交流运行电压下GIS中金属颗粒运动行为及放电特征

发布时间：2018-06-21 06:32

本文选题：GIS + 金属颗粒　；参考：《华北电力大学(北京)》2017年博士论文

【摘要】：金属颗粒是GIS中最常见的缺陷,且颗粒在GIS内部自由运动是GIS的一个重大安全隐患,不仅是因为颗粒可以运动到高电场区域内或附着在绝缘子上,而且在运动过程中,颗粒可能对电极产生微弱的放电,该放电可能引起绝缘的完全击穿。为提高GIS内金属颗粒检测的有效性,减少金属颗粒的危害,针对金属颗粒已进行了相对较多研究,目前的研究主要集中在单一颗粒在典型平板下的运动规律及局部放电现象,而缺少在运行电压下实际GIS同轴结构中的金属颗粒运动行为及放电特征的研究,现有的研究成果难以满足实际工程的应用。为此,本文研究了运行电压下实际GIS中不同类型金属颗粒的运动行为、局部放电及危害程度。为了研究颗粒的形状(片状颗粒、线形颗粒、球形颗粒、金属粉尘)、尺寸对颗粒运动行为的影响,本文基于不同形状、尺寸金属颗粒的带电量以及颗粒所受的库仑力的计算,获得了颗粒形状、尺寸对颗粒带电量和所受库仑力的影响规律,提出了在运行电压下不同类型金属颗粒起始跳动的条件,并通过试验研究了不同类型金属颗粒的运动行为。GIS运行电压下平躺的线性颗粒起始跳动条件:铝材质的线形颗粒半径小于0.139mm、铜材质的线形颗粒半径小于0.044mm、银材质的线形颗粒半径小于0.036mm。GIS运行电压下平躺的片状颗粒起始跳动条件:铝材质的片状颗粒厚度小于0.069mm、铜材质的片状颗粒厚度小于0.022mm、银材质的片状颗粒厚度小于0.018mm。GIS运行电压下球形颗粒起始跳动条件:铝材质的球形颗粒半径小于0.175mm、铜材质的球形颗粒半径小于0.052mm、银材质的球形颗粒半径小于0.044mm。金属颗粒的运动行为主要有4种运动状态:静止站立、小幅度跳动、大幅度跳动以及贯穿性跳动。其中片状颗粒和线形颗粒在电场梯度力的作用下向电场较强的屏蔽环处运动,当金属颗粒运动速度较慢且靠近绝缘子时,会静止的附着在绝缘子上,而球形颗粒/金属粉尘则倾向于向电场较弱的区域运动而难以附着在绝缘子上。为了研究颗粒的数量对金属颗粒运动行为的影响,本文试验研究了高压母线下不同数量的金属颗粒的运动行为,获得了颗粒数量对不同形状金属颗粒起举电压的影响规律。线形颗粒的存在会造成电场的畸变,使得相邻线形颗粒在相对较低的电压下起举站立,随着相邻线形颗粒数量的增加,线形颗粒的起举电压呈下降趋势,而颗粒的数量对球形颗粒的起举电压则几乎无影响。为了研究颗粒端部曲率半径的大小对颗粒运动行为的影响,本文对比分析了不同尖端曲率半径的线形颗粒的运动行为,并揭示了颗粒端部对颗粒运动行为产生影响的原因。端部无电晕金属颗粒随着外施电压的升高,其运动行为主要经历4种运动状态:静止站立、小幅度跳动、大幅度跳动以及贯穿性跳动。而端部有电晕金属颗粒,在起举电压下,曲率半径较小端部率先站立,随着外施电压的升高,金属颗粒仍进行小幅度跳动,不会出现大幅度跳动或贯穿性跳动,但颗粒端部旋转摆动幅度变大。研究了冲击外力对金属颗粒运动行为的影响,揭示了断路器等开关动作引起GIS腔体的振动对颗粒运动行为产生影响的原因。在冲击振动的作用下,线形颗粒出现一端向上偏转,另一端与地电极接触的状态,导致线形颗粒带电量急剧增加,线形颗粒在库仑力的作用下一直向上偏转,直至颗粒垂直站立,冲击外力的作用使得无害颗粒变为有害颗粒。以不同类型金属颗粒的运动行为为基础,获得了不同运动状态下金属颗粒的局部放电特征,建立了金属颗粒运动行为与局部放电的关系。在运行电压下不同类型金属颗粒的带电量的不同、跳动速度、跳动频率、跳动高度的差别造成颗粒放电量、放电脉冲簇宽度、放电脉冲个数的差异,金属颗粒的数量会造成半个工频周期内最大超声个数的差异,颗粒端部的曲率半径会造成放电脉冲信号相位相关性的差异。通过以上放电特征的分析可以判断出不同类型颗粒的运动行为。研究了不同类型金属颗粒(不同形状、不同数量、不同尺寸)运动到GIS腔体不同位置(高压母线、屏蔽环、绝缘子)时的击穿,获得了运行电压下有害颗粒的类型。研究结果表明:金属颗粒的贯穿性跳动与否和颗粒引发GIS的击穿没有必然的关系,在高压母线及屏蔽环下的单个线形颗粒和片状颗粒的自由跳动对GIS的危害性相对较小,而当线形颗粒和片状颗粒较多时,其危害性大大增加。当线形/片状颗粒附着在绝缘子上时,颗粒的沿面放电引起了绝缘子的劣化,对GIS的危害性较大。而在运行电压下由于自由运动的金属粉尘和球形颗粒向远离绝缘子处的电场较弱区域聚集,因此数量较少的金属粉尘和球形颗粒对GIS绝缘危害性较小(电压升至运行电压的两倍仍未击穿)。建立了金属颗粒运动行为、局部放电和危害程度间的关系,实现通过局部放电获得金属颗粒形状、尺寸、数量的估算,提出了金属颗粒危害程度的诊断方法。
[Abstract]:Metal particles are the most common defects in GIS, and the free movement of particles in GIS is a major safety hazard of GIS, not only because the particles can move into the high electric field area or attach to the insulators, but in the process of motion, the particles may have a weak discharge to the electrode. This discharge may cause the complete breakdown of the insulation. In order to improve the effectiveness of metal particle detection in GIS and reduce the harm of metal particles, relatively more researches have been carried out on metal particles. The current research mainly focuses on the motion laws and partial discharge phenomena of single particles under the typical flat plate, but lack of the movement behavior of metal particles in the actual GIS coaxial structure under the operating voltage. In this paper, the motion behavior, partial discharge and damage degree of different types of metal particles in actual GIS under operating voltage are studied. In order to study the shape of particles (flaky particles, linear particles, spherical particles, metal dust), the size of particle motion to particle motion is studied. The influence of behavior is based on the calculation of the charge quantity of metal particles and the Coulomb force of particles in different shapes and sizes. The influence of particle shape and size on the charge quantity and Coulomb force of the particles is obtained. The conditions for the starting jump of different types of metal particles under the operating voltage are proposed, and the different classes are studied by experiments. The moving behavior of the metal particles is the starting runout condition of the linear particles lying flat under the operating voltage of.GIS: the linear particle radius of the aluminum material is less than 0.139mm, the linear particle radius of the copper material is less than 0.044mm, and the linear particle radius of the silver material is less than that of the flaky particles lying on the flat surface of the 0.036mm.GIS under the operating voltage of the aluminum. The thickness of the particle is less than 0.069mm and the thickness of the sheet particle of copper is less than 0.022mm. The thickness of the sheet particle of the silver material is less than the starting condition of the spherical particles under the operating voltage of 0.018mm.GIS: the radius of the spherical particles of the aluminum material is less than that of 0.175mm, the radius of the spherical particle of the copper material is less than 0.052mm, and the radius of the spherical particle of the silver is less than that of 0.044mm. gold. The motion behavior of the particle is mainly 4 kinds of motion states: static standing, small jump, large beat, and penetration. In