电压源型双馈风电机组低压穿越控制策略

The inertia and damping in the control link of voltage-source doubly-fed wind turbines are not conducive to the low-voltage ride-through of wind turbines in the case of deep fault in the power grid. As the low-voltage ride-through strategy of current-source doubly-fed wind turbines is relatively mature, a low-voltage ride-through control method of voltage-source doubly-fed wind turbines was proposed based on mode conversion. That is, it switches to current source control mode during the fault, and switches to voltage source control mode after the fault recovery. By analyzing the control structure of voltage source type and current source type of doubly-fed wind turbines, a flexible mode switching method based on presynchronization of state variables was proposed, which realizes the impact-free switching of voltage source and current source operation modes. According to the relevant regulations of low-voltage ride-through of wind turbines, the schemes of impulse current suppression, active power recovery setting and dynamic reactive power compensation of wind turbines during transient state were formulated, and the low-voltage ride-through of voltage source doubly-fed wind turbines in the case of deep fault of power grid was realized. Effectiveness of the above methods is verified by simulation.