一种基于序列零初相位调制的新型正弦信号频率测量方法

高准确度的正弦信号频率测量技术有广泛的应用，如应用于系统信号的同步处理，系统的谐波和系统的阻抗测量.但在低频正弦信号频率测量方面，现有的频率测量方法普遍存在准确度不高和抗谐波噪声干扰性不强等问题.文中提出了一种主要由序列零初相位调制等方法构成的新型正弦信号频率测量方法，分析了序列零初相位调制的原理.新方法避开了输入序列任意初相位的影响，同时调制序列携带了数值较大的信号序列全相位差信息，可实现准确度较高的低频正弦信号频率测量，此外新方法还具有较强的抗谐波噪声干扰特性，将新方法具体应用于电力系统正弦频率的测量，显示出明显的优越性.通过数学计算、仿真实验及物理实验结果验证了新型正弦信号频率测量方法的正确性和可靠性.

A Novel Sinusoidal Frequency Measurement Method Based on Modulation of Sequence with Zero Initial Phase

High accuracy sinusoidal frequency measurement technologies have been utilized in a wide range, such as the system signal synchronization, the interconnection of harmonics and the system impedance measurement. The existing sinusoidal frequency measurement technologies have the limitation of low accuracy and weak anti-interference of harmonic for low-frequency sinusoidal signals. In this paper, a novel sinusoidal frequency measurement method based on modulation of sequence zero initial phase is proposed. The principle of this method is analyzed. The influence of arbitrary initial phase can be avoided by this method. Besides, the modulation sequence carries a large number of phase difference information. Thus, it can be used for low-frequency sinusoidal signals with high accuracy and strong anti-interference of harmonic characteristic. Mathematical calculation, simulation test and the physical experiment results also verify the correctness and effectiveness of the proposed method. Compared to existing technology, this new method has obvious advantage for electric power systems.