电力变压器内部故障仿真.pdf

摘要摘要电力变压器内部故障是一种常见的、破坏性很强的故障,其对整个电力系统的安全运行将带来一系列严重的影响,并且目前变压器保护的发展还不够完善,保护的正确动作率还比较低,主要原因在于对变压器内部故障的机理认识不够。因此,大力开展变压器内部故障仿真研究是十分必要的,它对于完善变压器绕组内部故障的分析与计算,提高大中型电力变压器的继电保护水平, 减少重大事故的发生等都具有十分重要的理论意义和实用价值。为此本文研究了变压器的内部故障仿真问题,并开发了一套电力变压器的内部故障仿真软件。在对电力变压器内部故障进行深入分析和研究的基础上开展了研究工作,主要内容有: (1)基于将变压器看作相互耦合的电阻、电感支路的理论,建立电力变压器正常工作状态下的数学模型。将磁路法应用于模型参数的求解过程中,根据变压器的磁路模型推导了数学模型中电感矩阵的计算。在分析变压器漏磁场的基础上,应用磁场能量法推导了变压器漏电感的计算公式。(2)将发生接地故障、匝间短路故障的变压器绕组分别分成2个或者3个绕组来模拟故障的发生,建立变压器故障运行状态下的数学模型。根据变压器正常工作状态下的模型参数、教障类型以及故障位置计算故障运行状态下的模型参数。(3)结合变压器一次测的电源、联结方式以及负载情况建立了变压器各种运行方式下的系统仿真模型,推导了不同运行情况时的电量计算微分方程组中的系数矩阵变换。(4)选用C++程序设计语言和Visual c十+,遵循人机界面友好的原则实现了电力变压器的内部故障仿真软件系统。以s僳10—30/lO变压器为例进行了各种运行状态下的仿真,并对仿真波形进行了理论分析,验证了仿真模型的正确性和仿真软件的有效性。关键词:电力变压器,内部故障,磁路法,磁场能量法,仿真模型 ABSTRACT ABSTRACT The internal fault of a power transformer is mOn and destructive fault。which may greatly affect the security of the power protection for transformer has not been developed perfectly so far。because there is inadequate understand of the transformer fault ,it isvery necessary to carry out the simulation for internal fault of power transformer, it is also important, both in theory and application,to advance the analysis methods ofthe internal faults,to improve therelay protection for the large power transformer,and to decrease the occurrence of serious on theanalysis of internal fault oftransformer,a software package is developed to simulate the internal fault effectively. Attributed to the deepanalysis and study on internal fault ofpowertransformer, the system isfulfilled and the main job is listed as follows: (1)Based on the theory,which treats the power transformer as mutual ly—coupled R,L mathematical model oftransfo瑚er under normal state is the application of ic circuit method into the calculation of parameters of ,all important parameter,the inductance matrix iscalculate也 Based on the analyzing of leakage ic field,the leakage ind