Optimized AC Fault Ride-through Strategy for Back-to-back VSC-HVDC System

Due to the AC fault of back-to-back VSC-HVDC system may cause the security and stability problems, this paper proposes an optimized AC fault ride-through strategy, which can take into account the transient response speed and stability of the system. At the same time, the solution is provided in order to avoid the influence of fluctuations in DC voltage, active power and reactive power on AC current during AC asymmetrical faults. This strategy reduces the DC voltage impact at the moment of the AC fault, improves the stability of the DC voltage during the AC fault, and has a faster fault response speed. Finally, this paper uses PSCAD/EMTDC to build a simulation model of the back-to-back VSC-HVDC system, and the simulation verifies the advantages of the optimized AC fault ride-through strategy proposed in this paper.