一种基于相位调制的新型低频正弦频率计算方法  

A Novel Low-frequency Sinusoidal Frequency Measurement Method Based on Phase Modulation

作　　者：王越超 李军 

机构地区：[1]广东电网有限责任公司电力科学研究院,广东广州510080

出　　处：《华北电力大学学报（自然科学版）》2015年第5期43-49,共7页Journal of North China Electric Power University：Natural Science Edition

摘　　要：精确的正弦频率测量是一些应用技术的重要基础,目前的频率测量技术在低频正弦频率测量上普遍存在准确度不高和抗噪声干扰性不强的问题,为提高低频正弦频率测量准确度,提出了一种主要由相位调制和精密相位计算方法等构成的新型低频正弦频率测量方法,分析了相位调制用于低频正弦频率测量的原理,指出了混频干扰是造成低频正弦频率测量误差的主要内在原因,通过对混频干扰的深度抑制,提高了低频正弦频率测量准确度。该方法用于测量电力系统的低频信号具有较高的准确度和较强的抗噪声和抗谐波干扰特性。数学计算、仿真实验和物理实验结果也验证了该方法的正确性和有效性。Precise sinusoidal frequency measurement is one of the fundamental methods for some applications.In the aspect of low-frequency sinusoidal frequency measurement,the current frequency measurement methods have the defects of low accuracy and weak anti-interference.To improve the accuracy of the low-frequency measurement,this article proposes a novel low-frequency measurement based on the phase modulation and the precise phase calculation method.In addition,the principle of low-frequency sinusoidal measurement based on Phase modulation is analyzed.It points out that the mixed-frequency interference is the main cause of the low-frequency measurement error.By severely inhibiting the interference of mixed-frequency,the accuracy of low-frequency sinusoidal measurement is improved.When applied in the measurement of power system＇ s low-frequency signal,the new method has the characteristics of higher accuracy,anti-noise and anti-interference of harmonic wave.Mathematical calculation,simulation test and the physical experiment results also verify the correctness and effectiveness of the proposed method.

关 键 词：相位调制 低频正弦频率测量 正交混频器 混频干扰 精密相位计算 

分 类 号：TM351[电气工程—电机]