Modular Converter Modeling With Cascaded Controllers for Enhanced Renewable Energy Integration

This paper introduces an average model tailored for a modular system and explores its implementation in renewable energy applications. The system under investigation features a modular configuration built upon a three-level boost converter architecture. In this setup, capacitors are arranged in series to generate several distinct voltage levels. Control of the source current and balancing capacitor voltages are essential. Additionally, precise control of the output voltage is required. A cascaded control structure is employed to address these requirements, consisting of an inner current loop with voltage balancing and an outer loop. The inner loop utilizes indirect-sliding mode control, while the outer loop employs energy control. The proposed model is developed through the formulation of system equations that encompass stage power dynamics, an indirect sliding-mode controller, and an energy management controller. The system is then simulated using MATLAB, and its eigenvalues are examined to assess dynamic behavior. Experimental findings are presented to confirm the accuracy of the simulation outcomes.