电力变压器铁芯剩磁的仿真、测量与削弱

发布时间：2018-11-04 18:13

【摘要】：针对电力变压器铁芯剩磁对励磁涌流问题及电力变压器安全运行的影响，进行电力变压器铁芯剩磁的仿真、测量与削弱方法的研究。首先在分析研究铁磁材料及变压器剩磁产生原理的基础上，建立电力变压器铁芯的仿真模型并进行仿真分析；然后搭建试验回路进行剩磁测量并分析确定剩磁方向，将剩磁测量结果与事先设定的封闭磁路剩磁数据相比较，验证剩磁测量方法的正确性。在已知剩磁的情况下分析退磁原理与退磁方法，进一步通过仿真和试验确定了更有效的直流退磁方法，从而为具有封闭磁路的电力设备中的剩磁研究提供分析、测量及削弱方法。主要研究内容包括以下几个方面：简要描述电力变压器结构和原理，分析不同类型变压器及其设计方式，以单相电力变压器为研究对象，借助电磁暂态分析软件仿真分析剩磁对励磁涌流的影响。建立环形变压器等效电路的数学分析模型。设定封闭铁芯结构尺寸及材料特性参数，通过改变剩磁线圈中的电流改变铁芯中的剩磁。在铁芯另一侧的测量线圈上加载适当大小的正、负方向直流电压。采用Magnet软件进行暂态仿真分析，得到给定剩磁所对应的测量电流变化值。对多组剩磁与测量电流变化值进行拟合，得到测量电流变化值与剩磁关系的数学表达式。以环形电力变压器铁芯为研究对象，搭建剩磁测量电路，进行剩磁测量。分析结果发现，测量计算得到的剩磁值同预设剩磁的相对误差在7%以内，说明了所提出的剩磁测量方法的有效性。归纳分析已有剩磁削弱方法进行，结合利用上述方法分析得到的剩磁进行退磁，通过仿真分析确定最优退磁方法。搭建退磁电路进行试验，验证退磁方法的可行性与有效性。
[Abstract]:Aiming at the influence of remanent magnetism of power transformer core on inrush current and safe operation of power transformer, the emulation, measurement and weakening method of power transformer core remanence are studied. Firstly, based on the analysis of ferromagnetic materials and the principle of transformer remanence, the simulation model of power transformer core is established and the simulation analysis is carried out. Then the remanent magnetic measurement circuit is built and the remanent magnetic direction is analyzed and determined. The remanent magnetic measurement results are compared with the closed magnetic circuit remanent magnetic data set in advance to verify the correctness of the remanent magnetic measurement method. The principle and method of demagnetization are analyzed under the condition of known remanence, and a more effective method of DC demagnetization is determined by simulation and experiment, which provides an analysis for the study of remanence in electric power equipment with closed magnetic circuit. Methods of measuring and weakening. The main research contents are as follows: briefly describing the structure and principle of power transformer, analyzing different types of transformers and their design methods, taking single-phase power transformer as the research object. The effect of remanent magnetization on inrush current is simulated by electromagnetic transient analysis software. The mathematical analysis model of equivalent circuit of ring transformer is established. The structure size and material characteristic parameters of the closed core are set, and the remanence in the core is changed by changing the current in the remanence coil. Load appropriate positive and negative DC voltage on the measuring coil on the other side of the core. The transient simulation analysis is carried out with Magnet software, and the measured current changes corresponding to the given remanent magnetism are obtained. The mathematical expressions of the relationship between the measured current and the remanent current are obtained by fitting the remanent magnetization and the measured current. Taking the core of ring power transformer as the research object, the remanent magnetic measurement circuit is built and the remanence magnetic measurement is carried out. The results show that the relative error between the calculated remanent magnetic value and the preset remanence is less than 7%, which shows the effectiveness of the proposed method. The existing methods of remanence weakening are summarized and analyzed. The optimal demagnetization method is determined by simulation analysis combined with the demagnetization obtained by the above method. Demagnetization circuit was built to test the feasibility and effectiveness of demagnetization method.
【学位授予单位】：河北工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM41

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