【摘要】：隨著石化能源限制問題和環(huán)境保護(hù)要求日益受到重視,我國風(fēng)電與光伏新能源接入的規(guī)模不斷增大。同時,受電力體制改革、廠網(wǎng)分開、管理主體多元化影響,電網(wǎng)頻率安全穩(wěn)定控制面臨很大的挑戰(zhàn)。一方面,新能源與火電、水電常規(guī)電源相比,缺乏慣量效應(yīng),并且波動性大,不具備一次調(diào)頻能力。因此,新能源接入后的電網(wǎng)調(diào)頻對常規(guī)機(jī)組的依賴性加大,需要加強對火電和水電常規(guī)機(jī)組調(diào)速器一次調(diào)頻特性的研究,明確傳統(tǒng)和數(shù)字電液式兩類調(diào)速系統(tǒng)的特點和差異,為對新能源接入后的電網(wǎng)頻率特性進(jìn)行準(zhǔn)確仿真、科學(xué)策略提供指導(dǎo)。另一方面,新能源接入系統(tǒng)與主網(wǎng)間發(fā)生解列故障是頻率安全穩(wěn)定研究的重要場景,應(yīng)全面考慮電源側(cè)頻率異常保護(hù)和電網(wǎng)側(cè)安全控制措施,研究解列故障面臨的高頻或低頻問題及控制策略。本文首先簡要介紹了所用到的新能源和常規(guī)機(jī)組的數(shù)學(xué)模型,并梳理總結(jié)了其各自的頻率異常耐受范圍,明確了兩類機(jī)組的頻率異常保護(hù)的配置特點和差異。隨后,對火電、水電機(jī)組的傳統(tǒng)和數(shù)字電液式兩類調(diào)速系統(tǒng)的特點和差異進(jìn)行了對比研究,著重于兩類調(diào)速系統(tǒng)的結(jié)構(gòu)、死區(qū)環(huán)節(jié)處理、動態(tài)調(diào)頻特性三個方面,分析了在小擾動、大擾動兩種工況下兩類典型調(diào)速器的特性。在此基礎(chǔ)上,對新能源接入系統(tǒng)后解列導(dǎo)致的高頻問題開展研究,建立了含多類型電源的送端典型系統(tǒng)算例,分析了對火電機(jī)組OPC保護(hù)定值進(jìn)行差異化設(shè)置的效果;指出新能源高頻保護(hù)定值過低而無序脫網(wǎng)將導(dǎo)致原高頻問題轉(zhuǎn)化為低頻問題的嚴(yán)重后果;研究了應(yīng)對高頻問題的連鎖切機(jī)方案,比較了切除常規(guī)機(jī)組和切除風(fēng)電機(jī)組對抑制頻率波動和最大功角差的不同效果,提出了兼顧頻率和功角因素的綜合切機(jī)策略。最后,對新能源接入系統(tǒng)后解列導(dǎo)致的低頻問題開展研究,以有大規(guī)模新能源接入的西北某省級電網(wǎng)為實例,研究了動態(tài)無功補償?shù)碾妷嚎刂�、常�?guī)機(jī)組的旋轉(zhuǎn)備用容量、新能源接入電網(wǎng)比例等因素對電網(wǎng)頻率調(diào)節(jié)特性的影響,并針對新能源接入易導(dǎo)致低頻減載輪次增多的問題,提出了低頻減載方案的優(yōu)化策略。
[Abstract]:With the increasing attention paid to the restriction of petrochemical energy and the requirement of environmental protection, the scale of new energy access to wind power and photovoltaic in China is increasing. At the same time, due to the reform of power system, the separation of power plant and power grid, and the influence of diversified management bodies, the frequency security and stability control of power network faces great challenges. On the one hand, compared with conventional power supply of thermal power and hydropower, new energy is lack of inertia effect, and is fluctuating, so it does not have the ability of primary frequency modulation. Therefore, the dependence of power grid frequency modulation on conventional units is increased after the new energy source is connected, so it is necessary to strengthen the study on the primary frequency modulation characteristics of the governor of thermal power and hydropower conventional units, and to make clear the characteristics and differences between the traditional and digital electro-hydraulic speed regulating systems. It provides guidance for accurate simulation of power grid frequency characteristics after new energy access and scientific strategy. On the other hand, the decoupling fault between the new energy access system and the main network is an important scene for the study of frequency security and stability. The frequency abnormal protection on the power side and the safety control measures on the grid side should be considered comprehensively. The problem of high frequency or low frequency and control strategy are studied. In this paper, the mathematical models of new energy sources and conventional units are briefly introduced, and their respective frequency abnormal tolerance ranges are summarized, and the configuration characteristics and differences of frequency abnormal protection between the two types of units are clarified. Then, the characteristics and differences of the traditional and digital electro-hydraulic speed regulating systems of thermal power and hydroelectric generating units are compared and studied, focusing on the structure of the two types of speed control systems, dead zone processing, dynamic frequency modulation characteristics. The characteristics of two kinds of typical governor under small disturbance and large disturbance are analyzed. On this basis, the high-frequency problem caused by the post-de-listing of the new energy access system is studied, and the typical system with multi-type power supply is established, and the effect of differential setting for the OPC protection of thermal power unit is analyzed. It is pointed out that the low fixed value of new energy high frequency protection and disordered disconnection will lead to the serious consequences of converting the original high frequency problem into the low frequency problem. This paper studies the scheme of interlocking cutting machine to deal with the problem of high frequency, compares the different effects of removing conventional unit and removing wind turbine on restraining frequency fluctuation and maximum power angle difference, and puts forward a comprehensive cutting strategy which takes into account the factors of frequency and power angle. Finally, the low-frequency problem caused by the post-de-listing of the new energy access system is studied. Taking a provincial power grid with large-scale new energy access as an example, the voltage control of dynamic reactive power compensation and the rotating reserve capacity of conventional units are studied. The influence of the proportion of new energy access to the power network on the frequency regulation characteristics of the power network is discussed. Aiming at the problem that the low frequency load reduction cycle increases easily due to the new energy access, the optimization strategy of the low frequency load reduction scheme is put forward.
【學(xué)位授予單位】：華北電力大學(xué)(北京)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TM712

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 孫志遠(yuǎn);負(fù)荷頻率特性及建模方法研究[D];西安理工大學(xué);2018年

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本文編號：2304228