本文選題：分布式發(fā)電　切入點：微電網(wǎng)　出處：《華北電力大學》2014年博士論文

【摘要】：隨著能源危機加劇、環(huán)境日益惡化,加之傳統(tǒng)的集中供電方式暴露出諸多弊端,分布式發(fā)電技術(shù)逐漸受到關(guān)注。該技術(shù)有助于推動可再生能源的利用,并在一定程度上為傳統(tǒng)電力系統(tǒng)提供了有效補充。然而在諸多優(yōu)勢的背后,其出力的隨機性和慣性較小的問題限制了其應(yīng)用范圍,大規(guī)模接入更是會對電網(wǎng)安全穩(wěn)定帶來負面影響。因此微電網(wǎng)應(yīng)運而生,成為分布式電源(DG)“友好”接入電網(wǎng)的途徑。 與以同步發(fā)電機為主的傳統(tǒng)電力系統(tǒng)不同,微電網(wǎng)包含多種類型的DG,它們的特性和控制方式差距較大,難以標準化。當微電網(wǎng)進行分層控制后,二級控制和三級控制可以依據(jù)微電網(wǎng)中的各種測量值進行系統(tǒng)級調(diào)節(jié)。只需要借助微電網(wǎng)內(nèi)部的通信,一些難以在DG本地側(cè)實現(xiàn)的功能可由更高級的控制執(zhí)行。這將有效的簡化本地控制結(jié)構(gòu),有利于實現(xiàn)微電網(wǎng)控制的標準化。本文在國家重點基礎(chǔ)計劃項目(“973”計劃)的資助下完成,研究內(nèi)容涉及以下四個方面：DG的初級控制、改善無功分布的二級控制、抑制功率脈動的二級控制以及微電網(wǎng)的經(jīng)濟運行,本文的具體內(nèi)容如下： (1)從微電網(wǎng)的架構(gòu)和多種DG的數(shù)學模型出發(fā),提出了一種微電網(wǎng)初級控制策略,協(xié)調(diào)了不同調(diào)頻性質(zhì)DG的控制,實現(xiàn)了儲能、柴油發(fā)電機、風力發(fā)電以及光伏發(fā)電在微電網(wǎng)內(nèi)共同運行。根據(jù)平均值建模方法,對微電網(wǎng)內(nèi)部可控的電力電子器件以受控電壓源和受控電流源形式進行建模,加快了多DG微電網(wǎng)仿真的速度。仿真結(jié)果驗證了所提控制策略在光伏出力波動、負荷突變、孤島與并網(wǎng)模式切換等情況下的可行性。 (2)針對傳統(tǒng)下垂控制無功分配不均的問題,從下垂增益、負荷側(cè)電壓以及微電網(wǎng)傳輸線路阻抗特性等方面分析了經(jīng)典電壓/無功下垂控制無功負荷分配的機理。在此基礎(chǔ)上,通過上傳至微電網(wǎng)中央控制器(MGCC)的DG功率信息,建立了基于二級控制的微電網(wǎng)無功控制策略。該策略利用無功出力分配關(guān)系和空載輸出電壓的偏離程度構(gòu)造勢函數(shù)。MGCC根據(jù)勢函數(shù)對各DG的空載輸出電壓進行集中調(diào)整,達到改善無功出力分配的目的。該控制方法不需要對經(jīng)典的下垂控制進行改動,只需借助于MGCC與DG間的通信。另外,在仿真的研究中利用正則環(huán)流無功概念量化了環(huán)流的程度,并在不同負荷下考察了環(huán)流的特點和抑制效果。 (3)微電網(wǎng)內(nèi)會包含一定比例的單相DG和負荷,這會導(dǎo)致微電網(wǎng)公共連接點(PCC)電壓的不對稱。在不對稱電壓下PQ控制的DG會產(chǎn)生有功和無功功率的二倍工頻波動。通過對有功和無功脈動的機理分析,首次推導(dǎo)了有功和無功功率脈動的解析關(guān)系,并進一步揭示了正負序電氣量對功率脈動的根本性影響。在此基礎(chǔ)上,提出一種抑制功率脈動的二級控制策略。該方案根據(jù)最優(yōu)化理論,以功率脈動幅值為優(yōu)化目標,以功率脈動率和PQ控制的功率給定值為約束建立優(yōu)化模型。利用優(yōu)化結(jié)果,二級控制能夠在無功脈動較大時實現(xiàn)對有功和無功脈動的同時抑制,達到功率脈動幅值和脈動率指標的深度優(yōu)化。 (4)經(jīng)濟運行控制根據(jù)優(yōu)化結(jié)果調(diào)整各DG的功率輸出給定值,可視為微電網(wǎng)的頂層控制策略。由于微電網(wǎng)包含較大比例的間歇性能源,其出力波動對制定微電網(wǎng)發(fā)電計劃帶來較大困難。因此提出了基于機會約束規(guī)劃的微電網(wǎng)經(jīng)濟運行模型,該模型考慮了儲能充放電、備用容量配置以及功率平衡方面的約束。另外,光伏發(fā)電采用了一種考慮云量和地理因素的概率模型,該模型能夠更真實地反映光伏出力的波動變化。在求解機會約束過程中,利用概率序列理論對光伏和風力發(fā)電的概率模型進行了離散化處理,將機會約束轉(zhuǎn)化成了確定性的約束形式,使之可以通過TOMLAB等商業(yè)優(yōu)化軟件求解。仿真結(jié)果表明,與隨機模擬求解相比,該方法具有計算速度快且結(jié)果穩(wěn)定的優(yōu)勢。此外,為了考察概率性序列的合理性,還討論了不同離散化步長對計算結(jié)果的影響,并進一步驗證了所提出方法的有效性。
[Abstract]:With the aggravation of energy crisis, the deteriorating environment, coupled with the traditional centralized power supply mode exposed many shortcomings, distributed generation technology has attracted increasing attention. This technology helps to promote the use of renewable energy, and to a certain extent, the traditional power system provides an effective supplement. However in many advantages behind the randomness of the the problem of small inertia and the limitation of its application, large-scale access is will have a negative impact on the security and stability of power grid. So the micro grid came into being, become the distributed power supply (DG) "friendly" access to the grid.
Different from the traditional power system for synchronous generator based, micro grid contains many types of DG, characteristics and control methods of gap is large, difficult to standardize. When the micro grid hierarchical control, two control and three level control can be based on various measured values in the micro grid system only needs the regulation. Micro grid communication inside, some difficult to achieve in the DG local side function can be executed by more advanced control. This will simplify the local control structure, conducive to the realization of microgrid control standard. The project of the national key basic ("973") supported by, the research involves the following four aspects: primary control of DG, improved two level control the distribution of reactive power, two level control and suppression of power fluctuation of the micro grid economic operation, the specific contents are as follows:
(1) starting from the mathematical model of the micro grid architecture and a variety of DG, this paper presents a micro grid primary control strategy, coordinated control of different frequency properties of DG, the energy storage, diesel generator, wind power and photovoltaic power generation in micro grid in joint operation. According to the modeling method of the average value, the power electronic devices the micro grid interior controllable modeling with controlled voltage and current source form, accelerate the DG micro grid simulation speed. The simulation results show that the proposed control strategy in photovoltaic output fluctuation, load mutation, feasibility of island mode and grid connected mode switching condition.
(2) the traditional droop control without the problem of uneven distribution of work, from the load side voltage droop gains, and the power grid transmission line impedance characteristics of classic voltage / reactive power droop control mechanism of reactive load distribution. On this basis, through the micro grid uploaded to the central controller (MGCC) DG the power of information, establish a reactive power control strategy for microgrid based on two level control. The distribution of reactive power output and no-load output voltage deviation from the.MGCC potential function is constructed for centralized adjustment based on the potential function of each DG no-load output voltage by using the strategies to improve the reactive power allocation. The control methods. Need to change the classic droop control, only by means of communication between DG and MGCC. In addition, in the simulation study using the regular circulation of reactive power concept to quantify the degree of circulation, and studied under different load. The circulation characteristics and the effect.
(3) the microgrid will contain a certain proportion of the single-phase DG and load, which will lead to the micro grid point of common coupling (PCC) voltage asymmetry. PQ control under asymmetrical voltage DG will produce two times the frequency fluctuation of active power and reactive power. The mechanism of the active and reactive power fluctuation on the analysis. For the first time in the analysis of the relationship between active power and reactive power fluctuation are derived, and further reveals the fundamental influence on positive and negative electrical power pulsation. On this basis, put forward a kind of restraining power pulsation two level control strategy. Based on the optimization theory, the power pulse amplitude as the optimization goal, given power to power fluctuating rate and control of PQ value optimization model is established for the constraint. By using the optimization results, two level control can suppress the reactive power ripple when reactive power fluctuation on power and at the same time, achieve the power pulsation amplitude and pulse rate and depth Optimization.
(4) the power output of a given economic operation control to adjust the DG value according to the optimization results, can be regarded as the top control strategy of micro grid. The micro grid contains a larger percentage of the output fluctuation of intermittent energy, making the micro grid generation program to bring greater difficulties. Therefore proposed the chance constrained programming model based on the economic operation of the micro grid. The model takes into account the charge and discharge, spare capacity allocation and power balance constraints. In addition, the photovoltaic power generation using a probabilistic model of cloud cover and geographical considerations, this model can reflect the variation of the PV output. In the process of solving chance constraint, using the probabilistic sequence theory of probability model of photovoltaic and the wind power generation is discretized into a chance constraint constraint form of uncertainty, so that it can be through the TOMLAB commercial optimization software solution. The simulation results show that compared with the stochastic simulation solution, this method has fast calculation speed and steady advantage. In addition, in order to investigate the rationality of probability sequence, different discretization step on the calculation result is also discussed, and further verify the effectiveness of the proposed method.

