【作者】 李智；

【导师】 刘明波； 许爱东；

【作者基本信息】 华南理工大学 ， 电子信息（专业学位）， 2024， 博士

【摘要】 未来十几年,随着现代能源体系逐步构建,新型电力系统的长足发展,新能源仍将迅猛发展,对电网的影响会愈发显著。新能源的高速发展使其在电网中的占比越来越高,电力系统电力电子化特性凸显,电力系统中的旋转备用容量及转动惯量相对减少,给电力系统安全稳定运行带来了较大压力。新能源采用的电力电子装置有其技术优势,但几乎没有转动惯量,难以参与电网调节,无法为电网提供必要的频率和电压支撑,也无法提供必要的阻尼。为改善新能源机组运行特性,缓解电网运行压力及新能源消纳压力,新能源机组亟需具备一定的主动支撑能力。本文在高比例新能源接入电网的大背景下,从电磁暂态建模、稳定性、振荡机理阐释、电网适应性分析与调频调压协调控制优化五个维度,围绕新能源主动支撑关键技术开展研究,建立主动支撑风电机组、光伏单元并网系统小信号分析模型;研究具有主动支撑电网能力的新能源机组并网振荡分析方法,探明并网振荡机理并提出抑制措施;分析多机并联并网运行系统稳定性,研究电网故障、不同新能源占比、电网强度下主动支撑新能源机组并网适应性,提出基于动态电压补偿的故障穿越控制策略;提出新能源机群主动调频调压协调控制策略,并对工程应用的主动支撑风电机组、光伏单元进行现场试验和控制器硬件在环仿真验证,主要研究成果与结论归纳如下:1.建立了主动支撑新能源发电机组全环节的小信号模型,为研究主动支撑新能源机组并网适应性问题提供基础。针对风电与光伏两类主动支撑新能源发电机组,分析其控制机理和运行特性,建立了涵盖空气动力学、传动轴、发电机、变流器和网侧环节的主动支撑风电机组小信号模型,构建了计及虚拟惯量、一次调频、励磁电压和电流内环的光伏单元小信号模型,用以研究主动支撑新能源发电系统的暂态响应性能与并网适应性。2.研究了主动支撑新能源发电机组并网振荡机理,提出了并网振荡抑制策略。针对主动支撑新能源发电机组可能存在的并网振荡问题,基于主动支撑新能源机组的小信号模型,研究其并网振荡机理与振荡模态,并针对主动支撑新能源机组的次同步振荡、高频谐振,分别提出基于有源阻尼的高频谐振抑制策略和基于带阻滤波器的次同步振荡抑制策略,通过电磁暂态仿真验证了策略的有效性,提升主动支撑新能源机组的并网运行的适应性。3.从故障穿越的角度分析主动支撑新能源机组的响应特性,提出适应主动支撑新能源机组的故障穿越控制策略。仿真分析主动支撑新能源机组在电网大扰动场景下的暂态特性,针对电网电压不平衡以和电网电压跌落等故障场景,提出了基于动态电压补偿主动支撑新能源机组的故障穿越控制策略,抑制故障情况下的电流不平衡,减小故障发生时的峰值电流冲击,从故障穿越的角度进一步提升主动支撑新能源发电机组的并网适应性。4.提出一种新颖的考虑多台主动支撑新能源机组控制参数和滤波参数的小信号分析模型,选定电网的D-Q坐标系为公共坐标系,将第i台主动支撑新能源机组的d-q分量变换至公共坐标系D-Q轴,建立用于稳定性分析的主动支撑新能源机组双机并联并网系统小信号模型,分析有功调频系数、惯量时间常数等控制参数,及线路阻感比、线路长度等网侧参数对特征根和振荡模态的影响,得出了具备工程实用性的振荡临界控制参数值和多机交互振荡特性。5.提出了主动支撑新能源机群的协同调频调压控制策略,提升机群和场站的运行协同性。针对主动支撑新能源发电机群并网运行时面临的难以协调控制的问题,提出了基于一致性算法的主动支撑新能源机群的协调运行控制策略。同时,针对新能源机群面临的暂态响应问题,提出基于参数调节的主动支撑新能源发电机组的暂态频率响应提升策略,进一步提升新能源机群的主动支撑能力。6.依托主动支撑新能源机组示范工程,分析了小信号模型稳定性分析和参数设计、有源阻尼法与带阻滤波器法的高频振荡与次同步振荡抑制、基于动态电压补偿的故障穿越策略、一致性算法和暂态响应优化协调调频调压控制策略等技术的工程应用效果,验证了论文所提出的优化控制策略和分析方法的有效性与工程实用性。更多还原

