在低壓電網中，高度的太陽光電變流器滲透率將影響電網的穩定度與可靠度，所以併網型變流器需利用一些控制策略來維持、改善電網的電力品質，因此本研究提出一種新型的實虛功控制策略應用於併網型單級式三相太陽光電系統，目的是要維持共同耦合點(PCC)上的電壓變動率，此控制策略不只注入實功至電網，還會依電壓變動程度注入虛功至電網或從電網中吸收虛功以符合電力公司之規範，同時在不超過變流器的容量限制下，提出另一種考量經濟效益的控制策略，將發電用戶的實功輸出、虛功補償做適當的調整，使回售利益最大化的提升。此外，還提出可調變步長之改良型增量電導法以提升最大功率點追蹤法(MPPT)的追蹤速度與準確度。而本研究所使用的單級三相電流控制電壓源變流器(CCVSI)具有最大功率點追蹤與功率控制的能力。最後，利用模擬與實驗結果驗證所提出實虛功控制策略應用於併網型單級三相太陽光電系統在電壓變動時之成效。;High penetration level of the photovoltaic (PV) inverters in low voltage (LV) distribution grid will impact the stability and reliability of the grid. The main objective of the control strategy of the grid-connected inverter is to maintain or improve the grid stability, reliability and power quality. Therefore, in this study, a novel active and reactive power control strategy of a single-stage three-phase grid-connected photovoltaic (PV) system is proposed to mitigate the voltage variation at the point of common coupling (PCC). The single-stage three-phase grid-connected PV system introduces a current-controlled voltage-source inverter (CCVSI) to achieve the maximum power point tracking (MPPT) control of the PV panel and the function of power control. Moreover, a modified variable step-size incremental conductance (VSSIC) method is proposed to improve the tracking speed and accuracy of the MPPT control of the PV panel. Furthermore, the single-stage three-phase grid-connected PV system will inject or absorb the reactive power into or from the grid to mitigate the voltage variation at the PCC according to the grid codes. In the meantime, an economics optimization method is proposed to determine the control values of the active and reactive power with guaranteeing the output power of the three-phase inverter within the rating of itself. Finally, some experimental tests are realized to validate the effectiveness of the proposed control strategy.
