动态电压恢复器基于模糊形态滤波器的检测方法研究

针对三相不平衡电压暂降,以及动态电压恢复器对电压检测的实时性要求,在常用dq变换的基础上,提出一种新的检测方法。该方法将模糊控制应用于数学形态滤波器,对电网中的谐波、随机以及脉冲等多种干扰进行初次滤除。再对各单相电压使用求导的方法,分别得到三相虚拟电压。最后对虚拟电压进行dq变换并用新型滤波器替代传统巴特沃斯低通滤波器,可实时、准确地检测出电压暂降起始与结束时间、幅值以及相角变化。通过仿真证明该方法与传统dq检测方法相比具有抗干扰能力强,延时小,运算简单的优点。

A novel fuzzy morphology filter detection algorithm for dynamic voltage restorer

In order to identify unbalanced three-phase voltage sags characteristics, as well as to meet the real time voltage detection requirements of dynamic voltage restorer, a new method based on traditional dq transformation to detect voltage sags is presented. At first, the fuzzy control is applied to mathematical morphology filter to pretreat harmonics and random/impulse noise in power grid. Then, a derivative method is used for each single-phase voltage to obtain a three-phase virtual voltage. Finally, voltage sags can be detected instantaneously with duration, magnitude and phase-angle jump when three-phase virtual voltage is treated by dq transformation and new filter replaces Butterworth low-pass filter. Compared with traditional dq detection algorithm, this method has advantages of good anti-jamming capability, high speed in execution as well as simple implementation.