- 學位論文
以混合式儲能提升獨立型太陽電池發電系統充電效率研究
Improvement of Stand-alone Solar PV Charging Using Hybrid Energy Storage Technique
摘要
本研究主旨在於探討混合式儲能裝置對於提升獨立型太陽能電池充電性能的原因，主要內容包括高頻脈衝電流對於鉛酸電池與混合式電池的影響，並利用實驗證明加入超級電容可減少電池的總內阻，以及超級電容擁有緩衝瞬間大電流的能力，最後利用戶外實際測試，發現利用磷酸鋰鐵電池(1AH)與一般電容(0.05F)也有提升獨立型太陽能系統充電效率的效果。 在高頻脈衝電電充電實驗中，發現提高PWM 定電壓充電頻率無法增加鉛酸電池的充電量，此結果並不符合理論推導，可能原因在於電池模型的建立方法過於簡化，無法徹底有效描述電池的特性，造成理論與實際驗證結果不合。 在找尋並聯超級電容提升鉛酸電池充電量的原因時，發現加入超級電容確實可減少總內阻，以及緩衝瞬間大電流的能力，但電池主要的充電增加並非在Phase2的PWM控制，而是因為太陽輻射量的變化，影響了太陽能板的輸出電流，而混合式電池可避免瞬間的電流變化造成電池極化速度的上升，使電池能以較高的電容量進入Phase2充電，提升電池的充電效率。在戶外實測中，證明並聯一般電容與鋰鐵電池也有提升充電的效果，當日輻射量≥15MJ/m^2，並聯288F超級電容、1AH磷酸鋰鐵與0.05F一般電容提升量分別為16.5%、12.9%與10.6%的日充電量，且提升1%充電量的成本降至約100台幣以下。
並列摘要
This research focuses on the study of improving charge performance of stand-alone solar PV power generation system by using hybrid energy storage, including the effect of high-frequency pulse current on the charging performance. It is experimentally found that supercapacitor (SC)-lead acid battery hybrid storage has lower overall internal resistance and improves the charging performance. The outdoor test results also show that hybrid storage using lithium iron phosphate battery and ordinary capacitor can improve solar charging performance. In high-frequency pulse current charging experiments, it has shown that high pulse-width modulation (PWM) frequency in constant-voltage charging cannot increase the charging performance of lead-acid battery alone. This result was not consistent with theoretical deduction, probably due to modeling error of battery. However, SC-LA hybrid storage has lower overall resistance and abilities to stabilize the instantaneous large current variation. This causes the battery voltage to rise slowly and smoothly during solar charging process with changing current. More charging is thus obtained. The improvement of charging performance of hybrid storage is not due to the PWM charging control in Phase2. The long-term outdoor comparative test results have shown that the lithium-ion battery (1AH) and normal capacitor (0.05F) have abilities to improve the charging efficiency of stand-alone solar system. The hybrid devices with SC 288F, lithium-ion battery (1AH) and ordinary capacitor (0.05F) can increase the daily solar energy generation by 16.5%、12.9% and 10.6% at solar irradiation > 15 MJ/m2. The additional cost is under NT$100 for one percentage of charging increase.