电力网络监控仪中数据采集模块的设计

The design of the data acquisition module in electricity network monitoring meter

讨论了一种电力网络监控仪的数据采集模块的设计方法。结合锁相环同步技术改进数据采集模块,加入锁相环频率跟踪电路,实现同步等间隔采样,减小了非同步采样引入的误差;针对快速傅里叶变换(FFT)算法的栅栏效应和频谱侧漏提出了加窗插值FFT算法,并把算法移植到ARM内核的微控制器LPC2138中,精确实现了电网各次谐波幅值频率和总谐波畸变率的计算。

For the synchronization error, the article studies the data acquisition module design in a power network monitoring device. This paper adds phase-locked loop frequency tracking circuit using PLL synchronization technology, realizing synchronous sampling, and reducing the error introduced by non- synchronous interval sampling. Due to spectral leakage and barrier effect in FFF, the thesis chose interpolating windowed FFT to process the data, and transplant the algorithm to microcontroller LPC2138. Every frequency harmonic wave＇s amplitude and frequency were calculated precisely, including the total harmonic distortion.