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- 2016
电力设备局部放电特高频电磁波 数值计算技术研究
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Abstract:
利用时域有限差分法(FDTD),采用单轴介质完全匹配层(UPML)作为理想的吸收边界条件,比较了UPML与完全匹配层(PML)边界条件的电磁波吸收效果,推导了相应数值离散方法和迭代过程。以气体绝缘全封闭组合电器(GIS)局部放电为例,基于M语言,建立了特高频电磁波仿真模型及编制了数值计算模型,探讨了数值稳定性条件和数值色散,对比研究了硬源和软源激励以及UPML和PML边界条件下的电磁波仿真差异,并仿真计算了GIS内部和泄露电磁波的传播特性及波导模式特性。计算结果表明:UPML边界条件对于电磁波的吸收效果好于PML;金属和非金属缺陷产生的局部放电电磁波可分别用硬源和软源脉冲电流激励来模拟,硬源下电磁波峰峰值为软源下的5倍;GIS内部最大电场强度方向为垂直于GIS的行波方向,而泄露电磁波最大电场方向则平行于其行波方向,两者频谱与GIS波导模式基本吻合,两者差异主要是因盆式绝缘子与金属螺栓所形成的缝隙天线的自有频响特性所造成的。
By finite difference time domain (FDTD) method with uniaxial perfectly matched layer (UPML) boundary condition, the comparison of the absorption effects between perfectly matched layer (PML) and UPML is performed, and the numerical discretization and iteration processes are deduced. Taking gas insulating switchgear (GIS) partial discharge (PD) as an example, the simulation model of electromagnetic (EM) wave is constructed, and the numerical stability condition and dispersion are discussed. The differences under hard source and soft source excitations are illustrated, and the GIS PD simulations at UPML and PML boundaries are also compared. It is revealed that the absorption of EM waves with UPML boundary condition is better than that with PML. The hard source and soft source of pulse current excitation can be employed to simulate the PD EM waves generated by metal and non？？metal defects, respectively. The peak？？peak value of EM wave under hard source is about five times larger than that under soft source. The largest electric field strength component inside GIS is perpendicular to the direction of travelling waves in GIS, and the largest electric field strength component of the leakage EM waves is along the direction of travelling waves in GIS. The main frequency spectrums of EM waves comply with the different waveguide modes in GIS. The difference between inside and leakage EM waves is caused by the self frequency response characteristic of the slot antenna formed by the insulating spacer and bolts
| [1] | ［1］JUDD M D, FARISH O, HAMPTON B F. The excitation of UHF signal by partial discharge in GIS ［J］. IEEE Transactions on Dielectrics and Electrical Insulation, 1996, 3(2): 213？？228. |
| [2] | ［2］OKABE S, KANEKO S, YOSHIMURA M, et al. Electromagnetic wave propagation in a coaxial pipe GIS model ［J］. IEEE Transactions on Dielectrics and Electrical Insulation, 2007, 14(5): 1161？？1169. |
| [3] | ［3］HIKITA M, OHTSUKA S, TESHIMA T, et al. Examination of electromagnetic mode propagation characteristics in straight and L？？section GIS model using FD？？TD analysis ［J］. IEEE Transactions on Dielectrics and Electrical Insulation, 2007, 14(6): 1477？？1483. |
| [4] | ［4］YOSHIMURA M, MUTO H, NISHIDA C, et al. Propagation properties of electromagnetic wave through T？？branch in GIS ［J］. IEEE Transactions on Dielectrics and Electrical Insulation, 2007, 14(2): 328？？333. |
| [5] | ［6］李军浩, 司文荣, 杨景岗, 等. 直线及L型GIS模型电磁波传播特性研究 ［J］. 西安交通大学学报, 2008, 42(10): 1280？？1284. |
| [6] | LU Qifu, ZHENG Shusheng, LI Xingwang, et al. Study on propagation characteristics of UHF signal via hole of GIS mental flange and development of external radiating antenna ［J］. Power System Technology, 2013, 37(8): 2303？？2309. |
| [7] | ［11］TAFLOVE A, HAGNESS S C. Computational electrodynamics: the finite？？difference time？？domain method ［M］. Norwood, MA, USA: Artech House, 2005: 28. |
| [8] | ［15］葛德彪, 闫玉波. 电磁波时域有限差分方法 ［M］. 西安: 西安电子科技大学出版社, 2005: 81. |
| [9] | ［16］MANSOURABADI M, POURKAZEMI A. FDTD hard source and soft source reviews and modifications ［J］. Progress in Electromagnetics: Research C, 2008, 3(3): 143？？160. |
| [10] | LI Junhao, SI Wenrong, YANG Jinggang, et al. Electromagnetic wave propagation characteristics in straight and L？？type gas insulated switchgear ［J］. Journal of Xi’an Jiaotong University, 2008, 42(10): 1280？？1284. |
| [11] | ［7］李信. GIS局部放电特高频检测技术的研究 ［D］. 北京: 华北电力大学, 2005: 30？？32. |
| [12] | ［8］卢启付, 郑书生, 李兴旺, 等. GIS金属法兰孔特高频信号传播特性研究与外置式发射天线开发 ［J］. 电网技术, 2013, 37(8): 2303？？2309. |
| [13] | ［9］刘君华, 姚明, 黄成军, 等. GIS中局部放电电磁波的模式特性 ［J］. 高电压技术, 2009, 35(7): 1654？？1660. |
| [14] | LIU Junhua, YAO Ming, HUANG Chengjun, et al. Characteristics of PD EM？？wave modes in GIS ［J］. High Voltage Engineering, 2009, 35(7): 1654？？1660. |
| [15] | ［10］YEE K. Numerical solution of initial boundary value problems involving Maxwell’s equations in isotropic media ［J］. IEEE Transactions on Antennas and Propagation, 1966, 14(3): 302？？307. |
| [16] | ［12］BERENGER J P. A perfectly matched layer for the absorption of electromagnetic waves ［J］. Journal of Computational Physics, 1994, 114: 185？？200. |
| [17] | ［13］SACKS Z S, KINGSLAND D M, LEE R, et al. A perfectly matched anisotropic absorber for use as an absorbing boundary condition ［J］. IEEE Transactions on Antennas and Propagation, 1995, 43(12): 1460？？1463. |
| [18] | ［14］GEDNEY S D. An anisotropic PML absorbing medium for the FDTD simulation of fields in lossy and dispersive media ［J］. Electromagnetics, 1996, 16(4): 399？？415. |
| [19] | ［17］REID A J, JUDD M D, STEWART B G, et al. Partial discharge current pulses in SF6 and the effect of superposition of their radiometric measurement ［J］. Journal of Physics: DApplied Physics, 2006, 39(19): 4167？？4177. |
| [20] | ［5］袁鹏. 油纸绝缘电力变压器局部放电的超高频特性及其应用研究 ［D］. 西安: 西安交通大学, 2009: 10？？15. |
