Current limiting ballast for a transformer
You actually need a device with a non-linear response. Typically this would be a 100 watt incandescent light bulb. This would be in series with the 230 VAC power to the transformer.

If there is no arcing the current is low and the bulb is dim or not lit at all. When arcing occurs the bulb flickers and heats up, increasing resistance and limiting the current to the transformer to about 1/2 amp (with a 250 volt 100 watt bulb).

For more current simply put more lamps in parallel until you reach the maximum current you want. 2 bulbs would give you 1 amp maximum current. 4 bulbs would give you 2 amps maximum current.

You could use 200 watt bulbs but they do cost more and tend to have a short life. It depends on how many hours of arcing you want.