Partial discharge (PD) detection and localization is one of the most effective methods in gas-insulated transmission lines (GIL) insulation fault diagnosis, which important to early troubleshooting safe operation. Compared with widely used ultrahigh frequency (UHF) acoustic PD methods, method based on optical signals has good resistance electromagnetic interference. However, current comes several shortcomings: narrow range, requiring field experiments accumulate data, installing a large...

ABSTRACT The optical detection method has attracted much attention in the field of partial discharge (PD) due to its strong anti‐interference ability. To improve performance PD sensors, a novel sensor based on light guide rod (LGR) is proposed. A simulation model constructed according actual dimensions gas‐insulated switchgear (GIS). properties LGR are analysed terms material, front microstructure, and length. Subsequently, an electrical system set up. Four typical defects designed....

Gas Insulated Switchgear (GIS) is a type of critical substation equipment in the power system, and its safe stable operation great significance for ensuring reliability system operation. To accurately identify partial discharge GIS, this paper proposes an acoustic identification method based on improved mel frequency cepstral coefficients (MFCC) dung beetle algorithm optimized random forest (DBO-RF) ultrasonic detection method. Firstly, three types typical GIS defects, namely free metal...

Partial discharge (PD) is one of the main causes rendering deterioration insulation state in gas-insulated transmission line (GIL). Accurate and timely localization PD source essential to ensure safe stable operation GIL. At present, optical detection technology shows advantages terms high sensitivity strong anti-interference performance. Therefore, an method based on simulation fingerprint database proposed. The introduction conquers difficulty obtaining a field experiments. This constructs...

Realization of an electrical aircraft demands a low-weight electric distribution and propulsion system. The use high voltage power electronics operated at switching frequencies is essential to achieve this objective. However, printed circuit boards (PCBs) in electrified are harsh working environment, which can make PCBs more susceptible generate partial discharges (PDs). current PD detection technology has poor immunity the electromagnetic interference acoustic operating environment...

Partial discharge (PD) is an important phenomenon that reflects the insulation condition of electrical equipment. In order to protect safety power grids, it significance diagnose type defects inside equipment accurately and early through PD pattern recognition. this article, phase resolved pulse sequence (PRPS) graphs in 3D were constructed by data gas-insulated switchgear (GIS) acquired, then histogram oriented gradient (HOG) features extracted directly from PRPS graphs, finally attribute...

The Nudum (Nud) gene controls the caryopsis type of cereal crops by regulating lipid biosynthetic pathways. Based on HvNud sequence and its homologous sequences in wheat, a conserved sgRNA was designed to obtain mutants from barley variety "Vlamingh" wheat "Fielder" via Agrobacterium-mediated transformation. A total 19 118 transgenic plants were obtained, 11 61 mutant identified T0 after PCR-RE detection, editing efficiencies targeted 57.9 51.7% respectively. grain shape naked. Five...

Optical partial discharge (PD) detection is an efficient means of diagnosing the insulation status power equipment. C <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> F xmlns:xlink="http://www.w3.org/1999/xlink">7</sub> N/CO xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> gas mixture a very potential environmentally-friendly SF xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> substitute gas, and its PD optical characteristics need to...

Sensitive signal perception and accurate fault diagnosis are key to partial discharge (PD) optical detection. To improve the effectiveness of PD detection diagnosis, this paper uses sensing technology based on a light guide rod (LGR) measure typical PDs in SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> . The characteristics signals analyzed method for detected by LGR is proposed. An electrical experimental platform built, four...

More electric aircraft (MEA) is an important direction for future development. The printed circuit boards (PCB) of power electronics equipment in MEA operates a complex environment low air pressure, square wave voltage, compact layout and strong electromagnetic interference, which makes the PCB more prone to partial discharge (PD). However, effective detection method related characteristics PD under voltage are still unclear. Therefore, this paper proposes based on fluorescent optical fiber,...

