Motivated by the issues that the cost of superconducting fault current limiter (SFCL) based fault ride through (FRT) scheme for permanent magnet synchronous generator (PMSG) is high, and it cannot tackle different voltage sags due to the constant resistance of SFCL, this paper presents a coordinated method for enhancing the FRT capability of PMSG based wind turbine (WT) under various grid faults. In the proposed method, the unbalanced power accumulated on dc-link during grid fault is dissipated by coordinating SFCL and decreasing power control (DPC) of machine side converter (MSC). Besides, a transient reactive power control (TRPC) module is implemented on the grid side converter (GSC) to meet the reactive requirement of grid codes. The coordinating mode of three modules assists theWTto tackle the severe grid faults while only the DPC is activated to deal with the mild grid faults. Several cases studies are conducted in PSCAD/EMTDC to verify the feasibility and superiority of the proposed method.
- Power decreasing control
- Coordinated control