A new resistive current extraction method based on orthogonality between the capacitive and (COM) is presented. Orthogonality of metal-oxide surge arrester (MOSA) in low region proven. The MOSA can be obtained accurately, regardless harmonic voltage. Several algorithms include point-on-wave method, compensation analysis proposed are used to extract simulated voltage leakage signal, study influence model parameters, capacitance, integral harmonics, noninteger harmonics signal frequency...

To obtain the criterion of whether optical fiber composite overhead ground wire (OPGW) is iced and to estimate ice thickness, this letter establishes a three-dimensional temperature field model for OPGW under icing conditions validates it through experiments. Based on this, sine function used simulate time-varying ambient temperature, lag characteristics are discovered simulation also experiment. The concept phase difference in curves between proposed, relationships mean fluctuation...

To improve the accuracy of static contact angle measurement in silicone rubber aging experiments, a high accurate algorithm combination with circle fitting and ellipse is proposed. The influence water drop volume noise on calculation accuracies two algorithms are analyzed. results reveal that more suitable for images small angle. However, relatively large critical volumes different hydrophobicities obtained by algorithms. And it used to select which calculate angles proposed algorithm....

To improve the accuracy in calculation of dynamic contact angle for drops on inclined surface, a significant number numerical drop profiles surface with different inclination angles, volumes, and angles are generated based finite difference method, least-squares ellipse-fitting algorithm is used to calculate angle. The influences above three factors systematically investigated. results reveal that errors, including errors left right evaluated by tend increase angle/drop volume/contact If...

It is difficult to accurately measure internal temperature of power capacitor. To and external temperatures an operating capacitor, a capacitor measurement system based on fiber Bragg grating (FBG) sensors developed. First, technical parameters the optical sensing interrogator are determined according practical situations. Second, calibrated using highly accurate thermostatic bath, their reproducibility checked. Third, in combination with ENLIGHT software, FBG set up. Finally, three...

Brillouin frequency shift (BFS) is the most frequently used quantity in distributed fiber temperature and strain sensor. To estimate error measured strain, influences of signal-to-noise ratio, linewidth (Δ v <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sub> ), number sweeps, sweep span (coefficient) on BFS are systematically investigated based a large numerically generated spectra Lorentzian profile-based fitting algorithm. The results...

In this study, an error analysis is performed to study real water drop images and the corresponding numerically generated profiles for three widely used static contact angle algorithms: circle- ellipse-fitting algorithms axisymmetric shape analysis-profile (ADSA-P) algorithm. The results demonstrate accuracy of based on Laplace equation. A significant number with different volumes, angles, noise levels are generated, influences factors accuracies systematically investigated. reveal that...

Temperature field simulation for self-healing power capacitor makes sense to the optimization and improvement of capacitor's rated voltage capacity. On basis reasonable simplifications assumptions structure, a 3-D temperature numerical model is formulated in Fluent 15.0. The ambient set 55 °C, applied ac 400 V. distributions shell core are obtained. results reveal that 2 °C-3 °C higher than shell. highest locates on large side surface, surface small surface. To validate above simulation,...

To improve the accuracy of static contact angle measurement for corona aged silicone rubber, a algorithm based on least-squares circle fitting is presented, and model, optimization algorithm, determination initial values convergence criterion are introduced in systematic way at same time best selections given by systematical comparison. With regards to numerically generated water drop profiles images computation goniometry, θ/2 method, ADSA-P (axisymmetric shape analysis-profile) analyzed...

The static contact angle calculation for superhydrophobic surfaces is systematically investigated. water drop profiles with different volumes, angles, rotational angles and apex coordinates are numerically generated based on the Laplace equation. Thereafter, goniometry, θ /2 method, circle ellipse fitting algorithms an improved axisymmetric shape analysis‐profile (ADSA‐P) algorithm used to calculate angle. results reveal that errors by increase volume/contact goniometry will introduce...

The dynamic contact angle is an important method to evaluate the hydrophobicity of material. To improve accuracy measurement, validity ellipse fitting algorithm in application measurement analyzed. Water drop profiles with different volumes, angles and inclination are numerically generated based on Laplace equation finite difference at same time, used calculate angle. results reveal that significant error (/sp Gt/7°) may be difficult find. increases water volume. not suitable for case too...

Errors in the extracted key parameters directly influence errors temperature and strain measured by fiber Brillouin distributed sensors. Existing parameter extraction algorithms for gain spectra are mainly based on simplified models, therefore, may have significant errors. To ensure high accuracy different cases, consequently to measure with accuracy, a algorithm exact Voigt profile is proposed. The objective function proposed using least-squares method. Levenberg-Marquardt used minimize...

To improve the accuracy of static contact angle evaluation for blurry drop images, a large number water images are numerically generated or acquired by instrument/digital camera. Based on these applicability circle Hough transformation and fitting algorithms is systematically investigated compared. The results reveal that least‐squares algorithm particularly suitable clear such as instrument. digital influence error investigated. critical values corresponding to various volumes given, which...

The blur around the contact points significantly decreases evaluated static angle for superhydrophobic surface which is clearly presented in paper. To improve accuracy surface, an accurate algorithm, namely ADSA-PH (axisymmetric drop shape analysis-profile and height), proposed. It discards extracted edge close to makes use of residual height determine angle. errors caused by are reduced. classical ADSA-P modified selected-plane method proposed algorithm used evaluate results validate...