【摘要】：近年來,由于在電壓轉換和電能質量變換方面的優(yōu)良特性,電力電子變壓器作為傳統(tǒng)變壓器的替代正受到人們的廣泛關注。其中,隔離級DC-DC變換器作為電力電子變壓器的中央關鍵環(huán)節(jié),正被國內(nèi)外學者作為重點課題深入研究。在諸多的研究成果中,以LLC型諧振變換器和DAB直流變換器為主拓撲的變換裝置成為了學者們關注的焦點。這兩種變換器在保證高電壓等級電能變換的同時,均具備軟開關能力。其中,LLC型諧振變換器在全負載范圍內(nèi)均能保證軟開關工作狀態(tài),并且具有恒壓調節(jié)能力,但其功率變換能力卻受到諧振電容電流能力的限制。而DAB線性直流變換器雖然具有大功率電能變換能力,但由于其輸出電壓與前后對應橋臂移相角之間并無直接聯(lián)系,因此需要較為復雜的控制系統(tǒng)與其配合,這無疑增加了變換器整體模塊的復雜程度,降低了系統(tǒng)可靠性。本文提出一種基于LLC諧振型變換器與DAB直流變換器混合運行的混合型高頻隔離DC-DC變換器。該變換器利用LLC諧振變換器恒壓調節(jié)的特性箝位模塊兩端電壓,并利用DAB直流變換器的大功率能力承擔大部分功率變換任務。在克服LLC型諧振變換裝置功率變換能力受到諧振電容電流能力限制的同時,極大地簡化了模塊整體的控制策略復雜程度。同時,為該變換器設計了一種簡單有效的閉環(huán)控制策略,該控制策略與所提出的結構相配合,能夠保證在增減負荷時變換器模塊能夠快速回復至穩(wěn)定狀態(tài)。最后,搭建了混合型高頻隔離直流變換器實驗樣機,驗證了所提出結構和控制策略的有效性和正確性。
[Abstract]:In recent years, due to the excellent characteristics of voltage conversion and power quality conversion, power electronic transformers, as the replacement of traditional transformers, have been paid more and more attention. As the central key link of power electronic transformer, isolation level DC-DC converter is being deeply studied by scholars at home and abroad. Among the many research achievements, LLC resonant converter and DAB DC-DC converter are the main topology converter, which has become the focus of scholars' attention. Both converters have soft switching capability while ensuring high voltage level power conversion. Among them, the LLC resonant converter can guarantee the soft-switching working state in the full load range, and has the ability of constant voltage regulation, but its power conversion ability is limited by the resonant capacitance current capability. Although the DAB linear DC / DC converter has high power conversion capability, there is no direct connection between the output voltage and the phase shift angle of the corresponding bridge arm, so the complex control system is needed to cooperate with it. This undoubtedly increases the complexity of the whole module of the converter and reduces the reliability of the system. This paper presents a hybrid high frequency isolated DC-DC converter based on hybrid operation of LLC resonant converter and DAB DC / DC converter. The converter uses the voltage at both ends of the characteristic clamp module regulated by the constant voltage of the LLC resonant converter and uses the high power capability of the DAB DC / DC converter to undertake most of the power conversion tasks. While overcoming the limitation of the power conversion ability of LLC type resonant converter by the resonant capacitance current capability, the complexity of the control strategy of the whole module is greatly simplified. At the same time, a simple and effective closed-loop control strategy is designed for the converter. This control strategy, in conjunction with the proposed structure, can ensure that the converter module can return to the stable state quickly when the load is increased and reduced. Finally, an experimental prototype of hybrid high frequency isolated DC / DC converter is built to verify the validity and correctness of the proposed structure and control strategy.
【學位授予單位】：東北電力大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM46

【參考文獻】

相關期刊論文 前9條

1 江添洋;張軍明;汪i襠，

本文編號：2467847