近年科技發展日新月異，隨著雲端技術的一日千里，相對的硬體設備需求也日益增加。伺服器中心所安裝的雲端運算及儲存機組，皆會具備有功率因數校正的功能，使得輸入電流為理想的正弦波。在交流側也需安裝濾波電容以符合電磁波干擾排放的規範法規。除此之外，為了預防臨時的無預警停電問題，伺服器中心通常都搭配使用不間斷電源系統(UPS)，其交流側也配備有電容。大量的交流側電容與市電側之等效電感造成共振而產生了較低的諧振頻率，當遇上較差的供電環境時，在用戶端的市電電壓及電流會產生嚴重波形失真，對於供電品質以及家用電器壽命都是一大威脅。
於本篇論文中，將會介紹幾種主動式阻尼控制技術，運用於壓制頻率共振所產生的諧波失真。針對市電側電感電流的微分控制以及針對交流側電容電壓的相位領先補償器控制都會被詳細的介紹及說明。大致上來說明，主動式阻尼控制技術是在市電側電感或是交流側電容串聯一虛擬電阻以達到抑制諧波的效果。實驗測試結果針對市電側電流以及責任分界點電壓的波形進行頻譜分析，用於評估主動式阻尼技術對於諧波抑制之效果，及對於結果進行探討。

In recent years, the server racks and cloud computing equipments are massively deployed, and they require PFC front-ends for ideal sinusoidal current inputs. However, in order to comply with industrial EMI standard, these front-ends are usually equipped with AC filtering capacitor. Furthermore, for overcoming power outage, these server centers require the aid of Uninterrupted Power Supplies (UPS), which are also equipped with rather large AC-side capacitors. Along with large grid side inductors, these capacitors result in low frequency resonance in hundreds Hz to few kHz. It leads to serious harmonic distortions on client voltage and grid side current caused by low power quality.
In this thesis, several kinds of active damping control for suppressing the harmonic distortions caused by frequency resonance are presented. The inductor current derivative control and capacitor voltage lead compensation control are introduced. In general, these methods simulate an resistor in series with grid side inductor or filter capacitor for harmonic damping. Both the simulation and experiment results are provided to evaluate performance of the proposed active damping control.

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