风电场故障仿真分析及继电保护研究

发布时间：2018-03-08 21:42

本文选题：双馈风机　切入点：风场等值　出处：《华中科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：全球性的气候变化、环境污染和能源危机已成为各国政府和人民关注的热点问题。风能分布范围广、蕴藏量巨大、可利用难度低，并且风力发电技术在过去的几十年内发展迅速，是新能源领域技术最成熟、最具规模化商业开发条件的发电技术，将在未来能源领域占有重要地位。然而，过去几年内发生的多起大规模风电机组脱网事故，给传统继电保护技术带来严重挑战，必须寻求适合风电接入的继电保护解决方案。本文首先建立双馈风机的PSCAD仿真模型，，通过数字仿真和物理仿真的方式分析单机-无穷大系统中风机侧的故障特性。参考实际风电场的典型接线，进行合理简化等值，搭建风电场模型，设置不同的故障点仿真分析其对继电保护的影响。研究表明系统侧的故障暂态特性与常规电网几乎无差别，不影响继电保护动作特性，影响主要集中在风场侧保护：（1）双馈风机低压穿越期间三相故障电流无法持续，带延时的电流保护难以准确动作；（2）低压穿越期间故障电流包含大量的非工频分量，其频率与转子转速相关，对相量距离保护动作特性有很大负面影响；（3）风电场35kV集电线和集电母线为中性不接地系统，单相接地选线困难。针对风电接入后对继电保护的影响提出相应的改进策略：采用瞬时测量电流电压综合保护解决风场侧三相故障电流不能持续的问题；基于解时域微分方程的自适应距离保护算法对频率不敏感并且耐过渡电阻能力强；零序电流比幅比相综合算法能正确实现单相接地选线，也可以改变中性点接地方式增大零序电流；电流相量纵联差动保护不受风场特殊暂态特性影响，保护性能优越，是最理想的保护方案。
[Abstract]:The global climate change, environmental pollution and energy crisis has become a hot issue of the government and people of all countries concerned. The wind energy distribution of a wide range of huge reserves, the difficulty is low, and the wind power generation technology in the past few decades the rapid development is the most mature new energy technology, power generation technology of most commercial development conditions the scale of the field of energy in the future, will play an important role. However, the events of the past few years a number of large-scale wind turbine off grid accidents bring serious challenges to the traditional relay protection technology, must seek for relay protection of wind power integration solutions.
The PSCAD simulation model of DFIG is established in this paper, the fault characteristics by digital simulation and physical simulation analysis of single machine infinite bus system of fan side. Typical connection reference actual wind farm, reasonably simplified equivalent model of wind farm, build, analysis of the different fault point simulation effects on relay protection. The results show that the transient characteristics of fault system and the conventional power grid side is almost no difference, does not affect the characteristics of relay protection action, mainly focuses on the influence of wind farm side protection: (1) the DFIG LVRT during three-phase fault current can not be sustained, current protection with the delay is difficult to accurately action; (2) low voltage across the period the fault current contains a large number of non frequency component, the frequency and the rotation speed of the rotor, has a great negative impact on the phase characteristics of distance protection; (3) wind farm 35kV set of wires and collector bus for The neutral grounding system, the single phase grounding line selection is difficult.
According to the wind power integration effects on relay protection put forward the corresponding improvement strategies: the instantaneous measurement of current voltage protection solution wind side three-phase fault current can not be sustained problems; solving differential equations in time-domain algorithm based on adaptive distance protection is not sensitive to frequency and resistance; zero sequence current magnitude and phase comparison algorithm can realize the correct grounding line, can also change the neutral grounding mode increases zero current; current phase differential protection is not affected by the special transient characteristics of wind field protection, superior performance, is the best protection scheme to.

【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM614;TM77

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