电压暂降过程中的双馈风力发电机无功功率调节能力

西班牙风力发电容量日益增加，已迫使输电系统运营机构（TSO）对电压骤降期间风力发电机无功出力提出新的要求．在稳态运行条件下，双馈风力发电机方便调节无功功率；但在电压暂降过程中，难于提供足够的无功功率．论文仿真分析了双馈风力发电机的无功出力，考虑保护系统和电网侧换流器共同作用，以满足无功平衡要求；故障瞬间，Crowbar电阻及其连接时间对无功平衡影响大，而电网侧换流器充当STATCOM作用，有助于改善电压波形，以实现转子侧换流器的重接．

Reactive power regulation capability of doubly-fed wind power generators during voltage dips

The growing of wind generation in Spain has forced its Transmission System Operator (TSO) to release new requirements that establish the amount of reactive power that a wind turbine has to supply to the grid during a voltage dip. Wind turbines equipped with doubly-fed induction generators (DFIG) can regulate easily the reactive power generated in steady state. However, difficulties appear when reactive power has to be generated during voltage dips. Simulations have been carried out in order to check whether DFIG wind turbines can fulfill the reactive power requirements. Protection system commonly employed with DFIG in order to achieve ride-through capabilities including crowbar plays an important role to meet the requirements together with grid-side converter. Resistance associated with the crowbar and its connection duration are crucial at the beginning of the fault. Grid-side converter acting as STATCOM helps to improve the voltage profile sufficiently to permit rotor-side converter recormeetion.