基于超导磁储能和变流器重构的DFIG连续故障穿越方案

由高压直流输电系统换相失败引起的送端风电场母线低高电压连续故障，会对双馈感应发电机(DFIG)产生严重的暂态冲击，现有单一的风机低压、高压故障穿越方案难以完全适应此类连续故障穿越的要求。为此，提出了一种结合重构式网侧变流器与超导磁储能装置的软硬件协同穿越方案，以提升DFIG的连续故障穿越能力。在故障期间，网侧变流器由并联运行模式切换至串联运行模式，以维持定子端电压不变为目标，并控制转子侧变流器根据并网点电压自适应发出动态感性/容性无功电流。仿真结果表明，所提方案既可以维持DFIG的机端电压，又可以为电网提供无功支撑，有效地实现DFIG的低高电压连续故障穿越。

Continuous fault ride-through scheme for DFIG based on superconducting magnetic energy storage and converter reconfiguration

The continuous low and high voltage faults of the sending-end wind farm bus caused by the commutation failure of the HVDC(High Voltage Direct Current) transmission system produce serious transient impact on the DFIG(Doubly-Fed Induction Generator). The existing single low or high voltage fault ride-through schemes of wind turbine are difficult to fully meet the requirements of this kind of continuous fault ride-through. In order to improve the continuous fault ride-though capability of DFIG, a hardware and software cooperative ride-though scheme based on the reconfiguration of grid-side converter and superconducting magnetic energy storage device is proposed. During the fault, the grid-side converter is switched from parallel operation mode to series operation mode to maintain the stator terminal voltage unchanged, and the rotor-side converter is controlled to generate dynamic inductive or capacitive reactive current adaptively according to the voltage of point of common coupling. The simulative results show that the proposed scheme can not only maintain the terminal voltage of DFIG, but also provide reactive power support for the power grid, and effectively realize the continuous low and high voltage fault ride-though of DFIG.