Application of numerical modelling for assessing electric and thermal operation modes of direct current catenary elements

2020 ◽  
pp. 90-93
Author(s):  
Andrey Borisovich Batrashov ◽  
◽  
Natalya Vladimirovna Gushhina ◽  
Keyword(s):  
Numerical Modelling ◽  
Direct Current ◽  
Thermal Characteristics ◽  
Thermal Loads ◽  
Main Principle ◽  
Thermal Operation ◽  
Operation Conditions ◽  
Operation Modes ◽  
Digital Copy

The paper proposes a method for assessing electric and thermal operation modes of direct current catenary elements that allows determining electric and thermal loads in operation conditions. The main principle is the determination of the most loaded section in the intersubstational zone and calculation of electric and thermal characteristics in conditions of real train schedule. The method is assumed to be used at digitalization of railways as a digital copy of direct current catenary.

scholarly journals Analysis of Subsynchronous Torsional of Wind–Thermal Bundled System Transmitted via HVDC Based on Signal Injection Method

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 474
Author(s):  
Junxi Wang ◽  
Qi Jia ◽  
Gangui Yan ◽  
Kan Liu ◽  
Dan Wang
Keyword(s):  
Wind Power ◽  
High Voltage ◽  
Direct Current ◽  
Computer Aided Design ◽  
Large Scale ◽  
Electromagnetic Transients ◽  
Torsional Mode ◽  
High Voltage Direct Current ◽  
Operation Conditions ◽  
Signal Injection

With the development of large-scale new energy, the wind–thermal bundled system transmitted via high-voltage direct current (HVDC) has become the main method to solve the problem of wind power consumption. At the same time, the problem of subsynchronous oscillation among wind power generators, high-voltage direct current (HVDC), and synchronous generators (SGs) has become increasingly prominent. According to the dynamic interaction among doubly fed induction generators (DFIGs), HVDC, and SGs, a linearization model of DFIGs and SGs transmitted via HVDC is established, and the influence of the electromagnetic transient of wind turbines and HVDC on the electromechanical transient processes of SGs is studied. Using the method of additional excitation signal injection, the influence of the main factors of DFIG on the damping characteristics of each torsional mode of SG is analyzed, including control parameters and operation conditions when the capacity of HVDC is fixed. The mechanism of the negative damping torsional of SGs is identified. A time-domain simulation model is built in Electromagnetic Transients including DC/Power Systems Computer Aided Design (EMTDC/PSCAD) to verify the correctness and effectiveness of the theoretical analysis.

Determination of Dipole Spacing in Electrical Landfill Leakage Detection

2010 ◽  
Vol 171-172 ◽  
pp. 171-174
Author(s):  
Hong Cheng ◽  
Peng Kun Liu ◽  
Yu Ling Wang ◽  
Chang Xin Nai
Keyword(s):  
High Voltage ◽  
Direct Current ◽  
Current Method ◽  
Leakage Detection ◽  
High Voltage Direct Current ◽  
The Impact

The dipole spacing can directly affects the detecting sensitivity and accuracy in the landfill leakage detection by the high voltage direct current method. Based on the high voltage DC detecting model, the impact of dipole spacing on locating leaks is analyzed taking a single leak and multiple leaks as example. The results show that the greater the dipole spacing is, the higher the detecting sensitivity is; the smaller the dipole spacing is, the higher the detecting accuracy is. For multiple leaks, only one leak can be located when the dipole spacing is greater than the distance between the two leaks. In order to detect all leaks correctly, the dipole spacing should be smaller than the distance between the two leaks.

scholarly journals Locomotive operation mode - the basis for developing the requirements for the energy storage device on railway transport

2018 ◽  
Vol 239 ◽  
pp. 01004
Author(s):  
Andrey Shatokhin ◽  
Alexandr Galkin
Keyword(s):  
Energy Storage ◽  
Direct Current ◽  
Electric Energy ◽  
Rolling Stock ◽  
Storage Device ◽  
Contact Network ◽  
Energy Storage Device ◽  
Electric Energy Storage ◽  
Operation Modes ◽  
Electric Rolling Stock

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.

scholarly journals Determination Of Thermal Parameters Of Solar Water Heating Collectors Using The “Dark” Testing Method

2020 ◽  
Vol 02 (11) ◽  
pp. 62-67
Author(s):  
Nizomjon Orifovich Usmonov ◽  
◽  
Xayrulla Sunnatullaevich Isakhojaev ◽  
Saodat Rakhsulaevna Akhmatova ◽  
Feruza Abdullaevna Khoshimova ◽  
...  
Keyword(s):  
Thermal Characteristics ◽  
Hot Water ◽  
Thermal Testing ◽  
Water Heating ◽  
Solar Water Heating ◽  
Solar Water ◽  
Testing Method ◽  
Hot Water Supply ◽  
Hot Water Supply System

In the production of flat solar water heating collectors, thermal testing occupies a special place, the purpose of which is to determine their thermal characteristics experimentally. The corresponding approximation expressions are proposed for determining the coefficient of heat loss, inclined to the horizon at an angle of 300 for the average conditions of their operation in the hot water supply system

scholarly journals CURRENT COLLAPSE MEASUREMENTS IN PULSED GAN TRANSISTORS

2020 ◽  
Vol 259 (4) ◽  
pp. 12-18
Author(s):  
I. M. Abolduev ◽  
N. V. Alkeev ◽  
V. S. Belyaev ◽  
E. V. Kaevitser ◽  
I. D. Kashlakov
Keyword(s):  
Initial Data ◽  
Technological Process ◽  
Semiconductor Device ◽  
Thermal Characteristics ◽  
Gan Hemt ◽  
Current Collapse ◽  
Operation Modes ◽  
Current Voltage ◽  
And Behavior ◽  
Insight Into

The article discusses the issues of design and methodology related to the current-voltage (I-V) characteristics of a GaN HEMT. Reliable I-V characteristics show the operability of a semiconductor device, provide initial data for functional application of the device, and provide insight into the quality and reproducibility of the technological process. The type and behavior of I–V characteristics are influenced by the design and technological features of a GaN HEMT. Measurements of I-V characteristics in continuous and pulsed operation modes provide more details about the electrical and thermal characteristics of the devices under study.

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