I'm trying to design a grid tie inverter.
I have designed a 4-layer PCB and I have a few questions about the layout and grounding.
I have been closely following this reference design but I'm using ordinary MOSFETS (STF35N60DM2.) My plan is to add in the microcontroller board to the header on the PCB here.
The 360 V DC bus is provided by a separate isolated supply and enters into J2 on the right of the PCB. I also have an isolated 16 V DC supply which enters into J1 on the left and provides power for all the logic and gate drive.
I have Hall effect current sensing on both phases, I have voltage sensing on both phases and I have a DC bus voltage sense. All these traces run back to the microcontroller unit.
In the reference design, they use a split ground (power ground and logic ground) with a single connection point. I have so far copied this but am wondering whether it'd be better to have a single ground plane.
The power components are all kept on the right of this PCB. With the split ground design, I'm concerned about the gate drive currents (that keep the bootstrap capacitors charged) causing interference on the analogue voltage and current sense readings.
Can someone offer advise about my layout and grounding choices?
There must be an optimal way of doing things. Is it ok to run my sensing traces like I have done?