电力变压器内部故障的非线性仿真模型  

A Nonlinear Model to Calculate Post-Internal Fault Parameters of Power Transformer

作　　者：杨利水[1] 杨旭 徐岩[3] 

机构地区：[1]保定电力职业技术学院,河北省保定市071051 [2]深圳供电局,广东省深圳市518000 [3]华北电力大学电气与电子工程学院,河北省保定市071003

出　　处：《电网技术》2009年第20期183-188,共6页Power System Technology

摘　　要：针对电力变压器内部故障分析和继电保护的需要,分析了现有变压器线性仿真模型中确定电感参数存在的问题。指出问题的关键是没有考虑发生内部短路故障后,变压器内部的磁场发生了变化,而且铁心存在饱和的非线性特征,因而用变压器的线性模型模拟和计算其电感参数是不准确的。为此,文中利用有限元分析法,提出了一种变压器内部故障的非线性仿真模型。该模型利用有限元分析法计算变压器内部故障后的参数,根据这些参数形成等值电路模型,并得到了需要研究的电流和电压值。为验证非线性模型的正确性,将1台模拟变压器的内部故障试验仿真数据与动模试验数据进行了比较。结果表明文中提出的变压器内部故障非线性模型是正确的。According to the demand of internal fault analysis of power transformer and corresponding protection, the defects in determining inductance parameter by existing linear simulation models for power transformer are researched. The crux of the defects is that the variation of internal magnetic field of power transformer and the nonlinear saturation characteristic of transformer core are not taken into account while the internal fault occurs, thus it is inaccurate to simulate and calculate inductance parameter of power transformer during its internal faults by its linear model. For this reason, a nonlinear simulation model for internal faults of power transformer is proposed, which uses finite element analysis to calculate transformer parameters after internal faults, and on this basis a equivalent circuit model is formed to obtain the values of current and voltage to be researched. To validate the proposed nonlinear model, the result of simulation experiment of internal fault of a simulated power transformer is compared with test data of dynamic simulation, and comparison result shows that the proposed nonlinear model for internal fault of power transformer is correct.

关 键 词：电力系统 电力变压器 内部故障 差动保护 励磁涌流 非线性模型 有限元分析 

分 类 号：TM772[电气工程—电力系统及自动化]