Efficiency of direct current catenary distance protection with adaptation to traction mode

2020 ◽  
pp. 100-103
Author(s):  
Ermek Kenzhebulatovich Khusainov ◽  
◽  
Yuriy Vladimirovich Kondratyev ◽  
Keyword(s):  
Direct Current ◽  
Peak Power ◽  
Total Efficiency ◽  
Distance Protection ◽  
External Characteristic ◽  
Traction Substation ◽  
Operating Current ◽  
Traction Substations ◽  
Maximal Peak

The paper considers efficiency of distance protection with adaptation to rectifier converters of traction substations with different number of pulsations. The authors have revealed the influence of inclination of the external characteristic of rectifier converters on total efficiency of protection. They have also introduced notions for indicators of efficiency of distance protection with adaptation: сoefficient that determines the increase ratio of peak operating current; coefficient that determines the decrease ratio of minimal voltage on traction substation buses; coefficient that determines the increase ratio of maximal peak power of catenary feeder realized by 3.3 kV direct current. The paper presents methods of their calculation.

Method of selecting main parameters of smoothing devices for railway DC substation

2020 ◽  
pp. 80-85
Author(s):  
Mikhail Mikhaylovich Nikiforov ◽  
◽  
Yuriy Vladimirovich Kondratyev ◽  
Ruslan Borisovich Skokov ◽  
Roman Vladimirovich Sergeev ◽  
...  
Keyword(s):  
Initial Data ◽  
State Standard ◽  
Direct Current ◽  
Traction Substation ◽  
Connection Line ◽  
Traction Substations

The paper presents main clauses of a method for selecting main parameters of smoothing devices for railway direct current traction substation, which are intended for developing a state standard. The authors have created a list of required initial data for selecting parameters of smoothing devices. For each type of the connection line the authors have proposed optimal types of smoothing devices with the consideration for characteristics of direct current traction substations. As a result, they have determined the order of calculation of the main parameters of the smoothing device.

scholarly journals Fault-Tolerant Control in a Peak-Power Reduction System of a Traction Substation with Multi-String Battery Energy Storage System

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4565
Author(s):  
Marcin Szott ◽  
Marcin Jarnut ◽  
Jacek Kaniewski ◽  
Łukasz Pilimon ◽  
Szymon Wermiński
Keyword(s):  
Energy Storage ◽  
Peak Power ◽  
Fault Tolerant ◽  
Storage System ◽  
Energy Storage System ◽  
Power Reduction ◽  
Battery Energy Storage System ◽  
Battery Energy Storage ◽  
Traction Substation ◽  
Battery Energy

This paper introduces the concept of fault-tolerant control (FTC) of a multi-string battery energy storage system (BESS) in the dynamic reduction system of a traction substation load (DROPT). The major task of such a system is to reduce the maximum demand for contracted peak power, averaged for 15 min. The proposed concept, based on a multi-task control algorithm, takes into account: a three-threshold power limitation of the traction substation, two-level reduction of available power of a BESS and a multi-string structure of a BESS. It ensures the continuity of the maximum peak power demand at the contracted level even in the case of damage or disconnection of at least one chain of cells of the battery energy storage (BES) or at least one converter of the power conversion system (PCS). The proposed control strategy has been tested in a model of the system for dynamic reduction of traction substation load with a rated power of 5.5 MW. Two different BESS implementations have been proposed and several possible cases of failure of operations have been investigated. The simulation results have shown that the implementation of a multi-string BESS and an appropriate control algorithm (FTC) may allow for maintenance of the major assumption of DROPT, which is demanded power reduction (from 3.1 MW to 0.75 MW), even with a reduction of the BESS available power by at least 25% and more in the even in fault cases.

scholarly journals Investigation of changes in the characteristics of LED matrices of the on-board luminaire during tests in the electrocycling mode.

2021 ◽  
Author(s):  
I.V. Frolov ◽  
◽  
V.A. Sergeev ◽  
A.M. Hodakov ◽  
S.A. Zaytsev ◽  
...  
Keyword(s):  
Leakage Current ◽  
Direct Current ◽  
Coefficient Of Variation ◽  
Convection Heat Transfer ◽  
Voltage Range ◽  
The Matrix ◽  
Operating Current ◽  
In Series ◽  
The Difference ◽  
A Current

