Research on low voltage ride through technology for symmetrical grid fault

With the wind power installation capacity sharply increasing, the effects caused by wind farms on the regional power system stability becomes very remarkable. Accordingly, more and more researches are focused on the low voltage ride through (LVRT) technology used for DFIG under short-time grid fault, and new power grid regulation requires power system to achieve LVRT capability. But we have no interrelated criterion in our country. First, the requirement and applying of LVRT is introduced, and the electromagnetism relation of DFIG stability factor under symmetrical grid fault is analyzed. Then based on the professional power system simulate software platform PSCAD/EMTDC, a LVRT simulation experiment which applied crowbar protection method when grid voltage falls down is done. Recur to this experiment, DFIG performance characteristic is analyzed and some helpful conclusions are achieved. The emulation experiment validate the availability of proposed electromagnetism relation, remarkable effect of improved crowbar, exactness of simulant model.