10-kV, 400-A, 10-kHz Solid-State Switch for Lightning Indirect Effect Test

The lightning indirect effect is the effect of magnetic field induced by lightning, and electrical devices frequently exposed to lightning require verification test against this effect. In order to simulate the lightning indirect effect defined in international test standards, a discharge switch to handle high-voltage and high-current pulses and to operate at high repetition rate is required. This article describes a solid-state switch achieving target simulated waveforms with a very simple structure. The two-pack module insulated gate bipolar transistor (IGBT) module is used for high-current discharge and six modules (12 IGBTs) are stacked in series to handle high voltage. Typical considerations for using a series-stacked structure include voltage balance, synchronized operation, and high-voltage insulation. To satisfy this, a special driving circuit using a high-voltage cable and a toroidal core was applied. Based on this, a totem pole structure-based gate driver that can be applied to a two-pack module was proposed, and it not only enables ON/OFF driving control but also includes a function to prevent self-turn with very simple structure. Through PSpice simulation and experiments, it was confirmed that the voltage balance and synchronized switching operation are achieved. Finally, the experiments to generate the simulated lightning indirect effect waveform were conducted and it was verified that the developed solid-state switch can output high voltage (over 10-kV), high-current (over 400-A) pulse, and operates stably under high repetition rate condition (over 10-kHz).