The paper presents the results of studies of changes in the characteristics of LED COB matrices of the GW P9LR31.EM - DURIS S 8 type as part of a LED luminaire when tested under the direct current in a continuous mode and in an electrocycling mode. The arrays consist of eight InGaN/GaN LED dies connected in series, coated with a phosphor. Calculation in the Comsol Multiphtsics environment of the temperature field of the luminaire at the rated operating current and free convection heat transfer showed that the maximum overheating of the matrices does not exceed 46 K, and the difference in their temperatures is 2 K. At the same time, the experimental values of the thermal resistances of the matrices of a real lamp vary from 42 to 58 K/W. Before testing, the I-V characteristics of the matrices differ markedly in the level of leakage current in the voltage range from 14 V to 19 V, and the LEDs in the luminaire matrices have a significant spread in the brightness of emission in the microcurrent mode. The degree of this scatter within each matrix was estimated by measuring the luminescence brightness of each die of the matrix and calculating the coefficient of variation γ. It was found that the coefficient of variation of the emission brightness of the COB matrix dies measured at a current of 100 nA strongly correlates with the leakage current. When testing a luminaire under the direct current, the most significant changes in the electrophysical and optical characteristics of COB matrices are observed in the range of microcurrents: the distribution of the emission brightness of the matrix dies at a current of 100 nA becomes more uniform. The greatest changes in matrix characteristics were observed after the first 700 hours of testing, that is, at the running-in stage. At the same time, no correlation was found between the degree of change in the characteristics of the matrices during tests and their thermal resistances.

scholarly journals Stationary energy storage system in a 3 kV DC – the conception comparison

2018 ◽  
Vol 180 ◽  
pp. 02013
Author(s):  
Włodzimierz Jefimowski
Keyword(s):  
Energy Storage ◽  
Peak Power ◽  
Storage System ◽  
Energy Storage System ◽  
Energy Utilization ◽  
Power Demand ◽  
Dc System ◽  
Traction Substation ◽  
Stationary Energy ◽  
Regenerative Energy

The paper presents the research results of a few different conception of stationary energy storage system in a 3 kV DC system. The most attention is focused on the comparison between two topologies of the ESS: energy storage system with supercapacitor and with supercapacitor and LFP battery. The variants are compared in terms of energy saving and peak power demand reduction. The implementation of ESS with SC results the decrease of active energy drawn from traction substation. Meanwhile the implementation of ESS with SC and LFP battery leads to achieving of two aims - decreasing of active energy consumption by maximization of regenerative energy utilization and reduction of 15 - min. peak power demand of traction substation.

scholarly journals Self-compression at 1 µm wavelength in all-bulk multi-pass geometry

2020 ◽  
Vol 126 (10) ◽  
Author(s):  
Sebastian Gröbmeyer ◽  
Kilian Fritsch ◽  
Benedikt Schneider ◽  
Markus Poetzlberger ◽  
Vladimir Pervak ◽  
...  
Keyword(s):  
Pulse Energy ◽  
Peak Power ◽  
Pulse Compression ◽  
Near Infrared ◽  
Average Power ◽  
High Peak Power ◽  
Total Efficiency ◽  
Highly Nonlinear ◽  
Infrared Spectral ◽  
Temporal Compression

Abstract We present directly oscillator-driven self-compression inside an all-bulk Herriott-type multi-pass cell in the near-infrared spectral range. By utilizing precise dispersion management of the multi-pass cell mirrors, we achieve pulse compression from 300 fs down to 31 fs at 11 µJ pulse energy and 119 W average power with a total efficiency exceeding 85%. This corresponds to an increase in peak power by more than a factor of three and a temporal compression by almost a factor of ten in a single broadening stage without necessitating subsequent dispersive optics for temporal compression. The concept is scalable towards millijoule pulse energies and can be implemented in visible, near-infrared and infrared spectral ranges. Importantly, it paves a way towards exploiting Raman soliton self-frequency shifting, supercontinuum generation and other highly nonlinear effects at unprecedented high peak power and pulse energy levels.

Modeling of direct current traction power system with the consideration for earth conductivity

2020 ◽  
pp. 75-79
Author(s):  
Dmitriy Valentinovich Lesnikov ◽  
Keyword(s):  
Mathematical Model ◽  
Power System ◽  
Direct Current ◽  
Skin Resistance ◽  
Railway Network ◽  
Traction Power Supply System ◽  
Traction Substations ◽  
Traction Power Supply ◽  
Earth Conductivity ◽  
Traction Power

Nowadays, one of the main tasks facing the JSC Russian Railways is the increase of volumes of freight transportation. The solution of this task is directly connected with the increase of the load on traction power system devices and their strengthening, which is primarily related to railways electrified with direct current that are characterized by high traction currents. In order to assess the possibility to strengthen a railway section and reveal «bottlenecks» in traction power supply system it is necessary to create a mathematical model of traction power system that must consider parameters of a specific section including earth conductivity that affects the values of skin resistance, potential of railway network and stray currents. The paper proposes a mathematical model of direct current traction power system that represents a combination of a catenary model and a model of railway network. The model considers parameters of traction substations, connection scheme of catenary suspensions and possible influence of rails from adjacent tracks on each other.

