#48 π Welcome to my New Lab
SuperPowers for Electrical Engineers π¦Έπ»ββοΈπ¦ΈπΌββοΈ
π Hello friends! Dr. Molina here π¨βπ§
Welcome to my new Place!
After almost a year with the Newsletter, a lot of things have changed and I needed to move forward and find a place that fits better with my personality.
I love Power Electronics, Design, and Science. I donΒ΄t consider myself good in any of them, but I have found very talented people to help me. And why not, this Newsletter is like the home where I receive you every week, therefore, I have asked a very talented designer (Hugo) to help me create a Lab with a great design.
Welcome to My Lab!!
Iβm creating a totally new space in my mind and life. This space is more scientific.
I want science to be more present in the industry of Power Electronics or in my life and I have started by the space of the Newsletter.
I would love to receive guests in the Lab and learn from them. Would you like to show us something?
Science at Power Electronics
In 1956 John Bardeen, William Shockley y Walter Brattain received the novel prize because of the invention of the transistor. John Bardeen, received two Nobel prizes, the second one because of conductivity. Only four scientists have achieved two times the Nobel prize in history and only one physicist, John Bardeen.
We are investing more money in Power Electronics than ever.
When will we have another Nobel prize changing the Power Electronics Industry?
I would love to see it and participate in it with Frenetic.
At our Lab, Iβm focused on finding scientists to support us with science the technology development.
Last week, I mention some of them but Iβm glad of introducing you to our last excellent addition.
Iβm happy to announce a new talented scientific joining the Frenetic Scientific Board, Jonas MΓΌhlethaler from Switzerland who had a lot of experience in two things:
Building a company - Gecko Magnetics, which was software for designing magnetics.
Magnetics Modeling. He obtained a Ph.D. in magnetics at ETH Zurich, one of the better places in the world in Power Electronics, with the distinguished Professor Johan W. Kolar.
He will be supporting us in improving our models and algorithms. Thank you Jonas for giving us the opportunity of learning from you π€.
The Classic Method: Spreadsheets
I have observed my old methods of designing magnetics and all of them are based on the algorithms in Excel and Mathcad. And you know what? I have discovered that they are a barrier to science.
Itβs not possible to really move forward without a database, an accuracy analysis, or a conversation with the manufacturers, who are finishing the product and introducing big changes there.
Itβs as if each engineer would be creating his own Matlab or language for magnetics. This is not the way we will get the next Nobel Prize in physics.
I have built a lot of excel files, which I have shared with a lot of friends. And that was the way to learn and experiment. But honestly, I donΒ΄t think we will create the next Bell Laboratories with excel.
One of the most famous consultants in magnetics sells a magnetic design product based on excel. He has included macro functions and he feels like an astronaut. This is probably the fastest way of shortcutting the long road of science.
But we need to face it once and for all if we want to achieve Better Magnetics in a shorter period of time.
I invite you to understand the algorithms of your spreadsheets and use online tools to track the evolution of your designs. I would love to help you. No, Iβm not interested in your data or algorithms. Data from external sources is not valid for us, because in the scientific method, we need to have the same conditions for all the data points or we will destroy the models.
Next week I will talk about a metric to be used in the magnetic design.
Losses in the core with Zero Voltage
I wanted to end this edition with an interesting contribution of Jonas in his thesis. When he started breaking down the origin of the losses in the core and analyzing the existing models, he reviewed the state of the art and did measurements to verify it.
There are three main phenomena producing core losses.
Magnetization. The area of the typical magnetization curve (hysteresis loop) of a soft magnetic material represents the losses per cycle.
Eddy Current losses, originated due to the magnetic flux, generating an electric current, and finally losses.
Residual losses. (The rest of the effects)
When Jonas was doing the measurements, he realized a particular phenomenon affecting the losses. The variations of the off-time for similar duty cycles were increasing the losses.
Phases I and III are the only ones affecting the losses in theory. Nevertheless, Jonas and other researchers realized that during Phase II (zero voltage applied to the core), there are residual losses.
Therefore, he developed a further improvement of the iGSE that takes this eο¬ect into consideration
He was able to measure and check with other publications that effectively, there are losses during the zero voltage. In the picture below are shown loss measurements for different dead times, verifying this effect.
The duration of t1 (and t2 as complementary) should not inο¬uence the energy loss per cycle, but, as can be seen, increasing t1 (and decreasing t2) has a substantial inο¬uence on the energy loss per cycle.
Thatβs all folks! See you next week! My takeaway message for this week:
If you share my work, You are doing enormous support to this community. That means, accelerating the transition to an electric world.
To a sustainable World. Join us, Loving the Planet.
β οΈ Adversiting Alert
Frenetic Online is our software for:
Design your Magnetics with maximum accuracy
Build Samples
Connect with your suppliers and customers
We have launched a new subscription plan to join our community, with access to Training and round tables of experts (coming soon).
Write me to know about FO without compromiseπ.
We will end up talking about Pizza π and I would love it.
References
[1] Thesis of Jonas