摘要
该文研究在不对称电网故障穿越的第2阶段,双馈式(doubly-fed induction generator,DFIG)风电场如何实现"自身不脱网安全运行并同时满足并网导则无功支撑要求"的问题。由于受限于变流器的容量,DFIG机组无法保证在所有故障情况下实现既定的控制目标。为此,通过引入最优化的方法,分析了变流器容量限制条件下DFIG机组的可控性问题,得到了以电网电压不平衡度所量化表示的可控区,指出为确保在不对称跌落故障较严重时能满足并网导则要求,有必要在DFIG风电场层面配置静止同步补偿器(staticsynchronous compensator,STATCOM)以降低场内DFIG机组的机端电压不平衡度。最后,设计了STATCOM所需容量最小的电压补偿控制策略,并给出了相应的容量匹配方法。仿真结果验证了该文提出的在不对称低电压穿越(lowvoltage ride-through,LVRT)第2阶段DFIG机组可控区的正确性、STATCOM辅助控制策略的有效性以及相应容量匹配方法的可行性。
In this paper, we focus on the solution for doubly-fed induction generator （DFIG）＇ based wind farm to achieve the control objective in the second period of asymmetrical grid faults ride-through, which is to support the network voltage by means of additional reactive current required by the grid codes while keeping connecting to the power grid with safe operation. However, the proposed control targets cannot be always satisfied due to the converter capacity constraint of the DFIG-based wind energy conversion system （WECS）. Therefore, the controllability of DFIG are analyzed by optimal method while its controllable regions presented by unbalanced degree of grid voltage is given, which points out that static synchronous compensator （STATCOM） with the function of reducing unbalanced degree of fault voltage is essential to the DFIG-based wind farm under severe fault situations. At the last, a voltage compensation control scheme needing minimum capacity of the STATCOM is proposed and respective capacity matching method is also given. The accuracy of calculated DFIG＇s controllable regions, and the effectiveness of proposed control scheme for STATCOM as well as the feasibility of respective capacity matching method are validated by the simulation results.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第19期27-38,22,共12页
Proceedings of the CSEE
基金
国家自然科学基金资助项目(60974130
61273045
61104046)~~
关键词
风力发电
双馈感应发电机
不对称电网故障
低电压穿越
静止同步补偿器
容量匹配
wind power generation
doubly-fed induction generator（DFIG）
asymmetrical grid faults
low voltage ridethrough（LVRT）
static synchronous compensator（STATCOM）
capacity matching
