干式空心电抗器匝间短路故障的空间磁场分布研究

发布时间：2018-03-10 20:20

本文选题：干式空心电抗器　切入点：空间磁场　出处：《山东大学》2017年硕士论文　论文类型：学位论文

【摘要】：干式空心电抗器(Dry-type Air-core Reactors,DAR)凭借电抗值线性、结构简单、重量轻、安装维护方便等优点,在电网无功补偿、滤波和限流等场合得到广泛应用。自DAR投入运行以来,出现了多起烧毁事故,大量分析结果表明,多数电抗器烧毁事故是由匝间短路故障引起的。为了减少DAR匝间短路故障问题,除提高电抗器制造水平外,还必须配有有效的匝间短路故障检测手段。但是,现有的匝间短路故障检测方法都存在灵敏度低或者可靠性差等缺陷。因此,针对电抗器匝间短路故障问题,探究一种灵敏度高、可靠性好的匝间短路故障检测方法有着重要意义。为了研究有效的DAR匝间短路故障检测方法,本文基于电抗器空间磁场分布规律开展了一系列的研究,主要内容有:研究DAR空间磁场计算方法,总结分析DAR空间磁场分布与匝间短路故障之间的关系,提出构建磁场变化量与故障程度或位置的拟合函数以得到DAR匝间短路故障的检测方法。探究DAR空间磁场计算方法对研究电抗器故障磁场变化规律具有重要意义。本文给出了 DAR空间磁场的定义,据此分析了 DAR的电气特性与等效电路,并根据基尔霍夫定律和麦克斯韦方程组建立了 DAR等效模型。研究出一种基于有限元计算电抗器线圈电感和空间磁场分布的方法,并对电抗器线圈电感和空间磁场分别进行有限元仿真,解析计算法对有限元仿真结果的验证证明了所建电抗器模型的准确性与所用有限元计算法的可行性。为进一步探索DAR匝间短路故障磁场分布规律,以电压等级为35kV的并联DAR为例,在故障模型的各不同位置设定不同程度的匝间短路故障,通过比较电抗器在不同故障下沿轴向中心轴(Axial Traverse in Center,ATC)和径向中心轴(Lateral Traverse in Center,LTC)两个方向的空间磁场分布,得出匝间短路故障对电抗器空间磁场的影响规律。本文基于DAR空间磁场变化规律提出一种匝间短路故障检测方法。将观测点磁场变化量和故障程度或位置作为拟合变量,分别建立了故障程度以及故障位置与观测点磁场变化量之间的故障检测函数。利用磁场变化量判断故障的方法来验证故障检测函数的应用效果,结果显示计算故障与实际故障误差在可接受范围内,证明故障检测函数具有很好的检测效果。
[Abstract]:Dry-type Air-core ReactorsDAR) has been widely used in reactive power compensation, filtering and current limiting since DAR was put into operation, because of its advantages of linear reactance, simple structure, light weight and convenient installation and maintenance. In order to reduce the problem of inter-turn short circuit in DAR, a large number of analysis results show that most reactor burnout accidents are caused by inter-turn short circuit fault, except to improve the manufacturing level of reactor. It must also be equipped with effective inter-turn short-circuit fault detection methods. However, the existing inter-turn short-circuit fault detection methods have some shortcomings, such as low sensitivity or poor reliability. Therefore, aiming at the problem of inter-turn short-circuit fault of reactor, It is of great significance to explore a method for detecting inter-turn short circuit fault with high sensitivity and good reliability. In order to study an effective method for detecting inter-turn short circuit fault of DAR, a series of studies are carried out based on the distribution of space magnetic field of reactor. The main contents are as follows: the calculation method of DAR space magnetic field is studied, and the relationship between DAR spatial magnetic field distribution and inter-turn short circuit fault is summarized and analyzed. A fitting function between magnetic field variation and fault degree or position is proposed to detect the inter-turn short circuit fault of DAR. It is of great significance to explore the calculation method of DAR space magnetic field for studying the variation rule of fault magnetic field of reactor. In this paper, the definition of DAR space magnetic field is given. Based on this, the electrical characteristics and equivalent circuit of DAR are analyzed. Based on Kirchhoff's law and Maxwell's equations, the equivalent model of DAR is established. A method of calculating inductance and space magnetic field distribution of reactor coil based on finite element method is developed. The inductance and space magnetic field of reactor coil are simulated by finite element method. The accuracy of the reactor model and the feasibility of the finite element method are verified by the analytical calculation method. In order to further explore the magnetic field distribution law of DAR inter-turn short-circuit fault, Taking the parallel DAR with a voltage grade of 35 kV as an example, different degrees of inter-turn short circuit faults are set at different locations of the fault model. By comparing the magnetic field distribution of the reactor along the axial axis Traverse in the ATC and the radial central axis lateral Traverse in the LTCs under different faults, the magnetic field distribution of the reactor is compared. The influence of inter-turn short circuit fault on the space magnetic field of reactor is obtained. Based on the variation rule of DAR space magnetic field, a detection method of inter-turn short circuit fault is proposed. The variation of magnetic field and the degree or position of fault at observation point are taken as fitting variables. The fault detection function between the fault location and the magnetic field variation of the observation point is established, and the application effect of the fault detection function is verified by the method of judging the fault by the variation of the magnetic field. The results show that the error between the calculation and the actual fault is within the acceptable range, and it is proved that the fault detection function has a good detection effect.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM47

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