Electronic – How to place two inductors on the pcb? Which is better: example A, B or C

inductorlayoutrectifier

I'm making a single phase pwm rectifier as my final year project. General topology consist of an inductor that connects ac voltage source with an inverter, as in the picture below:

pwm rectifier circuit

But since this is a prototype I decided to add the second inductor, so it will be easier for me to adjust the inductance and do tests. Also have heard the second choke is often used for EMC reasons.

So, my question here is, which placement in the pcb in such circut is correct/better? Note that pictures below are some random pcbs from the Internet, the only thing that matters is the inductors placement on the pcb.

Example A:enter image description here

Example Benter image description here:

Example C: enter image description here

Best Answer

Consider winding L1 and L2 on the same core and including X and Y capacitors which essentially form an EMI filter. You have two optimization goals. You'd want the components as close as possible to the switches in order to minimize parasitics that will affect switching waveforms, while making sure magnetic field produced by the inductors is small and negligible and won't affect the switches. This would require simulation or hand calcs and knowing the core material and current going through the inductors.