本論文著重於研發三相分源逆變器的電路優化，加入直交流側電壓控制、減少開關切換狀態策略與柔性切換等功能。使用傳統雙迴路控制應用於此電路會導致直流側電壓和交流側電壓耦合之問題，本論文提出新型直交流側電壓控制，可以使直流側電壓和交流側電壓分開控制，不再相互受到影響，並且可使直流側應用更加靈活。而此電路因為升壓電感充放電需平衡的關係，無法使用傳統不連續脈波寬度調變(DPWM)，必須使用修改型空間向量調變(Modified SVPWM)做控制，增加其電感充放電之穩定度。所以本論文提出一種減少開關切換狀態策略，觀察開關無用狀態，減少其開關切換次數，彌補無法使用不連續脈波寬度調變所造成的切換損失。此外本論文使用後緣鋸齒載波，可減少輸入端二極體之換向次數，減少換向損耗。最後因為此電路雙埠輸出關係，開關電流應力遠大於傳統三相六開關電路，加入柔性切換功能，使其開關切換損耗降低，以提升整體電路之效能，使其轉換效率提升。;This paper focuses on the circuit optimization of a three-phase split-source inverter, incorporating features such as DC-AC side voltage control, reduced switching state strategies, and soft switching. Using conventional dual-loop control for this circuit would lead to the problem of coupling between the DC-side voltage and AC-side voltage. This paper proposes a novel DC-AC side voltage control, which allows separate control of the DC-side voltage and AC-side voltage, eliminating their mutual influence and making the DC-side application more flexible. Due to the need for balancing the charging and discharging of the boosting inductor in this circuit, traditional discontinuous pulse-width modulation (DPWM) cannot be used. Instead, a modified space vector pulse-width modulation (Modified SVPWM) is employed to enhance the stability of inductor charging and discharging. Therefore, this paper presents a strategy to reduce switching states, identifying unused switching states and reducing the number of switch transitions to compensate for the switching losses incurred by the inability to use DPWM. Furthermore, this paper employs trailing-edge sawtooth carrier waveforms to reduce the number of diode commutations at the input side, thereby minimizing commutation losses. Finally, due to the dual-port output nature of this circuit, the stress on switch currents is much higher compared to traditional three-phase six-switch circuits. The addition of soft switching functionality reduces switch transition losses, enhancing the overall circuit efficiency and improving conversion efficiency.
