- 學位論文
光伏電模組新型零電流切換降壓式蓄電池充電器
Battery Charger of a Novel Zero-Current-Switching Buck Converter for Photovoltaic Modules
摘要
太陽能在能源的供應上取之不竭、用之不盡，又無污染等的再生能源，極具有發展潛力，近幾年來來已經被廣泛的使用。太陽能發電系統主要是由光伏電模組和能量儲存裝置所組成，利用陽光照射時，光子提供額外動能，激發電子流動將日光轉換成電能，然而經由蓄電池將能量儲存起來，當無日光時再將蓄電池所儲存的電能供給負載使用。 太陽能發電系統固然是好，但還是有缺點所在，就是整組系統的裝置費用較高，且能量轉換的效率較低，因此為了增加太陽能轉換的效率能被充分的利用，許多的充電技術陸續的被提並且運用。本論文提出一種簡單、快速且可靠的切換式轉換器將光伏電模組的能量轉換儲存到蓄電池。本篇論文所採用的充電電路是利用傳統零電流切換轉換器中增加一個輔助開關所演變形成的一種新型零電流切換降壓式蓄電池充電器。與傳統零電流切換蓄電池充電器相比較之下，本論文所採用的新型零電流降壓式蓄電池充電器，確實可以減少功率開關上開關電壓與開關電流重疊所造成的損失。 本論文所採用的新型零電流降壓式蓄電池充電器之最佳電路參數設計，是藉由電路結構的頻率響應曲線，且以等效電路為基礎，推導電路參數的設計方程式所設計出來。如果將傳統零電流切換蓄電池充電器與本論文所採用的新型零電流降壓式蓄電池充電器做比較，本論文所採用的新型零電流降壓式蓄電池充電器最主要的優點是較短的充電時間、較高的充電效率與較低的電路成本。最後，由實驗測量結果所顯示的效率曲線圖可知，充電總平均效率可達85%以上。
並列摘要
As a clean and renewable source, solar energy has been used widely in recent years. Solar energy generation systems generally consist of a photovoltaic array, which converts sunlight into electrical energy as the solar cells produce a flow of electrons through the absorption of light photons, and a energy storage device. Batteries are used to store the excess available energy from the photovoltaic array during the day and provide energy for the load during the times of little or no sun. The main drawbacks of solar energy generation systems are high fabrication cost, and low energy conversion efficiency. For increasing conversion efficiency, many charging techniques have been proposed and implemented. A simple, fast and reliable converter for rechargeable batteries with soft-switching schemes by photovoltaic arrays is proposed. Simply by inserting an auxiliary switch in series with the resonant capacitor in the traditional zero-current switching converter, a novel zero-current switching converter for battery charger is obtained in this paper. Moreover, when compared with the battery charger with the traditional pulse-width-modulated one, the novel battery charger with zero-current switching converter indeed reduces the loss between the switch voltage and the switch current of the active power switch, resulting in the reduction of switch losses. The optimal circuit parameters of the novel battery charger are designed by applying the frequency response curve and electric functions derived from the circuit configuration. The main advantages of the proposed battery charger as compared with conventional one are shorter charging time, higher efficiency and lower cost. Finally, the experimental test results are illustrated to show the efficiency of the topology, and the charging efficiency is as high as 85%.