基于标准频率相位均匀延迟的相位差测量研究

针对传统的相位差测量方法测量精度低、系统构成复杂的缺点,提出一种基于标准频率相位均匀延迟的相位差测量方法。在被测信号过零点间隔,对标准频率信号和经过均匀延迟的m-1个标准频率信号进行计数、平均滤波等操作,得到被测相位差。分析、计算表明该方法的测量误差是传统法的1/m。应用可编程片上系统(SOPC)设计了测量系统,进行了相位差测量实验。在给定条件下测量误差小于0.5°,精度高于0.14%。当提高标准频率及减少均匀延迟时间时,测量精度进一步提高。该方法比传统方法精度高、系统协同性好。

Research on Phase Difference Measurement Based on Uniform Delay of Standard Frequency Phase

Owing to the low accuracy of traditional method of measuring phase difference and complicated system structure, a new method based on uniform delay of standard frequency phase is proposed in this paper. The standard frequency signal and m-1 equal-delayed standard frequency signals within the zero-crossing interval of the measured signal are counted. The phase differences of the measured signal are obtained after average filtering. Analysis and calculation show that the error of this method is one mth of traditional method. In this method, system-on-a-programmable-chip (SOPC) is applied to design measurement system and phase difference measurement experiments are carried out. Results show that the measurement error is less than ±0.5° and precision is higher than 0.14% under the given conditions. When the standard frequency is increased and the uniform delay interval is reduced, measurement accuracy is further improved. It is concluded that this method has higher precision and better concertedness than traditional method.