It is of great significance to achieve the prediction building energy consumption. However, machine learning, as a promising technique for many practical applications, was rarely utilized in this field. The most important reason that predictive structure with best performance difficult be determined. To fill gap, paper offers one in-depth review, which focuses on accuracy analyses and model comparisons. Specifically, were conducted based different types buildings (e.g. residential building,...

In order to distinguish the influences of moisture and aging on frequency domain dielectric response oil-paper insulation better apply spectroscopy (FDS) assess condition power transformers, samples with different contents states were prepared in laboratory. The FDS tested a group characteristic parameters extracted from dissipation factor (tanδ) curves which could be used content respectively. quantitative relationship among parameters, degree polymerization (DP) (Km.c) was accurately...

Dielectric response techniques have been proven useful for evaluating the moisture content ( K m.c ) of oil‐paper insulation. However, an accurate model condenser bushing has not presented. This study designed a laboratory oil‐impregnated paper (OIP) to simulate moistened defects in bushings. Moreover, 10 kV OIP was simulated using COMSOL multiphysics AC/DC confirm that distribution potential meets design requirements. Furthermore, this work investigates effect on dielectric frequency and...

The life expectancy of a transformer is closely related to the condition its oil-paper insulation. In present study, oil impregnated pressboard samples with different aging states and water contents were prepared under controlled laboratory conditions analyze insulation power by dielectric response method. Dielectric measurements, i.e., polarization depolarization currents (PDC) frequency domain spectroscopy (FDS), conducted on at temperatures. Results show that responses pressboards are...

The service life of a transformer is determined by the condition its oil-paper insulation. A modified Cole-Cole model was introduced to describe frequency domain spectroscopy (FDS) curves based on classic Debye relaxation and thereby accurately ageing state insulation power using FDS. Oil-paper samples with different states are prepared under laboratory conditions, characteristic parameter extracted quantify their after detailed investigation dielectric properties samples. Results reveal...

This paper focuses on the in-depth analysis of physical mechanism broadband frequency domain spectroscopy oil-paper insulation. The complex permittivity shows two low-frequency dispersion phenomena, and real part conductivity exhibits slope changes under synergistic effect aging moisture. are mainly attributed to migration characteristics water molecules polar products with a degradation insulation, resulting in transition dependence between DC AC conductivity. When insulation deteriorates...

The ageing rate of cellulose insulation materials (paper/pressboard) in oil‐impregnated transformers is largely determined by moisture. In this paper, several experiments were conducted under controlled laboratory conditions to quantitatively diagnose the amount moisture using frequency domain spectroscopy (FDS) technique, which has been proven be an effective tool predict condition power equipment. dielectric response pressboards, content as well test temperature, was monitored carefully,...

Dielectric response testing is a non-destructive insulation method that widely used for assessing properties. Time-and frequency-domain dielectric spectra are closely dependent on conditions. In comparison with the time-domain spectrum, under sweep sinusoidal excitation has stronger anti-interference capability and more comprehensive information. However, wide application of measurement using hindered by its long time. A possible solution obtaining spectrum transforming tested such time- can...

Frequency domain spectroscopy (FDS) is widely used to diagnose the condition of transformer oil–paper insulation. However, FDS measurements are highly temperature dependent. The master curve technique most common method remove effect on FDS, but reliability this largely dependent value activation energy, which can be affected by moisture content and thermal degradation degree. To understand effects these two factors at different temperatures were performed oil‐impregnated pressboards with...

Frequency domain dielectric spectroscopy (FDS) is a non‐destructive method widely used to evaluate the state of materials. Traditional FDS measurement conducted in frequency sweep mode between 1 kHz and mHz. However, this requires long time when sweeping low frequencies (1 mHz–1 Hz), thereby limiting its field applications. Hammerstein model selected as mathematical for insulation systems according known property established based on system identification theory. An equivalent fitting...

To determine thermal parameters of porous building materials for and energy analysis, an experimental study is presently carried out, which applies constant relative humidity controlled by the saturated salt-water solution under isothermal conditions. The principle vapor sorption discussed method temperature control proposed. Experiments are first performed using routine concrete, mortars, clay brick whose data widely existed in previous studies, to confirm present work. Insulation expanded...

For the oil-impregnated power transformers in service, condition of main insulation system is very important. This article reports a non-destructive evaluation technique based on time-frequency domain dielectric characteristics. First, polarization/depolarization current and frequency-domain spectroscopy were well measured under controlled laboratory conditions. Then, recovery voltage curves polarization also obtained by using conversion method between extended Debye model. After that,...

The root systems of vegetation significantly contribute to enhancing slope stability. shear strength soil–root is a crucial parameter for assessing This study focuses on six types in the Yellow River Basin China (woodland: Populus przewalskii and Broussonetia papyrifera; shrubland: Periploca sepium Ziziphus jujuba; grassland: Artemisia hedinii Setaria viridis), employing situ tests Wu–Waldron model (Wu model) investigate systems. results show that stress–displacement curves P. przewalskii,...

In modern power transmission and distribution systems, transformers are critical components their electrical properties together with service lives determined by the insulation property of oil-paper insulation. To better apply frequency domain spectroscopy technique to assess transformer condition, a series experiments were performed under controlled laboratory conditions. First, this article presents dielectric response measurement results samples different moisture contents aging states,...

Frequency domain spectroscopy (FDS) is employed to evaluate the moisture content and aging state of oil-paper insulation in power transformers. Oil-paper samples with different states were primarily prepared laboratory. A method was proposed based on a study influence frequency dielectric property insulation. This distinguishes FDS through imaginary part complex relative permittivity (εr″). Relevant characteristic parameters that characterize oil-impregnated pressboards also extracted....

Abstract The present article proposes an enhanced hybrid neural network model that combines variational mode decomposition (VMD) and genetic algorithm-backpropagation (GA-BP) to tackle the accurate prediction task of nonstationary nonlinear power demand data. In comparison existing methods, this study employs North Gallic Hawk Optimization (NGO) algorithm preliminarily ensure optimization number VMD modes, K penalty factor, α. Furthermore, it utilizes envelope entropy criterion determine...

With the fault of composite insulator, unidentified flashover occupies a considerable proportion, in which environment factor is more prominent. This paper addresses analysis wind tunnel test to simulate effect scrapping on studies influence extent different velocity and direction voltage insulator. At same time, researches mechanism under scrapping. In accordance with actual operation condition, whole divided into three type approval test: clean dry dirty conditions artificial pollution....