电能质量检测的研究与仿真

根据相关国家标准中的电能质量的5个指标，从测量精度和软硬件实现难度两方面因素考虑，确定各指标的测量方法。采用快速傅里叶变换（FFT）分析电网谐波，通过跟踪电网频率，实现准同步采样，解决FFT的频谱泄露问题。利用FFT的运算结果，在频域里计算出电压电流的有效值、电压偏差、功率和功率因数、三相不平衡度。闪变的测量采用IEC的测量原理，并对其作了修正，通过双线性变换，实现了闪变测量的数字化。

The Study and Simulation about Measure of Power Quality

According to five indexes of the relevant national standards on power quality, we determined the methods of measurement, considering from measuring accuracy and software and hardware realizing difficulty. Fast Fourier Transform Algorithm（FFT ） is used to analyze harmonics of the power grid, and the quasi-synchronous sampling is implemented by tracking the grid frequency, which solving the problem of frequency spectrum leak. Calculating the effective value, voltage deviation, power and power factor and three-phase imbalance are based on the resul＇ts of FFT. The flicker is measured by IEC＇ s flicker measurement method, which was corrected. Bilinear Transform which transforms from s-domain to z-domain realized the digitization of the flicker measurement.