Design and validation of a multilevel voltage source inverter based on modular H-bridge cells

Generation, power conversion and subsequent integration of renewable energy generation systems, such as solar photovoltaic or wind, require an efficient power conversion system that can provide sufficient quality energy according to technical standards (e.g. IEEE 519-2022). In this context, this paper focuses on the analysis, design and experimental validation of a multilevel voltage source inverter (VSI) scheme based on H-bridge cells with a modular and scalable structure for its application in power electronic converter circuits. The designed and assembled experimental setup is a versatile platform for testing experimentally varied control strategies and power converter configurations, such as the number of levels (3, 5, 7 levels) and phases (single-phase or three-phase). Therefore, the hardware design process proposed for the H-bridge cell and the measurement and conditioning circuits for voltage and current signals necessary for implementing the control algorithms are explained in detail. Moreover, a quantitative analysis of the operation of the design was carried out from measurements made with the experimental platform to verify its correct operation. Among the analysed parameters, the generated harmonics level stands out, quantified by calculating the total harmonic distortion and the mean square error between the reference signals and the measured values.