#36 🚀 Dual Active Bridge Transformer 400V/24V 600W

SuperPowers for Electrical Engineers

May 29, 2022

👋 Hello Supergineers! Dr. Molina here! 👨‍🔧

Today I’m going to simulate, design, and build a Dual Active Bridge Transformer. In this process I will bring you a NEW FRENETIC SUPERPOWER:

Free Online Circuit simulation!!!

Next 2nd of June we will release our Online Simulator at frenetic.ai, which will be Free!!

Let’s start!!

Dual Active Bridge Design

Specs:

Vin = 400V
Vout = 20 to 28 V (24 Vnom)
Pout = 600W
Lmag = 3000 uH
Lserie= 130 uH

The values of Lmag and Llk are calculated previously, which I’m not describing today, however, if you need support, in the Technical Support of Frenetic we can help you with all these calculations.

Circuit Simulation

At our Online Circuit Simulator, based on Simba Technology, there is already a template of Dual Active Bridge, therefore, I just need to include the values of

Vin=400V
Turn Ratio= n2/n1=0.1
Rload = 1.04 ohm
Lmag=3000 uH
Lserie =130 uH
Values of Rds=5mohm, Vdiode=1V

I played with the phase shift until I got the output voltage and current desired using the two scopes and the measurements of the waveforms.

Ok, once I have the simulation as I expect, I will start the design of the transformer.

Transformer Design

I push this buttom, which will automatically download the waveforms of the transformer to be uploaded to Frenetic Online.

This is the bottom to upload the CSV file created in the circuit simulator and the waveform of the transformer appears, together with the rms, peak values...etc.

Once I had everything in Frenetic Online, together with the Senior Engineer Marcos Luna, who lead the decisions, we ended up in the following design.

We didn´t ask for suggestions, we went directly to design manually (Oh mama!).

We choose a PQ40/40 3C95 and we tested a different number of turns until we decided to move to 20 turns in primary. The goal was to move as many losses to the core as possible. Honestly, I feel much more confident controlling the losses in the core than in the winding. In the following link, you can see all the details.

Link to the design

Here you can see the details of the core selection and primary turns.

For the windings, we moved to an interleaving option using Litz wire in primary and secondary. Even with interleaving, due to the disposition, we have 10 uH of Leakage inductance, which means, we will need an AC inductor of 120 uH in series with the transformer.

Primary details

Secondary details

Go to the LAB!!

My favorite part is moving to the lab. Asking for samples, the technical engineer at Frenetic will verify the feasibility of manufacturing the component. Once the process is done, you will get the samples.

Here you can see the sample received 🚀🚀🚀

and the hardware results in the setup of the Frenetic Lab and the temperature measurements.

LINK to the Design

Here you have the link to see the details of the design.

If by causality, this design fits in your converter, we can provide samples 🥳.

🎁 SPECIAL GIFT FOR FRENETIC NEWSLETTER READERS 🎁

The last session of our High-Frequency Magnetics Training program will start on June 1st. We have still some available seats and we want to give the chance to some of our newsletter readers to participate under special conditions: a 25% discount 😱

All the info about the Training Program is here.