頻率是電力系統中一項重要參數,為了解系統之動態行為,廣域頻率量測為一有效之方法。本研究旨在研製廣域動態頻率量測系統雛形,文中介紹了系統之整體架構,包含同步電壓取樣平台及電腦端的頻率計算方法。同步電壓取樣平台是應用可程式系統晶片、GPS接收器與類比轉數位模組整合而成,用以同步取樣電壓訊號並傳送至電腦,電壓訊號的頻率值是使用離散傅立葉轉換加上後處理方式即時計算而得。文中比較了不同後處理方式的效能,包括使用一次模型的最小平方法、使用二次模型的最小平方法與平均法的方式。結果顯示只有平均法所得的頻率量測值,可符合IEEE同步相量量測標準中P-class所要求之穩態與動態訊號下的頻率誤差,最後展示研製之系統量測110V插座訊號的結果。
Frequency is one of the important parameters in power systems, and wide-area frequency measurement is an effective method for observing the dynamic behavior of systems. The study is to design and implement a prototype of wide-area dynamic frequency measurement system. This thesis describes the structure of wide-area dynamic frequency measurement system, including a platform for synchronous voltage sampling and calculation method for the value of frequency method. A System on a programmable chip, GPS receiver and ADC module are used to develop the synchronous voltage sampling platform. And, the voltage samples are transmitted to PC through Internet. The real-time frequency calculation by Discrete Fourier Transform plus post-processing is performed in remote computer. The performance of post-processing methods, including least-squares method (LSE) with linear model, LSE with quadratic model and average method, are compared in this thesis. The results show that only average method makes compliance with requirements of P-class under conditions of steady-state and dynamic signal in the IEEE standard. Finally, the measured values of synchronous frequency in voltage signals from 110V outlet are presented.