1682 IEEE TRANSACTIONS ON PLASMA SCIENCE, VOL. 38, NO. 7, JULY 2010 Experimental Study of Anode Activities in High Current Vacuum Arc Subjected to Axial Magnetic Fields Under Different Conditions Lijun Wang, Liuhuo Wang, Shenli Jia, Member, IEEE, Zongqian Shi, Dingge Yang, and Yu Liu Abstract—In this paper, high current vacuum arc (HCVA) char- acteristics and anode melting pool (AMP) ﬂow phenomena under different conditions are researched and analyzed. Particularly, rotation phenomena of AMP are observed and analyzed. First, the inﬂuence of different arc currents on arc column and anode ac- tivities is researched. Experimental results show that the rotation phenomena of AMP become more signiﬁcant when arc currents are very high. Then, the inﬂuence of electrode conﬁgurations on the AMP rotation is investigated. For larger h/D value electrode, vacuum arc can become more unstable and uncontrollable, the ro- tation of anode melting region cannot be found; for smaller h/D, the vacuum arc is more stable and the vacuum arc is controlled effectively by the axial magnetic ﬁeld (AMF), also signiﬁcant rotation of AMP has been found. For a smaller anode electrode, anode melting and rotation of AMP is more serious, which is due to the same energy inputs smaller electrode. Finally, the inﬂuence of pure Cu and CuCr30 electrode on anode melting and ﬂow is compared and analyzed. Experimental results show that AMP rotation with pure Cu material is more signiﬁcant than that with CuCr30 material for the same arc current interruption. Liquid macroparticles’ diameters with pure Cu electrode are signiﬁcantly larger than that with CuCr30 materials. Index Terms—Anode melting pool (AMP) ﬂow, axial magnetic ﬁeld (AMF) electrode, experimental research, vacuum arc. I. I NTRODUCTION V ACUUM ARC has widely appeared in many ﬁelds, such as vacuum interrupters [1], [2], vacuum arc thrusters [3]–[5], vacuum arc remelting [6], ﬁlm deposition [7], [8], and so on. At present, the internal mechanism of vacuum arc is still not very clear, particularly for the high current vacuum arc (HCVA), and needs to be further researched. For an HCVA subjected to an axial magnetic ﬁeld (AMF), when the breaking current reaches a certain level, the anode will become active due to the intense heat ﬂux density from arc column. Anode mode in vacuum arc has been reviewed by Miller [9], which Manuscript received February 11, 2010; revised April 2, 2010; accepted April 22, 2010. Date of publication June 1, 2010; date of current version July 2, 2010. This work was supported in part by the National Natural Science Foundation of China (Project numbers:50907045 and 50707022) NCET-06- 0830, in part by the State Key Laboratory of Electrical Insulation and Power Equipment (EIPE10306), and in part by the Doctoral Fund of Ministry of Education of China (200806981052 and 20090201110015). The authors are with the State Key Laboratory of Electrical Insulation and Power Equipment, Xi’an Jiaotong University, Xi’an 710049, China (e-mail: lijunwang@mail.xjtu.edu.cn). Color versions of one or more of the ﬁgures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identiﬁer 10.1109/TPS.2010.2049666 includes diffuse arc mode, footpoint mode, and anode spot mode. Herberlin and Gorman [10] observed more detailed vacuum arc modes: diffuse arc, diffuse column, constricted column, jet column, and anode jet. For jet column and anode jet modes, the interaction between anode jet and cathode jet becomes more signiﬁcant. Toya et al. [11] thinks the anode discharge mode will inﬂuence not only current distribution in arc column, but also the bunch of cathode spots. There are many experimental investigations about vacuum arc under AMF. Typical experiments have been conducted by Chaly et al. [12], S. Jia et al. [13], [14], W. Shang et al. [15], [16], Taylor et al. [17]–[19], Hartmann et al. [20], [21], Lindmayer et al. [22], [23], Yanabu et al. [24], [25], and Schellekens [26]. In [12]–[14], the inﬂuence of AMF dis- tributions on HCVA appearances and electrode erosions has been paid more attention to; their research results showed that Saddle-shaped AMFs were better than Bell-shaped AMFs to control vacuum arc. In [15]–[19], the transition of arc modes (diffuse vacuum arc, diffuse column arc, and multiple cath- ode spots arc) are researched and analyzed. Hartmann et al. paid more attention to HCVA at larger gap distances in [20]. They also paid more attention to cathode spots phenom- ena and dynamic vacuum arc structure under AMF in [21]. Lindmayer et al. paid more attention to the phenomena near current zero regions [22], [23]. Yanabu et al. have discussed the application of vacuum arc under AMF technology in the high-voltage power system [24]. They also have researched the inﬂuence of different electrode materials on interrupting capability [25]. In the above researches, some papers also paid attention to anode melting. However, the ﬂow of anode melting pool (AMP) under intense arc energy was seldom paid attention to in the above papers. Schellekens [26] has researched and analyzed the ﬂow of AMP, but only described the radial ﬂow of liquid; they also explained the disparity between larger melting area of the anode and smaller light diffuse column arc appearance through the analysis of AMP. Recently, for vacuum arc under AMF (pure copper electrode), the interesting phenomena of AMP rotation have been found [27], but single condition (single electrode conﬁguration and single electrode material) is adopted in the experiments. Anode activity also has been researched by many researchers based on modeling technology [28]–[31]. In this paper, in order to further research AMP rotation phenomena, arc behaviors and anode activities under different electrode conﬁgurations and electrode materials will be paid attention to. 0093-3813/$26.00 © 2010 IEEE Authorized licensed use limited to: University of Maryland College Park. Downloaded on July 23,2010 at 01:54:34 UTC from IEEE Xplore. Restrictions apply.