本文主旨在研發一太陽能電池之最大功率追蹤器。當日照強度發生改變時,此追蹤器可追蹤至太陽能電池之最大功率點,並且在太陽能電池呈現部分被遮蔽情況下,亦可使太陽能電池輸出最大功率。 整個追蹤法則是以阻抗匹配為基礎觀念,並且配合擾動觀察法的技巧,根據太陽能電池的物理特性,擷取太陽能電池輸出的端電壓及端電流,改變追蹤器之工作週期,使追蹤器之輸入阻抗與太陽能電池之內阻互相匹配以獲得最大功率的輸出。同時在部分遮蔽扭曲原有PV特性曲線的情況下,仍然可以使太陽能電池藉由此阻抗匹配法追蹤到最大功率。 本系統中使用Microchip PIC18F4520單晶片微控制器,配合適切的周邊硬體及軟體來建構上述所提出的方法,以期達到最大功率輸出的追蹤,文中並以實作之軟硬體驗證所提出之理論。
The purpose of this thesis is to develop the maximum power tracker of solar cell. In order to react to the illumination condition changed, the tracker can track the maximum power point of solar cell. It can also track the maximum power point in the partial shade of solar cell. The entire tracing principle is taked the impedance matching as the foundation idea, and coordinate perturbation observation method skill. According to the characteristics of the solar cell, this power tracker can get the output voltage and current of solar cell, while detecting the output power. It can also adjust the duty cycle of the tracker and to make its input impedance match the solar cell’s internal impedance, while obtaining the maximum power output. Under the condition that partial shade distorting original PV curve, the tracker is still able to keep the solar cell getting the maximum power by impedance match method. A single-chip microprocessor, PIC18F4520, is used in the system, and an experimental hardware scheme with software algorithm is established to prove the proposed principle in the expectation to attain maximum power tracking.