Short circuit protection in DC/AC inerters

[adnan012]

Hi,

How over load and short circuit works in DC/AC inverters? Is is handled in software or hardware? How mosfets are protected during short circuit in AC inverter stage?

Regards!

 

[BradtheRad]

I found blown fuses when I opened my store-bought inverter, after carelessly hooking it up in reverse polarity to the car battery. The very sort of mistake that causes a short circuit.

There were four blown fuses, 20 or 30 amp, automotive blade-type. Replacing them restored the unit to normal function.

 

[andre_luis]

There is no general answer; for well behaved loads (e.g resistive, non hot-plugged) you could even think of using fast action fuses at the load side in addition with A,B curve circuit breakres - when affordable for the application. Any protection on the firmware side is mandatory to cut off the switching device when current exceeds expected value. Of course, we are talking about sampling the current on the shunt of the switching device as fast as possible, multiple times the mains frequency.