Development and testing of a 200kA, 10/350μs lightning impulse current generator switch module

A switch module assembly utilizing a power crowbar circuit and high-pressure plasma closing switch technology has been designed, constructed and tested. The switch module is the central block of a lightning impulse current generator under development, capable of producing a 10/350μs waveform at a peak magnitude in excess of 200kA (W/R = WMJ/Ω). The circuit consists of two separately charged capacitor banks, a fast start bank and a slow sustain bank responsible for the generation of the pulse wave-front and wave-tail respectively. These are switched in sequence to the load by means of two electrically triggered, graphite electrode high-action integral spark gap switches. The switch module assembly was tested for a number of different switch parameters and circuit operation modes. The produced output current pulse had a magnitude of 30kA for a start and sustain capacitor bank charging voltages of -40kV and +3.5kV respectively. In addition, the operational performance and trigger range characteristics of the two switches were investigated.