A reliable prognostic model is very useful for industries to forecast equipment behaviors. The aim of this research verify the effectiveness neuro-fuzzy in predicting health condition bearings. Simulation and an experiment have been carried out model, with results showing that a robust forecasting tool, more accurate than radial basis function network. In experiment, vibration data collected from used predict future condition.

Mulching practices have been used to improve peach growth and production across the globe. However, impact of mulching on physiochemical properties soil characteristics orchards remains largely unknown. This study aimed decipher impacts various patterns environment quality Prunus persica fruit in “Zijinhuangcui”. Three treatments were set up, which included black ground fabric mulch (BF) two living grass (HV: hairy vetch RG: ryegrass). The results showed that different effects soil, plant...

The traction transformer of a high-speed railway is long-term subjected to the effects impulse loads, such that aging status multilayer insulation paper between high and low voltage windings non-uniformly distributed due non-uniform distribution temperature. To enhance use frequency domain dielectric spectroscopy (FDS) method in engineering, this studies thermal on spectrum paper. Based experimental designs preparation materials, with uniform was tested. Afterwards, were discussed analyzed...

Oil-immersed transformer is one of the most important electrical equipment in power distribution and transmission systems. Dielectric response method a well-recognized to diagnose insulation defect oil-immersed transformers. However, applicability this restricted due long testing time. Under some special field conditions, not even applicable. In article, novel proposed based on following ideas: first, low-frequency dielectric parameters are extracted by using mixing frequency excitation;...

With the rapid development of China's high-speed railway (HSR), large-scale traction transformers have been put into use. In order to realize batch prediction hot-spot temperature (HST) transformer group and perform estimation thermal capacity well, this article was devoted HST modeling for based on genetic programming (GP). First, HST, load factor, ambient data used in were measured from A further divided training set set. Training driven by GP. An explicit expression model, which could...

Abstract For microscopic analysis of the effect doping with carbon nanotubes (CNTs) different radii on thermal and mechanical properties addition liquid silicone rubber (ALSR) composites, models pure composites containing CNTs were constructed based a molecular dynamics approach using vinyl-capped polydimethylsiloxane (VPDMS) as base polymer polyhydroxymethylsiloxane (PHMS) cross-linker. The microstructures analyzed compared. It was found that could change thermomechanical small radius had...

<title>Abstract</title> Global plantations, crucial for restoring degraded landscapes, face rising invasive pest threats, in recent decades. This study highlights that the invasion and proliferation of fall webworm have been facilitated by global afforestation boom last 80 years could pose a threat to all ecological projects until 2050. Since 1940, this polyphagous has spread 40 countries, following an <italic>S-</italic>curve pattern. The distribution is positively correlated with expansion...

Abstract The influence of assembly misalignment and welding crack on the maximum pressure in pipeline repair was investigated using numerical simulation methods this work. result indicated that doesn’t need to be depressurized when is less than or equal 5mm for calculated X70 X80 pipelines. Besides, specifications pipe 1219×22 mm, depth diameter 0.20~0.40, length 0.20~0.80, level highest, with a range 8.2~11.4 MPa. distributed 7.1~9.5 MPa thickness decreased 18.4 mm. increased increase wall...

Oil-immersed bushing is one of the most important accessory equipment a transformer, whose insulation status crucial. Moisture an factor that affects oil-immersed bushing. It has very significance to estimate moisture content accurately. Here, 72.5 kV samples with different contents were made. Afterwards, frequency domain dielectric spectrum (FDS) tested at 15°C. The Havriliak–Negami equation was modified based on analysations complex planes, then it used analyse experimental results....

Frequency-domain dielectric spectrum (FDS) is an effective testing method to reflect the changes of internal insulation status oil-impregnated paper (OIP) bushing. In field application, results FDS test can be both affected by aging defects and damp defects, then OIP bushing cannot diagnosed in detail, which issue discrimination multiclass classification. To solve this problem, a diagnose proposed based on least square support vector machines (LS-SVMs) optimized cuckoo search (CS) algorithm....

In order to dig out more potential of design parameters besides nameplate information, a set pre-physical modeling methods was proposed and integrated into the dynamic thermal procedure, aiming optimize key individually. this method, global oil momentum model created considering flow resistance, for problem heat transfer between windings, flow, radiator, whole established based on principle energy conservation. Then, double logarithmic linear regression applied quantify value exponents....

