变速恒频双馈风力发电柔性并网控制

Flexible Grid-connection Control Strategy for VSCF Wind Power Generation

传统的风力发电并网方式为"刚性并网",在并网瞬间会产生很大的冲击电流。本文根据交流励磁变速恒频风力发电的运行特点,将矢量控制的定子电压定向技术应用在双馈发电机的并网控制上,对风力发电的"柔性并网"进行了分析,即根据电网电压和电机转速来调节转子的励磁电流,在变速条件下实现无冲击电流并网,实现了输出有功和无功功率的解耦控制。建立了交流励磁发电机空载并网、负载并网、并网后的稳态运行和电网波动情况下的不脱网控制模型,完整的仿真研究验证了变速恒频风力发电柔性并网控制策略的正确性与有效性。

Traditional wind power generation was rigidly cut in, and the current impact on grid connection is extremely high. In this paper, by analyzing run characteristic of AC-excited variable speed constant frequency （AEVSCF） wind power generator, stator voltage oriented vector control technique is used in doubly fed induction generator（DFIG）, flexible grid-connection technique is analyzed, grid voltage and rotor speed are calculated to make generator output voltage meet grid-connection condition without overshoot current by excitating rotor current control, and obtain decoupling control of active power and reactive power. The modes of idle-load and on-load grid connection, running in ready state and fault ride through are established, complete simulation confirms the accuracy and validity of flexible grid-connection control strategy for VSCF wind power generation.