Monitoring of Dry Bands and Discharge Activities at the Surface of Textured Insulators with AC Clean Fog Test Conditions

Pollution flashover occurs when soluble and nonsoluble materials cover the surface of an insulator, and this may ultimately cause a reduction in its performance. In this paper, the common type of sodium chloride (NaCl) was used as a soluble pollutant (ESDD) and kaolin as a nonsoluble pollutant (NSDD). Samples of silicone rubber (SiR) insulators were selected for this study and fabricated at the Advanced High Voltage Engineering Research Centre (AHIVEC) at Cardiff University. The samples were preconditioned and polluted according to standard specifications. Additionally, the AC voltage ramp technique was used to achieve flashover (FOV) voltage with different pollution levels. The aim of this work was to investigate the effect of nonsoluble materials on flashover characteristics to understand their interaction with dry-band arcs by using FOV electrical equations and experimental data. The test results show that the FOV voltage of the silicone rubber insulator substantially decreased with the increase in both ESDD and NSDD values. It was also identified from these results that the dry-band arcs were considerably influenced by both ESDD and NSDD levels. This impact can be quantified by determining the variation of discharge parameters (N, n). Based on the FOV equations and experimental data, a mathematical model was suggested, taking into account the effect of both ESDD and NSDD.

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“…Postprocessing software is used for data analysis. More details about the experimental setup are given in [28][29][30][31][32].…”

Section: Methodsmentioning

confidence: 99%

Experimental Study and Modeling of the Effect of ESDD/NSDD on AC Flashover of SiR Outdoor Insulators

et al. 2022

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“…In this section, we describe a quick thermoelectric numerical simulation that was carried out using a 69 kV Sediver composite insulator with a uniform pollution layer [19]. The aim of this simulation is to verify the location of the concentration of the leakage current, as well as the maximum temperature, as reported in the literature [15][16][17]. The general geometry and characteristics of the insulator used in this study are shown in Figure 1 and Table 1.…”

Section: Model Of the 69 Kv Composite Insulatormentioning

confidence: 99%

“…In this section, we describe a quick thermoelectric numerical simulation tha ried out using a 69 kV Sediver composite insulator with a uniform pollution l The aim of this simulation is to verify the location of the concentration of the lea rent, as well as the maximum temperature, as reported in the literature [15][16][17] eral geometry and characteristics of the insulator used in this study are shown i and Table 1. As the 69 kV Sediver composite insulator is supposed to be uniformly polluted, simulations can be performed using a 2D-axisymmetric finite element method (FEM) with the commercial software Comsol Multiphysics ® from COMSOL, Inc., Burlington, VT, USA, version 5.5.…”

Section: Model Of the 69 Kv Composite Insulatormentioning

confidence: 99%

“…Archad A. et al [15], in their numerical simulations of polluted insulators, modeled dry bands as clean portions, thus creating a break in the pollution layer. Numerical simulations [15,16] and infrared thermography images [17] also show that, for composite insulators, electrical and thermal stresses are relatively greater at the junctions between the rod and sheds [15,16]. Unfortunately, these results cannot be observed using rectangular geometries.…”

Section: Introductionmentioning

confidence: 99%

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Development of a Simple Experimental Setup for the Study of the Formation of Dry Bands on Composite Insulators

2022

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This paper introduces a new geometry for the study of dry band formation. Firstly, a thermoelectric simulation of a 69 kV uniformly polluted composite insulator was performed. The results obtained show that thermal stress is greater at the rod surface where current density is maximum. In order to experimentally reproduce the constriction of current density lines on the insulator rod surface, which is the cause of dry band formation, the development of a new simple geometric setup, which was then tested experimentally, was proposed. For this purpose, an ESDD value corresponding to a high level of pollution was used for each polluted sample, and the samples were placed in a climate chamber at constant 90% relative humidity and a constant ambient temperature of 20 °C. Low-voltage tests permitted the determination of the wetting duration, which corresponds to the maximum surface conductance of the polluted layer. The values obtained agree with the 10–40 min duration recommended in IEC 60507. Moreover, the tests performed at a higher voltage demonstrated the efficiency of the proposed setup to simulate the complex process of dry band formation in a reproducible way in terms of leakage current and temperature behavior. The proposed setup is a new and simple method that can be easily used by the electrical industry to develop new material for the next generation of overhead line composite insulators without requiring costly HV equipment.

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“…The results showed that the float potential metal has a strong distortion effect on the current density, and it is easy to form a dry band through the contaminated layer, which triggers the arc discharge. Several scholars have carried out experimental and simulation studies on the dry band discharge on the insulator surface [14][15][16][17]. However, there are connections between the composite rod and metal/composite plate in the tower, which may also lead to electric field distortion.…”

Section: Introductionmentioning

confidence: 99%

Suppression Measures of Partial Discharge at Rod–Plate Connection in Composite Tower

Hao¹,

Huang²,

Fang³

et al. 2023

Energies

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Rods and plates at the connections in composite insulating material towers are commonly fixed to each other by metal bolts, which may cause electrical field distortion at the connections. So, the rod–plate connections are prone to partial discharge under polluted and wet conditions, and the resulting electric field and temperature changes can affect the mechanical and electrical performance of the whole tower. In this paper, an artificial pollution test synchronous observation platform with an infrared and visible light imager, leakage current, and voltage measurement was built to observe the dry band formation and partial discharge at the simplified rod–plate connections in the composite towers. Then, the electric field simulation of the rod–plate connection specimen showed the current density distribution. When combining the test and the simulation, it was concluded that the cause of the partial discharge was the distortion of the current density and, thus, measures to suppress the partial discharge at the rod–plate connections were proposed. Finally, it was verified that the measures can improve the current density distortion phenomenon, delay dry band formation, and effectively suppress the partial discharge at the rod–plate connections under the same test conditions.

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Monitoring of Dry Bands and Discharge Activities at the Surface of Textured Insulators with AC Clean Fog Test Conditions

Cited by 15 publications

References 13 publications

Experimental Study and Modeling of the Effect of ESDD/NSDD on AC Flashover of SiR Outdoor Insulators

Experimental Study and Modeling of the Effect of ESDD/NSDD on AC Flashover of SiR Outdoor Insulators

Development of a Simple Experimental Setup for the Study of the Formation of Dry Bands on Composite Insulators

Suppression Measures of Partial Discharge at Rod–Plate Connection in Composite Tower

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