Plasma Sci. Technol.
  2019,Vol. 21(7): 74010-074010
  2018 National Conference on High Voltage and Discharge Plasmas
Dynamic dielectric recovery performance of serial vacuum and SF6 gaps in HVDC interruption and its regulation method
doi: 10.1088/2058-6272/ab1720
Dynamic dielectric recovery performance of serial vacuum and SF6 gaps in HVDC interruption and its regulation method
Xian CHENG (程显)1,2, Peiyuan YANG (杨培远)1,2, Guowei GE (葛国伟)1,2, Qiliang WU (吴启亮)1 and Wei XIE (谢伟)1,3
1 School of Electrical Engineering, Zhengzhou University, Zhengzhou 450001, People’s Republic of China
2 Henan Engineering Research Center of Power Transmission & Distribution Equipment and Electrical Insulation, Zhengzhou 450001, People’s Republic of China
3 Electric Power Research Institute, State Grid Henan Electric Power Company, Zhengzhou 450001, People’s Republic of China
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Abstract:

Vacuum gaps have rapid dynamic dielectric recovery speed while SF6 gaps have high insulation strength. The series-connected vacuum and SF6 gaps are used as the main switch (MS), which combines their advantages. The work aims to verify the feasibility of serial vacuum and SF6 gaps in mechanical HVDC interruption. The test circuit of the dynamic dielectric recovery performance (DDRP) is set up. The DDRP is tested under free recovery condition by the high voltage pulse source. The DDRP of the vacuum circuit breaker (VCB) and SF6 gas circuit breaker (GCB) in DC interruption with active current injection is analyzed and compared. The test results indicate that the dielectric recovery duration of the VCB is below 30 μs while that of the GCB is above 100 μs. In order to achieve the cooperation between the VCB and GCB, a novel hybrid HVDC circuit breaker (CB) based on series-connected vacuum and SF6 gaps is proposed. The ‘voltage-zero’ duration is created by introducing the follow current loop and there more recovery time for the dielectric recovery of the MS. The voltage distribution is controlled by the voltage dividing method so that the VCB undertakes the initial transient recovery voltage (TRV) and the later TRV is took by the GCB. The theoretical synergy characteristic of the novel HVDC CB is obtained. The paper supplies a new method to improve the custom mechanical HVDC CB, which is useful to achieve the HVDC CB with less serial breaks.

Key words: dielectric recovery performance,  vacuum interrupters,  SF6 interrupters 
Received: 13 November 2018    
Fund:

This work was supported by National Natural Science Foundation of China (Nos. 51407163, 51777025), National Rail Transportation Electrification and Automation Engineering Technology Research Center (No. NEEC-2017B07), and China Postdoctoral Science Foundation (No. 2017M622370).Key scientific research projects of colleges and universities in Henan(16A470014, 19A470008).