Wind generating set low voltage ride through circuit and corresponding control method

The invention relates to a wind generating set low voltage ride through circuit and a corresponding control method. According to the invention, a rectifier bridge is additionally arranged at a generator rotor output line terminal of a wind generating set and positive and negative ends of a converter DC bus, and the rectifier bridge is connected to a converter bus in parallel. Meanwhile, a DBR circuit is connected to both ends of the converter DC bus in parallel. When the wind generating set is in a dropping process of grid voltage (u/ur>=20%), release of DBR resistance energy is realized through turn-on or turn-off of an IGBT (insulated gate bipolar transistor) in the DBR circuit, thereby maintaining dynamic balance of the converter DC bus dynamically, realizing current transformation of the wind generating set, and riding through a grid fault successfully; and in the dropping process of the grid voltage (u/ur<20%), the IGBT in the DBR circuit is turned off, a Crowbar in a Crowbar circuit is triggered to release energy accumulated on the rotor, thereby protecting the converter or the generator. The wind generating set low voltage ride through circuit and the corresponding control method can reduce or decrease various transient characteristics produced by the wind generating set in the whole dropping process of the grid voltage, improves harmful effects imposed on the wind generating set and a power grid by the various transient characteristics, improves the performance of the wind generating set and prolongs the service life of the wind generating set.