title: Characteristics of a symmetrical Cockcroft-Walton power supply of 50 Hz 1.2 MV∕50 mA.
abstract: A 1.2 MV∕50 mA symmetrical Cockcroft-Walton (SCW) power supply of over 83% power efficiency, driven by 50 Hz frequency, was developed for an industrial electron beam irradiator. It is constructed by capacitors of 45 nF and 28.13 nF in the coupling column and capacitors of 18.75 nF in the smoothing column. Working status of the rectifier in high power output condition was analyzed, and the conduction angle of the rectifier was calculated. The power factor (PF) of the SCW circuit has been studied, and the equivalent condensance of the circuit has been derived. Measurements were done for the PF compensation. The surge impact during the short circuit transient process was considered in choosing the protection resistance. Test results showed that design specifications of the power supply were achieved, with the non-load voltage being up to 1.32 MV and the ratio of ripple voltage to output voltage as 9.4%.
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China. hezifeng@sinap.ac.cn
authors.forename: Zi-Feng
authors.initials: ZF
authors.lastname: He
authors.forename: Jin-Ling
authors.initials: JL
authors.lastname: Zhang
authors.forename: Yong-Hao
authors.initials: YH
authors.lastname: Liu
authors.forename: Yu-Tian
authors.initials: YT
authors.lastname: Zhang
authors.forename: Yin
authors.initials: Y
authors.lastname: Zhang