A digitally controlled linear power supply for HALF fast orbit correctors

Abstract

The fourth-generation synchrotron radiation source Hefei Advanced Light Facility (HALF) requires higher stability of the beam orbit. The corrector power supply with fast response and high stability can effectively reduce the latency of the Fast Orbit FeedBack (FOFB) system and improve the beam quality. In this paper, an FPGA-based, fully digitally controlled linear power supply based on H-bridge topology is proposed. Multiple buck circuits are cascaded as the front stage power supply, and the linear amplification of the H-bridge MOSFETs provides the power for the corrector load. The PI closed loop is calculated by the FPGA and finally drives the MOSFETs through the high precision Digital to Analog Converter (DAC) chip. As a result, the response bandwidth of the power supply can reach 5 kHz, and the long-term stability and current ripple are better than 20 ppm, which will improve the beam quality of HALF. The design can also be easily extended to other magnet power supply and fast power conversion technologies.