Tesis ini membentangkan penuh jambatan LLC penukar salunan yang meningkatkan voltan input daripada 24V ke 320V untuk pengunaan PV. Analisis terperinci, reka bentuk dan pelaksanaan LLC penukar salunan ditunjukkan dalam tesis ini. Penukar salunan boleh dibahagikan kepada tiga bahagian utama, iaitu penukar penuh jambatan, tangki salunan dan penerus dengan penapis kapasitor. Dengan mengunakan frekuensi pensuisan yang berbeza, voltan keluaran dapat dikawal. Suis kuasa beroperasi dengan sifar pensuisan voltan dan diod output beroperasi dengan sifar pensuisan semasa. Untuk mencapai kecekapan yang tinggi dalam julat voltan input yang besar, nisbah kearuhan daripada pengaruh salunan dan magnetizing perlu ditentu mengikut gandaan voltan tangki LLC salunan. Keputusan simulasi telah ditunjukkan dalam tesis ini untuk mengesahkan operasi dan prestasi penukar. A prototaip penukar dibina. Prinsip operasi dan mod operasi pengubah dikaji dan keputusannya disahkan melalui pengukuran makmal menyeluruh. Perubahan frekuensi, kajian kecekapan dan peraturan beban penukar telah dijalankan. Dengan beban 748Ω, kecekapan penukar LLC adalah 87,19% pada frekuensi 120 kHz. Pada frekuensi dan rintangan beban yang tetap, kecekapan LLC penukar salunan boleh mencecah sehingga 81.83% pada 34.2V voltan input. Kajian peraturan beban dijalankan dengan mengubah beban dengan voltan input tetap. Kecekapan penukar LLC tidak berubah pada Rload≥ 460Ω.
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This thesis presents a full bridge LLC resonant step-up dc-dc converter. The converter steps up the input voltage from 30V to 350V for the PV application. The detailed analysis, design and implementation of the LLC resonant converter is presentedin the thesis. The resonant converter consists of three main parts, which are full bridge converter, resonant tank, and rectifier with filter capacitor. The output voltage of the converter is regulated by varying the switching frequency.Consequently, the power switches operate with zero voltage switching and output diodes operate with zero current switching. In order to achieve desired output voltage range with considerable input voltage range, the inductance ratio of resonant and magnetizing inductor is designed according to the voltage gain of the LLC Resonant tank. Simulation results are given in the thesis to validate the operation and performance of converter. A prototype of converter is built. The operating principles and modes of operation of the converter are studied and the results are verified through comprehensive laboratory measurements. Frequency variation, efficiency study and load regulation of the converter are conducted. With a load of 748Ω, the efficiency of the LLC converter is measured to be 87.19% at frequency 120 kHz. At constant frequency and load resistance, the efficiency of LLC resonant converter can reach up to 81.83% at 34.2V input voltage. Load regulation study is conducted by varying the load with constant input voltage. The efficiency of the LLC converter tends to stay constant at Rload ≥ 46Ω.
Design and analysis of LLC resonant DC-DC converter using UCC25600 controller / Pauline Chuo See Sze