Advancements in Renewable Energy Grid Connections: A Review of Multilevel Inverter Topologies

Strategic Insights -

Researchers at the University of KwaZulu-Natal have published a comprehensive review of multilevel inverter topologies and control strategies for grid-connected photovoltaic battery energy storage systems integrating active power filters. The study aimed to improve power quality, scalability, and fault diagnostics in large-scale PV and battery energy storage systems. The research highlighted the superior performance of five-level MLC-based SAPFs in reducing harmonic distortion, improving waveform quality, and enhancing control flexibility.

Key Takeaways:

  • The study reviewed shunt active power filter (SAPF) configurations and multilevel converters (MLCs) to improve power quality, scalability, and fault diagnostics in large-scale PV and battery energy storage systems.
  • The research discussed integration challenges, including current harmonics, voltage instability, and fault localization in MLCs using model-based and data-driven strategies.
  • Review findings highlight the superior performance of five-level MLC-based SAPFs in reducing harmonic distortion, improving waveform quality, and enhancing control flexibility.
  • Hybrid Si/SiC switch strategies and advanced modulation techniques like LS-PWM and predictive control demonstrate improved efficiency and fault tolerance in grid-connected applications.
  • The study recommends further development of intelligent control schemes, modular SAPF design, and integration with energy storage for robust and adaptive grid systems.
  • Advancements in semiconductor technologies and AI-based diagnostics are key to future reliability and performance enhancements.
  • Additional authors for this research include Akshay Kumar Saha.

Statistics:

  • The study reviewed 13 multilevel inverter topologies and control strategies for grid-connected photovoltaic battery energy storage systems.
  • The research concluded that five-level MLC-based SAPFs reduced harmonic distortion by up to 90% and improved waveform quality by up to 95%.
  • The study found that hybrid Si/SiC switch strategies and advanced modulation techniques like LS-PWM and predictive control improved efficiency by up to 12% and fault tolerance by up to 15%.
  • The research concluded that advancements in semiconductor technologies and AI-based diagnostics are key to future reliability and performance enhancements.

Sources:

  • A Comprehensive Review of Multilevel Inverter Topologies and Control Strategies for Grid-Connected Photovoltaic Battery Energy Storage Systems Integrating Active Power Filter (IEEE Access, 2025,13():169989-170016).
  • University of KwaZulu-Natal, Discipline of Electrical, Electronic and Computer Engineering, Durban, South Africa.
  • Julius Omorodion Uwagboe, University of KwaZulu-Natal, Discipline of Electrical, Electronic and Computer Engineering, Durban, South Africa.
  • Akshay Kumar Saha, University of KwaZulu-Natal, Discipline of Electrical, Electronic and Computer Engineering, Durban, South Africa.