How to suppress overvoltage caused by lightning strikes on power DTUs?

Suppressing DTU lightning overvoltage requires a multi-stage surge protection network. The first stage uses a 2R600L-8×6 gas discharge tube with a current carrying capacity of 20kA. The second stage uses a 14D511K varistor with a clamping voltage of 510V. The third stage uses a TVS diode SMCJ24CA with a clamping voltage of 38.9V. Decoupling inductors (10μH) are used between each stage. A surge protection box is installed at the power line inlet, with a grounding resistance of less than 4Ω. The protection circuit response is verified through simulation to ensure effectiveness under an 8/20μs waveform. In actual testing, surge immunity testing (IEC61000-4-5) is performed, and the system should pass the ±4kV test. Suppressing lightning overvoltage protects equipment safety.