Wavelet-Based Time-Domain Solutions for Common-Mode Currents on Open-Form Conductors Modeled With Band-Limited Scattering Parameters

One of the technical challenges of future naval surface combatants in utilizing medium-voltage dc distribution systems is common-mode coupling and galvanic isolation for managing faults and personal safety. The behavioral modeling reported in this paper is computationally efficient to be used in modeling distributed common-mode currents and potentials throughout the open-form conductor, which in this case is the ship structure. Physics-based modeling is used to form a multiport S-parameter behavioral model of the ship structure that complements the S-parameter models of parasitic paths to grounded equipment enclosures and cables sheaths. A time-domain common-mode conduction example is presented to illustrate the workflow that converts physics-based models of elementary hull elements into a complete S-parameter behavioral model of an arbitrary hull structure with power cables running along it. Because of the measurement and the simulation bandwidth limitation, the frequency domain model based on S-Parameters is band-limited. A novel approach for reconstructing the system impulse response in the time domain from its band-limited S-parameter model is introduced using continuous wavelet transform utilizing fast Fourier transform.