在本文中提出了MMC穩態精確模型，由於此模型是使用時間域的方法，因此輸出的諧波不會受到計算諧波的次數所影響。此外，由於VSC具有非線性和時變的特性，因此使用了疊代方法使模型充份表現出轉換器的穩態特性。本文也提出了一種混合方法，該方法在時間域中對MMC建模，而控制器則是在頻率域中建模，因此產生了高效的諧波模型。而使用所提出的方法來預測諧波，其結果與PSCAD/EMTDC相比，不僅計算時間比較少，而且具有很高的相似度，藉此證明了此方法的有效性。

In this thesis, an accurate steady-state model for an MMC is proposed by using time domain method, such that the output harmonics do not suffer from harmonic truncation errors. Moreover, because of the non-linear and time-varying nature of the VSC, an iterative approach is used in the models in order to fully characterize the steady-state behavior of the converter. This thesis also proposes a hybrid method, where the MMC is modeled in time domain while the controller is modeled in frequency domain, thus yielding a highly efficient harmonic model. The harmonics predicted by the proposed method are in great agreement with those of PSCAD/EMTDC, and the speed of calculation is faster than that of PSCAD/EMTDC, demonstrating the validity of the proposed method.

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