大气压下短气隙放电过程分析
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摘要
局部放电是高压电器设备绝缘劣化的主要原因,又是评定其绝缘老化程度的重要参数,存在于绝缘中的气泡或气穴是触发局部放电的主要根源。因此,短气隙放电特性的研究对高压电器设备在线监测和故障诊断具有实际意义。
为了研究电力设备绝缘结构短气隙放电,并深入理解绝缘结构短气隙放电过程中的动力学行为,研究交流电压下介质表面积聚电荷对短间隙气体放电的影响,本文建立了一维自洽流体力学的气体放电模型,主要包括电子和离子的连续性方程和动量方程,同时耦合泊松方程。数值仿真的简化物理模型是由电极覆盖的平行圆板电极和短气隙构成。计算结果显示,当气隙中电场超过其击穿阈值时,形成放电电流脉冲,也就是气体中空间电荷运动形成电子雪崩放电,同时,获得了大气压下电子雪崩放电过程中气体间隙电场,电子密度,离子密度的时空分布。仿真结果表明,短气隙、电压幅值和驱动频率不仅会影响气隙放电电流脉冲的幅值,还会促使脉冲数目发生变化;短气隙放电具有较明显的混沌特征;介质表面积聚电荷是形成多脉冲气隙放电的根本原因。
本文针对短气隙放电设计了5种实验电极模型,用于模拟不同气隙下电场分布。采集短气隙放电信号,利用连续小波进行处理,获取放电电流脉冲的时频特征,结果显示气隙放电信号的频带能量可以作为模式识别的输入特征向量。
The gas discharge in the short-gap is not only the main cause of insulation degradation in high voltage electric apparatues, but also it is a crucial parameter for evaluating insulation ageing, thus the researching on the gas discharge in the short-gap has important practical significance for on-line monitoring and fault diagnosis of high voltage power equipment.
With the purpose of studying partial discharge in the short-gap of the insulating coordination and deeply understanding kinetic behavior of gas discharge in gas-dielectric insulation, the one dimensional and self-consistent fluid model of the gas discharge was established based on the electron and ion continuity and momentum transfer equations coupled to Poisson’s equation, then the micro-discharge evolution of the short-gap and its influence of the surface charges depositing on dielectrics applied alternating voltage were analyzed and demonstrated in detail. The models of mathematical simulation, representing a plane-parallel electrode arrangement covered with solid dielectric and comprising an short gas-gap, were made up, then the results were obtained for the case when the applied field in the gas exceeds its breakdown threshold and discharge current pulses can be formed, i.e. charge transfer in the gas phase takes place in the form of an electron avalanche discharge, simultaneously, the facts were found that the temporal and spatial distributions of the electric field, electron density and the ion density obtained in the electron avalanche discharge at atmospheric pressure. Simulation results show that the gap dimensions, applied voltage amplitudes and frequencies can also influence on the numbers and the amplitudes of current pulses. Furthermore, the characteristic of chaos that gas discharge is obvious in the gas discharge with short gas-gap, surface charge accumulation on dielectrics in opposite polarity, forming reversed field relatived to the applied field, is the essential reason.
The five models of short gas-gap discharge for different electric field are designed and made, and then experiment data of gas gap discharge are collected. In signal analysis, the continuous wavelet is always used for signal decomposition, which is an effective time-frequency analysis method for observing the time-frequency property of discharge current in the short gas-gap. The consequence is excting satisfaction, which extract frequency energy of discharge current and take as features for pattem recognition.
为了研究电力设备绝缘结构短气隙放电,并深入理解绝缘结构短气隙放电过程中的动力学行为,研究交流电压下介质表面积聚电荷对短间隙气体放电的影响,本文建立了一维自洽流体力学的气体放电模型,主要包括电子和离子的连续性方程和动量方程,同时耦合泊松方程。数值仿真的简化物理模型是由电极覆盖的平行圆板电极和短气隙构成。计算结果显示,当气隙中电场超过其击穿阈值时,形成放电电流脉冲,也就是气体中空间电荷运动形成电子雪崩放电,同时,获得了大气压下电子雪崩放电过程中气体间隙电场,电子密度,离子密度的时空分布。仿真结果表明,短气隙、电压幅值和驱动频率不仅会影响气隙放电电流脉冲的幅值,还会促使脉冲数目发生变化;短气隙放电具有较明显的混沌特征;介质表面积聚电荷是形成多脉冲气隙放电的根本原因。
本文针对短气隙放电设计了5种实验电极模型,用于模拟不同气隙下电场分布。采集短气隙放电信号,利用连续小波进行处理,获取放电电流脉冲的时频特征,结果显示气隙放电信号的频带能量可以作为模式识别的输入特征向量。
The gas discharge in the short-gap is not only the main cause of insulation degradation in high voltage electric apparatues, but also it is a crucial parameter for evaluating insulation ageing, thus the researching on the gas discharge in the short-gap has important practical significance for on-line monitoring and fault diagnosis of high voltage power equipment.
