Hardware-In-the-Loop Simulation of a High Frequency Interleaved Converter based on a Low-Cost FPGA Platform

Hardware-In-the-Loop (HIL) simulation is commonly used in multiple applications to validate control systems. Nevertheless, its application to high frequency power converters is particularly challenging due to the low time step required. This paper reports the setup of an HIL real time simulation bench, used to test the closed-loop control of a high frequency converter. A single phase interleaved bridgeless totem pole PFC running at a switching frequency of 100 kHz is simulated and driven by a C2000 microcontroller unit. The solver is based on a state-space representation and precomputed matrices, and implemented on a low-cost Artix-7 FPGA. Running with a time step as low as 50 ns, the simulation shows a good fidelity both in open-loop and closed-loop control. A detailed breakdown of error contributions is provided and analyzed in the frequency domain. Dynamic response analysis in closed-loop operation is also carried out comparing HIL results with an offline simulation and a small-signal model. The proposed bench shows the precomputed matrices method is reliable and accurate, with an excellent performance to platform cost ratio.