关键词: 载波移相, 同步整流, 双电流闭环负反馈, Buck 电路

Abstract:  ITER steady-state magnetic field test device can produce specific magnetic field conditions, so as to conduct steady-state magnetic field qualification test for experimental equipment entering ITER project site. Magnet power supply is a key component, which provides high-precision, stable and high current for steady-state magnet. This paper first introduces the basic topology of the steady-state magnet power supply with 13.5kA. On this basis, in order to improve the power efficiency, the synchronous rectification working mode is introduced, and then a dual current closed-loop control strategy is proposed, which is combined with the carrier phase-shifting modulation mode to reduce the load current ripple, ensure the good current sharing effect between each branch, and control the accuracy of the output steady-state magnet current within 0.5%. Finally, the simulation and experimental results show that the design of the steady-state magnet power supply system is reasonable. 

Key words: Carrier phase shift, Synchronous rectification, Double current closed-loop negative feedback; Buck converter