本研究研製一額定容量為10 kVA高低頻互補換流器並改善其漣波補償效率和加入功率調配等功能，其中包含兩台並聯之三相四線半橋式換流器，並使用兩顆微控制器Renesas RX62T晶片分別操作於不同頻率。低頻換流器額定功率較高，高頻換流器額定功率較低。本換流器透過高低頻電流互補控制，以消除低頻電感漣波電流。在漣波消除操作模式下，動態響應與等效漣波電流由高頻換流器主導。高切換頻率使系統有較快之動態響應與較小之電流濾波器。通過高低頻換流器功率配置，傳統大功率且高頻換流器與系統內對應規格之零件可由低頻大功率和高頻低功率元件取代，達到相同功率與動態響應，同時符合併網換流器電力品質規範。
在換流器控制方面，分切合整數位控制可省去abc-dq座標軸轉換，直接由電流誤差計算對應的開關責任比，同時抵消直流鏈電壓、開關切換頻率以及電感值變動的影響，故適合用於低頻電感漣波電流計算與互補消除。此外，分切合整數位控制可針對低頻漣波計算斜率並精準補償將漣波消除。把分切合整數位控制法實際應用於換流器的控制，以模擬與實測結果來驗證此系統的可行性。

This thesis shows research results of a 10 kVA division-summation (D-Σ) digital controlled hybrid-frequency inverters (HbFIs) and the refinement of the ripple compensation and power scheduling. The system consists of two parallel three-phase four-wire half-bridge inverters with different switching frequencies and power ratings and with microcontroller Renesas RX62Ts as control kernels. Low Frequency Inverter operates with high power rating, while High Frequency Inverter operates with low power rating. HbFIs cancel out the low frequency current ripples with the ripple cancellation control. With ripple cancellation, the dynamic response and equivalent switching frequency of the system is dominated by the High Frequency Inverter. Higher switching frequency increases the dynamic response and reduces the size of its LCL filter. Also, with power scheduling, the components in the high power high frequency inverter can be replaced with high power low frequency and low power high frequency ones while satisfying the high power high dynamic response specifications and the power quality regulation for grid connected applications.
Regarding the control of the inverter,the D-Σ digital control calculates the command for SPWM from current error without operating abc-dq frame transformation. Variations of dc bus voltage, ac side voltage and inductance have been taken into consideration. Hence,the D-Σ digital control is suitable for low frequency current ripple cancellation. Besides,D-Σ digital control can accurately calculate the slope of the low frequency current ripple and cancel the ripples precisely. Finally,the D-Σ digital control for ripple cancellation is conducted on a practical system. And the feasibility of HbFIs is verified by both simulated and experimental results.

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