Tailoring the high anisotropic thermal conductivity of polymer dielectrics for enhanced high-temperature breakdown strength with potential capacitive energy storage.

Aromatic polymer films with high glass transition temperatures (Tg) exhibit superior thermal stability, making them ideal for high-temperature dielectric capacitors in advanced electrical and electronic systems. However, the leakage current...

The adhesion of ice to high -voltage overhead transmission lines should be small ensure ease shedding under external forces. In this work, we studied the influence microstructure superhydrophobic surfaces on strength at a working temperature −6 °C. Compared bare aluminum surface, did decrease strength. with larger number micro-holes produced lowest adhesion; its was ∼163.8 times lower than that for samples. Furthermore, such had water contact angles 150° and sliding less 8.2° even low values...

Bubbles will reduce the electric strength of transformer oil, and even result in breakdown insulation. This paper has studied voltages oil oil-impregnated pressboard under alternating current (AC) direct (DC) voltages. In this paper, three types electrodes were applied: cylinder-plan electrodes, sphere-plan cone-plan measured both no bubbles bubbles. The sphere-sphere used to study voltage pressboard. results showed that influence bubble, electrode dropped most, least. motion was key factor...

Abstract Accurate surface charge inversion can guide the research on modification of insulators in GIS/GIL. The current algorithms have disadvantages high computational cost and low accuracy. Based that, integral equation method (IEM) is proposed to calculate transformation matrix. Compared with traditional analytical (AM), IEM has a simple calculation process. speed much faster than that AM. To suppress numerical divergence IEM, Tikhonov regularisation introduced Tikhonov‐IEM proposed. For...

Abstract To address the subjective issue of selecting measurement points based on mainstream line methods for hotspot temperature inversion in oil‐immersed power equipment, this paper demonstrates an reactor field method random forest (RF) point optimisation. Firstly, a calculation 22‐kV is proposed. In combination with Latin hypercube sampling, 50 sets data are calculated. Based these samples, selection RF feature importance and training genetic algorithm‐optimised back propagation (GA‐BP)...

This article presents the preparation of Kevlar aramid fiber (AF) braided fabric/epoxy resin (EP) composite laminates through plasma treatment and a hand-folding process. The electrical mechanical properties these are compared analyzed. modified AF cloth is examined using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR). results confirm an increase in number C <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML"...

In the present study, a discrete spectral interference (DSI) suppressing method based on bivariate empirical decomposition mode (BEMD) related to partial discharge measurements is presented. PD complex-valued signals are generated first, whose real part DSI polluting and imaginary zero mean white Gaussian noise (WGN) signals. decomposed BEMD, intrinsic functions (IMFs) can be sifted by this decomposition. The of IMFs (RIMFs) results (IIMFs) WGN With assistance signals, mixing effect in RIMFs...

The construction of ultra‐high‐voltage direct‐current power transmission projects in high‐altitude areas calls for the research into discharge characteristics air gaps valve hall a converter station such areas. Tests on switching impulse sphere‐plane gap were conducted at Yangbajing test base (Tibet, China) an altitude 4300 m conditions that there burrs 1.3 diameter shield balls. characteristics, under influences with different lengths and locations, obtained compared data from low‐altitude...

In this work, a combined photoelectric detecting system is established using devices such as photomultiplier, an electric field sensor based on optoelectronic integration, and high-speed camera. The used to measure the instantaneous optical power, spatial strength, image during discharge of 3-m-long sphere–plane gap under standard switching surge voltage positive polarity. test results show that initial streamer can be divided into strong weak ionization according rate rise power strength....

The condition and health of large oil-immersed power transformers' insulation have a direct impact on the safety stability grid. Therefore, it is crucial to investigate aging characteristics oil-paper in transformers. In this study, we developed computational model for reclosing current calculation multiphysics coupling models magnetic-circuit-force, electrostatic field, temperature field simulations. calculated resulted mechanical stress 8.71 MPa, an electric strength 2.26 × 106 V/m, 113.7...

The detection of hydrophobicity is an important way to evaluate the performance composite insulators, which helpful safe operation insulators.Image processing technology used judge makes results more accurate and overcomes subjective drawbacks traditional methods.As Canny operator requires manual intervention in selecting variance Gaussian filter threshold, paper presents a method edge based on improved operator.First, adaptive median replaces filter, can eliminate impact from remove noise...

The dimension and surface state of shielding fittings in ultra high voltage direct current (UHVDC) converter station valve halls have a great influence on their electric field switching impulse characteristics, which are important parameters confirming the air gap distance hall. characteristics discharge under different lengths, dent degrees burrs around scratches Φ1.3 m shield balls with 2 sphere-plane length were tested, UHVDC testing base Hebei Electric Power Research Institute. ball...

With the rapid development of China’s electrical industry, safe operation facilities is very important for social stability and people’s property safety. The failure detection method conventional equipment hand detection, which has high experience person, lacks error efficiency low. artificial intelligence technology, computer-assisted substation inspection now possible, using an intelligent robot equipped with infrared device one main methods. In this paper, experiments are carried out...

Partial discharge (PD) detection is essential for electrical equipment. Focusing on the noise suppression of PD signal, a signal denoising method based rapid sparse decomposition was proposed. Through analysis time-frequency characteristics, correlated atom and overcomplete dictionary were designed, which to original pulse while uncorrelated or weak-correlated random discrete spectral interference (DSI) signal. Denoising noisy by matching pursuit algorithm correlation ratio iteration...

Condition evaluation on large power transformer is an important approach to improve reliability of and provide proper decision-making for condition-based maintenance by means combining multilevel extension assessment method with influencing factors condition, a new condition based was presented in this paper. Extension analytic hierarchy process (EAHP) applied calculate the weight information. At last two examples were taken prove be correct effective.

Insulators will be in operation process when insulation performance drop coincided with a surface discharge, the state detection by UV camera can found fault insulator effectively, which timely maintenance and low breakdown. Combined DCUHV engineering technology national laboratory (Kunming) site demand design, we develop set of ultraviolet data management system use Delphi SQLServer2000, take modular thought. Establish basic information management, image processing, broadcast statement such...

The study established a test platform for long sphere‐plane air gap in the hall of ultra‐high voltage (UHV) direct current(DC) Testing Site. Under gaps with 3, 5 and 7 m distance, carried out experiment on discharge characteristics under switching impulses shield ball which surface tips had different lengths at locations. By comparing data obtained conditions smooth same laws influence are shown as follows: presence greatly decreased maximum decrease amplitude 39.0%. Moreover, degree was...