A new single-phase cascaded multilevel inverter topology using an H-bridge inverter is proposed to reduce the number of active components and improve power quality. The topology is comprised of two or more cascaded H-bridges to increase the number of voltage levels and power handling capability. The basic unit of the proposed inverter is comprised of a voltage-level generator (VLG) connected to the input of the classical H-bridge. The main advantage of this setup is a significant reduction in the number of switches and voltage sources required to generate the desired number of voltage levels. As a result, the output power quality, cost and size are significantly improved. To verify the benefits of this topology, in a more complete way, both the symmetric and asymmetric configurations are investigated. MATLAB/Simulink models for symmetric 9-level and asymmetric 31-level cascaded multilevel inverter configurations are used to validate the performance of the proposed topology, and satisfactory results are reported.

The increasing integration of large solar PV and wind farms into the power grid has fueled, over the past two decades, growing demands for high-power, high-voltage, utility-scale inverters. Multilevel inverters have emerged as the industry’s choice for megawatt-range inverters because of their reduced voltage stress, capability for generating an almost-sinusoidal voltage, built-in redundancy and other benefits. This paper presents a novel switched-source multilevel inverter (SS MLI) architecture. This new inverter shows superior capabilities when compared to existing topologies. It has reduced voltage stress on the semiconductor, uses fewer switches (i.e., reduced size/weight/cost) and exhibits increased efficiency. The proposed SS MLI is comprised of two voltage sources ( $V_1,V_2$ ) and six switches. It is capable of generating five-level output voltage in symmetric mode (i.e., $V_1=V_2$ ) and seven-level output voltage in asymmetric mode (i.e., $V_1\ne V_2$ ). We present simulations results (using MATLAB^®/Simulink^®) for five- and seven-level output voltages, and they strongly support the validity of the proposed inverter. These positive results are further supported experimentally using a laboratory prototype.

The past two decades has seen a growing demand for high-power, high-voltage utility scale inverters mostly fueled by the integration of large solar PV and wind farms. Multilevel inverters have emerged as the industry choice for these megawatt range inverters because their reduced voltage stress, capable of generating an almost sinusoidal voltage, in-built redundancy, among others. This paper present a new Switched-Source Multilevel Inverter (SS MLI) architecture. The new inverter show superior over existing topologies. It has reduced voltage stress on the semiconductor, uses less number of switches –reduced size/weight/cost and increased efficiency. The new SSMLI is comprised of two voltage sources (V₁, V₂) and 6 switches. It is capable of generating 5-level output voltage in symmetric modes (i.e., V₁ = V₂), and 7-level output voltage in asymmetric modes (i.e., V₁ ≠ V₂). To demonstrate the validity of the proposed inverter, simulations results using MATLAB^® /Simulink^® for 5- and 7-level output voltages are presented . The simulations are also verified experimentally using a laboratory prototype.