The high-voltage DC acceleration grid power supply (AGPS) is an important component of the negative-ion-based neutral beam injection (NBI) system in large fusion devices. The fluctuation of its output voltage affects the divergence of the ion beam, which in turn affects the heating efficiency of the system. The AGPS output voltage ripple is affected by many factors. This article analyzes the correlation between the DC bus voltage ripple and the output voltage fluctuation. Based on the original circuit topology, the limitations and deficiencies of the original scheme and existing research were analyzed. The DC bus voltage ripple was taken into account in the high-voltage DC power supply. And the state space averaging method was used to construct a small signal model to get the transfer characteristics, it is concluded that the output voltage fluctuation of the AGPS is greatly affected by the fluctuation of the DC bus 10~10kHz ripple.

accelerator grid power supply,voltage ripple,state space averaging method,small signal model,transfer characteristics