All too often I read on other forums of someone asking where he can get components and this is accompanied by a pic of a PCB with blackened burned out components.
As an electronics tech I would not recommend an inexperienced soul attempt something like this. Most companies supporting this type of equipment will not attempt to repair and either replace the module or scrap the complete inverter.
So insurance has it’s place…
Your normal CBI type surge arrester on the AC incoming side is basically all you can do. It will take any voltage above 275 volt to earth. That is the only quick fix protection you can install. We normally install DC surge protection on the PV side as well. Most insurances I have dealt with wants to see the surge protection stipulated on the COC, if not, they dont insure.
For the rest you have to rely on the inverter’s internal protection. Most of the inverters will only connect to the incoming AC, when ever the volts goes to high or to low the inverter will disconnect from it.