Study On Relay Protection At The Grid Connection With LVRT Capacity Of Fan

With the increasing proportion of wind power in grid, requirement the network fan unitwith low voltage ride through capability, as well as protection associated with it to ensure thecompletion of its functions. Otherwise, even if the fan has a low voltage ride through function,when the outside is not the correct action to protect the unit, it can not fulfill its functiontoo.For this research topic, this paper use the grid failure characteristics with wind farmswhich containing LVRT capability DFIG fan to analyze the shortcomings of existing voltageand current protection of wind farms and outlets, proposed to complex multi-stage voltage-current protection strategies to adapt the low voltage ride through and use PSCAD softwaresimulate different short-circuit faults in the grid, to verify the reliability of protection. Thenanalyzing the applicability of the principle of distance protection after wind farms are on thegrid and simulation the distance protection setting round action of wind farms side, and thenanalyzing the accuracy impact of the distance protection by Crowbar protecting circuit andmade some improvements.Finally discussing the effects of former and back acceleration re-closure brake after thewind farms connected to the grid, depending on the impacts and giving the correspondingimprovements. And thus obtaining conclusions that in different locations of the fault, not allof the wind farm will be able to run across a fault.