which the flake particles and linear particles move to the stronger shielding ring under the action of the electric field gradient force. When the velocity of the metal particles is slow and close to the insulation, it will adhere to the insulation. In order to study the influence of the number of particles on the movement of metal particles, the motion behavior of different quantities of metal particles under high pressure bus is studied in this paper, and the number of particles on different shapes of metal particles is obtained. The influence of the lifting voltage. The existence of the linear particles will cause the distortion of the electric field, which makes the adjacent linear particles stand up at a relatively low voltage. With the increase of the number of adjacent linear particles, the lifting voltage of the linear particles is decreasing, but the number of particles has little effect on the lifting voltage of the spheroidal particles. The effect of the radius of the curvature of the end of the particle on the motion of the particles is investigated. The motion behavior of the linear particles with different radius of curvature of the tip is compared and analyzed, and the cause of the effect of the end of the particle on the motion of the particles is revealed. With the increase of the external application voltage, the motion behavior of the end is mainly 4 kinds of transport behavior. Dynamic state: static standing, small amplitude beating, large beat and penetration. At the end, there are corona metal particles. At the lifting voltage, the end of the smaller curvature radius is the first to stand. With the increase of the external application voltage, the metal particles still have a small jump, which will not jump out of a large amplitude or run through the runout, but the end of the particle rotates. The effect of the impact force on the movement of metal particles is studied. The cause of the effect of the vibration of the GIS cavity on the motion of the particles caused by the switch action of the circuit breaker is revealed. The linear particle appears to be deflected upward and the other end contact with the ground electrode under the impact of the shock vibration. The quantity of electricity increases sharply, and the linear particles have been deflected upward under the action of Coulomb force until the particles stand vertically. The effect of the impact force makes the harmless particles become harmful particles. Based on the movement behavior of different types of metal particles, the partial discharge characteristics of metal particles in different state of motion are obtained, and the metal particle transport is established. The relationship between the dynamic behavior and the partial discharge. The difference in the charge quantity of different types of metal particles at the operating voltage, the difference in the pulsation speed, the beat frequency and the jump height causes the discharge of the particles, the width of the discharge pulse cluster, the difference of the number of discharge pulses, the number of metal particles will cause the difference of the maximum ultrasonic number in the half frequency period. The curvature radius of the grain end will cause the difference in phase correlation of the discharge pulse signal. Through the analysis of the above discharge characteristics, the motion behavior of different types of particles can be judged. The movement of different types of metal particles (different shapes, different numbers, different sizes) to the different positions of the GIS cavity (high pressure bus, shielding ring, insulators) The results show that the penetration of the metal particles is not necessarily related to the breakdown of the particles caused by the GIS, and the free beating of the single linear particles and flake particles under the high pressure bus and the shielding ring is relatively less harmful to the GIS, while the linear particles and the flakes are flake. When there are more particles, its harmfulness is greatly increased. When the linear / flake particles are attached to insulators, the discharge of the particles along the surface causes the deterioration of the insulators, which is more harmful to the GIS. The metal dust and spherical particles insulation less harmful to GIS (two times not to the breakdown voltage of the operating voltage) was established. The movement behavior of metal particles, the relationship between partial discharge and harm degree of the realization of metal particle shape, partial discharge through the estimation of the number, size, proposes the diagnosis method of metal particle damage.
【学位授予单位】：华北电力大学(北京)
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TM595

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