosively_pumped_flux_compression_generator

Capacitors are reservoirs for electrons. Disconnected from the charging source and load the charge remains.

An inductor is a reservoir for a current induced magnetic field. As long as it has current applied it will store energy in a magnetic field. Disconnecting will produce a jolt to a load when the magnetic field collapses. A large bank of inductors will produce a more powerful jolt to a load.

Connecting and disconnecting inductors is how automobile ignition sustems work.

The low voltage winding is pulsed for a short time to build a magnetic field and when the disconnected the field collapses quickly and the high voltage winding puts out a very energetic spark.

Would you like to hear about switching power supplies now?

Jon

yes.

The input winding of a transformer is pulsed to build and collapse a magnetic field and induce current in the output winding(s).

What! No ones mensioned Nikola Tesla yet:-

Any switch-mode power supply uses this to store energy for microseconds.

Many early laser power-supplies used this too, in reality it was the flashlamp driving with a mixed set of big capacitors and inductors to set power and pulse-form and pulse-width.

We had an early one from LASAG in 1978 that yielded 6J per shot of laser-energy used for balancing gyro rotors - no need for start-stop operation of balancing procedure.

This needed half a cubic meter for the capacitors and inductors. So I assume these stored around 600 to 1200 J. This was outdated with the first GTO and IGBT transistors.

If you include rotational energy - as stated above - there is a high power application in the coil-gun development.

RHABE

I have a flash slave unit that's about the size of a car battery. It puts out 2000 Joules per pulse on max. Fries xenon tubes real good. Turns them into sand!!!

What is the rating of the tube?

Should be near 5KJ for single shot. Then only a powerful lightpulse will result.

Switching may be difficult?

Military surplus sale (drmo.gov) sometimes offers old and unused radar switches, likely Ignitron types, I got one a long time ago for nothing that - as the accopanying SN no and sheet stated did cost above 50K$.

RHABE

Car ignition.

Turns spark plugs into slag.