Design of the protection system of the inverter used for the photovoltaic system

When an inverter used for the photovoltaic system is running, all kinds of protection need to be taken into account, so that it can act in time and properly. Overload current protection and short circuit current protection are considered especially in this paper. When short current occurs, short circuit current protection closes off SPWM wave in time, and anti time limit protection enables the system to bear overload for a moment. The hardware protection has the high speed character; it includes low voltage protection and short circuit current protection. The software protection has flexibility; it includes overheat protection, overdischarge protection, overload protection.