三相不平衡度数字检测系统设计

Design of three-phase imbalance degree tester

提出了一种基于MSP430单片机的三相不平衡度的数字检测系统。在滤波器的设计中采用了硬件模拟滤波器和软件数字滤波器共同组成,硬件滤波器采用开关电容型低通滤波器,软件滤波采用加海明窗函数的线性相位FIR数字滤波器。系统的算法实现主要采用三相不平衡度的定义,通过交流采样值分别求出正序分量和负序分量的采样值,正序分量和负序分量的均方根值的比值便是三相不平衡度。较之纯硬件滤波或纯软件滤波系统,整个系统的响应速度快。通过实验证明了该系统具有较高的可行性和实用性。

A digital three-phase imbalance degree tester based on MSP430 is presented. It has both HW and SW filters. The hardware filter adopts the switching-capacitor-type low-pass filter while the software filter applies the linear-phase FIR digital filter with Hamming window function. Based on the definition of three-phase imbalance degree,it calculates the positive and negative sequence components from AC sampling values and the ratio of their root mean squares to obtain the three-phase imbalance degree tested. The tester has better system response speed than pure hardware filter system or pure software filter system. Results show its better feasibility and practicability.