Proof that higher permeable cores require less energy

[PaulLowrance]

Dear researchers,

I added a new page to my research, which breaks down, step-by-step, the energies, voltages, gauss, and current involved in a RL circuit.  If we only consider the energy required to energize the inductor in addition to any resistance then it takes exactly half the energy to energize a core that has twice the permeability.  The required energy to energize to inductor drops by half with a double in permeability.  Additionally the resistance energy also drops by half.  The reason the required wasted dc resistance energy drops by half is because the higher permeable material requires half the current to bring the magnetic core to the same magnetic field strength.

When time permits I will create a graph of the two examples.

http://peswiki.com/index.php/Directory:PaulL:Energize

[hartiberlin]

Well done Paul.
Now the question is, whether this lower energy input
also will remain in the dynamic state, when you attract a permanent magnet rotor
to the energized stator core ?
Then we have different effects coming into play, as the magnet rotor
is moving and will induce counter EMF into this energized stator.
Can you also calculate the energy for this dynamic state please,
if you have the right software to do this ?

Many thanks.

Regards, Stefan.

[TechStuf]

Interesting observations Stefan and thanks for the info Paul.

 

[hartiberlin]

Yes, if the core is moving you have to battle the Lentz law,
which is not so easy to overcome.
Regards, Stefan.

[PaulLowrance]

Dear Stefan,

As you know all magnetic materials are permanent magnets. Well, there are techniques to make magnets better though.? In other words, all magnetic materials have residual flux.? Materials with high residual flux and coercivity make better permanent magnets.

A while back I ran similar experiments.? I was more interested in materials with low coercivity.? The reason is because you can't turn off a permanent magnet.? So, it requires a lot of energy to pull the magnetic and stator apart.? Where as if you replace the magnet with low coercivity material, then you only need to collapse the applied field.? Then the only required energy to pull them apart merely depends on the materials coercivity.

Nearly all the emf can be eliminated by saturating the core.? If you don't want to saturate the core then theoretically once the magnetic field is obtained, then it requires no energy to maintain that field.? For example, if you had superconducting wire windings shorted around the core once the core was magnetized, then the magnetic field will be remain regardless if you move a magnetic next to the core.? Although the current required to maintain that field strength may change depending if the cores effective permeability changes.? I was getting simulation efficiencies up to 900% using this technique.? That was of course the mechanical FE design.? It's the solid state FE machine that has my interest.

Kind regards,
Paul