how can constant current regulator maintains cocstant current in open circuit and short circuit cindition used in air ground lighting systems

May be it is a Constant Current transformer with Thyristor control. Bcoz of which the Prescribes Current is maintained.

Hello boby

A constant current generator controls the voltage applied to the load so that the current operates at the requried level. There are many way that this can be achieved.
There is a maximum voltage output, and if the impedance of the load goes too high, the current will be less than the required level becausse the voltage can not go high enough.
A constant current generator can not produce the required current into an open circuit because it would not matter what the voltage was, no current could flow into an open circuit until there was an insulation breakdown.

For example, a one amp generator will produce 1 volt into one ohm, 10 volts into ten ohms, 100 volts into 100 ohms. If the maximum output voltage was 200 volts, then if the loads was 200 ohms, there would be 1 amp. If the load was 400 ohms, there would only be 0.5 amps. - the generator is voltage limited at 200 volts.

Best regards,