Impact of Enhanced Synchronization Techniques of Wind Power Plants on the Short-Circuit Current

Within this paper, the impact of enhanced synchronization techniques of wind power plants with full-scale converter on the short-circuit current is presented. The reaction of the full-scale converter with three different synchronization techniques are compared to each other. As reference the reaction of the model with a synchronous reference frame PLL for the synchronization is used. The reference scenario is compared firstly to the reaction of the model with the same synchronous reference frame PLL combined with a low-pass filter and secondly to the reaction of the model with a decoupled double synchronous reference frame PLL. During voltage drops, the reaction as a low-pass filter of the enhanced synchronization techniques leads to a significant transient response in settling with high currents. This is problematic for the short-circuit current calculation according to IEC 60909, which considers wind power plants with full-scale converter as a constant short-circuit current source.