双馈变速恒频风力发电空载并网控制策略

Research on Idle Load Grid-Connection Control Strategy for Variable-Speed Constant-Frequency Wind Power Generation

传统的风力发电并网方式主要有直接并网和降压并网,在并网瞬间会产生很大的冲击电流。根据交流励磁变速恒频风力发电的运行特点,将矢量控制的电网电压定向技术应用于双馈发电机的并网发电上,提出一种基于电网电压定向的双馈变速恒频风力发电空载并网控制策略,即在定子开路条件下,根据电网电压和电机转速来调节转子的励磁电流,在变速条件下实现几乎无冲击电流并网和输出有功、无功功率的解耦控制,建立了交流励磁发电机空载并网及稳态运行控制模型。仿真和实验结果表明,本文所提出的空载并网方式是变速恒频风力发电的一种较理想的并网方式。

Traditional wind power generation is directly or step-down grid-connectea, me current impact is extremely high. In this paper, according to characteristic of AC-excited variable speed constant frequency （VSCF） wind power generation, vector control technique is used in doubly fed induction generator （DFIG）, and idle load grid-connection control strategy is put forward based on grid voltage orientation. When stator circuit is open, according to grid voltage and rotor speed, rotor excitating current is adjusted to connect grid without overshoot current, and decoupling control of active power ;and reactive power is obtained. The models of idle load grid-connection and running in ready state are established. The simulation and experimental results validate the grid-connection mode is a ideal approach for VSCF wind power generation.