本文提出注入電流法實現併網型太陽光電發電系統之最大功率點追蹤。利用注入市電系統之平均功率約等於太陽能板之輸出功率關係，以及透過變流器之控制系統將注入市電電流同步於市電電壓前提下，本法僅藉由調整注入市電電流大小即可間接調控太陽能板之最大功率輸出。所提之最大功率點追蹤方法，它採單一變數(注入電流)控制方式來間接調控太陽能板最大功率點的出現，是較傳統多變數(太陽能板之電壓、電流及功率等)的直接控制方式來得簡單，且易於實現，其相對可靠度亦較高。實測結果顯示，本研究方法可獲致太陽能板近似最大發電能力、不增加系統處理無效電力(虛功)的負擔、不造成太多的諧波源注入電力網及可接受的系統轉換效率等系統性能要求。

An approach based on the injected current into power utility systems to track the maximum power point for grid-connected photovoltaic (PV) generation systems is suggested in this paper. Applying the relations that the average powers injected to power utility systems are approximately equal to output powers from the PV panels, and controlling the injected current synchronizing to the voltage of AC power systems through the inverter control system, the maximum output powers from solar panels can be indirectly controlled by only adjusting the amplitude of the injected currents to AC power sources. The proposed tracking strategy takes such control with a single variable (a grid-connected current only) indirectly to modulate and control the appearance of a maximum power point from a solar panel. The proposed tracking strategy is simpler and easier to implement than the conventional one, and possesses a high reliability, relatively. The experimental results reveal that the proposed approach can achieve the required system performances, such as the ability to output maximum powers approximately from solar panels, without the burden on the cost for processing the injected reactive power into power utility systems, the injected currents with less harmonic source into AC power sources, and the acceptable conversion efficiency from PV generation systems.