基于模糊控制的改进频移式孤岛检测方法

An improved frequency drift islanding detection method based on fuzzy control

针对孤岛检测中传统正反馈主动频移法的初始截断系数和反馈系数只能取固定值,导致的检测盲区大、检测时间长以及总谐波失真过高等问题,同时通过对主动频移法中施加的扰动量与公共耦合点电压频率关系的分析,提出一种改进的带正反馈主动频移式孤岛检测方法。利用模糊控制算法对反馈系数进行模糊化处理,并对反馈量做出基于三次幂函数的变换,建立起新的截断系数。与传统正反馈主动频移法相比,改进后的方法减小了检测盲区,缩短了检测时间,并且降低了总的谐波畸变率,提高了电能质量。最后利用MATLAB/Simulink平台对该方法进行了仿真验证。

For the initial truncation coefficient and feedback coefficient of the traditional active frequency drift with positive feedback method in islanding detection can only take a fixed value,resulting in large detection blind zone,long detection time and high total harmonic distortion.An improved frequency drift islanding detection method based on fuzzy control was proposed in this paper.By analyzing the relationship between the disturbance and the voltage of the common coupling point in the active frequency drifting method,fuzzy control algorithm was used to process the feedback coefficient,and the feedback quantity was transformed based on the third power function to establish a new truncation coefficient.Compared with the traditional positive feedback active frequency drifting method,the improved method has reduced the blind zone,shortened the detection time,reduced the total harmonic distortion rate,and improved the power quality successfully.Finally,the new method was verified by MATLAB/Simulink simulation platform.