Abstract
A nowadays，on account of the problems of environmental pollution and exhaustion of energy sources become worse，To meet the economic activities of the increasing demand for energy ,the photovoltaic application has been a hot spot that most countries compete against each other to develop. As the main development trend of photovoltaic applications grid-connected photovoltaic system will certainly be promoted rapidly. A grid-connected PV is simulated by using C51as the main controller，application SPWM technology changes DC to Ac sine. Push-pull output circuit is used for maximum power point tracking (MPPT) function and protected push-pull output and the inverter circuit don't work. It can achieve synchronization with the grid frequency automatically. Also has under-voltage, over-current protection functions.
