| 引用本文: | 文超,钟俊.一种适用于GPS信号异常情况的高精度主时钟设计方法[J].电力系统保护与控制,2016,44(3):103-108. |
| WEN Chao,ZHONG Jun.A design method for high-accuracy master clock applied to the circumstance of abnormal GPS signal[J].Power System Protection and Control,2016,44(3):103-108 |
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| 摘要: |
| 合并单元采样同步是智能变电站正常工作的前提。GPS信号正常时利用最小二乘法建立晶振的误差估计模型，GPS信号异常时利用晶振产生秒脉冲，并用已建立的晶振误差估计模型对这些秒脉冲进行误差补偿后用以作为各合并单元的同步时钟，提出了一种利用GPS信号接收机和晶振共同组成主时钟的设计方法。该方法综合考虑了晶振已有的频率偏差和在GPS信号异常期间由于晶振老化所带来的误差，估计并补偿了GPS信号异常时晶振秒脉冲的误差。仿真结果表明该方法能有效消除晶振累积误差，所产生秒脉冲的误差在前10 min内不超过50 ns，满足系统对时钟的精度要求。 |
| 关键词: GPS 合并单元 时钟精度 最小二乘法 误差补偿 |
| DOI：10.7667/PSPC150612 |
| 分类号: |
| 基金项目:四川省科技支撑计划(2012GZ0009，2014GZ0010) |
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| A design method for high-accuracy master clock applied to the circumstance of abnormal GPS signal |
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WEN Chao, ZHONG Jun
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College of Electrical Engineering and Information Technology, Sichuan University, Chengdu 610065, China
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| Abstract: |
| Merging Unit (MU) synchronous sampling is essential for smart substation. Building the crystal-PPS error model by least squares at the normal GPS signal, and generating PPS that be amended according to the error model by the crystal when the GPS signal is abnormal, a new design method that the master clock could be consist of GPS signal receiver and crystal is proposed. The amended PPS generated by crystal is the uniform clock to MUs. Frequency deviation and frequency aging of the crystal are both considered. Calculating and amending the crystal-PPS error according to the real datum is the main method. The proposed design method has been applied to Matlab test system, the results validate the proposed method could remove accumulative error of crystal, the crystal-PPS error is less than 50 ns for the initial 10 min, and the results meet the requirements of the substation system. |
| Key words: GPS merging unit clock accuracy least squares error amended |
