scholarly journals Quantitative Analysis of the Sensitivity of UHF Sensor Positions on a 420 kV Power Transformer Based on Electromagnetic Simulation

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 3 ◽  
Author(s):  
Chandra Prakash Beura ◽  
Michael Beltle ◽  
Stefan Tenbohlen ◽  
Martin Siegel
Keyword(s):  
Sensitivity Analysis ◽  
High Frequency ◽  
Continuous Monitoring ◽  
Power Transformer ◽  
Tank Wall ◽  
Realistic Situation ◽  
Three Phase ◽  
Signal Sensitivity ◽  
Sensitive Sensor ◽  
Sensor Positions

With an increasing interest in ultra-high frequency (UHF) partial discharge (PD) measurements for the continuous monitoring of power transformers, it is necessary to know where to place the UHF sensors on the tank wall. Placing a sensor in an area with many obstructions may lead to a decrease in sensitivity to the UHF signals. In this contribution, a previously validated simulation model of a three-phase 300 MVA, 420 kV power transformer is used to perform a sensitivity analysis to determine the most sensitive sensor positions on the tank wall when PD activity occurs inside the windings. A matrix of UHF sensors located on the transformer tank is used to perform the sensitivity analysis. Some of the windings are designed as layer windings, thus preventing the UHF signals from traveling through them and creating a realistic situation with very indirect propagation from source to sensor. Based on these findings, sensor configurations optimized for UHF signal sensitivity, which is also required for PD source localization, are recommended for localization purposes. Additionally, the propagation and attenuation of the UHF signals inside the windings and the tank are discussed in both oil and air.

A Simple Technique for Estimating the Winding Stray Capacitance of High-Frequency Three-Phase Common-Mode Inductors

2019 ◽  
Vol 139 (3) ◽  
pp. 339-347 ◽  
Author(s):  
Shotaro Takahashi ◽  
Satoshi Ogasawara ◽  
Masatsugu Takemoto ◽  
Koji Orikawa ◽  
Michio Tamate
Keyword(s):  
High Frequency ◽  
Simple Technique ◽  
Stray Capacitance ◽  
Common Mode ◽  
Three Phase

Resonant BLDC Motor Drive System for Medical Applications

2019 ◽  
Vol 14 ◽  
Author(s):  
C. Vidhya ◽  
V. Ravikumar ◽  
S. Muralidha
Keyword(s):  
High Frequency ◽  
Pulse Width Modulation ◽  
Power Converter ◽  
Low Power Consumption ◽  
Motor Drive ◽  
Medical Applications ◽  
Bldc Motor ◽  
Three Phase ◽  
High Frequency Ac ◽  
Motor Drive System

: The objective of this paper is to implement an ac link universal power converter controlled BLDC motor for medical applications. The ac link universal power converter is a soft switched high frequency ac link converter, created using the parallel combination of an inductor and a capacitor. The parallel ac link converter handle the ac voltages and currents with low reactive ratings at the link and offers improved power factor, low power consumption, more efficiency and less weight on comparison with the traditional dc link converter. Because of the high throughput, BLDC motors are preferred widely medical applications. A modulation technique called Space Vector Pulse Width Modulation (SVPWM) is used to generate the three phase power for the BLDC motors from the input DC supply. To validate the proposed system, simulations are performed in MATLAB – Simulink and an experimental prototype is constructed to supplement the simulation results.

scholarly journals Turn-to-Turn Fault Diagnosis on Three-Phase Power Transformer Using Hybrid Detection Algorithm

2021 ◽  
Vol 11 (6) ◽  
pp. 2608
Author(s):  
Chien-Hsun Liu ◽  
Willybrordus H. P. Muda ◽  
Cheng-Chien Kuo
Keyword(s):  
Fuzzy System ◽  
Power Transformer ◽  
Detection Algorithm ◽  
Current Response ◽  
Negative Sequence ◽  
Three Phase ◽  
Hybrid Detection ◽  
Incipient Faults ◽  
Increase In Accuracy ◽  
Negative Sequence Current

A power transformer (PT) in power generation or transmission is critical to maintaining electrical continuity. Fault detection on a PT is needed, especially of incipient faults, which are often caused by a turn-to-turn fault (TTF) before it develops into a more severe fault. We use a hybrid algorithm between conventional and modern techniques to detect a developing fault in a PT. The current response signals from a negative sequence current directional algorithm, extended park vector algorithm (EPVA), differential negative sequence current, and EPVA-fuzzy system are combined to distinguish the possibility of a TTF. The subalgorithms are combined using a hybrid detection algorithm to distinguish the faults. The model is a 10 MVA, three-phase PT with Δ-Y configuration 150/300 kV, simulated using MATLAB Simulink software. The results show that by combining the subalgorithms, several limitations are distinguished within the TTF with a slight increase in accuracy.

Electromagnetic Property of La0.7Sr0.3MnO3/Ag Composite at High Frequency

2015 ◽  
Vol 655 ◽  
pp. 182-185
Author(s):  
Ke Lan Yan ◽  
Run Hua Fan ◽  
Min Chen ◽  
Kai Sun ◽  
Xu Ai Wang ◽  
...  
Keyword(s):  
High Frequency ◽  
Single Phase ◽  
Low Frequency ◽  
Electromagnetic Property ◽  
High Frequency Range ◽  
Frequency Range ◽  
Free Electron Concentration ◽  
Theoretical Simulation ◽  
Electrical And Magnetic Properties ◽  
Three Phase

The phase structure, and electrical and magnetic properties of La0.7Sr0.3MnO3(LSMO)-xAg (xis the mole ratio,x=0, 0.3, 0.5) composite were investigated. It is found that the sample withx=0 is single phase; the samples withx=0.3 and 0.5 present three phase composite structure of the manganese oxide and Ag. With the increasing of Ag content, the grain size of the samples increases and the grain boundaries transition from fully faceted to partially faceted. The permittivity of spectrum (10 MHz - 1 GHz) and the theoretical simulation reveal that the plasma frequencyfpincrease with Ag content, due to the increasing of free electron concentration, which is further supported by the enhancement of conductivity. While for the permeability (μr'), theμr'decrease with the increasing of Ag content at low frequency range (f< 20 MHz), while at the relative high frequency range (f> 300 MHz), theμr'increased with Ag content. Therefore, the introduction of elemental Ag resulted in a higherμr'at the relative high frequency range.

Multipoint Fiber-Optic Hot-Spot Sensing Network Integrated Into High Power Transformer for Continuous Monitoring

2008 ◽  
Vol 8 (7) ◽  
pp. 1264-1267 ◽  
Author(s):  
A. B. Lobo Ribeiro ◽  
N. F. Eira ◽  
J. M. Sousa ◽  
P. T. Guerreiro ◽  
J. R. Salcedo
Keyword(s):  
High Power ◽  
Continuous Monitoring ◽  
Fiber Optic ◽  
Power Transformer ◽  
Hot Spot
Sign in / Sign up

Export Citation Format

Share Document