一种基于d-q-0坐标变换的频率测量算法

A frequency measuring algorithm based on d-q-0 transformation

传统的基于离散傅立叶变换或改进离散傅立叶变换算法所需数据量大,计算复杂,动态特性较差,不易实现。提出一种基于三相电网的频率检测算法,该算法利用广义d-q-0变换,将三相电量变换到d-q-0静止坐标系,然后分别对d轴分量和q轴分量进行低通数字滤波获得基波分量,对滤波后的基波分量进行计算得出电网频率。该算法所需数据量少,计算量简单,不需要考虑初相角。通过Matlab软件对各种信号进行了仿真,仿真结果表明该算法计算简单,易于实现,能够以高精度快速跟踪上系统频率。

The traditional discrete Fourier transform based algorithm or the improved algorithm requires large quantity of data,and has complex computation,and poor dynamic performance,which is not easy to realize.A frequency detection algorithm based on three-phase power grid is proposed in this paper.This algorithm uses generalized d-q-0 transformation to transform the three-phase power into the d-q-0 stationary frame.Then each of the d-axis component and q-axis component is sent to a low-pass digital filter to get fundamental component.Through calculation of filtered fundamental component,the grid frequency could be obtained.There are lots of advantages of the algorithm,such as less of required data,easy to calculate and no consideration of initial phase angle.Matlab simulation shows that the algorithm is simple,easy to implement and able to fast track the system frequency with high precision.