存在電力系統中之諧波，對於供電品質之影響甚鉅，因此亟需有一套準確之諧波量測技術，以協助擔任諧波改善之工具。目前於諧波量測方式上，常藉由使用快速傅立葉轉換，但在直接應用此快速傅立葉轉換作為諧波含量之分析時，卻往往因洩漏效應(Leakage Effect)、摺疊效應(Aliasing Effect)、柵欄效應(Picket-Fence Effect)的發生，致使錯估量測值之可能性大幅提高。因此如何有效改進量測準確度，已為諧波量測中亟待解決之問題。
本文提出兩種不同形式之複數型卡爾曼濾波器，並將其應用於電力系統中電壓及電流諧波含量之估測，期能改進傅立葉轉換所估測的準確度及增進卡爾曼濾波器應用的效能。但有鑑於實數卡爾曼濾波器在量測值發生驟變時，卻有無法即時追蹤之缺點，因此本文即針對此一缺點分別提出複數量測矩陣及複數狀態轉移矩陣來改善，並藉由數值模擬及實際電流諧波含量之估測。將所提方法與實數卡爾曼濾波器之測試結果予以比較，以驗證其可行性。

With the existence of harmonics, they are known notorious to downgrade the quality of supplying power. Hence, it becomes crucial to develop an efficient technique as an aid to decrease the effects of power system harmonics. Most approaches proposed nowadays were based on the fast Fourier transform method. Although such approaches were seen feasible for certain scenarios, the resultant leakage effects, aliasing effects and picket-fence effects were deemed side-effect nuisances, which may deteriorate the monitoring performance significantly.
To improve such drawbacks, two complex Kalman filters are proposed in this thesis with anticipation of tracking voltage and current harmonics at a higher performance. By use of the proposed complex Kalman filter-based method, even when the measurements encounter drastic variations, the method can help grasp the harmonic characteristics more effectively. In order to validate the proposed method, the simulated harmonic source was first used for the performance evaluation of frequency tracking. This is followed by the on-site experiments made on the arc furnace using the data recorded. From simulated results and experimental outcome, they help support the feasibility and practicality of the method.

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