Transient stability analysis of Shanghai Power Grid with multiple HVDC links

With the development of China´s power system, more and more HVDC links are located in close proximity in a common AC system and thus multi-infeed HVDC systems are developed. Due to the interaction between AC system and DC systems, as well as the interaction amongst DC systems, the behavior of such multi-infeed HVDC system is much more complicated than a single-infeed HVDC system. This paper investigates into an example of such multi-infeed HVDC systems, i.e. Shanghai Power Grid. There are three HVDC links terminating in the load center of Shanghai Power Grid by 2010. The inverter stations of the three HVDC links are near to each other and thus the interaction of AC and DC systems is very strong and has a great impact on the secure and stable operation of the system. Transient stability under various faults, as well as the effect of load characteristics and spinning reserve, are studied in this paper. Conclusions are obtained according to the simulation results, which provide useful instruction for the operation of Shanghai Power Grid and other similar multi-infeed HVDC systems.