Nonlinear Behavioral Modeling and Real-Time Simulation of Electric Propulsion System for the High-Fidelity X-in-the-Loop Applications

The electric propulsion system (EPS) is an important enabling technology for electrified transportation. The short time-to-market of such a system relies on real-time simulation (RTS)-based efficient X-in-the-loop testing. To ensure high fidelity, the RTS should include the detailed behavior as much as possible while complying with the constraints of the model computing time. Therefore, a nonlinear behavioral real-time modeling approach is proposed for the EPS in this article, including the adaptive curve-fitting (ACF)-based device-level power electronics model and the nonlinear flux-linkage-based spatial harmonic (FLSH) PMSM model. The real-time models are designed and implemented on the NI FLEXRIO FPGA module. Ultralow RTS latencies are realized for the ACF power converter model and the FLSH PMSM model, which are 25 and 160 ns, respectively. The simulation accuracies are consistent with the off-line simulation tools. Moreover, the ACF model and the FLSH model are used in the RTS of a fuel cell electric vehicle (FCEV) EPS together with the generic fuel cell model, the battery model, and the vehicle dynamic motion model. The RTS results prove that the proposed EPS real-time model is an excellent candidate for RTS applications.