Measurement and analysis of two-layer sheets' shielding effects against transient field for pulsed power supplies

Pulse power supplies generate strong radiated electromagnetic interferences, which is significant at the front of air-core reactors that could probably jeopardize surrounding devices and staff. For limiting this interference around air-core reactors, we performed experiments with shielding sheets and analyzed the results of theoretical analysis and numerical calculations. Firstly, we developed shield plates and used them in experiments of radiated field reduction. The plates had two layers made of different materials, namely duralumin and steel rolling plates. Then using commercial FEA calculation software, we calculated the shielding effect and the influence of the shield sheets on power supplies by taking power supply circuits into consideration, and obtained some results regarding the structure and material of shield sheets. Comparison between the experimental results and simulation indicates that the reduction of radiated field mainly comes from material with high conductivity, while the material with low conductivity supports the structure mechanically. With shield sheets, the amplitude of radiated field's magnetic induction is reduced by more than 90 percent, indicating that the proposed method is effective for limiting radiated electromagnetic interferences.