电网故障下直流链路电压同步型风力发电机组的控制

The dc-link voltage-synchronized grid-forming (GFM) control is increasingly applied in wind turbine generators (WTGs) for its effective control of dc-link voltage. However, the bandwidth of the synchronization loop is relatively high due to the small inertia of the capacitor. When the voltage–current cascaded control loop is utilized in the grid-side converter (GSC), the coupling between these loops introduces the risk of instability. Using a single ac-voltage loop is considered a promising alternative due to its simplicity and stability. However, the lack of inherent current-limiting mechanism makes it challenging to handle transient overcurrent. Additionally, the dc-link voltage dynamics are clamped by the chopper during faults, which leads to a loss of synchronization and may result in transient power angle instability. To address the above issues, a novel fault ride-through (FRT) strategy for the dc-link voltage-synchronized GFM WTG is proposed in this article. This strategy achieves overcurrent limitation under different fault types without relying on a current closed-loop control. Moreover, it ensures power angle stability and provides spontaneous reactive power support during grid faults. The proposed strategy is verified through comprehensive simulations and hardware-in-loop (HIL) experiments.