This paper presents the design and construction of a variable air-core inductor for lightning impulse current test on surge arresters. The designed inductance value of the developed air core inductor is in the range of 6.4 H to 50 H. To confirm the inductor design, it is employed in the impulse current generation circuit. In the experiment, the impulse currents were generated in the short-circuit condition and were injected to an arrester. The generated waveforms are compared with the simulation. Good agreement is observed. From the comparison of experimental and simulated results, it can be confirmed that the developed air core inductor can be used to adjust impulse current waveform to that according to the standard requirement efficiently.
