Abstract: In allusion to voltage fluctuations at point of common coupling (PCC) caused by photovoltaic generation system (PVGS) connected to distribution network, this paper launches a comprehensive study on factors that affect the PCC voltage variations, using typical examples to quantitatively analyze and sum up the laws. It is expected to make full use of the capacity of PVGS, and optimize the distribution of active and reactive output of PVGS to improve PCC voltage quality. On this basis, two strategies are proposed. One is a reactive setting strategy for suppressing voltage fluctuations under different active output conditions with allowable voltage deviation. Another is for maximizing PCC voltage support under voltage sags. These strategies could suppress PCC voltage fluctuations as active output fluctuating violently and increase PCC voltage under voltage sags. The simulation verifies the validity and feasibility of the proposed strategies.