Improved Hybrid FDTD Method for Complex Thin Wire Structures Inside Enclosure for Accurate Differential-Mode Prediction

This article focuses on calculating differential mode (DM) current in the star-quad cables located within an enclosure with a slit, using a modified hybrid finite difference time domain (FDTD) method. Traditional approaches fail to predict these currents accurately due to oversimplified assumptions about electrical parameters, which do not adequately capture the nuances of DM currents. Our improved hybrid FDTD model carefully considers the effects of terminal inductance, which is crucial for the accurate prediction of DM currents. To address real-world applications and enhance the scope of the study, the investigation has been extended to the bundle of the star-quad cables. As each star-quad cable contains four wires, the complexity increases significantly when multiple cables are bundled together. Determining common mode and DM currents is challenging due to the complex electromagnetic interactions that occur when multiple cables are bundled together. The results from our method show excellent agreement with those obtained from the commercial software FEKO, yet demonstrate superior computational efficiency in terms of both time and memory usage. This study highlights the importance of detailed electrical modeling in predicting electromagnetic behaviors in complex cable configurations inside metallic enclosures.