摘要
随着风力发电规模和风电机组单机容量不断增大,要求大型风电机组具有低电压穿越能力,因此需要研究三相对称故障下双馈风力发电机控制方法。在电网电压突然跌落时,由于双馈发电机中的电磁耦合关系,在定转子中感应出过电压过电流,为保护转子侧变换器,需要通过crowbar来短路双馈发电机的转子。针对传统的passive crowbar的不足,采用active crowbar电路的控制方法。当电网故障造成双馈发电机转子过流时,开启active crowbar电路来旁路转子侧变换器。当转子电流下降到一定程度时断开crowbar,转子侧变换器恢复工作,此时双馈电机可以向电网同时提供有功无功支持。理论分析的基础上进行了仿真研究。仿真结果证实了采用active crowbar可以有效地实现双馈风力发电机的低电压穿越。
With the development of wind power generation system, LYRT （low voltage ride through） ability in grid fault condition is required for wind generator, so it＇ s necessary to research on the control method of DFIG （doubly fed induction generator） under symmetry voltage tault condition. During the occurrence of a grid fault, because of electromagnetic relationship in DFIG, over current way induced in slator and rotor winding. In order to protect the converter, crowbar was used to short DFIG rotor. When over current was induced in rotor, the rotor side converter was bypassed by active crowbar circuit. When rotor current decreased to a certain degree, the crowbar circuit was opened. At the same time the rotor side converter was activated, active and reactive power was fed to the grid. The theory analysis was verified by the simulation result and the LVRT operation of DFIG was achieved through the active crowbar.
出处
《电机与控制学报》
EI
CSCD
北大核心
2009年第1期99-103,共5页
Electric Machines and Control
基金
教育部博士点基金资助项目(N20060213027)
台达环境与教育基金会<电力电子科教发展计划>
