Research on transient stability under HVDC block fault in wind-thermal-bundled power base transmitted by AC/DC system

It has been the main exploitation mode for wind energy that wind power is generated in large-scale wind-thermal-bundled power base and is transmitted by AC/DC combined system. A Typical scenario is defined for that mode in this paper, based on which the transient characters and corresponding mechanism of sending-end power system are researched under DC block fault. Firstly, based on unbalanced energy theory in dynamics, the transient stability mechanism of sending-end power system is addressed. Secondly, different transient behaviors in wind-thermal-bundled power system are compared in different situations, including different proportions of wind power, different reactive power control modes for wind turbines, different capacity margins of converter in wind turbines and different peak-load regulation ways by thermal power units. Finally, based on the simulation results, the rules for transient stability of sending-end power system are given. The research in this paper can provide valuable reference for transient stability of wind-thermal-bundled power base transmitted by AC/DC system.