靜態同步補償器(Static Synchronous Compensator, STATCOM)至今已經研發出許多不同的控制方法，例如：直交軸解耦合控制、滯環控制、預測電流控制、比例諧振控制……等等。而大部分電壓源換流器之控制方法都設計在低功率高開關頻率；然而，在大功率系統為了降低功率開關切換的損失，必須運行在極低的開關切換頻率下，將造成傳統控制方法產生穩態誤差，影響電流補償之效果。
本論文提出結合電路模型之擬似牛頓控制法，取代傳統比例積分控制。其優勢為可操作在開關頻率極低的情況下，能夠有效的補償且穩態誤差較小。本論文除了利用電磁暫態分析軟體(PSCAD/EMTDC)離線模擬以外，還利用LabVIEW PXI作為控制器的開發平台，並在即時數位模擬器(Real-Time Digital Simulator ,RTDS)中建構平衡與不平衡靜態同步補償器之硬體閉迴路模擬。將控制策略實現於離線與線上模擬，相互比較與討論。

Many control strategies have been developed for Static Synchronous Compensator (STATCOM) nowadays such as decoupled dq frame control, hysteresis control, predictive control, proportional resonant control, etc. Most of the control methods were designed for low power and high switching frequency systems. However, in high power system, voltage source converters should be operated in low switching frequency in order to reduce switching power loss. Traditional control methods may cause significant steady-state error and affect the effectiveness of current control.
This thesis proposes an iterative control method based on Quasi-Newton method, which is more suitable to use at low switching frequency in a high power system. The proposed control strategy is applied for STATCOM in balanced and unbalanced condition to compensate the reactive power at the point of common coupling. The results have been both verified by offline simulation with PSCAD/EMTDC and by hardware-in-the-loop simulation with Real-Time Digital Simulator (RTDS).

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