Abstract To study the effect of doping hexagonal boron nitride (h-BN) on thermal properties and insulation resistance epoxy resin (EP) mechanism this effect, h-BN/epoxy composites with h-BN content 0, 10, 20, 30, 40 phr were prepared. Meanwhile, corresponding molecular dynamics model was established, conductivity, volume resistivity, glass transition temperature, microstructure parameters obtained. When is phr, conductivity composite increased by 138% compared to pure EP, temperature 76 K....

It is a challenging task to accurately diagnose railway bearing fault since vibration signals are under strong interferences from wheel–rail excitations. The commonly used Kurtogram-based methods often trapped in components induced by the excitations while adaptive mode decomposition sensitive input control parameters. To address these issues, based on recently developed powerful signal method, that is, chirp (ACMD), novel method called bandwidth-aware ACMD (BA-ACMD) proposed this article....

The Long Short-Term Memory (LSTM) neural network model is an effective deep learning approach for predicting streamflow, and the investigation of interpretability models in streamflow prediction great significance transfer improvement. In this study, four key hydrological stations Xijiang River Basin (XJB) South China are taken as examples, performance LSTM its variant runoff were evaluated under same foresight period, impacts different periods on results investigated based SHapley Additive...

Thermal aging of insulation paper has obvious effects on its moisture absorption property. The presented studies aim to investigating the diffusion in oil-immersed paper. Based experimental designs and preparation materials, transient contents with different status were obtained at conditions. Then, results discussed. Furthermore, factors equilibrium time constants extracted based model paper, which are applicable our studies. Finally, thermal factor constant analyzed. show that: 1) With...

Oil-impregnated paper (OIP) bushing is essential equipment in power substations, and moisture intrusion one of the major faults during its operation. In this article, a method proposed to diagnose fault by hidden Markov model (HMM) shuffled frog-leaping algorithm (SFLA). First, HMM employed characterize probabilistic relationship between states frequency-domain spectroscopy (FDS). Then, SFLA adopted optimize locatable results point (MIP) bushing. Next, extensive simulated data are used for...

Ethylene propylene rubber (EPR) cable terminations have great potential in improving the operational reliability of electric multiple units, for their high elasticity and low loss. However, breakdown EPR frequently occurred northwestern China during winters. In this study, tests were conducted to investigate effect temperature (−40 20°C) on partial discharges (PDs) characteristics, characteristic transition temperature, process termination. samples with no artificial defects, it was found...

The windings of a traction transformer are always be threatened by the fluctuation load. Frequency response analysis (FRA) is regarded as most effective method to diagnose winding deformation. Appropriate FRA modelling may help predict typical faults for large transformers. existing model usually simplify dozens disks into several disks, it applicable when analysing small displacement. However, between seriously misplaced, conventional not suitable. This study presents an improved lumped...

Velocity of the acoustic signal generated by partial discharge (PD) in transformer is considerably affected temperature. Because thermosiphon effect, internal temperature gradually decreases from top to bottom, which leads propagate faster upper part transformer. Besides, due complex structure transformer, it difficult for PD source sensor along a straight line. In order further enhance accuracy localization results, this paper proposes correction-iteration method with considering influence...

Traction transformer is vital equipment in high-speed railway. Insulation status decides its safety and reliability, the frequency-domain dielectric spectrum (FDS) test one of most effective methods reflecting changing insulation status. For field applications, following problems should be addressed: 1) how to obtain result paper from combined oil-paper system 2) discriminate defects between aging damp. In this article, first problem was transferred a nonlinear equation set, cuckoo search...

Modern pulse width-modulated (PWM) converter-fed locomotives generate current harmonics which propagate along traction line. The line is distributed at high frequencies, so the injected may cause resonances. This paper presents a way for analyzing resonance in electrified high-speed system, by calculating harmonic According to voltage generation process and characteristics of line, formulas representing spectra PWM converter input impedance system are presented. Frequency spectrum simulated...

Temperature has obvious effects on the tested results of frequency domain dielectric spectrum (FDS) method. To estimate moisture content field oil‐immersed bushing, temperature must be considered and eliminated. In this study, frequency‐domain 72.5 kV bushing samples with different contents was at temperatures. The law that affects FDS tests analysed concluded. Afterwards, a method to transfer reference (15°C) proposed. Finally, an estimation for proposed testified. following conclusions can...

Catenary icing seriously affects the safety and reliability of traction power supply systems electric railways. To prevent damage without interrupting normal train traffic, an online anti‐icing technique using Joule‐effect is presented. In this scheme, current flows are adjusted over entire catenary in accordance with not only environmental parameters, but also network voltage requirements. Determination requisite based on a circuit analysis direct feeding system. The viability for system...