东北电网大规模双馈风电短时功率缺失冲击下的频率安全应对策略OA

The scale of the Northeast Power Grid is small,and the slow recovery of active power after the successful low-voltage ride-through of a large number of doubly-fed wind turbines will cause serious frequency security problems.During low-voltage ride-through,reactive power is prioritized,and the active current is set to the residual maximum output capacity of the converter,so the optimization space for the fan's electrical aspect is limited.In this paper,coping strategies are presented from two perspectives:the wind turbine and the power grid.In terms of wind turbines,a simplified model of dynamic torque for the drive shaft of doubly-fed wind turbines has been constructed,the impact of different factors on the active power recovery rate has been analyzed,the feasibility of increasing the mechanical strength of transmission shaft to improve the active power recovery rate of wind turbine is studied,suggested values for the active recovery rate of newly built wind turbines are provided,primarily based on grid demand and to a certain extent taking into account the cost of the turbines.At the same time,based on the initial active power of the wind turbine and the degree of terminal voltage drop,a scheme for setting the active power recovery rate in sections is proposed for the wind turbine during operation.In terms of the power grid,the energy storage's primary frequency modulation is used to quickly and accurately fill the active power loss of the doubly-fed wind turbine.Finally,the effectiveness of the strategy is verified through grid data simulation.The main strategies proposed in this paper have been applied in the Northeast Power Grid,providing a solution to the frequency security problem caused by the low penetration of doubly fed wind turbines.