A novel single-DC source self-balanced symmetrical capacitors voltage-based 5-level inverter topology with output voltage boosting capability for UPS application

This paper introduces a novel single-DC source five-level inverter, consisting of six switches, two diodes, and two capacitors. The proposed inverter achieves a five-level output voltage with a 2.0 times voltage-boosting capability relative to the input DC voltage. The capacitors in this configuration maintain equal voltage levels to the input, ensuring balanced operation without complex control mechanisms. The in-phase disposition pulse-width modulation (IPD-PWM) technique is employed to generate triggering pulses that maintain capacitor voltage balance. The natural voltage balancing inherent to this topology also simplifies the modulation algorithm. Key results from the study show that the proposed topology achieves a voltage boost factor of 2× while using fewer components compared to existing topologies. The inverter operates with a total harmonic distortion (THD) of 33.44 % in voltage and 1.58 % in current at the rated load. Efficiency is also enhanced, with the proposed topology demonstrating 97.69 % efficiency at maximum input voltage (250 V) and 97.17 % at minimum input voltage (50 V). The inverter is designed to operate at both low and high output power levels. The low output power is 82.8 W, while the high output power is 2096.25 W. Loss analysis and component value optimization (capacitor and inductor) were performed to maximize performance. These findings are validated through MATLAB/Simulink simulations and experimental prototypes using a TMS320F28379D controller. The results confirm the feasibility and robustness of the proposed inverter for UPS applications, as verified by a comparison of theoretical calculations, simulation outcomes, and experimental results.