PV 追日機發電預測模型與分析

Modeling and Analysis of Solar Energy Generation for PV-trackers

潘亦倫(Yi-lun Pan)

指導教授 ： 蔡鍚錚

國立中央大學/工學院/機械工程學系/碩士(2013年)

摘要

本論文研究之目的為建立簡單且容易使用的太陽光電(photovoltatic，簡稱PV)發電預測模型，以提供太陽能發電設備投資時的評估。此模型以實際量測氣象資料對不同地區考慮日射量與電池溫度之影響，並採用全年逐時之發電量進行計算。同時也納入不同類型PV追日機（包括固定式、單軸、雙軸追日機）追日時造成之能量損失的偏差角計算。
　　以本論中所發展之模式，針對中壢(24.97°N)及恆春(22°N)安裝之太陽光發電裝置進行不同條件之理論發電量分析，結果顯示追日機與固定式相較之下晴天時較具優勢，陰天時則幾乎沒有差別。全年發電量來看，雙軸追日與單軸追日相近，雙軸追日多約2%~3%；傾斜固定與水平固定相近，傾斜固定多約0%~3%；整體而言，追日機較固定式多約15%~16%，恆春較中壢多約34%~36%。單軸追日之最佳傾角於中壢為15°，於恆春為18°；固定式之最佳傾角於中壢為14°，於恆春為17°；且容許全年發電量下降1%的角度範圍約±10°。單軸追日之避免陣列遮陰模式中，「反向追日」比「復歸平面」全年發電量僅多約3%~4%。
　　另一方面，為驗證本論文所建立發電預測模型準確性，本論文亦與現有軟體、實測資料等進行比較。與商用PVsyst軟體比較，兩者之全年發電量差異約3%~4%。與國內能源局提供資料比較，兩者之全年發電量差異約7%~8%。由安裝於中央大學與屏東科技大學等追日機實際量測發電量比較結果，單月模擬差異皆約在±6%以內。顯示本論文之PV發電量模型考慮的參數雖然簡單，但模擬結果仍相當接近實際量測發電量。

關鍵字

太陽能 ； 光電發電 ； 追日機 ； 預測模型

並列摘要

The main purpose of this thesis is to develop a simple and convenient predicting model of PV-energy production while in evaluating the investment of solar energy facilities. The model calculates the cumulative hourly PV-power to the whole year by using the measured meteorological data at the location of the installed PV-facilities under consideration of the effects of solar irradiation and cell temperature. The calculation of the power loss due to the deviation in tracking angle for the sun on different kinds of PV tracker (fixed-panel, single-axis tracker and dual-axis tracker) is also included in the model.
The model developed in this thesis is at first used to analyze the theoretical solar energy generated in different PV-facilities which are installed at Chungli (24.97°N) and Hengchun (22°N), respectively, under different conditions. The results show that solar trackers in compraison with fixed-panel have advantage at clear days, but no significant difference at cloudy days. The power generated by a dual-axis tracker is similar to a single-axis tracker for a whole year, whereby the dual-axis tracker gains about 2%~3% more than the single-axis tracker. On other hand, the power generated by an inclined fixed-panel is only about 0%~3% more than a horizontally fixed-panel. In general, the trackers (two-axis of single axis) gain 15%~16% more than the fixed-panels. Furthermore, the power generated at Hengchun is 34%~36% more than Chungli. The optimal inclined angle of a single-axis tracker is 15° for installation at Chungli and 18° at Hengchun. The optimal inclined angle of a fixed-panel is 14° for installation at Chungli and 17° at Hengchun. The tolerance range for mounting the inclined angle which affects 1% reduction of generated solar energy is about ±10°. Two methods to avoid array shading of single-axis tracker are also compared for generated solar power. The analysis results show that the power generated by the “back-tracking” method is 3%~4% more than that generated by the “origin position” method for a whole year.
The accuracy and reliability of the proposed prediction model is also validated by comparing with available software and measured data. In comparison with the commercial software PVsyst, the difference of solar energy production in a whole year is about 3%~4%. Compared with the data that domestic Bureau of Energy provides, the difference of solar energy production in a whole year is about 7%~8%. Comparing with measured data of PV-power generation from the trackers installed at National Central University and National Pingtung University of Science and Technology, the simulated energy production for a single month is only within ±6%. The results of the investigation show that the simulated results have a good agreement with the measured data, although the parameters considered in the proposed model are simple.

並列關鍵字

Solar energy ； Photovoltaic ； Sun tracker ； Predicting model

參考文獻

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