电网电压对称骤升下DFIG的HVRT协调控制策略

Coordinated Control Strategy for HVRT of DFIG Under Symmetrical Sudden Rise of Grid Voltage

为解决双馈风电机组(DFIG)中的高电压穿越(HVRT)问题,保证持续并网运行,提出在DFIG转子侧变流器引入附加阻抗控制,网侧变流器采用双闭环矢量控制,电网发生故障后,根据电网电压骤升幅度吸收部分无功功率,当电网电压对称骤升至1.3倍额定电压时,启动风电场已有无功补偿装置发出感性无功功率。通过上述协调控制策略抑制DFIG定、转子过电压、过电流及电磁转矩波动,减小了系统冲击,实现了DFIG的HVRT能力,缓解了大规模风电机组脱网问题。在Matlab/Simulink上进行仿真,验证了所提策略的有效性和可行性。

In order to solve hgih voltage ride through (HVRT)of doubly fed induction generator (DFIG),and ensure its continuous grid connection operation.An additional impedance control is introduced into the rotor side converter of a DFIG.Double closed loop vector control is used in grid-side converter.When the fault occurs,the reaetive power is absorbed according to the voltage surge amplitude.When the voltage of the power grid rises to 1.3 times rated voltage symmetrically,the reactive power compensation device of the wind farm has sent out the inductive reactive power. Through the coordination control strategy mentioned above,the fluctuation of stator,rotor overvohage,overcurrant and electromagnetic torque of DFIG is restrained,the system shock is reduced,and the restoration of grid voltage is supported.The high voltage traversing ability of DFIG is realized,and the problem of large scale wind turbine decoupling is alleviated.The simulation on Maflab/Simulink verifies the effectiveness and feasibility of the proposed strategy.