Coordinated optimization method and system for improving multi-infeed direct current voltage stability

The invention belongs to the field of direct-current transmission control, and relates to a coordinated optimization method and system for improving multi-infeed direct-current voltage stability, which derives transient reactive power characteristics of LCC-HVDC based on a low-voltage current limiter through a mathematical method, clarifies a coupling mechanism among the low-voltage current limiter, short-term voltage stability and high-voltage direct-current power recovery, and improves the multi-infeed direct-current voltage stability. Carrying out optimization modeling; providing a control system optimization target in a high-voltage direct-current transmission recovery process and a converter voltage evaluation index to represent short-term voltage stability; and performing cooperative control among the multi-infeed direct current lines by using a cooperative optimization strategy, and performing optimal control according to a cooperative control target function. According to the invention, the stability