With the purpose of studying partial discharge in the short-gap of the insulating coordination and deeply understanding kinetic behavior of gas discharge in gas-dielectric insulation, the one dimensional and self-consistent fluid model of the gas discharge was established based on the electron and ion continuity and momentum transfer equations coupled to Poisson’s equation, then the micro-discharge evolution of the short-gap and its influence of the surface charges depositing on dielectrics applied alternating voltage were analyzed and demonstrated in detail. The models of mathematical simulation, representing a plane-parallel electrode arrangement covered with solid dielectric and comprising an short gas-gap, were made up, then the results were obtained for the case when the applied field in the gas exceeds its breakdown threshold and discharge current pulses can be formed, i.e. charge transfer in the gas phase takes place in the form of an electron avalanche discharge, simultaneously, the facts were found that the temporal and spatial distributions of the electric field, electron density and the ion density obtained in the electron avalanche discharge at atmospheric pressure. Simulation results show that the gap dimensions, applied voltage amplitudes and frequencies can also influence on the numbers and the amplitudes of current pulses. Furthermore, the characteristic of chaos that gas discharge is obvious in the gas discharge with short gas-gap, surface charge accumulation on dielectrics in opposite polarity, forming reversed field relatived to the applied field, is the essential reason.
The five models of short gas-gap discharge for different electric field are designed and made, and then experiment data of gas gap discharge are collected. In signal analysis, the continuous wavelet is always used for signal decomposition, which is an effective time-frequency analysis method for observing the time-frequency property of discharge current in the short gas-gap. The consequence is excting satisfaction, which extract frequency energy of discharge current and take as features for pattem recognition.
引文
[1]刘子玉.电气绝缘结构设计原理(中)[M].北京市:机械工业出版社,1988:69-101.
[2]葛景滂,邱昌容,谢恒.局部放电测量[M].北京市:机械工业出版社,1984:1-38.
[3] V Nikonov,R Bartnikas and M R Wertheimer.Surface charge and photo ionization effects in short air gaps undergoing discharges at atmospheric pressure[J].J.Phys.D:Appl.Phys.,2001,34:2979-2986.
[4] Yuriy V.Serdyuk and Stanislaw M.Gubanski.Computer Modeling of Interaction of Gas Discharge Plasma with Solid Dielectric Barriers[J] .IEEE Transactions on Dielectrics and Electrical Insulation,2005,12(4):725-735.
[5] Xiaohui Yuan , Jichul Shin , Laxminarayan L . Raja . One-dimensional simulation of multi pulse phenomena in dielectric-barrier atmospheric-pressure glow discharges[J].Vacuum,2006,80:1199-1205.
[6] G E Georghiou,A P Papadakis,R Morrow and A C Metaxas.Numerical modeling of atmospheric pressure gas discharges leading to plasma production [J].J.Phys.D:Appl.Phys.,2005,38:R306-R307.
[7]任成燕,成永红,陈小林,等.基于SIMULINK的气隙局部放电仿真技术研究[J].西安交通大学学报,2004,38(8):824-827.
[8]王新新,李成榕,蒲以康,等.用50Hz工频电压产生大气压下辉光放电[J].高电压技术,2002,28(120):39-40.
[9]吕博,王新新,罗海云,等.大气压氦气介质阻挡辉光放电的数值仿真计算[J].电工电能新技术,2008,27(3):63-67.
[10]梁卓,罗海云,王新新,等.大气压氦气介质阻挡放电的二维演化过程[J].高电压技术,2008,34(2):377-381.
[11]王艳辉,王德真.介质阻挡均匀大气压氮气放电特性研究[J].物理学报,2006,55(11):5923-5929.
[12]王艳辉,王德真.大气压下多脉冲均匀介质阻挡放电的研究[J].物理学报,2005,54(3):1295-1300.
[13] H. J . M. Blennow,Μ.Α。.S.Leijon, S .M . Gubanski . Active High Voltage Insulation [J].Journal of Electrostatics,2000,55:159-172.
