本文關(guān)鍵詞： 模塊化多電平級聯(lián)變換器 城市電網(wǎng) 電能質(zhì)量 輸電能力 通用實驗平臺　出處：《華北電力大學(xué)(北京)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：城市電網(wǎng)是現(xiàn)代化城市建設(shè)中的重要基礎(chǔ)設(shè)施,提高城市電網(wǎng)的供電質(zhì)量與輸電能力是城市電網(wǎng)發(fā)展的基本目標(biāo)。模塊化多電平級聯(lián)變換器(modular multilevel cascaded converter,MMCC)是一類基于全控型電力電子器件、由功率模塊級聯(lián)構(gòu)成的高壓大容量電能變換裝置的統(tǒng)稱。MMCC可根據(jù)應(yīng)用場合靈活組合成多種拓?fù)浣Y(jié)構(gòu),直掛于中壓母線處,具有占地面積小、損耗低、支持四象限運行等優(yōu)點。本文圍繞MMCC內(nèi)特性及其在城市電網(wǎng)中的應(yīng)用開展了如下研究:本文總結(jié)了MMCC內(nèi)特性中的基本共性問題,即內(nèi)部功率波動與環(huán)流。本文將MMCC拓?fù)浣Y(jié)構(gòu)等效為連通圖形式,利用圖論基本理論分析了MMCC共性問題的產(chǎn)生機理。在此基礎(chǔ)上,提出了一種MMCC內(nèi)特性通用分析方法,該方法可準(zhǔn)確求得MMCC內(nèi)部功率波動與環(huán)流的幅頻特性,適用于不同拓?fù)浣Y(jié)構(gòu)、功率模塊類型、輸入/輸出特性的各類MMCC。進(jìn)而,針對MMCC環(huán)流問題,提出了一種通用環(huán)流抑制策略,該方法具有明確的物理意義,實現(xiàn)簡單,并可以與支路能量均衡控制相結(jié)合。MMCC共性問題研究為其在城市電網(wǎng)中的應(yīng)用提供了理論基礎(chǔ)。敏感、非線性負(fù)荷的電能質(zhì)量問題集中、綜合治理可最大程度降低治理成本,是提高城市電網(wǎng)供電質(zhì)量的關(guān)鍵技術(shù)手段之一。統(tǒng)一電能質(zhì)量控制器(unified power quality conditioner,UPQC)為電能質(zhì)量問題綜合治理裝置,本文提出了一種串并聯(lián)混合型MMCC-UPQC拓?fù)浣Y(jié)構(gòu),直掛于中高壓母線處綜合治理電能質(zhì)量問題。本文提出的串并聯(lián)混合型MMCC-UPQC將串聯(lián)補償電壓作為并聯(lián)補償輸出電壓的一部分,因此所使用的模塊數(shù)與開關(guān)器件數(shù)較傳統(tǒng)高壓大容量UPQC大大減小,進(jìn)而增加了裝置的功率密度,并具有較高的經(jīng)濟性。針對電壓暫降問題,本文提出了一種協(xié)同無功注入式UPQC電壓暫降補償策略,最大程度的利用了裝置電流容量,延長電壓暫降補償?shù)某掷m(xù)時間。并且在考慮載流受限的前提下,確定了零有功功率注入補償域及相應(yīng)的換流器限流方式。最后,通過仿真對本文提出的串并聯(lián)混合型MMCC-UPQC及電壓暫降補償策略進(jìn)行了驗證。在現(xiàn)有城市電網(wǎng)輸電走廊的基礎(chǔ)上,采用先進(jìn)輸配電技術(shù)提高輸電線路容量為提高城市電網(wǎng)輸電能力的關(guān)鍵技術(shù)手段。本文針對城市電網(wǎng)電纜輸電系統(tǒng),提出了一種基于三星型全橋(triple star bridge cell,TSBC)MMCC的低頻輸電系統(tǒng)。該系統(tǒng)在電纜線路的兩端分別加裝TSBC-MMCC實現(xiàn)工頻-低頻的電能變換,降低了電纜的工作頻率,既可以減小電纜充電功率,提高線路輸電能力,也可以較好的與現(xiàn)有交流設(shè)備兼容互聯(lián)。本文著重分析了TSBC-MMCC的低頻工作特性,推導(dǎo)了功率波動與內(nèi)部環(huán)流的幅值、頻率特性。在此基礎(chǔ)上,定義了TSBC-MMCC低頻工作下的特征環(huán)流,分析了相關(guān)參數(shù)對特征環(huán)流幅值特性的影響,推導(dǎo)得到了換流器受環(huán)流影響較小的工作區(qū)間。進(jìn)而,本文建立了TSBC-MMCC數(shù)學(xué)模型,并設(shè)計了基于TSBC-MMCC的雙端低頻輸電的四種運行模式,實現(xiàn)了靈活的潮流控制。最后,對基于TSBC-MMCC的低頻輸電系統(tǒng)進(jìn)行了相關(guān)仿真驗證。為實現(xiàn)對各類MMCC及其應(yīng)用的全面、深入研究,本文研制了MMCC通用實驗平臺,主要包括三個組成部分,即主電路部分、系統(tǒng)級控制器及通用軟件部分。平臺的主電路部分以MMCC功率橋臂為基本單元,詳細(xì)闡述了其參數(shù)計算方法、器件選型、橋臂主控制器構(gòu)架設(shè)計等,并搭建了功率橋臂測試回路,以保證MMCC整體裝配的可靠性。與此同時,本文以統(tǒng)一設(shè)計、分層運行的方式研制了MMCC系統(tǒng)級控制器,該控制器支持MMCC功率模塊數(shù)大量擴展的需求。通用軟件部分中,本文重點研究了MMCC通用實驗平臺的底層調(diào)制算法,提出了一種混合調(diào)制算法,實現(xiàn)了電平數(shù)較少下精準(zhǔn)、高效的電壓輸出。最后,應(yīng)用MMCC通用實驗平臺搭建了TSBC-MMCC物理樣機,實現(xiàn)了靈活的四象限運行,并驗證了通用實驗平臺的正確性及先進(jìn)性。
[Abstract]:City power grid is an important infrastructure of modern city construction, improve the quality of power supply and transmission capacity of city power grid is the basic goal of the development of city power grid. The modular multilevel cascade converter (modular multilevel cascaded converter, MMCC) is a kind of full controlled power electronic devices based on high voltage and large capacity power conversion device is composed of the power module cascaded collectively.MMCC according to application of flexible combination topology, hanging in medium voltage bus, has a small footprint, low loss, support four quadrant operation and other advantages. In this paper, and its application in the city grid is carried out as follows: around the MMCC characteristic in this paper summarizes the basic common problems MMCC Nate in, namely the internal power fluctuation and circulation. The MMCC topology is equivalent to the graph form, using the basic theory of graph theory analysis of MMCC common problems The mechanism. On this basis, a method is proposed for analyzing MMCC characteristics of general, amplitude frequency characteristics of the method can accurately calculate the MMCC internal power fluctuation and circulation, suitable for different types of topology, power module, input / output characteristics of various types of MMCC. and MMCC, according to the circulation problem, put forward a control strategy general circulation, has clear physical meaning, this method is simple, and can be combined on the common problems of.MMCC provides a theoretical basis for its application in the city grid and branch