Boron nitride nanosheets (BNNSs) have garnered significant attention across diverse fields; however, accomplishing on-demand, large-scale, and highly efficient preparation of BNNSs remains a challenge. Here, an on-demand (OdP) method combining high-pressure homogenization short-time ultrasonication is presented; it enables controllable from bulk hexagonal boron (h-BN). The pressure number cycles are adjusted, the production efficiency yield reach 0.95 g

Epoxy composite is expected to become the substrate insulation of gate bipolar transistors (IGBTs) that can replace ceramics if it has high thermal conductivity. Fillers with conductivity were added epoxy resin, while this often suffers from lowering in breakdown (BD) strength. In order reveal above phenomena and clarify mechanism, we carried out experiments using several electrode structures, i.e. an MB-PWB (metal-base printed wiring board) simulated structure, a rod-to-plane for PD erosion...

This paper presented an assessment of lightning energy absorption by dedicated surge arresters (SA <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DT</sub> ), which are provided to protect the distribution transformers on 10kV overhead lines (OHLs). A hybrid Partial Element Equivalent Circuit-Multi-conductor Transmission Line (PEEC-MTL) code was applied evaluate surges SA . method has capability modeling both short and long wires in OHL systems...

In this paper, a new zero voltage current transition (ZVZCT) boost DC-DC converter using coupled inductor is proposed. This topology provides the main switch ZVZCT for turn-on and switching (ZVS) turn-off. Moreover, auxiliary turns on at (ZCS) off ZVS. The diode with ZVT ZCS, other diodes also operate under soft-switching conditions. Besides, due to coupling effect, proposed improves efficiency additionally since resonant energy in resonance tank could be transferred output, circulating can...

In the pursuit of fuel economy improvement and emission reduction, a trajectory optimization-based engine multioperating-point control strategy is proposed in this paper for auxiliary power unit (APU) an extended range electric vehicle. This design deeply considers transient process operating point switching that somehow influences emission, was often ignored. First, combined cost MAP fully integrating several indices, including consumption rate, CO, HC, NOx emissions, presented to...

In this paper, a new zero-voltage zero-current transition (ZVZCT) boost converter using coupled inductors is proposed. The feature of topology is: the main switch can be switched on with ZVZCT, and off switching, without any voltage current stress. auxiliary turned switching. Other semiconductor devices also achieve soft switching (SS). Due to existence coupling effect, impact completely suppressed when it off. Lower input output in interval switch-off for are just equivalent running at low...

Aiming at the reduction of influence dead time setting on power level and efficiency inverter double-sided LCC resonant wireless transfer (WPT) system, a soft switching optimization method for metal–oxide–semiconductor field-effect transistor (MOSFET) is proposed. At first, mathematic description charging system established, operating mode analyzed as well, deducing quantitative characteristic that secondary side compensation capacitor C2 can be adjusted to ensure circuit inductive. A design...

Epoxy resin is widely used in high voltage apparatus, electrical machines etc due to its excellent mechanical, and chemical properties. Great progress has been made application on insulation, casting potting. The epoxy containing nano-size micro-size Al <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> of various contents are prepared. purpose efforts we engaged study the nano , micro...

According to the principle of Photoacoustic Spectroscopy, HPAS-1000 Online Dissolved Gas Analysis Monitor is developed monitor dissolved gas in power transformers online, which can directly extract oil sample from running transformer and measure content Hydrogen, Acetylene, Ethylene, Methane, Ethane, Carbon monoxide dioxide real time. Field Monitor-INNOVA 1412 module employed for it only takes a few milliliters achieve measurement sensitivity reach less than 0.5ppm. In order separate vacuum...

In the long-distance XLPE power cable partial discharge detection, due to existence of jacket cross-interconnect structure, defect phase signal will flow into other two-phase jacket, making detection and analysis are very difficult. To determine position difference source, cross-connect system is simulated modeled. Combined with actual measurable points in process live time domain characteristics distribution signals at different simulated. The simulation results show that pulse quite...

