An FPGA-based Real-Time Simulation of a Hybrid Fuel Cell/Battery Source

This paper presents a new approach for the modeling and real-time simulation of an embedded hybrid power source comprised of a fuel cell (FC) and a battery. The proposed modeling is based on a state-space-like representation of the system equations obtained from the modified-augmented nodal analysis. Systematic formulation of system equations is presented and the solution to the non-linear equations are discussed. The proposed model was implemented on an entry level Field Programmable Gate Array (FPGA), and demonstrates sub-microsecond simulation time-step capability. The real-time solution is obtained by precomputing the system equations for all switch state combinations, and using the backward Euler integration scheme for solving differential equations. A fixed point number representation is utilized for speed and reduced configurable resource utilization. Our results show a high fidelity of the proposed model over a wide range of simulation time-steps and switching frequencies.