A combination of auxiliary circuits and reactive current control to improve low voltage crossing ability of offshore wind grid connection system

At present, as an important part of clean energy, wind energy access to the capacity of integrated energy systems is growing rapidly, which puts higher requirements on the operational stability of offshore wind farms as a wind resource-rich wind turbine aggregation. Among them, low voltage ride-through (LVRT) capability to face voltage dip faults is one of the important parts. In order to improve the LVRT capability of offshore wind farm, this paper, based on the development of an equivalent model for doubly-fed induction generator (DFIG), utilizes the addition of Crowbar circuit, Chopper circuit to the turbine structure and uses a reactive power support of DFIG considering dynamic voltage range to improve the LVRT capability of DFIG. The simulation result verifies that the optimized offshore wind farm can well protect the relevant components from damage, quickly restore the output power to normal and help the grid to recover the voltage in the face of low voltage drop faults.