【學位授予單位】：華北電力大學
【學位級別】：博士
【學位授予年份】：2014
【分類號】：TM732

【參考文獻】

相關(guān)期刊論文 前10條

1 王智冬;向孟奇;王永甲;蔣衛(wèi)平;李煥明;;基于EMTP-RV的中俄直流背靠背工程交流操作過電壓研究[J];東北電力大學學報;2007年01期

2 江岳文;陳沖;溫步瀛;;含風電場的電力系統(tǒng)機組組合問題隨機模擬粒子群算法[J];電工技術(shù)學報;2009年06期

3 肖朝霞;方紅偉;;含多分布式電源的微網(wǎng)暫態(tài)穩(wěn)定分析[J];電工技術(shù)學報;2011年S1期

4 唐西勝;鄧衛(wèi);齊智平;;基于儲能的微網(wǎng)并網(wǎng)/離網(wǎng)無縫切換技術(shù)[J];電工技術(shù)學報;2011年S1期

5 姚勇;朱桂萍;劉秀成;;電池儲能系統(tǒng)在改善微電網(wǎng)電能質(zhì)量中的應(yīng)用[J];電工技術(shù)學報;2012年01期

6 吳衛(wèi)民;何遠彬;耿攀;錢照明;汪i襠，

本文編號：1703245