太陽能高壓鈉燈照明系統之設計與研製

DESIGN AND IMPLEMEMENTATION OF A SOLAR-POWERED HIGH PRESSURE SODIUM LAMP LIGHTING SYSTEM

本文旨在設計及研製一個太陽能高壓鈉燈照明系統。系統結合太陽能板及蓄電池，經由功率轉換器，在白天時刻將太陽能儲存於蓄電池，並於夜間時由蓄電池提供能量給高壓鈉燈使用。系統以零電壓切換直流轉換器做為蓄電池充電器之電路架構，可減少開關切換損失，提高轉換效率，並以擾動與觀察之最大功率追蹤控制方法，做為太陽能板之功率控制。昇壓點燈電路則結合推挽式直流轉換器與串聯諧振並聯負載電路，合成為推挽式串聯諧振並聯負載電子安定器，直接將蓄電池電壓24伏特昇壓後點燈，以簡化系統架構，提高安定器效率。本文以Pspice模擬軟體完成零電壓切換直流轉換器及推挽式電子安定器之電路模擬，並以數位信號處理器做為控制器的核心，以減少硬體元件，加速電路設計時程。由實驗結果顯示，本文所提的太陽能照明系統具有高效率與架構簡單之優點，適合裝設於日照強度大，且市電困難到達之場所。

This paper presents the design and implementation of a solar energy powered high pressure sodium lamp lighting system. The system is constructed with solar cells, battery chargers, and a power converter as well as batteries. In daytime the batteries are charged by solar energy, and then release the energy for high pressure sodium lamps at night. To reduce switching losses and increase power conversion efficiency, a zero voltage switching (ZVS) DC/DC converter is applied as a battery charger. The perturb and observe maximum power point tracking (MPPT) algorithm is realized in the solar cell system. By combining a push-pull DC/DC converter and a series resonant parallel loaded circuit as a push-pull series resonant parallel loaded electronic ballast, the ignition circuit directly drives the lamps on 24V DC battery voltage; therefore it simplified the structure of the system and increased the power conversion efficiency of the electronic ballast. In this paper, zero voltage switching DC/DC converter and push-pull electronic ballast are simulated by Pspice software. Then, the digital signal processor is used to implement the system, to reduce the number of circuit components and speed up the circuit design stage. The result of the experiment shows that the proposed lighting system has the advantages of high efficiency and simple structure. The lighting system is particularly suitable when installed at those areas where there is powerful sunshine and without power utility service.