Abstract: At present，the focus of research on doubly fed induction generator（DFIG）high voltage ride through is a single high voltage fault.However，after DFIG low voltage ride through，due to the irrationality of the reactive power compensation strategy，a low/high voltage compound fault have be caused，which have a certain impact on the transient analysis of the secondary voltage surge.Therefore，the rotor current formula was reasonably derived under the second voltage surge on the premise of the low voltage recovery stage，and a rotor over-current suppression strategy was proposed. Then，based on the reactive power demand of the system during fault ride through，the control strategy of the grid-side converter was improved. On the one hand，the strategy can reduce the switching frequency of crowbar protection，and to a certain extent avoid the uncontrollability caused by the bypass of the rotor-side converter.On the other hand，it can provide maximum reactive power support to the unit，keep the DC bus voltage in a stable state，and improve the reliability of high voltage ride through.

      Key words: doubly fed induction generator（DFIG）；low/high voltage ride through；low voltage recovery stage；crowbar circuit；rotor over-current suppression