A New 19-Level Switched Capacitor Multilevel Inverter With Self-Managing Voltage Balance

This paper introduces a novel single-phase multilevel inverter utilizing a switched-capacitor technique that generates 19-levels while minimizing component count to 12 switches, three diodes, two DC sources, and three capacitors. For the gate driver, a compact gate driver designed and all gate drivers powered with only one DC source. A significant challenge in switched capacitor multilevel inverters (SC-MLIs) is charge balancing across capacitors, especially at low values of the modulation index; however, the proposed design effectively self-manages this balance, eliminating the need for complex control circuits. Increasing the output levels significantly reduces harmonic distortion, particularly at lower modulation indices. Performance evaluation against existing SC-MLI configurations shows that the proposed 19-level inverter experiences lower total stress voltage (TSV) on its switches, enhancing reliability. The staggered application of voltage sources allows switches in each stage to operate at lower duty-cycle fractions, enabling the use of less expensive, lower-rated switches. Validation through laboratory prototyping and PLECS simulations confirmed an efficiency of 96.3% at a power output of 500 W. Additionally, high-frequency modulation techniques can effectively shift undesirable harmonics to higher frequencies, which can be filtered out with smaller component filters. The inverter meets stringent IEEE standards for total harmonic distortion (THD), confirming its suitability for dynamic voltage restorers and distributed generation systems, thereby enhancing power conversion in renewable energy applications.