High-Stability and High-Precision Power Supply for Superconducting Coils of SC200 Cyclotron

The superconducting coils of SC200 cyclotron put forward strict demand for the accuracy and stability of power supply. In this paper, a rectifier-based constant-current power supply is presented for this application, which is composed of phase-controlled rectifier, pulse-width modulation (PWM) active filter and LCR passive filter. Low-frequency harmonics can be eliminated by passive filtering, while PWM active filtering device acts as the role of suppressing non-characteristic harmonics. Transfer function is studied in detail and the scheme of the power supply is simulated using MATLAB/Simulink software. The simulated and measured results both indicate that the proposed power supply meets the requirements of SC200 superconducting coils in terms of precision, stability as well as dynamic response.