Abstract
One of the critical components in the high energy density pulsed power systems which are used to generate short high-voltage, high-power (10s MW to several GW), impulses is a gas filled plasma closing switch. In recent years significant research efforts have been aimed at finding environmentally friendly gases with advanced dielectric properties which can be used as substitution for SF6 [1] in the plasma closing switches. Several gases have been considered as potentially suitable alternatives including Zero Grade air, nitrogen, carbon dioxide and their mixtures. However, the lack of knowledge of their dielectric behaviour limits their practical applications as working fluids in the plasma closing switches. Therefore, further investigation of the dielectric characteristics of such gases is required in order to establish their applicability for practical use in high voltage high power pulsed power systems.
The present paper investigates the breakdown and pre-breakdown characteristics of Zero Grade air, N2, CO2 gases and Ar/O2 gas mixture. A dedicated two-stage plasma closing switch with highly divergent electric field has been designed and constructed (Figure 1). The sharp needle electrodes attached to the central trigger electrode are used to generate pre-breakdown non-thermal plasma (corona) discharges to achieve potential corona stabilisation effect. It was shown that the designed switch can operate under both positive and negative voltage stress. The operational characteristics of the switch has been obtained for all tested gases in the pressure range from 1 bar to 10 bar (absolute). The obtained results will help to identify gas type and pressure to achieve the optimal performance of the plasma closing switch.
The present paper investigates the breakdown and pre-breakdown characteristics of Zero Grade air, N2, CO2 gases and Ar/O2 gas mixture. A dedicated two-stage plasma closing switch with highly divergent electric field has been designed and constructed (Figure 1). The sharp needle electrodes attached to the central trigger electrode are used to generate pre-breakdown non-thermal plasma (corona) discharges to achieve potential corona stabilisation effect. It was shown that the designed switch can operate under both positive and negative voltage stress. The operational characteristics of the switch has been obtained for all tested gases in the pressure range from 1 bar to 10 bar (absolute). The obtained results will help to identify gas type and pressure to achieve the optimal performance of the plasma closing switch.
Original language | English |
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Number of pages | 1 |
Publication status | Published - 12 Oct 2017 |
Event | The 15th UK Technological Plasma Workshop - Coventry, United Kingdom Duration: 11 Oct 2017 → 12 Oct 2017 |
Conference
Conference | The 15th UK Technological Plasma Workshop |
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Country/Territory | United Kingdom |
City | Coventry |
Period | 11/10/17 → 12/10/17 |
Keywords
- plasma closing switch
- environmentally friendly gases
- dielectric properties