ABSTRACTThis brief presents a modeling approach for a nonlinear series resistor–inductor–diode (RLD) circuit powered by either a direct or alternating voltage source—a configuration commonly encountered in power electronics and energy conversion systems. Due to the diode's nonlinear current–voltage characteristic and the inductor's dynamic response, the circuit is governed by a nonlinear differential equation. Because this equation lacks a closed‐form analytical solution, a novel approximate solution is proposed by applying a g‐function. This method enables accurate and robust computation across various operating conditions without relying on piecewise approximations or purely numerical solvers. The results are verified through MATLAB/SIMSCAPE simulations, demonstrating excellent agreement. Additionally, the MATLAB code is provided to support reproducibility and further research.
