本文選題：LLC諧振變換器 + 滑�？刂���； 參考：《浙江大學》2014年碩士論文

【摘要】：LLC諧振式變換器可以實現(xiàn)寬輸入電壓范圍內(nèi)原邊開關管的零電壓開通(ZVS)和副邊整流二極管的零電流關斷(ZCS),負載適應能力強,具有高效率、高功率密度、低電磁干擾等優(yōu)點,在工業(yè)電源和消費電子領域都得到了廣泛的應用。隨著產(chǎn)品性能的不斷提高,對于LLC變換器動態(tài)性能的要求也越來越高。然而,LLC諧振變換器存在動態(tài)特性漂移問題,同時光耦的時變寄生電容和自身非線性特性也對控制器的設計也帶來了很大的挑戰(zhàn)。 本文提出了一種新穎的離散脈沖頻率調(diào)制方式,成功地將滑模變結構控制應用于LLC諧振變換器,可以有效地增強系統(tǒng)魯棒性,大幅度提高LLC變換器的動態(tài)性能。 首先基于擴展描述函數(shù)方法對LLC諧振變換器進行小信號建模和分析,并給出詳細的數(shù)學推導過程。通過理論計算和仿真結果比較,驗證了擴展描述函數(shù)模型的穩(wěn)態(tài)精度和動態(tài)跟蹤性能。 基于擴展描述函數(shù)模型,采用輸入/輸出反饋線性化方法設計系統(tǒng)滑�？刂品匠�,可以實現(xiàn)特定的輸出電壓響應,并且能夠得到包含輸出電壓變量的線性化子系統(tǒng)。利用傳統(tǒng)線性系統(tǒng)的分析方法,驗證系統(tǒng)的穩(wěn)定性條件,給出了滑�？刂茀�(shù)的設計流程。 最后分別搭建了基于滑�？刂坪蚉I控制的實驗樣機平臺,驗證滑模變結構控制方案的可行性,給出了系統(tǒng)的穩(wěn)態(tài)運行波形和輸出電壓穩(wěn)態(tài)精度。通過與PI控制實驗樣機對比,證明了滑�？刂品桨竷�(yōu)良的動態(tài)響應性能。對于輸出電壓紋波要求較高的應用場合,提出了輸出電壓微分近似方法,有效地降低輸出電壓紋波,同時仍能夠保持滑模控制的快速動態(tài)響應特性。 LLC變換器的滑�？刂品桨改軌虼蠓鹊靥岣呦到y(tǒng)的動態(tài)響應速度,適用于動態(tài)性能要求較高的應用場合,文中提出的模型、設計思路和控制方法對于LLC變換器動態(tài)性能的研究具有一定意義。
[Abstract]:LLC resonant converter can realize ZVS (ZVS) and ZCSS with zero current turn-off of side rectifier diode in wide input voltage range. It has the advantages of high load adaptability, high efficiency, high power density, low electromagnetic interference and so on. It has been widely used in the field of industrial power supply and consumer electronics. With the continuous improvement of product performance, the dynamic performance of LLC converter is becoming more and more demanding. However, the dynamic drift problem exists in LLC resonant converters, and the time-varying parasitic capacitance and nonlinear characteristics of optical coupling also pose a great challenge to the design of the controller. A novel discrete pulse frequency modulation scheme is proposed in this paper. The sliding mode variable structure control is successfully applied to the LLC resonant converter, which can effectively enhance the robustness of the system. The dynamic performance of the LLC converter is greatly improved. Firstly, the small signal modeling and analysis of the LLC resonant converter are carried out based on the extended description function method, and the detailed mathematical derivation process is given. The steady-state precision and dynamic tracking performance of the extended description function model are verified by theoretical calculation and simulation results. Based on the extended description function model, the sliding mode control equation is designed by the input / output feedback linearization method. The output voltage response can be achieved, and the linearized subsystem with output voltage variables can be obtained. Using the traditional linear system analysis method, the stability condition of the system is verified, and the design flow of the sliding mode control parameters is given. Finally, the experimental prototype platform based on sliding mode control and Pi control is built, respectively. The feasibility of the sliding mode variable structure control scheme is verified, and the steady-state operation waveform and output voltage steady-state precision of the system are given. By comparing with Pi control experimental prototype, it is proved that the sliding mode control scheme has excellent dynamic response performance. In order to reduce the ripple of output voltage effectively, a differential approximation method of output voltage is proposed for the application of high requirement of output voltage ripple. The sliding mode control scheme of LLC converter can greatly improve the dynamic response speed of the system, which is suitable for applications with high dynamic performance requirements. The design idea and control method have certain significance for the study of LLC converter's dynamic performance.
【學位授予單位】：浙江大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TM46

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本文編號：2001822