3 phase power inverter, 20V 5A

[Vinrys]

Hi, I am currently working on a project of 3 phase power inverter. The requirements are for it to be 20V input and 5 A output max. Now I have a few questions:

1) IR2110 components
I have a knowledge about bootstrap capacitor, why is it used etc. But in datasheet there are other capacitors (marked at the picture). Are they used to lower supply voltage fluctuations?

2) Voltage supply for drivers
Right now I have designed separate input pins for each driver, but since our supply voltage is 20V can I use it also to supply drivers (via connecting them on pcb). I will attach drawing of my circuit.

3) Transistors
Is IRF1404 right for the application? Its Vdss is 40 V and Vgs is 20 V so for me it seems so. What is disturbing is possibility for high Id (162 A). I know we want reach that amount but still, maybe there are other transistors better suited for this application.

4) PCB trace width
I am searching for reliable formula for trace width. All I am seeing online are caltulators but I would like to know why and how. Best I have seen is this (attached file nr 3) but i wanted to see if its correct.

Also if you have any tips about pcb overall I would highly appreciate them. Thank you for your help.

 

[betwixt]

I think you need some significantly fatter tracks on that PCB and a good ground plane would be highly advisable.
Where does the VB boost voltage come from?
Also consider the placement of the heat sinks, if you use a sheet metal heat sink it may intersect R2/R4/R6.

Brian.

 

[KlausST]

Hi,

IR2110 are one of the most discussed topics here. Please read through the exiting threads. They answer (almost) everything you ask for.

I´ve answered in many threads already ... the same again and again.

In short: Switching power applications is not a task for beginners. There are so many different things to care for.
Solid GND plane, hight current, sometimes high voltage, high frequency (caused by high dV/dt and dI/dt), trace impedance, trace resistance, signal loops, loop area...
If you are not familiar with the above topics, then you risk to get your electronics to kill itself (by ringing and spikes) often long term killing over weeks or months, but it may end in explosion and fire. Another problem is EMI/EMC ..which makes your application illegal to be operated.

Klaus

 

[murus]

And as always - not a single blocking capacitor on the power supply terminals of the IC.
Immediately after switching on, black smoke will come out from the board

 

[D.A.(Tony)Stewart]

Are we to assume Vout, Hz , Tmax p.f. , Psurge, 4kV isolation?
If > 1kW I understand the unit must have unity p.f. and of course EMC requirements.
Do you know where to look up trace temp rise with current? (Saturn PCB tools) And how to create air gaps for isolation.

Do you know how to define load regulation by transforming load to source? If 1% Vout/Imax on output what impedance do you think that needs at primary?