With the widespread application of power electronic switching technology, equipment is facing new electrical stresses brought about by multilevel staircase voltages during testing and operation. Therefore, partial discharge (PD) behavior five typical defects in under waveform needs to be investigated. This article mainly analyses phase-resolved PD (PRPD) pattern pulse repetition rate (PRR) sinusoidal voltage with different number levels. Also, step responses are By analyzing reasons behind...

A Two-dimensional simulation of the atmospheric pressure needle-plane streamer discharge is presented in this paper. The model consists three continuity equations for electrons and ions coupled with Poisson’s equation. Photon flux was estimated by impact ionization reactions. distributions electric field photon from primary to secondary are discussed, where velocity 2.16×105 m/s radius filament varied 0.012 cm 0.02 cm. variation similar that field. When close cathode, exponentially increased...

A method for separating multisource partial discharges (PDs) in a substation is proposed based on selected bispectra of ultrahigh frequency (UHF) electromagnetic waves. Bispectra are sensitive to Gaussian noises and processes symmetrical distribution. The phase information contained can be useful important further signal processing. Bifrequencies where Fisher-like class separability measures between signals’ achieve their maximums as characteristic parameters the signals. Then, utilized...

Optical detection of partial discharge (PD) is an important means to diagnosis the insulation status equipment. However, current optical either unable perform simultaneous multispectral features or it can only be applied under laboratory conditions. Moreover, PD different gases will correspond characteristic distributions, but research aimed at study SF <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sub> . Therefore, this article proposes a...

Optical detection and ultrahigh frequency (UHF) are two significant methods of partial discharge (PD) in the gas-insulated transmission lines (GIL), however, there is a phenomenon signals loss when using types detections to monitor PD different defects, such as needle defect free particle defect. This makes optical UHF not correspond strictly actual signals, therefore characteristic information patterns incomplete which reduces accuracy pattern recognition. Therefore, an image fusion...

For 110 kV and above tunnel-installed high-voltage (HV) cross-linked poly-ethylene (XLPE) cable systems, it is a normal procedure to adopt cross-bonding scheme. The high-frequency current method frequently used in the cross-bonded systems for on-site or online partial discharge (PD) detection by monitoring signals on wires. To further study amplitude distribution characteristics of PD signals, parametric characteristic admittance model three-phase system tunnel established based Tylavsky’s...

Partial discharge (PD) leads to the generation of electrical, acoustic, optical, and thermal signals. The propagation characteristics optical signals in gas insulated metal-enclosed transmission lines (GIL) are basis detection research. This paper simulates PD GIL through modeling with different structures specification parameters. By analyzing parameters on probe surface points when source position is different, influence difference specifications caused by voltage level signal studied....

Piping cracks are widely spread in the nuclear power plants, which affect safety and economy of reactors. The leak before break (LBB) concept detects leakage through afterwards takes human intervention, to avoid rupture pipes. As a precondition for application LBB technology, constant monitoring system is necessary. based on temperature humidity method can be used location quantitative analysis, but how set reasonable alarm threshold directly affects whether put into use normally. This paper...

More and more printed circuit boards (PCBs) will be used in electric aircraft to achieve higher power density of the on-board system, while PCBs are likely generate partial discharges (PDs) due external factors such as compact structure low air pressure. Therefore, this paper proposes a fluorescent fiber-based method for detecting evaluating PDs on PCBs. The detection is effectively immune against presence electromagnetic, acoustic vibration interference. Based optical detection, evolution...

C4F7N gas mixture is considered to be a very promising SF6 replacement gas. In order study the surface discharge characteristics of under needle-plane electrodes, fluid model was established using COMSOL Multiphysics for simulation, and change patterns electric field photon flux during development streamer were obtained. By obtaining law flux, it can provide theoretical discharge. The simulation results show that process divided into three phases: generation phase, deceleration phase...

As gas-insulated transmission line (GIL) is widely used, the partial discharge (PD) phenomenon that occurs during their operation one of main reasons for deterioration insulation status. Therefore, detection and localization PD in GIL plays an important role ensuring safe stable equipment. At present, methods are mainly ultrahigh frequency (UHF) method ultrasonic method, while these susceptible to mechanical vibration electromagnetic interference. Optical detection, as a sensitive effective...