TRANSFORMER-LESS STATIC SYNCHRONOUS COMPENSATOR (STATCOM) TOPOLOGICAL STRUCTURE BASED ON MODULAR MULTILEVEL CONVERTER (MMC)

摘要

Transformerless static synchronous compensator (STATCOM) topological structure based on modular multilevel converter (MMC) comprises three phases that are composed of multiple standard power units of modular multilevel converters connected in series. One ends of serially connected standard power units are connected with each other while other ends are connected with inductors. The inductor is connected with a charging resistor. The charging resistor is connected with a switch in parallel, and is connected to an electrical grid through another switch. The standard power unit is supplied with power by charging the resistor and the capacitor so as to provide direct current voltage. The STATCOM topological structure has no transformer at the synchronization side of a traditional STATCOM, so the STATCOM topological structure is simplified, and the space required for accommodating STATCOM topological structure and costs are reduced.