[14] H. J. M. Blennow ,Μ. L. ?Α。.Sj?o? berg,Μ.Α。.S.Leijon and S.M.Gubanski.Electric Field Reduction Due to Charge Accumulation in a Dielectric-Covered Electrode System[J].IEEE Transactions on Dielectrics and Electrical Insulation,2000,7(3):340-345.
[15]Μ. L. ?Α。.Sj?o? berg, H . J . M . Blennow , S . M . Gubanski ,Μ.Α。.S.Leijon.On Discharge Phenomena in a Covered Electrode System in Air[C].Conference Record of the 2000 IEEE Intemational Symposium on Electrical Insulation,Anaheim,CA USA,2000:345-348.
[16] H . J . M . Blennow ,Μ. L. ?Α。.Sj?o? berg,Μ.Α。.S.Leijon,S.M.Gubanski.Effects of Charge Accumulation in a Dielectric Covered Electrode System in Air[C].1999 Conference on Electrical Insulation and Dielectric Phenomena,1999:484-487.
[17] Y . V . Serdyuk , S . M . Gubanski , H . J . M . Blennow ,Μ.Α。.S.Leijon.Electrical Discharge in an Air Gap with Dielectric-Covered Electrodes [C] . Proc . Conf . On Electrical Insulation and Dielectric Phenomena,2000:397-400.
[18]Μ. L. ?Α。. Sj?o?berg, C . Rein , S . M . Gubanski ,Μ.Α。.S.Leijon. Surface charge accumulation in a dielectric-covered electrode system in air[C] . Proceedings of the 2001 International Symposium on Electrical Insulation Materials,Himeji,Japan,2001:399-402.
[19]黄平,汪伟,张宏亮,等.局部放电混沌分析方法的研究现状及发展[J].高压电器,2009,45(1):89-94.
[20]罗旖旎.局部放电非线性动力学特征研究[D].长沙:长沙理工大学,2008:9-20.
[21] Wu C and Kunhardt E E.Formation and propagation of streamers in N2 and N2-SF6 mixtures[J].Phys.Rev.A,1988,137(11):4396-4406.
[22] Guo J M , et al . Two-Dimensional Non-equilibrium Fluid Models for Streamers[J].IEEE Trans. Plasma Sci.,1993,21(6):684-685.
[23] Massines F,Rabehi A,Decomps P,et al.Experimental and theoretical study of a glow discharge at atmospheric pressure controlled by a dielectric barrier[J].J.Appl.Phys.,1998,83(6):2950-2957.
[24] Li J and Dhali S K.Simulation of micro-discharges in a dielectric-barrier discharge[J].J. Appl. Phys.1997,82(9):4205-4210.
[25] Brauer I,Punset C,Purwins H G and Boeuf J P.Simulation of self-organized filaments in a dielectric barrier glow discharge plasma[J] .J.Appl.Phys.,1999,85(11):7569-7572.
[26] Gadri R B.One Atmosphere Glow Discharge Structure Revealed by Computer Modeling [J].IEEE Trans on Plasma Science,1999,27(1):36-37.
[27]张远涛.大气压介质阻挡放电时空演化行为理论研究[D].大连:大连理工大学,2006:5-6.
[28] D.L.SCHARFETTER AND H.K.GUMMEL.Large-Signal Analysis of a Silicon Read Diode Oscillator[J].IEEE TRANSACTIONS ON ELECTRON DEVICES, 1969,ED-16(1):64-77.
[29] H.K.GUMMEL.A Self-Consistent Iterative Scheme for One-Dimensional Steady State Transistor Calculations[J] . IEEE TRANSACTIONS ON ELECTRON DEVICES,1964,455-465.
[30] Boeuf J P . A two-dimensional model of dc glow discharges[J].J.Appl.Phys.1988,63(5):1343-1147.
[31] Boeuf J P.Numerical model of rf glow discharges[J].Phys.Rev.A.,1987,36(6):2782-2792.
[32] Boeuf J P , Pitchford L C . Pseudospark Discharges Via Computer Simulation[J] . IEEE TRANSACTIONS ON PLASMA SCIENCE ,1991,19(2):286-296.
[33] Yanpeng HAO , Enlai TU , Lin YANG , et al . Mechanism of Glow Discharges in Helium at Atmospheric Pressure Based on Voltage-Current Characteristics[C].Proceedings of the 9th ICPADM,Harbin,China,2009:606-609.
[34] Xiaolei WANG,Yanpeng HAO,Lin YANG.Formation of Multi-pulse Glow Dielectric Barrier Discharge in Helium at Atmospheric Pressure[C].Proceedings of the 9th ICPADM,Harbin,China,2009:610-613.