energy balance control. Sensitive, non line load power quality problem, comprehensive management can minimize the cost of governance is. One of the key techniques to improve the quality of power supply of the city grid. Unified power quality controller (unified power quality conditioner, UPQC) for comprehensive power quality control device is presented in this paper. A series parallel hybrid MMCC-UPQC topology, straight hanging point comprehensive control in high voltage electric bus qualityproblems. Series parallel hybrid MMCC-UPQC method is put forward in this paper as part of a series compensation voltage shunt compensation of output voltage, so that the number of module number and switching devices used by the traditional high voltage and large capacity UPQC greatly reduced then, increase the power density of the device, and has high economic. In order to solve the problem of voltage sag, this paper presents a co reactive power injection UPQC voltage sag compensation strategy to maximize the use of the device's current capacity, the duration of voltage sag compensation. And considering the current limited under the zero active power compensation into the domain and the corresponding converter current limiting mode. Finally, through the series parallel hybrid MMCC-UPQC and Simulation of the proposed voltage sag compensation strategy Verified. Based on the existing city power grid transmission corridor, the use of advanced technology to improve the transmission capacity of transmission lines is the key technique to improve the transmission capacity of city power grid. Based on the cable transmission system of city power grid, based on Samsung FB (triple star bridge cell, TSBC) low frequency transmission system MMCC at both ends of the system in the cable lines were added TSBC-MMCC - low frequency realizes the frequency conversion of electrical energy, reduce the working frequency of the cable, the cable can reduce charging power, improve the ability of transmission, can be compatible with the existing communication equipment interconnection. This paper analyzes the characteristics of low frequency TSBC-MMCC, derived amplitude. The power fluctuation and internal circulation frequency characteristics. On this basis, the definition of TSBC-MMCC work under the low frequency circulation characteristics, analysis of the related parameters on the characteristics of current amplitude The value of properties, derived work interval converter by circulation is less affected. Then, this paper establishes the TSBC-MMCC mathematical model, and design four kinds of double end TSBC-MMCC low frequency power transmission operation mode based on achieving flexible flow control. Finally, the low frequency transmission system based on TSBC-MMCC simulated in order to verify. All kinds of MMCC and its application to comprehensive, in-depth research, this paper developed a general MMCC experimental platform mainly consists of three parts, namely the main circuit, system level controller and general software. Main circuit based on MMCC power bridge as the basic unit, elaborated its parameter calculation method the device selection, the main controller, arm architecture, and built a power arm test loop, in order to ensure the reliability of MMCC assembly. At the same time, based on the unified design, hierarchical operation The development of the MMCC system level controller, the controller supports MMCC power module the number of expansion needs. The general software part, this paper focuses on the general experimental platform MMCC modulation algorithm, we propose a hybrid modulation algorithm, the level number is less accurate, high voltage output. Finally, the general laboratory the application of MMCC platform TSBC-MMCC physical prototype was built up, the four quadrant operation is flexible, and verify the validity and superiority of general experiment platform.

【學(xué)位授予單位】：華北電力大學(xué)(北京)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TM46

【相似文獻(xiàn)】

相關(guān)期刊論文 前10條

1 唐伏良,莊朝暉,熊有倫;一類新型的多電平逆變拓?fù)溲芯縖J];中國電機工程學(xué)報;2000年12期

2 白路;史U，

本文編號：1539496