Power Converter Half-bridge Models in the Light of Real-time FPGA Implementation

Real-time Hardware-In-the-Loop (HIL) simulation tools used at various levels in the development of modern power electronics are inevitable, either testing the control board implementations with signal-level simulators or validating the power converters with power HIL solutions. The high computational power of FPGA devices used in HIL tools offers many advantages, but the developers have to make a trade-off between the precision of HIL models and the resources required by the realization. The half-bridge is the building block of many power converters, its efficient real-time model is useful in the development of HIL simulators of more complex systems. In this paper the advantages and disadvantages of real-time models of the half-bridge are studied. The simple switching function model, the more complex but widely used Associated Discrete Circuit (ADC) model, and a PI controller based model with enhanced Discontinuous Conduction Mode (DCM) emulation are compared.