本文選題：直流微網(wǎng)　切入點：分布式發(fā)電　出處：《重慶理工大學(xué)》2015年碩士論文

【摘要】：隨著能源需求的不斷發(fā)展,分布式發(fā)電(Distributed Generation,DG)已成為必由之路。微網(wǎng)作為具有自發(fā)自用能力的可控系統(tǒng),既可與主網(wǎng)互聯(lián)運行,又可脫離主網(wǎng)孤島運行。當DG輸出突變、大量負荷同時投切、并網(wǎng)孤島切換時,很可能引起母線電壓波動,甚至使控制或保護系統(tǒng)誤動作。因此,研究直流微網(wǎng)穩(wěn)定運行的控制技術(shù),維持母線電壓的穩(wěn)定性,同時實現(xiàn)能量最優(yōu)協(xié)調(diào)控制,具有重要的理論意義及實際應(yīng)用價值。基于此,文內(nèi)以直流微網(wǎng)系統(tǒng)為研究對象,分析設(shè)計了有關(guān)單元變換器控制策略及基于電壓分層控制的系統(tǒng)控制策略。首先,分析了直流微網(wǎng)的有關(guān)問題及其在未來城鄉(xiāng)區(qū)域供配電系統(tǒng)中的趨勢,對直流母線電壓穩(wěn)定控制及網(wǎng)內(nèi)能量優(yōu)化協(xié)調(diào)控制的現(xiàn)狀進行了分析研究。構(gòu)建了滿足系統(tǒng)運行穩(wěn)定性和可靠性要求的直流微網(wǎng)系統(tǒng)模型,為直流微網(wǎng)內(nèi)單元變換器自主控制策略及系統(tǒng)控制策略的研究提供基礎(chǔ)。第二,以光伏發(fā)電單元、并網(wǎng)接口變換器單元、蓄電池單元、燃料電池單元和負荷單元構(gòu)成的直流微網(wǎng)系統(tǒng)為研究對象,研究建立各單元變換器工作狀態(tài)自主切換控制策略,以便實現(xiàn)各變換器在不同工作狀態(tài)間快速、平滑地自主切換。第三,建立了一種直流微網(wǎng)在并網(wǎng)運行狀態(tài)下及孤島運行網(wǎng)內(nèi)功率平衡狀態(tài)下的能量最優(yōu)利用控制策略。所建立的控制策略能夠在直流微網(wǎng)并網(wǎng)運行狀態(tài),以及孤島運行網(wǎng)內(nèi)供需平衡狀態(tài)下,維持母線電壓的穩(wěn)定,同時實現(xiàn)可再生能源及蓄電池的最優(yōu)利用。第四,為解決直流微網(wǎng)孤島運行時,網(wǎng)內(nèi)功率不平衡引起的母線電壓波動問題,設(shè)計了一種儲能充放電自主調(diào)節(jié)控制策略。當母線電壓進入該策略預(yù)設(shè)電壓區(qū)間時,利用蓄電池的功率緩沖能力,以蓄電池單元作為網(wǎng)內(nèi)平衡節(jié)點,蓄電池單元變換器根據(jù)母線電壓變化自主切換至下垂充電控制或下垂放電控制狀態(tài),使網(wǎng)內(nèi)功率重新達到平衡,從而實現(xiàn)母線電壓的穩(wěn)定控制。最后,構(gòu)建了一種考慮網(wǎng)內(nèi)功率嚴重不平衡的直流微網(wǎng)極限運行控制策略。所構(gòu)建的控制策略以保證直流微網(wǎng)在極限運行狀態(tài)下的可靠性為目標,通過光伏單元輸出自主控制及輔助電源的投入運行,有效抑制因網(wǎng)內(nèi)功率嚴重不平衡引起的母線電壓大范圍波動,有效避免系統(tǒng)崩潰可能性。
[Abstract]:With the continuous development of energy demand, distributed generation DG has become the only way. As a controllable system with spontaneous self-use capability, microgrid can not only run interconnected with the main network, but also run off the island of the main network. When a large number of loads are switched on and off at the same time, it is likely to cause bus voltage fluctuation and even make the control or protection system misoperate. Therefore, the control technology for steady operation of DC microgrid is studied to maintain the stability of bus voltage. At the same time, the realization of optimal coordinated control of energy has important theoretical significance and practical application value. Based on this, the DC microgrid system is taken as the research object in this paper. The control strategy of cell converter and the system control strategy based on voltage stratification control are analyzed and designed. Firstly, the problems related to DC microgrid and its trend in the future power supply and distribution system in urban and rural areas are analyzed. The current situation of DC bus voltage stability control and energy optimization and coordination control in the grid is analyzed and studied. A DC microgrid system model which meets the requirements of system operation stability and reliability is constructed. It provides the foundation for the research of the self-control strategy and system control strategy of DC micro-grid converter. Second, the photovoltaic unit, grid-connected converter unit, battery unit, The DC microgrid system composed of fuel cell unit and load unit is studied. The independent switching control strategy of each unit converter is established in order to realize the fast switching between different working states of the converter. Thirdly, a control strategy for optimal energy utilization of DC microgrid in grid-connected operation and power balance state in islanding operation network is established. The proposed control strategy can operate in DC microgrid grid-connected state. Under the condition of equilibrium of supply and demand, the bus voltage can be kept stable, and the renewable energy and battery can be utilized optimally. Fourth, in order to solve the problem of DC microgrid isolated island operation, Based on the problem of bus voltage fluctuation caused by power imbalance in the network, a self-regulating control strategy for energy storage charge and discharge is designed. When the bus voltage enters the preset voltage range of the strategy, the power buffering capacity of the battery is utilized. With the battery unit as the balance node in the network, the battery cell converter switches to the droop charging control or the droop discharge control state according to the voltage variation of the bus, so that the power in the network can be rebalanced. So as to realize the stable control of bus voltage. Finally, In this paper, a DC microgrid limit operation control strategy considering the serious power imbalance in the grid is proposed. The goal of the control strategy is to ensure the reliability of the DC microgrid under the limit operation condition. Through the output autonomous control of photovoltaic unit and the operation of auxiliary power supply, the fluctuation of bus voltage caused by the serious imbalance of power in the grid is effectively restrained, and the possibility of system collapse is effectively avoided.
【學(xué)位授予單位】：重慶理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TM61;TM712

【參考文獻】

中國期刊全文數(shù)據(jù)庫 前8條

1 李鵬;張玲;王偉;楊希磊;趙義術(shù);;微網(wǎng)技術(shù)應(yīng)用與分析[J];電力系統(tǒng)自動化;2009年20期

2 趙宏偉;吳濤濤;;基于分布式電源的微網(wǎng)技術(shù)[J];電力系統(tǒng)及其自動化學(xué)報;2008年01期

3 丁明;張穎媛;茆美琴;;微網(wǎng)研究中的關(guān)鍵技術(shù)[J];電網(wǎng)技術(shù);2009年11期

4 張文亮;湯涌;曾南超;;多端高壓直流輸電技術(shù)及應(yīng)用前景[J];電網(wǎng)技術(shù);2010年09期

5 米為民;荊銘;尚學(xué)偉;徐丹丹;蔣國棟;付輝;;智能調(diào)度分布式一體化建模方案[J];電網(wǎng)技術(shù);2010年10期

6 傅書，

本文編號：1657873