Impact of the Converter Controller on Power Hardware-in-The-Loop Testing Stability and Accuracy

Power electronics play a crucial role in integrating renewable energy sources into modern power systems. To ensure their reliable deployment, advanced testing methods such as Power Hardware-in-the-Loop (PHIL) are essential for evaluating their behavior under realistic grid conditions. This paper investigates the impact of the Hardware of Interest (HoI)—a three-phase grid-following DC/AC converter—on the stability and accuracy of PHIL setups. A loop-based transfer function model is developed to represent the PHIL system, including the HoI dynamics, power interface, and real-time simulator. Using this model, a sensitivity analysis is performed to examine how the converter's control parameters—particularly the current controller bandwidth—affect PHIL stability and accuracy. Perturbation-based frequency-domain scans are conducted in MATLAB/Simulink and experimentally validated on a 45 kVA PHIL platform.