Magnetic Circuits - Magnetic Circuit with an Air Gap

[@JACARTISTEOFFICIEL]

I Hope you will see my comment ! Your courses are absolutely wonderful. Thanks a lot

[@EnergyConversionAcademy]

Thank you for your nice feedback

[@insoleafptyptd3801]

Consistently good content and communication of ideas well done. Looking forward to see more videos from you. Be very interested in as series of video's on Synchronous Reluctance motors that are now gaining considerable attention. The tesla ev motor is a good example. Would love to see a specific motor series

[@EnergyConversionAcademy]

I agree with you and my plan to cover reluctance motor in future. Thank you for you feedback and I appreciate your learning energy.

[@robertpearson8546]

Adding a 1mm air gap to a ferrite core decreases the relative permeability from 1500 to 3000 to around 2. That is only 2 times as effective as a non-magnetic core.

[@EnergyConversionAcademy]

Thanks for your comment. Please refer to the example in this lecture which compare two magnetic circuits, one without airgap and one with airgap. Basically, you can modify the example and evaluate what is the impact of using 1 mm airgap. With this way you can get better idea about the impact of the airgap and how can be used.

[@robertpearson8546]

The air gap drops the relative permeability from 1500-3000 down to 2. At this point, just use a wooden core.

[@farshidtavakoli6107]

Thanks a lot dear Ehsan🤓

[@EnergyConversionAcademy]

You are very welcome.

[@robertpearson8546]

Not true. The air gap is traditional, not required. The slope of the B-H curve is the inductance. The air gap reduces the inductance making the magnetic circuit less effective. Also, machining a 1 mm air gap is not trivial. If you can guarantee that the average current through the core is 0, then you don't have the DC offset caused by 1920-vintage circuits which creeps up until the core saturates. All of these methods are trying to make up for the initial poor choice of power converter circuits. At least one motherboard manufacturer had to put 39 buck converters in parallel to provide CPU power and attempt to make up for the large ripple.

[@EnergyConversionAcademy]

Thanks for your comment. Most inductance design in industry add airgaps to adjust the inductance value. This is a practical approach. There are several factors such as cost, core size, and winding number that justify the use of airgaps in the design of inductance. If you are talking about transformer, then the answer is Yes. Transformer design does not include airgap. Also, there are some special applications that design inductance without airgap. These applications use very high frequency (radio frequency). These applications have special design.

[@robertpearson8546]

@@EnergyConversionAcademy The air gap is "traditional". It is used to prevent the core from saturating. To "adjust the inductance value", use a different material (wood, stone, glass, air).