Modified W-type configuration for a single-phase reduced parts count 81-level inverter

Area of Science:

• Electrical Engineering
• Power Electronics
• Renewable Energy Systems

Background:

• Modern power systems are integrating renewable energy sources, increasing demand for efficient power electronic converters like inverters.
• Existing multilevel inverter (MLI) topologies often require output filters or excessive hardware for high voltage levels.
• Photovoltaic (PV) systems require reliable grid integration solutions.

Purpose of the Study:

• To introduce a new single-phase 81-level inverter topology, the Modified W-Type Multilevel Inverter.
• To demonstrate a reduced component count and filter-free sinusoidal output for grid integration.
• To provide design equations and validate the proposed inverter's performance.

Main Methods:

• Development of the Modified W-Type Multilevel Inverter configuration.
• Derivation of general design equations for switches, voltage levels, and DC sources.
• Simulation using MATLAB/Simulink and hardware prototype validation.
• Loss, efficiency, and total harmonic distortion (THD) analysis.

Main Results:

• The proposed inverter achieves an 81-level output voltage with only 18 power switches and 4 DC sources.
• Output voltage THD is 1.04%, meeting grid integration standards without an output filter.
• Comparative analysis shows reduced parts count and higher voltage levels compared to existing MLI topologies.
• Practical efficiency analysis confirms good performance during dynamic operation.

Conclusions:

• The Modified W-Type Multilevel Inverter is an effective and novel solution for renewable energy grid integration.
• The topology significantly reduces hardware requirements while achieving high-quality output.
• The proposed inverter meets grid code requirements for THD without external filtering.