Hi,
As part of my degree thesis I am building a BLDC motor controller, on which I have a main thread which can be found at the end of this post.
I have made some calculations to determine what Hear losses I will have on the FETs. I found 2 application notes from infineon on which I calculated the heat losses based on my parameters.
Attached I have included a PDF which shows off step by step the calculations I made. I have also included an Excel file which shows the heat losses as a function of the Duty Cycle Used. The links to the application notes can be found in the PDF. Please note I am using the !20 degree switching strategy.
If anyone has the time, can you guys give a quick look to see if I made any mistakes in my methodology/calculations. Marked in red in the PDF is a parameter which I am not really sure about.
Here are the results I gathered:
Here are the losses at 30kHz switching frequency:
Here are the lossses at 10kHz switching frequency:
As can be seen with the reduced switching frequency, the high side mosfet losses improved significantly, however the low side mosfet losses were largely unchanged since the diode losses were dominant.
Hope some can confirm my work!
Feel free to use the excel files and date I have posted
Cheers!
Link to my Project:
https://www.eevblog.com/forum/projects/bldc-motor-controller-rc-snubber-design-waveforms/