Research on effects of large-scale wind farms integration on bus protection

Different from synchronous machines integration system, the short current of DFIG integration system contains lots of aperiodic components caused by non-fault branch when a bus external fault occurs. That makes the linear transfer area of CT saturated secondary current reduced or even lost, thus increasing the number of sampling points which meet the latch to open criterion. It will affect the accuracy of blocking component's action. The PSCAD/EMTDC simulation results also show that wind farm integration indeed has a negative impact on action of bus blocking component.