biswaIITH
Full Member level 4
Hello all,
Currently i am designing a 2.0kW Half-bridge LLC with center tapped secondary for EV Applications
Input Voltage:- 400VDC Nominal
Output Voltage;- 40 to 60VDC
Output Current:- 35A
Fs_min:- 91 khz
Fs_resonant:- 151 khz
fs_maximum:- 225khz (Short circuit protection limited)
I am operating the converter equal to or below resonance region(boost mode) under all normal operating conditions. The converter goes into above resonance mode (Buck Mode) under some input disturbances depending on overall gain.
I have designed a transformer using PQ 50/50(N97) from TDK. It is not an integrated design i.e. resonant inductor is separate.
Transformer Designed
Flux Swing(Delta B):- 0.22 T
Primary Turns:- 15 (38 AWG/450 strands)...Secondary turns:- 3 (16 mil copper foil)..
Winding Pattern
First Layer:- 8 turns primary(Almost half Primary)
Second Layer:- 3 turns secondary( One half of center tap config)
Third layer;- 3 turns secondary (Other half of center tap config)
Fourth layer:- 7 turns of primary(Other half primary)
I have calculated theoretical loss around 10W using iGSE(improved Generalized Steinmetz Equation) for core loss estimation & sinusoidal Dowell's curve for winding loss estimation.
Is the t/f winding pattern & core size ok???
I would request experienced design engineer to give suggestion to improve transformer design
Thanks
Currently i am designing a 2.0kW Half-bridge LLC with center tapped secondary for EV Applications
Input Voltage:- 400VDC Nominal
Output Voltage;- 40 to 60VDC
Output Current:- 35A
Fs_min:- 91 khz
Fs_resonant:- 151 khz
fs_maximum:- 225khz (Short circuit protection limited)
I am operating the converter equal to or below resonance region(boost mode) under all normal operating conditions. The converter goes into above resonance mode (Buck Mode) under some input disturbances depending on overall gain.
I have designed a transformer using PQ 50/50(N97) from TDK. It is not an integrated design i.e. resonant inductor is separate.
Transformer Designed
Flux Swing(Delta B):- 0.22 T
Primary Turns:- 15 (38 AWG/450 strands)...Secondary turns:- 3 (16 mil copper foil)..
Winding Pattern
First Layer:- 8 turns primary(Almost half Primary)
Second Layer:- 3 turns secondary( One half of center tap config)
Third layer;- 3 turns secondary (Other half of center tap config)
Fourth layer:- 7 turns of primary(Other half primary)
I have calculated theoretical loss around 10W using iGSE(improved Generalized Steinmetz Equation) for core loss estimation & sinusoidal Dowell's curve for winding loss estimation.
Is the t/f winding pattern & core size ok???
I would request experienced design engineer to give suggestion to improve transformer design
Thanks