基于一种快速变量正负序分离方法的不平衡电压下双馈发电系统控制策略

CONTROL OF A DFIG-BASED WIND TURBINE UNDER UNBALANCED GRID VOLTAGE DIPS BASED ON A NEW METHOD TO SEPARATE POSITIVE AND NEGATIVE SEQUENCE COMPONENTS

根据正交坐标系的数学关系,提出一种快速变量正负序分离方法,称之为"准无延迟正负序分离算法"。相较传统的基于广义二阶积分滤波器设计和T/4延迟分离法,该方法可更快速准确地实现三相交流变量的正负序分离。仿真表明配合双馈风力发电系统的不平衡电压控制策略,可有效提高该系统在电网电压不平衡情况下的控制性能。

According to the mathematical relationship of the orthogonal coordinate system, a fast variable positive and negative sequence separation method called ＂quasi-positive and negative sequence separation algorithms without delay＂. Compared to conventional separation methods based on the aration method was introduced. It is shown that the new generalized second integral filter design and the T/4 delay sep- method is more quickly and accurately to separating a three- phase AC variables positive and negative sequence. Simulation results showed that this method act in concert with unbal- anced voltage control strategy, which can effectively improve the control performance of double-fed wind power genera- tion system in case of grid voltage unbalance.