本論文提出一種結合零序回授補償與無通訊之載波同步，應用於並聯雙向交直流轉換器之環流抑制，對於高頻開關零序環流與三倍基頻分量零序環流，皆有抑制效果。隨著電力電子的高速發展，對於高功率轉換器的需求也日漸提升，使用並聯的多模組化轉換器，有助於提高系統性能並降低成本，不僅可以增加額定容量，還可以提高供電系統的餘裕。然而，當轉換器間有不匹配參數時，由於轉換器PWM控制策略或時序不同，會產生非預期路徑上的零序環流，導致電流失真、降低系統性能。 透過所提控制法，對三倍基頻諧波環流使用回授控制消除零序環流，藉由無通訊的載波同步法，消除轉換器間載波時序不同造成環流的高頻包絡線，並且可以在整流模式與反流模式下雙向進行，達到交直流功率潮流雙向皆適用的效果。 本論文透過模擬與實作，驗證所提方法，對於兩台並聯雙向交直流轉換器，在多種條件不匹配情形下，皆能達到同時抑制零序環流的高頻開關成份與三倍基頻效果，透過消除零序環流，可以減少轉換器內部三相電感電流的失真，驗證了所提方法的可行性。 ;In this thesis, a method combing zero-sequence feedback compensation and carrier synchronization without communication is proposed for the zero sequence circulating current (ZSCC) suppression of paralleled bidirectional AC/DC converters. Both the high frequency switching ZSCC component and the triple fundamental frequency ZSCC component are suppressed. Due to the rapid development of power electronics, the demand for high-power converters is also increasing day by day. The use of parallel multi-modularized converters has benefitsefit to improve the system performance and reduce the total cost. It not only can increase the system power capcity, but also can improve the margin of the power rating. However, when there exist mismatched parameters between paralleled converters, due to the different PWM strategy and timing of converters, ZSCC on the unexpected path will be generated, resulting in current distortion and system performance degradation. Through the proposed control method, The ZSCC is eliminated by using feedback control without communication. Using carrier synchronization without communication, the high frequency envelope caused by different carrier timings between converters is reduced. and it can be utilized in both the rectifier mode and inverter mode. For two paralleled AC/DC bidirectional converters, the high frequency switching ZSCC components and triple fundamental frequency ZSCC can be suppressed simultaneously under a variety of conditions. By eliminating the ZSCC, the distortion of the three-phase current in each paralleled converter can be reduced. Through the simulation and experiment, the validity of the proposed method is verified.
