Comparison and Analysis of Full Power Inverter Topology for Large Capacity Variable Speed Pumped Storage Units

Variable speed pumped storage units have significant advantages over traditional fixed speed pumped storage units in terms of efficiency and adaptability to operating conditions. Full power frequency converters are key equipment for variable speed pumping and storage units, and studying the application of various frequency converter topologies in large capacity variable speed pumping and storage units is of great significance. This article takes a 100 megawatt variable speed pumped storage unit as an example, and based on existing devices, compares and analyzes three-level back-to-back converter (NPC), five-level back-to-back converter (SMC) The design schemes of Modular Multilevel Converter (MMC) and Modular Multilevel Matrix Converters (M3C) with four topologies applied to high-power, 13.8 kV connected variable speed pumped storage units are compared and analyzed in terms of cost and topology advantages and disadvantages. It can be concluded that NPC and SMC are more suitable for low-voltage situations, and transformers need to be added to increase voltage in high-voltage situations, MMC and M3C have more advantages in high-pressure situations.