本文關鍵詞：基于SiC MOSFETs的三相固態(tài)變壓器的研究　出處：《山東大學》2017年碩士論文　論文類型：學位論文

  更多相關文章： 三相固態(tài)變壓器 拓撲 高壓碳化硅器件 控制策略

【摘要】：在能源互聯(lián)網的大背景下,固態(tài)變壓器作為智能電網應用中的關鍵設備,在未來電力系統(tǒng)中占有重要地位,可以實現(xiàn)電力系統(tǒng)復雜的要求:對環(huán)境友好,改變/控制用戶電壓等級,保持單位功率因數(shù)運行,監(jiān)測能量使用情況并記錄信息,提供直流母線等。因為三相模塊級聯(lián)型固態(tài)變壓器拓撲和控制復雜,需解決模塊之間均壓均功率等問題,本文采用簡單的基于碳化硅器件的三相固態(tài)變壓器拓撲,其拓撲與控制相對簡單,使傳統(tǒng)拓撲重新煥發(fā)生機,因而具有很強的現(xiàn)實意義。本文介紹了固態(tài)變壓器相較于傳統(tǒng)變壓器的優(yōu)點,從單相、三相以及基于碳化硅器件的固態(tài)變壓器三個方面概述了固態(tài)變壓器的研究現(xiàn)狀以及工作原理,介紹了隨著碳化硅電力電子器件的發(fā)展,基于碳化硅器件的固態(tài)變壓器的優(yōu)勢。本文對所研究SiC-SST系統(tǒng)的三級結構進行了拓撲分析,對其前端整流級及DAB級的電路分析并相應建模。分析了前端整流級電路,建立了前端整流級abc坐標系下的數(shù)學模型與dq坐標系下的數(shù)學模型,給出了兩種模型的轉換矩陣;分區(qū)間介紹了 DAB級的工作過程,給出了等效漏感電流在各個區(qū)間內的表達式,分析了能量傳輸過程。本文研究了 SiC-SST各級的控制策略,前端整流級采用電流內環(huán)和電壓外環(huán)雙閉環(huán)控制,其中電流內環(huán)采用了具有快速電流響應的直接電流控制策略;中間DAB級采用了單移相控制,推導了其一階小信號模型以及傳遞函數(shù)表達式,完成了 DAB級電壓閉環(huán)設計;分析了在電網電壓不平衡下SiC-SST系統(tǒng)的控制策略,使用PSIM仿真軟件分別對電網電壓平衡/不平衡時SiC-SST系統(tǒng)的兩種控制策略進行了仿真驗證。SiC MOSFET與傳統(tǒng)的硅基MOSFET在驅動特性上差異很大,同時如果沒有有效的保護或者保護過慢將會影響碳化硅器件使用壽命甚至嚴重損壞器件。本文分析了碳化硅MOSFET的特性與電路模型,介紹了目前學者對于SiC MOSFET驅動及過流保護電路的研究情況,在已有硅基器件驅動與保護的基礎上,提出一種新型高壓SiC MOSFET驅動及其過流保護電路,滿足了 SiC MOSFET對驅動電壓的特殊要求,動作迅速的保護電路在器件過流時能及時有效保護,并對設計的驅動及過流保護電路進行了仿真與實驗驗證�；趯iC-SST系統(tǒng)的理論與仿真結果以及SiC MOSFET驅動和過流保護電路,本文選用CREE公司的C2M0080120D碳化硅器件搭建SiC-SST系統(tǒng)的前端整流級實驗樣機,包括SiC-SST系統(tǒng)的硬件與軟件設計,初步完成了對所介紹理論與仿真結果的驗證。
[Abstract]:In the context of the energy Internet, solid-state transformer, as the key equipment in the application of smart grid, plays an important role in the future power system. It can meet the complex requirements of the power system: environmentally friendly. Change / control user voltage grade, maintain unit power factor operation, monitor energy usage and record information, provide DC busbar, etc., because of the complex topology and control of three-phase modular cascaded solid-state transformer. In order to solve the problem of the average voltage and average power between modules, this paper adopts a simple topology of three-phase solid-state transformer based on silicon carbide device, its topology and control is relatively simple, which makes the traditional topology revitalized again. This paper introduces the advantages of solid-state transformer compared with the traditional transformer, from the single-phase. The research status and working principle of solid-state transformer are summarized in three aspects, which are three-phase and solid-state transformer based on silicon carbide device. The development of power electronic device based on silicon carbide is introduced. The advantage of solid-state transformer based on silicon carbide device. In this paper, the three-level structure of the studied SiC-SST system is analyzed in topology. The circuit of the front rectifier stage and DAB level are analyzed and the corresponding models are established. The mathematical model of the front end rectifier level abc coordinate system and the dq coordinate system are established. The transformation matrix of two models is given. In this paper, the working process of DAB stage is introduced, the expression of equivalent leakage inductance current in each region is given, and the process of energy transmission is analyzed. The control strategy of SiC-SST level is studied in this paper. The front-end rectifier adopts double closed loop control of current inner loop and voltage outer loop, in which the current inner loop adopts direct current control strategy with fast current response. In the middle DAB stage, the single-phase shift control is used, the first-order small-signal model and the expression of the transfer function are derived, and the closed-loop design of the DAB stage voltage is completed. The control strategy of SiC-SST system under unbalanced voltage is analyzed. Two control strategies of SiC-SST system under voltage balance / unbalance of power network are simulated with PSIM simulation software. Sic is used to verify the control strategy of SiC-SST system. The driving characteristics of MOSFET are very different from those of traditional silicon based MOSFET. At the same time, if there is no effective protection or too slow protection will affect the service life of silicon carbide devices and even seriously damaged devices. This paper analyzes the characteristics and circuit model of silicon carbide MOSFET. This paper introduces the current research situation of SiC MOSFET driver and over-current protection circuit, based on the existing silicon based device drive and protection. A novel high voltage SiC MOSFET driver and its overcurrent protection circuit are proposed, which meet the special requirements of SiC MOSFET for driving voltage. The protection circuit with rapid action can protect the device in time and effectively when the device is overcurrent. Based on the theory and simulation results of SiC-SST system and SiC MOSFET drive and over-current protection circuit, the design of the driver and over-current protection circuit is simulated and verified. In this paper, CREE C2M0080120D silicon carbide device is used to build the front-end rectifier prototype of SiC-SST system, including the hardware and software design of SiC-SST system. The theory and simulation results are preliminarily verified.
【學位授予單位】：山東大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TM41

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相關碩士學位論文 前1條

1 于程皓;基于SiC MOSFETs的三相固態(tài)變壓器的研究[D];山東大學;2017年

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本文編號：1403436