基于故障电流解析表达的FCL协助DFIG低电压穿越研究

发布时间：2018-09-03 15:22

【摘要】：双馈感应电机(DFIG)与公共耦合点(PCC)间投入故障电流限制器(FCL)实现低电压穿越(LVRT)时,定子电压受FCL阻抗与网侧变流器(GSC)电流影响,无法设定定子电压,需要对DFIG与FCL整体建模以分析故障电流。基于恒定电流控制策略推导转子侧变流器(RSC)与GSC电流,提出DFIG故障电流的解析表达式。考虑到电压定向下定子相角振荡会导致dq轴恒定电流在xy轴下变化,不利于定子电流稳定,采用dq轴与xy轴相重合的定向方案。对比不同的RSC与GSC电流参考值、FCL阻抗值与切出时间下DFIG LVRT过程中的电磁转矩振荡,选择LVRT性能较好的一组控制参数。仿真结果表明,FCL阻抗取值受RSC与GSC电流参考值影响,且FCL阻抗越大,所取切出时间越短。
[Abstract]:The stator voltage is affected by the FCL impedance and the (GSC) current of the grid-side converter, so the stator voltage can not be set when the low voltage traversing (LVRT) is realized by the fault current limiter (FCL) between the double-fed induction motor and the common coupling point (PCC). DFIG and FCL need to be modeled as a whole to analyze the fault current. Based on the constant current control strategy, the (RSC) and GSC currents of the rotor side converter are derived, and the analytical expression of the DFIG fault current is presented. Considering that the stator phase angle oscillation under the voltage direction will cause the constant current of the dq axis to change under the xy axis, which is not conducive to the stator current stability, the directional scheme of overlap between the dq axis and the xy axis is adopted. The electromagnetic torque oscillations in the DFIG LVRT process with different RSC and GSC current reference values and cutting time are compared, and a group of control parameters with good LVRT performance are selected. The simulation results show that the impedance of FCL is affected by the current reference values of RSC and GSC, and the larger the FCL impedance is, the shorter the cutting time is.
【作者单位】：合肥工业大学电气与自动化工程学院;
【基金】：国家自然科学基金资助项目(51277049)~~
【分类号】：TM614

【相似文献】