本研究設計與製作一部額定容量為100 kVA且具備多功能的換流器，其中以三相四線半橋式的電路架構作為高功率的傳輸媒介，並將微控制器Renesas RX62T作為控制核心。本換流器主要有兩種操作模式，分別是交流穩壓模式與併網模式。在交流穩壓模式下，換流器採用電壓型分切合整數位控制法，其中包含負載阻抗估測法，使換流器能夠輸出穩定的三相弦波電壓供三相負載使用；在併網模式下，換流器則採用電流型分切合整數位控制法，此時換流器便能依照實虛功平面輸出或輸入不同大小的實虛功，進而補償電網電壓與電網頻率。
在換流器控制方面，本研究使用的分切合整數位控制免除傳統abc-dq座標軸轉換，大大地簡化推導受控體與控制法則的過程，並藉由設計控制器抵消直流鏈電壓、開關切換頻率以及電感值變動對受控體的影響。分切合整數位控制將實際上會隨電流大小改變的電感值納入考量，並允許寬廣的變化，可避免因電感值衰減造成輸出波形失真，也可選用較小的電感鐵芯以降低體積與成本。此外，結合分切合整數位控制的正弦脈寬調變(Sinusoidal Pulse Width Modulation, SPWM)將三相換流器等效成三個單相換流器分別進行控制，也降低控制上的複雜度。最後，將分切合整數位控制法實際應用於換流器的控制，再以模擬與實測結果驗證此換流器系統的可行性。

This thesis presents design and implementation of a 100 kVA division-summation (D-Σ) digital controlled multi-function inverter. A three-phase four-wire half-bridge circuit structure is adopted for high power transferring and the microcontroller Renesas RX62T is the control center of the system. The inverter can be operated in grid-connected mode and ac-voltage regulation mode. In the ac-voltage regulation mode, the voltage tracking with D-Σ digital control, including load impedance estimation, is used for the inverter to output stable three-phase sinusoidal voltage. In the grid-connected mode, the current tracking also with D-Σ digital control is utilized. Therefore, the inverter is able to adjust the output of active power and reactive power to stabilize grid voltage and grid frequency.
Regarding the control of the inverter, D-Σ digital control avoids conventional abc to qd frame transformation. Consequently, derivation of the plant and control law can be significantly simplified. The controller with D-Σ digital control is designed to eliminate the effects caused by the variation of dc bus voltage, switching frequency, and inductance. D-Σ digital control takes into account the inductance variation. It has the benefits such as allowance of wide inductance variation and reduction of core size and cost. Moreover, an SPWM combined with D-Σ digital control separates a three-phase inverter into three single inverters and reduces complexity of control. Finally, simulated results and experimental results have verified the feasibility of the inverter system.

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