In the process of accelerating the achievement of carbon neutrality goals and building a new power system, energy storage technology is gradually becoming one of the key technologies supporting the stable operation of the new power system and optimizing resource allocation. Among these, the PCS (Power Conversion System) energy storage converter, as the core equipment of the energy storage system, directly impacts the overall efficiency and stability of the energy storage system through its performance and application. This paper will conduct an in-depth analysis and interpretation of PCS energy storage inverters from aspects such as their definition, working principles, main characteristics, operating modes, application scenarios, and future development trends.