新型电力网络仪表的谐波测量方法与实现

研制高性能电力参数监测设备已成为市场的迫切需要。文中介绍了一种新型数字式电力监测网络仪表的设计方法。采用快速傅里叶变换(FFT)的基-2算法,通过傅里叶分解对畸变波形的各种分量进行分析,将采样取得的N个离散信号通过离散傅里叶变换得到各次谐波分量的频谱,目的是为了计算出电流电压有效值及其相应的总谐波畸变率,并且可以测量出功率、功率因数等各种电力参数,通过CAN现场总线实现对电网电能质量的远程自动监测。该方法采用数字信号处理器(DSP)在PMM 2000数字式电力监测网络仪表中得以实现,电流电压的测量精度为0.2%,其它电力参数的测量精度为0.5%。

Harmonic Measuring Approach and Realization Using New Type Electric Meter

A design of new type digital electric monitoring instrument for power network is introduced in this paper.FFT base-2 algorithm is adopted,and various components of the distorted waveform are analyzed by Fourier decomposition.Then the spectrum of harmonic components is obtained from N sampled discrete signals by discrete Fourier transform.Thus various electrical parameters,such as virtual value of the voltage and current,total harmonic distortion,power and power factor,can be worked out.Electric network power quality can be monitored automatically and remotely through CAN-bus.The design is implemented in PMM2000 digital electric monitoring instrument using DSP.The measuring precision is within 0.2% for voltage and current,and 0.5% for other parameters.