该函数基于的IEC 61000-4-7标准，计算谐波谱值，需要10分钟测量电压和电流信号，对平均值每10期的测量信号进行谐波分析。-IEC 61000-4-7 standard is based on the function to calculate the value of the harmonic spectrum, takes 10 minutes to measure voltage and current signals, the average of every 10 of the measurement signal harmonic analysis.