The Average Modeling of Active Neutral Point Clamped (ANPC) Converters

To simplify the representation of power electronics converters, the average modeling emerges as a promising solution as it eliminates the detailed switching behavior of individual components, yielding a model characterized by reduced complexity and focused on the fundamental dynamics of the converter. This paper aims to advance the average modeling of active neutral point clamped (ANPC) converters. The model configuration is like two-level average models with bipolar dc-link, circumventing unnecessary complexities in modeling. The dependent sources' magnitude is calculated by multiplying the phase duty cycles and the same phase ac-side current or dc-link capacitor voltages. Although it is represented for the five-level ANPC inverter, the model maintains its validity for the ANPC configuration of any level, in that not any parameter from the flying capacitors within phase legs appear in equations when the converter is modeled at its terminals. Sufficient information is still preserved to model the voltage of flying capacitors, as discussed in the paper. The properness of the proposed model is proved by simulation in MATLAB / Simulink, where the results from the switch model are compared to those from the proposed average model to verify the accuracy of the model.