Modelling and Analysis of Capacitive Effects in a High Frequency Coaxial Transformer

2012 ◽  
Vol 466-467 ◽  
pp. 607-611
Author(s):  
Xiao Guang Yang

A new model is proposed for analyzing the capacitive effects in a newly developed high frequency coaxial transformer (HFCT). The proposed model can describe both the electric energy storage and common-mode (CM) electromagnetic interference (EMI) noise behaviors of a transformer, considering the voltage distribution in the HFCT windings. To determine the parameters of the model, a parasitic capacitance network is developed to describe the HFCT’s real winding’s structure, and the distributed parasitic capacitances of the network are evaluated using FEM based on the theory of capacitances in a multi-conductor system. The calculated inter-capacitance of the HFCT is in good agreement with the experimental results.

2018 ◽  
Vol 239 ◽  
pp. 01004
Author(s):  
Andrey Shatokhin ◽  
Alexandr Galkin

Increasing the efficiency of cargo transportation by rail is not only one of the main directions of the company JSC “Russian Railways” but also one of the main tasks of our country in order to achieve sustainable economic growth. Electric rolling stock is the largest consumer of electric energy in the company, that’s why its effective and failure-free operation is the way to solve the set tasks. The paper deals with studies related to the operation modes of a freight electric rolling stock of direct current for the purpose of determining the requirements for electric energy storage device, since it is the electric rolling stock that determines the daily schedule of electric load. The order of the analysis of experimental trips of freight electric locomotives of a direct current on the basis of cartridges of recorders of traffic parameters installed on the locomotive is determined. On the basis of the analysis of conducted trips, the main requirements for the energy storage device were obtained with a single running of electric DC rolling stock, namely the average duration of the operation modes of the electric locomotive, the maximum, minimum, and average values of voltage and current, the average value of the electric energy returned to the contact network, time of charge/discharge, and the useful energy intensity of the electric energy storage device. The studies were carried out with the support of the Russian Foundation for Basic Research for the project No 17-20-01148 ofi_m_RZD/17.


2017 ◽  
pp. 181-194
Author(s):  
Przemyslaw Komarnicki ◽  
Pio Lombardi ◽  
Zbigniew Styczynski

2021 ◽  
Vol 304 ◽  
pp. 117839
Author(s):  
Urbain Nzotcha ◽  
Jean Calvin Nsangou ◽  
Joseph Kenfack ◽  
Paul Salomon Ngohe-Ekam ◽  
Oumarou Hamandjoda ◽  
...  

Author(s):  
G. P. Ong ◽  
T. F. Fwa ◽  
J. Guo

Hydroplaning on wet pavement occurs when a vehicle reaches a critical speed and causes a loss of contact between its tires and the pavement surface. This paper presents the development of a three-dimensional finite volume model that simulates the hydroplaning phenomenon. The theoretical considerations of the flow simulation model are described. The simulation results are in good agreement with the experimental results in the literature and with those obtained by the well-known hydroplaning equation of the National Aeronautics and Space Administration (NASA). The tire pressure–hydroplaning speed relationship predicted by the model is found to match well the one obtained with the NASA hydroplaning equation. Analyses of the results of the present study indicate that pavement microtexture in the 0.2- to 0.5-mm range can delay hydroplaning (i.e., raise the speed at which hydroplaning occurs). The paper also shows that the NASA hydroplaning equation provides a conservative estimate of the hydroplaning speed. The analyses in the present study indicate that when the microtexture of the pavement is considered, the hydroplaning speed predicted by the proposed model deviates from the speed predicted by the smooth surface relationship represented by the NASA hydroplaning equation. The discrepancies in hydroplaning speed are about 1% for a 0.1-mm microtexture depth and 22% for a 0.5-mm microtexture depth. The validity of the proposed model was verified by a check of the computed friction coefficient against the experimental results reported in the literature for pavement surfaces with known microtexture depths.


Sign in / Sign up

Export Citation Format

Share Document