转子Crowbar自适应切除控制策略--提高DFIG低电压穿越性能

Rotor crowbar adaptive excision control strategy--Improve DFIG low voltage ride through performance

针对传统转子Crowbar电路控制策略存在反复切除与投入Crowbar电路和投入Crowbar电路工作时间过长的问题。文章通过对转子Crowbar电路模型进行分析,将DFIG的电学变量转化为以转子转速建立坐标系的数学模型,根据DFIG数学模型对切除Crowbar电路后的转子暂态进行分析,通过实时计算在当前时刻切除Crowbar电路产生的转子电流最大值与Crowbar电路投入工作电流阈值进行比较实现Crowbar电路自适应切除控制策略。通过仿真实验,比较传统控制策略和自适应控制策略在不同电压跌落程度中投入工作的时间,验证文章所提策略降低了反复切除Crowbar电路时间。

The traditional control strategy of rotor Crowbar circuit has the problem of repeated removal and too long working time of Crowbar circuit and Crowbar circuit. By analyzing the Crowbar circuit model of the rotor, the electrical variable of the DFIG is transformed into a mathematical model based on the rotating speed of the rotor to establish the coordinate system. According to the mathematical model of the DFIG, the transient state of the rotor after the removal of the Crowbar circuit is analyzed. The real-time calculation of the maximum rotor current generated by cutting off the Crowbar circuit at the current time is compared with that of the working current threshold of the Crowbar circuit. The self-adaptive control strategy of Crowbar circuit is presented in this paper. The simulation results show that the traditional control strategy and the adaptive control strategy work in different voltage sags to verify that the proposed strategy reduces the time to resect the Crowbar circuit over and over again.