[35] Lin YANG,Yanpeng HAO,et al.Mechanism and Characteristic of Dielectric Barrier Multi-pulse Glow Discharge in Helium at Atmospheric Pressure[C].Proceedings of the 9th ICPADM,Harbin,China,2009:655-658.
[36]王艳辉.均匀大气压介质阻挡放电特性及其模式识别[D].大连:大连理工大学,2006:13-16.
[37] Napoleon Leoni,Bhooshan Paradkar.Numerical Simulation of Townsend Discharge,Paschen Breakdown and Dielectric Barrier Discharges[J].To be published and presented at NIP 2009 , Loiusville , KY , 2009 , HP Laboratories HPL-2009-234.
[38] R Morrow and J J Lowke.Streamer propagation in air[J].J.Phys.D: Appl.Phys., 1996,30:614-627.
[39]陆宇航.基于光纤电流传感器的局部放电检测方法研究[D].天津:天津大学,2008:64-70.
[40]葛哲学,陈仲生. MATLAB时频分析及其应用技术[M].北京市:人民邮电出版社,2005:9.
[2]葛景滂,邱昌容,谢恒.局部放电测量[M].北京市:机械工业出版社,1984:1-38.
[3] V Nikonov,R Bartnikas and M R Wertheimer.Surface charge and photo ionization effects in short air gaps undergoing discharges at atmospheric pressure[J].J.Phys.D:Appl.Phys.,2001,34:2979-2986.
[4] Yuriy V.Serdyuk and Stanislaw M.Gubanski.Computer Modeling of Interaction of Gas Discharge Plasma with Solid Dielectric Barriers[J] .IEEE Transactions on Dielectrics and Electrical Insulation,2005,12(4):725-735.
[5] Xiaohui Yuan , Jichul Shin , Laxminarayan L . Raja . One-dimensional simulation of multi pulse phenomena in dielectric-barrier atmospheric-pressure glow discharges[J].Vacuum,2006,80:1199-1205.
[6] G E Georghiou,A P Papadakis,R Morrow and A C Metaxas.Numerical modeling of atmospheric pressure gas discharges leading to plasma production [J].J.Phys.D:Appl.Phys.,2005,38:R306-R307.
[7]任成燕,成永红,陈小林,等.基于SIMULINK的气隙局部放电仿真技术研究[J].西安交通大学学报,2004,38(8):824-827.
[8]王新新,李成榕,蒲以康,等.用50Hz工频电压产生大气压下辉光放电[J].高电压技术,2002,28(120):39-40.
[9]吕博,王新新,罗海云,等.大气压氦气介质阻挡辉光放电的数值仿真计算[J].电工电能新技术,2008,27(3):63-67.
[10]梁卓,罗海云,王新新,等.大气压氦气介质阻挡放电的二维演化过程[J].高电压技术,2008,34(2):377-381.
[11]王艳辉,王德真.介质阻挡均匀大气压氮气放电特性研究[J].物理学报,2006,55(11):5923-5929.
[12]王艳辉,王德真.大气压下多脉冲均匀介质阻挡放电的研究[J].物理学报,2005,54(3):1295-1300.
[13] H. J . M. Blennow,Μ.Α。.S.Leijon, S .M . Gubanski . Active High Voltage Insulation [J].Journal of Electrostatics,2000,55:159-172.
[14] H. J. M. Blennow ,Μ. L. ?Α。.Sj?o? berg,Μ.Α。.S.Leijon and S.M.Gubanski.Electric Field Reduction Due to Charge Accumulation in a Dielectric-Covered Electrode System[J].IEEE Transactions on Dielectrics and Electrical Insulation,2000,7(3):340-345.
[15]Μ. L. ?Α。.Sj?o? berg, H . J . M . Blennow , S . M . Gubanski ,Μ.Α。.S.Leijon.On Discharge Phenomena in a Covered Electrode System in Air[C].Conference Record of the 2000 IEEE Intemational Symposium on Electrical Insulation,Anaheim,CA USA,2000:345-348.
[16] H . J . M . Blennow ,Μ. L. ?Α。.Sj?o? berg,Μ.Α。.S.Leijon,S.M.Gubanski.Effects of Charge Accumulation in a Dielectric Covered Electrode System in Air[C].1999 Conference on Electrical Insulation and Dielectric Phenomena,1999:484-487.
[17] Y . V . Serdyuk , S . M . Gubanski , H . J . M . Blennow ,Μ.Α。.S.Leijon.Electrical Discharge in an Air Gap with Dielectric-Covered Electrodes [C] . Proc . Conf . On Electrical Insulation and Dielectric Phenomena,2000:397-400.