There have been some researches on the use of deep learning algorithm in work power patrol inspection. With current object detection algorithms as core, a grid image recognition system can be built to detect abnormal operation or foreign invasion grid, which could save manpower and material resources improve security grid. Deep requires number effective samples work. are few real images hidden dangers, cannot meet demand. This paper aims explore feasible data expansion scheme. One possible...

Mechanical fault diagnosis of Gas Insulated Switchgear (GIS) is a popular research topic in recent years. Inspired by the fact that experienced inspectors can detect failure GIS only sound, this paper proposes novel framework for mechanical based on sound classification. We extract Mel Frequency Cepstral Coefficient (MFCC) features from input signal and make an improvement to adapt underlying GIS's sounds. Using machine learning, we classify extracted with support vector (SVM) obtain model...

Abstract This paper proposed a power allocation mechanism and mode switching strategy for the series-parallel hybrid electric vehicles. A test-data based simulation platform plug-in vehicles is established developed theoretical verification. The results indicate that control realized more reasonable distribution in combined system under various working modes, which means remarkable improvement vehicle fuel economy.

This paper investigates the lightning performance on 10kV overhead distribution lines grounded with counterpoise wires under extremely low soil conductivity. A partial element equivalent circuit model considering lossy ground is used for surge analysis, and Monte Carlo method adopted evaluating flashover rate. It found that conductivity, simple vertical grounding rod not effective in protection, while significantly increased extended wires. The single-row wire a length of pole span performs...

Windings of power transformer may suffer short circuit currents or mechanical forces, which lead to different winding displacements such as axial and radial displacements. Measurement leakage inductance is one the most effective methods identify these In this paper, an on-line detection system based on WinCE platform for deformation proposed. Based equivalent low frequencies, formula calculate derived. practice, using signals gained from voltage transformers current transformers, with help...

As a routine within the planning and operation of electrical power system, Short-term load forecasting (STLF) is an essential issue in energy fields. Its prediction accuracy precision specifically have effect on basic safety, stability economic efficiency system. Moreover, actual result also has impact operations such as startup shutdown units, switching, equipment maintenance, etc. Nonlinear Autoregressive models with Exogenous Input (NARX) Neural Network been utilized for STLF proved its...

Dielectric characteristics of LDPE filled with micro- and nano-sized particles SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> were studied in this paper. The dependence the loss factor dielectric constant composites on frequency was investigated a relatively wide range, roles size loading level filler are discussed. Compared additive-free LDPE, incorporating can effectively reduce tanδ all nanocomposites low while only an...

This study aims to explore the influence of vowels and sound intensity on formant, so as provide reference for selection samples vocal methods in acoustic detection.

We investigated the influence of surface modification Al nanoparticles on electrical conduction polyethylene composites. Octyl-trimethoxysilane was used as a coupling agent for treatment nanoparticle. It found that incorporation octyl groups onto nanoparticle altered time dependence behaviors polarization and depolarization current increased percolation threshold resistivity is concluded that, based our morphology observation nanocomposites, improved properties could be directly ascribed to...

A piezoelectric generator based on the stacked elements is applied to realize electro- mechanical energy conversion in this paper. The constructed. relational expression about output electrical characteristic parameters, constructional dimension parameters of stack and external driving forces discussed here. Theoretical predictions confirmed by experimental results show that produces power with higher efficiency, harvesting circuit can harvest from effectively.

Thermally stimulated depolarization current (TSDC) measurement is a useful method to determine the charges transportation and trap levels in dielectric. By testing temperature differences polyester (PET) films' TSDC curves of electrodes with different size structure, this paper analysis influence gradient on test. The result shows that asymmetric electrode structure can uneven heating condition specimen, then produces specimen's thickness direction, complete curve consists two distinct peaks...