一种基于改进dq变换的电压骤降检测方法  

Voltage sag detection method based on improved dq transformation

作　　者：李燕平[1] 李开成[2] 王海元 何顺帆[2] 

机构地区：[1]广东电网公司阳江供电局,广东阳江529500 [2]华中科技大学电气与电子工程学院,湖北武汉430074 [3]湖南省电力科学研究院,湖南长沙410007

出　　处：《华北电力大学学报（自然科学版）》2013年第3期25-29,共5页Journal of North China Electric Power University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51077058)

摘　　要：对于可有效补偿电压骤降的动态电压恢复器(DVR)来说,准确检测出电压骤降的骤降幅值、持续时间和可能出现的相位跳变值这三大特征量十分关键。当电网的频率波动较大时,dq变换法为DVR提供的特征量参数的准确性会受到严重影响。为了提高dq变换法的适用性,提出了一种改进的dq变换电压骤降检测方法,该方法通过dq变换后的相位曲线得到频率偏差值,在进行频率跟踪的同时对特征矩阵C进行频率修正。仿真结果分析表明,该方法不仅能实时检测频率,而且在信号有频偏和含谐波的情况下均能准确检测出电压骤降的特征量,满足DVR的实时性和准确性要求。The accurate detection of the three characteristics of the voltage sag-amplitude, duration and potential phase jump, is of great importance to the dynamic voltage restorer, which can be an effective remedy to the voltage sag. Fre- quency fluctuation of the power grid can seriously undermine the correctness of sag characteristics from dq transforma- tion. In order to improve the applicability of dq transformation, this paper develops an voltage sag detection method based on improved dq transformaion. With this method, we can acquire the frequency deviation value through the phase curve provided by dq transformation, and have frequency correction to feature matrix C with frequency tracking. The a- nalysis of simulation results show that, the proposed method not only detects frequency on grid, but also accurately gives the voltage sag characteristics even with harmonic and frequency deviation, which can meet the real-time and ac- curacy requirements of DVR.

关 键 词：电压骤降 DVR 频率偏移 频率修正 相位跳变值 

分 类 号：TM835[电气工程—高电压与绝缘技术]