Application of current limiting device based on high-temperature superconductivity for direct current traction substations

2019 ◽  
pp. 74-79
Author(s):  
Alexey Leonidovich Kashtanov ◽  
◽  
Mikhail Mikhaylovich Nikiforov ◽  
Darya Alexandrovna Gorbunova ◽  
Mariya Gennadyevna Medovik ◽  
...  
Keyword(s):  
High Temperature ◽  
Direct Current ◽  
High Temperature Superconductivity ◽  
Current Limiting ◽  
Traction Substations

scholarly journals Analysis of rail potential and stray current in MVDC railway electrification system

2021 ◽  
Author(s):  
Salman Aatif ◽  
Haitao Hu ◽  
Fezan Rafiq ◽  
Zhengyou He
Keyword(s):  
Quantitative Analysis ◽  
Simulation Model ◽  
Direct Current ◽  
High Speed ◽  
Safe Distance ◽  
Stray Current ◽  
Long Distance ◽  
Medium Voltage ◽  
Traction Substations ◽  
Train Loading

AbstractIn contrast to the conventional direct current railway electrification system (DC-RES), the medium voltage direct current (MVDC)-RES is considered promising for long-distance high-speed corridors. In the MVDC-RES, traction substations (TSSs) are placed much farther and train loads are much heavier than in the conventional DC-RES. Hence, the MVDC-RES brings a drastic change in catenary voltage, TSS spacing, and train loading, which affects rail potential and stray current. In this connection, this work performs some significant quantitative analysis of rail potential and stray current in the MVDC-RES environment. An MVDC simulation model is proposed and different grounding schemes are analyzed for a single-train and two TSSs scenario as well as for a multi-train multi-TSS scenario. According to the simulation and analysis, the maximum values of rail potential and stray current at MVDC-RES distances and the maximum safe distance between adjacent TSSs are determined.

Assessment of performance reliability of transformers

Innotrans ◽  
2020 ◽  
pp. 50-53
Author(s):  
Alexander V. Okunev ◽  
◽  
Anastasia A. Ivanova ◽  
Alexander A. Philipiev ◽  
◽  
...  
Keyword(s):  
Calculation Model ◽  
Rolling Stock ◽  
Equipment Failure ◽  
Voltage Level ◽  
Traction Substation ◽  
Freight Traffic ◽  
Electric Rolling Stock ◽  
Traction Substations ◽  
Electrical Apparatus

Increase of freight traffic resulted in increased loads on traction substations and, respectively, in increase of their equipment failure risks. In the context of maintaining the required voltage level and power quality, which determine appropriate values in reliability for traction substation transformers, the article looks upon solving the problem of determination of reliability essential parameters. A proposed calculation model makes it possible to simplify the choice of electrical apparatus for uninterrupted power supply of electric rolling stock traction.

scholarly journals The laser beamline in SULF facility

2020 ◽  
Vol 8 ◽  
Author(s):  
Zongxin Zhang ◽  
Fenxiang Wu ◽  
Jiabing Hu ◽  
Xiaojun Yang ◽  
Jiayan Gui ◽  
...  
Keyword(s):  
Peak Power ◽  
Contrast Ratio ◽  
Laser Pulses ◽  
Stable Operation ◽  
Chirped Pulse ◽  
Peak Intensity ◽  
Laser Facility ◽  
Chirped Pulse Amplification ◽  
Maximal Peak ◽  
Laser Condition

In this paper, we report the recent progress on the $1~\text{PW}/0.1~\text{Hz}$ laser beamline of Shanghai Superintense Ultrafast Laser Facility (SULF). The SULF-1 PW laser beamline is based on the double chirped pulse amplification (CPA) scheme, which can generate laser pulses of 50.8 J at 0.1 Hz after the final amplifier; the shot-to-shot energy fluctuation of the amplified pulse is as low as 1.2% (std). After compression, the pulse duration of 29.6 fs is achieved, which can support a maximal peak power of 1 PW. The contrast ratio at $-80~\text{ps}$ before main pulse is measured to be $2.5\times 10^{-11}$ . The focused peak intensity is improved by optimizing the angular dispersion in the grating compressor. The maximal focused peak intensity can reach $2.7\times 10^{19}~\text{W}/\text{cm}^{2}$ even with an $f/26.5$ off-axis parabolic mirror. The horizontal and vertical angular pointing fluctuations in 1 h are measured to be 1.89 and $2.45~\unicode[STIX]{x03BC}\text{rad}$ , respectively. The moderate repetition rate and the good stability are desirable characteristics for laser–matter interactions. The SULF-1 PW laser beamline is now in the phase of commissioning, and preliminary experiments of particle acceleration and secondary radiation under 300–400 TW/0.1 Hz laser condition have been implemented. The progress on the experiments and the daily stable operation of the laser demonstrate the availability of the SULF-1 PW beamline.

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