导　　师： 文福拴

学科专业： 080802

授予学位： 博士

作　　者： ;

机构地区： 华南理工大学

摘　　要： 在能源和环境的双重压力下，风力发电技术受到了越来越普遍的重视，正逐步走向规模化和产业化，越来越多的大中型风电场相继建成并与电力系统联网运行，其在电网中的比例日益增大，接入电压等级从最初的配电系统发展到高压输电系统。大量风电并网对电力系统的安全稳定运行带来了挑战，其影响也越来越广泛和复杂，开展风电并网带来的一系列技术问题的相关研究非常重要和迫切。在此背景下，本文对风电并网对电力系统的稳定性影响问题进行系统而深入的研究，使得大规模风电场能合理平稳地接入电力系统，为风力发电的政策制定、规划设计、生产运行提供理论准备和技术支撑。 本论文的具体内容如下： 1.为系统地分析风电机组对电力系统小干扰和暂态稳定性的影响，对三种常见类型的风力发电机组接入后的电力系统稳定性进行了系统的比较研究。首先确定了这三类风力发电机组的动态模型，之后以WSCC3机9节点和8机24节点系统为例，采用特征值分析和动态时域仿真方法，系统地比较了在同一母线接入异步风力发电机、双馈感应风电机组和永磁直驱风力发电机与接入同等容量同步发电机组对系统小干扰稳定和暂态稳定性的影响。 2.为研究风电并网对互联系统低频振荡的影响，基于完整的双馈感应风力发电机组模型，定性分析了两区域互联系统在风电机组并网前后阻尼特性的变化情况，给出了风电场在系统送电侧和受电侧时系统的阻尼增量。从双馈感应风力发电机组并网输送距离、并网容量、互联系统联络线传送功率/(大小与方向/)、是否加装电力系统稳定器等多方面多角度分析了风电场并网对互联系统小干扰稳定及低频振荡特性的影响。之后，在两个2区域系统算例上进行了比较分析。 3.为了改善风电并网后互联系统的动态稳定性，将附加阻尼控制静止无功补偿器/(Static Var Compensator，SVC/)引入含风电的互联系统。以含双馈感应发电机的风电系统功率关系为基础，推导了在转子电流限制条件下风电机组的无功功率极限，借助开环系统的留数指标定位SVC加装点；从暂态能量的角度分析了含SVC的互联系统区域模式振荡的能量描述问题；设计了用于改善系统阻尼特性的SVC附加阻尼控制器，并采用特征根灵敏度法确定控制器参数。最后在IEEE2区域4机系统上进行有效性验证和研究。 4.电力系统稳定器/(Power System Stabilizer，PSS/)为励磁系统产生辅助控制信号来改善系统的阻尼进而抑制低频振荡。迄今为止，已提出了多种不同的PSS设计方法，并得到了不同程度的应用。为推动不同类型的PSS在电力系统中的实际应用，对4种有代表性的PSS设计方法的原理和特性进行比较研究，包括传统PSS、单神经元PSS、自适应PSS和多频带PSS。为使比较研究具有共同的基础,这4种PSS的参数都采用最速下降法优化确定。最后，以8机24节点系统为例对这4种PSS设计方法的性能进行了比较分析。 Wind farms have been increasingly integrated into power systems over the last fewdecades because of the global energy crisis and the pressure on environmental protection, andgradually going to the road of large-scale and industrialization. In recent years, the installationof wind power energy has moved from small wind farms with a few wind turbines to largewind farms with more than hundreds of MW of capacity, and the connection point of windfarm have developed from low voltage level’s electricity distribution system to high voltagelevel’s electricity transmission system. With the penetration level increasing, the impact ofwind power on power system dynamics and stability become increasingly complicated, whichmake it necessary to research on a series of technology problems of wind power integratedsystem. Given these backgrounds, many systematic and in-depth investigations on the impactsof wind farms on power system stability have been done in this dissertation for the reasonableand stable penetrations of wind farms into power system. Meanwhile, the researching workcan provide theoretical preparation and technology support for the programming, designing,operation and policy-making of wind farms. Specifically, the main contents of this dissertation are as follows: 1. To systematically examine the impacts of wind power on the small signal stability aswell as transient stability, so as to investigate the countermeasures. A comprehensive study iscarried out to compare the dynamic performances of a power system respectively with threewidely-used types of wind power generators integrated. First, the dynamic models aredescribed for three types of wind generators, i.e. the squirrel cage induction generator /(SCIG/),doubly fed induction generator /(DFIG/) and permanent magnet generator /(PMG/). Then, theimpacts of these three kinds of wind generators on the small signal stability and transientstability are compared with that of a substituted synchronous generator /(SG/) having the samecapacity at the same connection point in the WSCC three-machine nine-bus system byemploying the eigenvalue analysis and dynamic time-domain simulations. 2. In order to investigate the impacts of wind power integration on the low frequencyoscillation characteristics of an interconnected power system, the damping performances of atwo-area interconnected power system with and without wind power integration are analyzedbased on the comprehensive model of the doubly fed induction generator, and the dampingincrement is given with the wind farm at the sending end and at the receiving end. Theimpacts of several factors, including the DFIG transmission distance, DFIG capacity, tie-line power of the interconnected system, with//without a power system stabilizer /(PSS/), on the lowfrequency oscillation characteristics of the interconnected power system are examinedsystematically. Then, a two-area four-machine system and a two-area eight-machine systemare employed to carry out detailed analysis and comparisons. 3. An auxiliary damping control /(ADC/) static var compensator /(SVC/) is applied in adoubly fed induction generator /(DFIG/) integrated interconnected power system and theimpact of ADC-SVC on the damping characteristics of the interconnected power system isstudied. Firstly, the dynamic models of wind turbines based on DFIG is described; thereactive power limit of DFIG wind power generation system is deduced based on the powerrelationships of overall system; the energy process of area mode oscillations including SVC isanalyzed from the point of view of area transient energy using the conception of energyconservation under zero damping; the ADC at SVC is designed to improve the dampingcharacteristic of powe system, and the control parameters are determined by the eigenvaluesensitivity method. The performance was validated on an IEEE4-machine2-area system. 4. To ensure the small-signal stability of a power system, power system stabilizers /(PSSs/)are extensively applied for damping low frequency power oscillations through modulating theexcitation supplied to synchronous machines, Up to now, various kinds of PSS designmethods have been proposed and some of them applied in actual power systems with differentdegrees, and increasing interest has been focused on developing different PSS schemes totackle the threat of damping oscillations to power system stability. Given this background,four different PSS models and investigates their performances on damping power systemdynamics using both small-signal eigenvalue analysis and large-signal dynamic simulations.The four kinds of PSSs examined include the Conventional PSS /(CPSS/), Single Neuron basedPSS /(SNPSS/), Adaptive PSS /(APSS/) and Multi-band PSS /(MBPSS/). To make thecomparisons equitable, the parameters of the four kinds of PSSs are all determined by thesteepest descent method. Finally, an8-unit24-bus power system is employed to demonstratethe performances of the four kinds of PSSs by the well-established eigenvalue analysis as wellas numerous digital simulations.

关 键 词： 电力系统 风电并网 小干扰稳定 暂态稳定 低频振荡 特征值分析 静止无功补偿器 阻尼控制 电力系统稳定器

分 类 号： [TM614 TM712]

领　　域： [电气工程] [电气工程]