基于BOOST-BUCK變換器的低壓控制系統 摘要:本文從提高光伏發電系統整體效率的角度出發,以光伏發電系統中電能變換裝置作為研究對象,研究光伏發電中的關鍵技術環節之一 ——光伏陣列的最大功率跟蹤點技術。主要研究適用于光伏發電系統的最大功率跟蹤變換器的拓撲;研究光伏發電系統的最大功率點跟蹤變換器的控制方法。本文在分析研究了幾種基于DC/DC變換器的最大功率跟蹤算法及各自優缺點和適用場合。在拓撲研究方面,分析研究了Buck、Boost和Boost-Buck電路應用于光伏發電中的優缺點以及適用的最佳功率等級,并對這三種電路的功率損耗進行分析,通過仿真實驗進行驗證。探討了把軟開關技術、三電平技術應用于光伏發電的可行性,并詳細分析了應用于光伏發電系統的Boost-Buck DC/DC變換器電路的換流過程。在理論分析的基礎上,將傳統的Buck變換器與Boost變換器相結合,采用變換器結合的方式,研究了一種雙開關Boost-Buck變換器。該變換器根據輸入輸出條件,可分別工作于Boost模式,Buck模式和臨界模式。與傳統的Boost-Buck變換器相比較,具有正極性的輸出電壓和更寬的輸入電壓范圍。仿真結果表明該電路性能良好。 關鍵字: 光伏發電系統 Boost-Buck變換器 DC/DC變換器 軟開關 三電平 最大功率跟蹤點 The low-pressure starting systems based on boost-buck topology Abstract: In order to improve the overall efficiency of photovoltaic power generation system, these articles close the conversion devices as a researcher goal and did some researches on the key Technologies of photovoltaic power generation—the maximum power point tracking techno- -logy of photovoltaic array. It did some major researches on the topology applicable to the maximum power point tracking convector and on its control methods.Analyzing the principle and output characteristics of solar cells,this article introduced several maximum power point tracking algorithms based on the DC/DC convector and their respective advantages and dis- -advantages.On the topology research,this article analyzed the advantages and disadvantages of the Buck and Boost and BUCK-BOOST circuits when they were applied in the photovo- -ltaic power generation and summarized their best applicable power rating.Then it provedThe correctness of Theoretical calculation by simulation. Discussed the feasibility of the appl- -ication of soft-switch and three-level technology using in the photovoltaic power generation and detailed the converter process of the phase—BUCK-BOOST DC/DC converter. through the theoretical analysis,combine a traditional buck converter with a boost converter. The buck-boost converter includes a boost-voltage mode, a buck-voltage mode and a critical working mode in accordance with the input and output conditions. Compared with the tradi- -tional. buck-boost converter, its output voltage is positive and the input voltage ranges are wider. The simulation results prove that the buck-boost converter has good performance. Keywords: PV generation system , buck-boost converter, DC/DC convector, soft-switch, three-level technology, the maximum power point tracking