考量電力系統的配電架構，並結合分散式發電與備用電源裝置，本研究提出一應用於電力調節系統之單相三線式雙向換流器，可調節直流鏈與交流電網間的電力潮流，同時亦擁有不斷電系統的功能。此換流器可分為電力級與控制級，電力級採用雙半橋架構，而控制級以微控制器Renesas RX62T 做為數位控制核心，實現所推導出之開關責任比率。
本研究之主要貢獻可摘要如下：第一點貢獻為提出一多功能單相三線式換流器，其操作模式包含併網模式和穩壓模式。當市電正常時，換流器操作於併網模式，若直流鏈電力充足時，換流器執行電力注入功能，將直流鏈電力饋入市電；當直流鏈電力不足時，換流器執行整流功能，由市電將電力送至直流鏈。若市電發生異常，換流器切換至穩壓模式，使負載可以持續運作。第二點貢獻為採用分切合整控制法，將交流電壓與電感值納入控制法則推導，因此換流器可避免因交流電壓諧波而造成輸出電流失真，同時可允許寬廣的電感值變化，有效減少電感鐵芯的損失與尺寸，並降低輸出電流漣波。第三點貢獻為藉由阻抗估測法將分切合整控制法運用在穩壓模式，同時導入重複控制，有效降低穩壓模式之電壓總諧波失真。最後實作一部單相三線式雙向換流器，並經由實測結果驗證本研究所提出之理論與換流器操作之可行性。

Considering the power distribution system, this research develops a single-phase three-wire bidirectional inverter for integrating renewable and battery back-up energy into uninterruptible power system (UPS). The inverter can control the power flow between the DC bus and utility power. Additionally, it can also work as a UPS. The inverter consists of a power stage and a control stage. The power stage is realized with a dual half-bridge configuration, and a single-chip microcontroller Renesas RX62T is adopted to realize the control stage.
The major contributions of this research can be summarized as follows. First, a multifunctional single-phase three-wire inverter is proposed. The operation of the inverter includes grid-connection and voltage-regulation modes. When utility power operates normally, the inverter operates in grid-connection mode. There are two functions in grid-connection mode, power-injection and rectification. With power-injection function, the inverter will inject real power to utility power. With rectification function, the inverter will buy power to replenish the DC bus. When utility power fails, the inverter can transit seamlessly from grid-connection mode to voltage-regulation mode and function as a UPS. Secondly, the control law includes inductance and grid voltage with division-summation (D-Σ) digital control. Hence, the inverter is allowed to have a wide inductance variation, reducing core loss and size significantly. Thirdly, with load impedance estimation and repetitive control, the D-Σ control can be applied to voltage-regulation mode and the inverter with the D-Σ control can shape sinusoidal output voltage with low harmonic components under various types of load conditions. Finally, the inverter has been implemented and tested. Simulated and experimental results have verified the proposed control scheme and feasibility of the inverter.

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