Research Review of Power Electronic Technology in Power Grid Stability Improvement

When renewable energy are connected to the power grid through power electronic technological (such as inverters), ensuring the stability of the power grid becomes a very valuable challenge. This is because power electronic converters usually encounter some problems when converting electrical energy, such as unstable voltage, the presence of high-frequency or low-frequency harmonics, islanding effect, leakage current, etc. To solve these problems and enhance the stability of power grids when new energy is connected, improvements can be made to the components and topological structure of power electronic modules, or more precise and comprehensive control strategies can be adopted. This paper outlines the topological structures and control strategies of inverters in photovoltaic grid-connected systems, including innovative topological structures, control algorithms, and analysis methods. It summarizes recent research achievements in improving grid stability through inverters, discovering several disadvantages and raising some possible development directions of inverters in the future.