Forces affecting metallic particle motion in GIS

Song

et al. 2021

Coatings

A conductive metallic particle in a gas-insulated metal-enclosed system can charge through conduction or induction and move between electrodes or on insulating surfaces, which may lead to breakdown and flashover. The charge on the metallic particle and the charging time vary depending on the spatial electric field intensity, the particle shape, and the electrode surface coating. The charged metallic particle can move between the electrodes under the influence of the spatial electric field, and it can discharge and become electrically conductive when colliding with the electrodes, thus changing its charge. This process and its factors are mainly affected by the coating condition of the colliding electrode. In addition, the interface characteristics affect the particle when it is near the insulator. The charge transition process also changes due to the electric field strength and the particle charging state. This paper explores the impact of the coating material on particle charging characteristics, movement, and discharge. Particle charging, movement, and charge transfer in DC, AC, and superimposed electric fields are summarized. Furthermore, the effects of conductive particles on discharge characteristics are compared between coated and bare electrodes. The reviewed studies demonstrate that the coating can effectively reduce particle charge and thus the probability of discharge. The presented research results can provide theoretical support and data for studying charge transfer theory and design optimization in a gas-insulated system.

Section: Lifting Process Of Charged Conductive Particlesmentioning

confidence: 99%

“…In the coaxial electrode, the floating voltage of linear metal particles, E l , on the shell surface represents the particles [36,42]:…”

Section: Force (Wedge Electrode) Direction Amplitudementioning

confidence: 99%

Restraining Surface Charge Accumulation and Enhancing Surface Flashover Voltage through Dielectric Coating

Song

et al. 2021

Coatings

“…The influence of metal particles at different positions of the insulator on the characteristics of partial discharge is related to the size of the particle, the electric field, and the characteristics of the discharge magnitude, frequency, discharge spectrum, and ultraviolet image of the partial discharge were obtained [17][18][19][20][21]. The applied voltage is also important influence factor for particle movement and discharge, the discharge initiation of particles under lightning impulse overvoltage and operating impulse overvoltage was studied, and the effectiveness of PD measurement in detecting various defects was determined [22][23][24][25][26]. In ref.…”

Section: Introductionmentioning

confidence: 99%

Partial discharge characteristics of free moving metal particles in gas insulated systems under DC and AC voltages

IET Generation Trans & Dist

Fan

et al. 2022

Free conductive particles in a gas-insulated metal-enclosed system produce partial discharges during movement, resulting in insulator flashover and insulation failures. This study focuses on the partial discharge property of free conductive particles under DC and AC voltages. The relationship between the micro-discharge property and the intrinsic properties of the particles was obtained based on experimental tests. The results show that under DC conditions, the local discharge property varies linearly with particle size and density. The discharge probability of particles in SF6 is significantly reduced compared with that in air, while the discharge magnitude rapidly increases if the lift voltage exceeds a certain value. Under AC conditions, the partial discharge generated by the particle becomes less random, and the amplitude and phase angle of the discharge are not significantly related. As the size of the electrode decreases, the partial discharge current generated by the particles on the surface of the electrode with an uneven electric field increases significantly. This research provides a basis for the optimization of withstand voltage test method and its applications.

“…In order to eliminate the metal particles in GIS, particle capture traps are usually designed in the production with the withstand voltage test before its operation, which enables particles to move to the trap [1][2][3][4][5][6][7][8][9]. In order to optimise particle traps and apply withstand tests, there are many researches on particle movement characteristics [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. In reference [10,12], a wedge of electrode structure was established after analysing the electric field among insulator, electrodes, and gas in GIS.…”

Section: Introductionmentioning

confidence: 99%

“…In order to optimise particle traps and apply withstand tests, there are many researches on particle movement characteristics [10–26]. In reference [10, 12], a wedge of electrode structure was established after analysing the electric field among insulator, electrodes, and gas in GIS.…”

Section: Introductionmentioning

confidence: 99%

Metal particle movement and distribution characteristics under AC voltage and ball‐plane electrodes

Chen

et al. 2019

High Voltage

Metal particles, difficult to be eliminated in gas-insulated metal-enclosed switchgear (GIS), can cause GIS discharge and breakdown between electrodes, or flashover on the insulator surface. It influences the development of ultra-high voltage (UHV) projects. Therefore, the work optimised the model of metal particle movement under AC voltage, studying the metal particle movement and distribution characteristics between ball-plane electrodes through experiment and simulation. Under AC voltage, the particle jumps on a small scale on the plane surface. With the increase of voltage, the jump amplitude increases. However, the collision frequency decreases until the particle collides with the ball electrode. When the initial phase angle of power changes, the particle-moving pattern is symmetrical in the angle ranging from 0 to 180°, and from 180 to 360°. The collision frequency changes slightly with the increase of jump amplitude when the angel ranges from 0 to 120°.