Analysis on design points of large synchronous condenser for UHVDC project

To improve the ability of reactive power support at Ultra High Voltage Direct Current (UHVDC) project sending and receiving terminals, State Grid Corporation will install large synchronous condensers which gives high requirements in transient and dynamic characteristics. Some performance indexes of large synchronous condenser are very different from traditional turbo-generator. The change of performance index will have great influence on equipment design, production, operation and manufacture. And there is contradiction between the higher transient, dynamic characteristics and equipment safety. The paper analysised the performance index, technical requirements, equipment characteristics of large synchronous condenser for UHVDC project. Compared with the 412MVA synchronous turbo-generator. Mainly analyzed the differences and influences of leading phase operation capability, short-circuit-ratio, direct-axis transient time constant, direct-axis subtransient reactance and forced excitation ability. Finally the paper gives some advices on improving the design of large synchronous condenser for UHVDC project to ensure the quality of performance index and the safety of equipment.