This paper proposes a novel 7-level switched capacitor multilevel inverter (SC-MLI) topology with soft charging capability and analyzes the performance in terms of efficiency and component optimization. The proposed structure achieves high efficiency up to 97.32% while producing the same output level with fewer components compared to existing SC-MLI designs in the literature. Moreover, the total cost function (CF) value of 3.26 is among the lowest values, indicating that the system offers an economically advantageous solution. Simulation and experimental studies confirm that the system generates stable output waveforms under resistive and inductive loads and operates stably over a wide frequency and modulation index (MI) range. In particular, the effect of the soft charging technique on capacitor currents has been investigated and it has been found that this technique minimizes switching losses by reducing inrush current transients. The SPWM method using high switching frequency produces a natural soft charging effect on the capacitor currents, producing lower peak currents compared to NLC control and improving the overall efficiency of the system. The study shows that SC-MLI is optimized as a function of low component count, high efficiency and low cost. The results reveal that this structure is suitable for high-performance applications such as renewable energy systems, electric vehicle power conversion systems, uninterruptible power supplies (UPS), microgrids, and motor drives. These findings provide an important reference for the future development of SC-MLI designs.

This paper introduces an innovative multi-level inverter (MLI) topology operating with a single DC source. The proposed structure consists of a DC-DC rectifier (HFL), a switched capacitor (SC) unit and a Packaged U-Cell (PUC) module. The topology synthesizes 17 voltage levels at the output with only 10 power switches, offering low control complexity and high power efficiency. The high number of levels at the output voltage provides a high quality output voltage wave. A soft charging cell (SCC) is used to suppress impulsive charging currents in the switched capacitors. Experimental results show that SCC effectively suppresses impulsive currents in switched capacitors. The high frequency link (HFL) used to provide high voltage gain improves the cost efficiency of the system by reducing transformer sizes and costs. Simulation and experimental results show that the proposed topology achieves 96.92% efficiency, near sinusoidal current output and total harmonic distortion (THD) values between 4.99% and 1.23%. Moreover, with a low cost function (CF) value of 1.60, it is proven to offer a viable alternative for applications such as Renewable Energy Systems (RES) and Electric Vehicles (EVs). These findings demonstrate the applicability of the proposed MLI topology in these areas with low cost, high efficiency and quality power output.