【Abstract】 In the decade years,with the gradual construction of the modern energy system and the rapid development of the new-type electrical power system,new energy power generation will keep developing rapidly,and the impact on the power grid will become more and more significant.The rapid development of new energy power generation makes its proportion in the power grid become higher,the power electronic characteristics of the power system are highlighted.In additional,the rotational reserve capacity and inertia in the power system are relatively reduced,which brings great pressure to the safe and stable operation of the power system.The power electronics used in new energy power generation have its technical advantages,however,power electronics devices are almost no inertia,it is difficult to participate in the regulation under the condition of power grid is fault,and it cannot provide the necessary frequency and voltage support for the power grid,nor can it provide the necessary damping.In order to improve the operation characteristics of new energy generation units,alleviate the pressure of power grid operation and new energy power consumption,new energy generation units urgently need to have certain active support capabilities.In the context of the high proportion of new energy connected to the power grid,this paper focuses on the key technologies of new energy active support from five dimensions: electromagnetic transient modeling,stability analysis,oscillation mechanism and suppression strategy,power grid adaptability analysis and frequency and voltage regulation coordination control optimization.Research on small signal analysis model of grid-connected new energy generation unit,the oscillation mechanism analysis of new energy generation units with the ability to actively support the power grid,proposed related suppression strategy,analysis the stability of multi-units grid-connected operation system,research the adaptability of grid-connected new energy generation units under grid fault conditions,different new energy ratios and power grid strength.In additional,proposed the fault ride-through control strategy based on dynamic voltage compensation,proposed new energy power generation cluster active frequency and voltage regulation control strategy,the active support wind turbines,photovoltaic power units are field test and controller hardware-in-the-loop simulation for engineering applications.The main research results and conclusions are summarized as follows:1.Building the small signal model of the whole process of new energy generation units with active support functions,which provides the basis for research on the adaptability to the grid.Analysis of control mechanism and operation characteristics of wind power and photovoltaic power generation units,the small signal model of wind turbines with active support covering aerodynamics,drive shaft,generator,converter and power grid was built,and the small signal model of photovoltaic power unit considering virtual inertia,primary frequency regulation,excitation voltage and current inner loop,in order to research on the transient response performance and grid-connected adaptability for new energy power generation units with active support functions.2.The oscillation mechanism of new energy generation units with active support was studied,and the oscillation suppression strategy was proposed.In view of the possible oscillation problems of new energy generation units with active support,based on the small signal model of new energy generation units with active support,the oscillation mechanism and oscillation mode are analysis,and for the subsynchronous oscillation and high-frequency resonance of new energy generation units with active support,the high-frequency resonance suppression strategy based on active damping and the subsynchronous oscillation suppression strategy based on band-stop filter are proposed,and the effectiveness of the strategies is verified by electromagnetic transient simulation,the improve the adaptability of the grid-connected operation of new energy generation units with active support.3.From the perspective of fault ride-through,the response characteristics of the new energy generation units with active support functions are analyzed,and the fault ride-through strategy is proposed.Considering the operation problems of the power grid fault situation faced by the new energy generation units with active support functions,the grid-connected fault ride-through control strategy of new energy generation units with active support is proposed to suppress the imbalance problem in the fault situation and reduce the peak current impact when the fault occurs.From the perspective of fault ride-through,the grid-connected adaptability of ew energy generation units with active support functions is further improved.4.Proposed a novel small signal analysis model considering the control parameters and filtering parameters of multiple new energy generation units with active support,select the D-Q coordinate system of the power grid as the common coordinate system,transform the d-q component of new energy generation units with active support to the D-Q axis of the common coordinate system,build a small signal model of the dual-machine parallel grid-connected system of the new energy generation units with active support for stability analysis,analyze the control parameters such as the active frequency regulation coefficient and the time constant of inertia,and the power line resistance-inductance ratio,meanwhile the influence of grid-side parameters such as line length on the eigenroot and oscillation mode is obtained,and the values of the oscillation critical control parameters and the multi-units interactive oscillation characteristics are obtained for further engineering practicability.5.A cooperative frequency and voltage regulation control strategy of new energy generation units with active support is proposed,to improve the operation synergy of the cluster and the new energy stations.In order to solve the problem of difficult coordination and control of new energy generation cluster with active support when connected to power grid,the coordinated operation control strategy of new energy generation cluster with active support based on consistency algorithm was proposed.In additional,in view of the transient response problem faced by new energy generation cluster with active support,the transient frequency response improvement strategy based on parameter adjustment was proposed to further improve the active support capacity of the new energy generation cluster.6.Relying on the new energy generation units with active support functions demonstration project,the engineering application effects of the stability analysis based on the small signal model and control parameter designation,the high-frequency oscillation and subsynchronous oscillation suppression,and the band-stop filter method,the fault ride-through strategy based on dynamic voltage compensation,the consistency algorithm and the transient response optimization coordination frequency and voltage regulation control strategy are analyzed,and the effectiveness and engineering practicability of the proposed strategies in the paper are verified.更多还原