大规模风电并网的谐波谐振与谐波不稳定研究

发布时间：2018-04-21 16:43

本文选题：风力发电 + 谐波建模　；参考：《西南交通大学》2017年硕士论文

【摘要】：近年来,风电产业快速发展,其中,中大型风力发电机组已在世界上40多个国家陆地和近海并网运行。本硕士论文针对中大型风电场中存在大量电缆敷设和海底电缆传输,其对地电容与感性电力系统之间相互作用,从而激发的谐波谐振问题以及风电机组中电压源换流器(voltage source converter,VSC)的输出阻抗在部分频域呈现负阻尼所带来的谐波不稳定问题进行分析研究。基于模态敏感度分析、Nyquist判据等方法,本文研究大规模风电接入的谐波谐振与谐波不稳定现象,并提出抑制措施,以保障风电场及其并入电网安全、稳定、高效地运行,主要工作有:(1)风电场建模与谐振、谐波不稳定问题分析方法。基于对背靠背型VSC谐波模型和异步电机谐波模型的研究进一步建立随风速变化的双馈风力发电机的(doubly fed induction generator,DFIG)谐波模型。同时,建立风电场的主要电气设备部分谐波模型,主要包括:电缆、变压器、电网侧、无功补偿装置等谐波模型。对模态分析法、敏感度分析、Nyquist判据等谐波谐振、谐波不稳定问题的研究方法进行了分析研究。(2)风电场谐波特性分析以及谐振机理研究。研究网侧变换器(grid-side converter,GSC)和转子侧变换器(rotor-side converter,RSC)给风电场注入谐波的规律。结合实测数据,总结归纳了风电场中的谐波规律。进一步,利用频率扫描法仿真分析拓扑结构变化、工况变化等不确定因素引起的不同谐振情况,以及各参数对谐振频率、谐振幅值的大致影响规律。(3)基于敏感度分析法的谐波谐振研究及抑制策略。利用模态分析法研究了不同运行工况、不同系统参数、不同模态的谐振规律,定义了节点敏感度指标,量化了风电场中每个节点对谐振情况的影响,揭示谐振的渗透、传播规律。利用敏感度分析法,进一步定义阻抗敏感度指标和频率敏感度指标,为谐振问题的抑制提供依据,深入量化了风电场中各元件参数对风电场每一次谐振的影响程度。并且利用频率转移法配合滤波器提出谐振抑制方案。(4)建立基于控制参数的VSC阻抗模型,探究风电机中网侧VSC输出特性。探究谐波在VSC控制环中的传输、放大规律。进一步利用Nyquist稳定性判据,分析了谐波不稳定的影响因素。本硕士论文利用模态分析法,结合实测数据对风电场的谐波谐振问题进行了深度剖析与探究,进一步研究了谐波不稳定问题机理,可为风电场谐振及不稳定问题的相关研究提供支持。
[Abstract]:In recent years, wind power industry has developed rapidly. Among them, medium and large scale wind turbines have been connected to land and offshore in more than 40 countries in the world. In this thesis, there are a large number of cable laying and submarine cable transmission in large wind farms, and the interaction between the earth capacitance and the inductive power system is discussed. The harmonic resonance caused by the excitation and the harmonic instability caused by the partial negative damping of the output impedance of the voltage source converter (VSC) in the wind turbine are analyzed and studied. Based on the modal sensitivity analysis and Nyquist criterion, this paper studies the harmonic resonance and harmonic instability in large-scale wind power access, and puts forward some restraining measures to ensure the safe, stable and efficient operation of the wind farm and its integration into the power grid. The main work is: 1) wind farm modeling and resonance, harmonic instability analysis method. Based on the research of back-to-back VSC harmonic model and asynchronous motor harmonic model, a doubly fed induction generator harmonic model of doubly-fed wind turbine with wind speed variation is established. At the same time, the harmonic model of the main electrical equipment of wind farm is established, including: cable, transformer, power grid side, reactive power compensator and so on. The methods of modal analysis, sensitivity analysis and Nyquist criterion for harmonic resonance and harmonic instability are studied. The law of harmonic injection into wind farm by grid-side converterside GSC) and rotor-side converterside RSCs is studied. Combined with the measured data, the harmonic law in wind farm is summarized. Furthermore, the frequency scanning method is used to simulate and analyze the different resonant conditions caused by the uncertainties such as the change of topological structure and the change of working conditions, as well as the resonance frequency of each parameter. The effect of harmonic amplitude on harmonic resonance and its suppression strategy based on sensitivity analysis. The resonance law of different operating conditions, different system parameters and different modes is studied by using modal analysis method. The sensitivity index of nodes is defined, and the influence of each node on resonance in wind farm is quantified, and the penetration of resonance is revealed. The law of propagation. By using sensitivity analysis method, impedance sensitivity index and frequency sensitivity index are further defined to provide the basis for the suppression of resonance problem, and the influence degree of each element parameter in wind farm on each resonance of wind farm is quantified. The frequency transfer method and filter are used to establish the VSC impedance model based on the control parameters to explore the VSC output characteristics of the grid side of the wind motor. Probe into the law of harmonic transmission and amplification in VSC control loop. Furthermore, the influence factors of harmonic instability are analyzed by using Nyquist stability criterion. In this thesis, the harmonic resonance problem of wind farm is deeply analyzed and explored with modal analysis method and measured data, and the mechanism of harmonic instability problem is further studied. It can provide support for the research of wind farm resonance and instability.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM614;TM711

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