  Railway Wireless Power Transfer (WPT) is a promising non-contact power supply
solution, but constructing prototypes for controller testing can be both costly
and unsafe. Real-time hardware-in-the-loop simulation is an effective and
secure testing tool, but simulating the dynamic charging process of railway WPT
systems is challenging due to the continuous changes in the nonlinear magnetic
coupling components. To address this challenge, we propose an FPGA-based
half-step implicit-explicit (IMEX) simulation solver. The proposed solver
adopts an IMEX algorithm to solve the piecewise linear and nonlinear parts of
the system separately, which enables FPGAs to solve nonlinear components while
achieving high numerical stability. Additionally, we divide a complete
integration step into two half-steps to reduce computational time delays. Our
proposed method offers a promising solution for the real-time simulation of
railway WPT systems. The novelty of our approach lies in the use of the IMEX
algorithm and the half-step integration method, which significantly improves
the accuracy and efficiency of the simulation. Our simulations and experiments
demonstrate the effectiveness and accuracy of the proposed solver, which
provides a new approach for simulating and optimizing railway WPT systems with
nonlinear magnetic coupling components.
