Low voltage ride-through control scheme

The invention relates to a low voltage ride-through control scheme which comprises the following steps of: 1. monitoring the direct current bus voltage and the electric network voltage of a frequency transformer set connected between a wind generator rotor and an electric network by a control circuit; if judging that the monitored direct current bus voltage of the frequency transformer set is higher than a design value, controlling a thyristor in a Crowbar protection circuit connected to the wind generator rotor to be closed by the control circuit to carry out current dividing protection; 3. after closing the thyristor, controlling a stator breaker connected between a wind generator stator and the electric network to break the connection of the wind generator stator and the electric network by the control circuit; 4. after breaking the connection of the electric network and the wind generator stator by the stator breaker, further controlling the breaker of a current dividing circuit to firstly break and then close by the control circuit and automatically breaking the thyristor to recover the protecting function of the current dividing circuit; and 5. keeping the state until the control circuit monitors the voltage recovery of the electric network, rapidly enabling a generator to synchronously control the breaker to close and recovering normal operation.