Recently, the global energy demand has noticeably increased due to population growth and economic revolutions in developing countries. Concern has grown over fossil fuel exhaustion and other environmental problems that are a result of conventional power generation. It is a challenge to generate a secure, available, and reliable energy source and at the same time reduce greenhouse gas emissions. One of the most effective and suitable solutions to meet the worldwide energy demand is renewable energy resources (RESs). There are different sources of renewable energy such as wind, solar energy, wave energy, etc. These RESs can be used for supplying power to stand-alone loads or can be connected with the grid.

Photovoltaic (PV) solar energy has received a lot of attention among the RESs as it appears to be one of the most promising sources of energy. PV systems can be divided into two groups: standalone and grid-connected. In order to connect PV plants to the grid, power electronic converters need to be present. Grid-connected inverters can be classified according to the number of the generated voltage levels into two-level and multilevel inverter (MLI) topologies. The two-level voltage generated by the two-level inverter contains a large number of harmonic contents, which leads to using a large filter size to minimize these harmonic contents and inject clean current to the grid. Therefore, the two-level inverter is suitable for low voltage PV-grid applications. For interfacing with the medium and high voltage utility grid, multilevel inverters are more suitable. Several MLI topologies have been proposed in the literature to increase the number of the generated voltage levels. Some of the attractive features of the MLIs are: low voltage stress on switches; the THD of the voltage and current is reduced and the power quality improved; low power dissipation on switches during on state; reducing the filter sizes; and lower switching frequency, etc. MLI topologies have received attention in many applications such as grid-connected PV applications, STATIC VAR compensation, active power filter applications, etc. Nabae introduced the first MLI in 1975, which was composed of a series combination of multiple three-level full-bridge converters. MLI can be categorized into three groups: neutral point converter (NPC), flying capacitor (FC), and cascaded H-bridge (CHB).

This Special Issue seeks recent advancements in power electronic converter topologies, their control schemes, PV-grid integration, and related topics. The aim of this Special Issue is thus to collect recent advancements in power converter topologies, control techniques, stability, and reliability. Original research and review articles are welcome.

Potential topics include but are not limited to the following:

• Novel MLI topologies for PV-grid applications
• Power quality enhancement using multilevel inverters
• New power converters topologies for high voltage, high power PV systems
• Recent advances in control schemes of inverters to meet PV-grid requirements
• Active power filter applications
• Harmonic mitigation techniques
• Hybrid systems for integration with the grid
• PV plants with energy storage system
• Real-time and HIL simulation of PV systems
• Stability studies of converter-based PV systems
• Recent advances in maximum power point tracking of PV modules
• Computer models and tools for designing PV-grid energy systems