A time-efficient modeling and simulation strategy for aggregated multiple microinverters in large-scale PV systems

This paper presents a time-efficient modeling and simulation strategy for aggregated microinverters in large-scale simulations, with a 20-panel system used as an example. As the microinverter configuration emerges to overcome reliability and loss mismatch issues in centralized PV inverters, a model that can be used for rapid prototyping is required. This model is also helpful in predicting behaviors of individual microinverters in a large-scale system, e.g., power generation under partial shading conditions and harmonic interaction. Dynamic microinverter models that include switching action may not be suitable for simulating multiple microinverters as they yield a significant computational burden and long simulation time compared to simplified but accurate average models. This paper introduces the average model of a basic microinverter composed of a boost stage and an H-bridge represented by a single matrix form aggregation of multiple microinverters in a larger system to achieve faster simulation times with accurate transient and steady-state results. A 200W prototype microinverter board is tested to verify the proposed average and dynamic models. Furthermore, MATLAB/Simulink is used to show the improved simulation speed and accuracy in the multiple-microinverter configuration.