[18]Μ. L. ?Α。. Sj?o?berg, C . Rein , S . M . Gubanski ,Μ.Α。.S.Leijon. Surface charge accumulation in a dielectric-covered electrode system in air[C] . Proceedings of the 2001 International Symposium on Electrical Insulation Materials,Himeji,Japan,2001:399-402.
[19]黄平,汪伟,张宏亮,等.局部放电混沌分析方法的研究现状及发展[J].高压电器,2009,45(1):89-94.
[20]罗旖旎.局部放电非线性动力学特征研究[D].长沙:长沙理工大学,2008:9-20.
[21] Wu C and Kunhardt E E.Formation and propagation of streamers in N2 and N2-SF6 mixtures[J].Phys.Rev.A,1988,137(11):4396-4406.
[22] Guo J M , et al . Two-Dimensional Non-equilibrium Fluid Models for Streamers[J].IEEE Trans. Plasma Sci.,1993,21(6):684-685.
[23] Massines F,Rabehi A,Decomps P,et al.Experimental and theoretical study of a glow discharge at atmospheric pressure controlled by a dielectric barrier[J].J.Appl.Phys.,1998,83(6):2950-2957.
[24] Li J and Dhali S K.Simulation of micro-discharges in a dielectric-barrier discharge[J].J. Appl. Phys.1997,82(9):4205-4210.
[25] Brauer I,Punset C,Purwins H G and Boeuf J P.Simulation of self-organized filaments in a dielectric barrier glow discharge plasma[J] .J.Appl.Phys.,1999,85(11):7569-7572.
[26] Gadri R B.One Atmosphere Glow Discharge Structure Revealed by Computer Modeling [J].IEEE Trans on Plasma Science,1999,27(1):36-37.
[27]张远涛.大气压介质阻挡放电时空演化行为理论研究[D].大连:大连理工大学,2006:5-6.
[28] D.L.SCHARFETTER AND H.K.GUMMEL.Large-Signal Analysis of a Silicon Read Diode Oscillator[J].IEEE TRANSACTIONS ON ELECTRON DEVICES, 1969,ED-16(1):64-77.
[29] H.K.GUMMEL.A Self-Consistent Iterative Scheme for One-Dimensional Steady State Transistor Calculations[J] . IEEE TRANSACTIONS ON ELECTRON DEVICES,1964,455-465.
[30] Boeuf J P . A two-dimensional model of dc glow discharges[J].J.Appl.Phys.1988,63(5):1343-1147.
[31] Boeuf J P.Numerical model of rf glow discharges[J].Phys.Rev.A.,1987,36(6):2782-2792.
[32] Boeuf J P , Pitchford L C . Pseudospark Discharges Via Computer Simulation[J] . IEEE TRANSACTIONS ON PLASMA SCIENCE ,1991,19(2):286-296.
[33] Yanpeng HAO , Enlai TU , Lin YANG , et al . Mechanism of Glow Discharges in Helium at Atmospheric Pressure Based on Voltage-Current Characteristics[C].Proceedings of the 9th ICPADM,Harbin,China,2009:606-609.
[34] Xiaolei WANG,Yanpeng HAO,Lin YANG.Formation of Multi-pulse Glow Dielectric Barrier Discharge in Helium at Atmospheric Pressure[C].Proceedings of the 9th ICPADM,Harbin,China,2009:610-613.
[35] Lin YANG,Yanpeng HAO,et al.Mechanism and Characteristic of Dielectric Barrier Multi-pulse Glow Discharge in Helium at Atmospheric Pressure[C].Proceedings of the 9th ICPADM,Harbin,China,2009:655-658.
[36]王艳辉.均匀大气压介质阻挡放电特性及其模式识别[D].大连:大连理工大学,2006:13-16.
[37] Napoleon Leoni,Bhooshan Paradkar.Numerical Simulation of Townsend Discharge,Paschen Breakdown and Dielectric Barrier Discharges[J].To be published and presented at NIP 2009 , Loiusville , KY , 2009 , HP Laboratories HPL-2009-234.
[38] R Morrow and J J Lowke.Streamer propagation in air[J].J.Phys.D: Appl.Phys., 1996,30:614-627.
[39]陆宇航.基于光纤电流传感器的局部放电检测方法研究[D].天津:天津大学,2008:64-70.
[40]葛哲学,陈仲生. MATLAB时频分析及其应用技术[M].北京市:人民邮电出版社,2005:9.