scholarly journals Controlled Switching of the T402 Transformer in the Križovany 400kV Substation

2010 ◽  
Vol 61 (1) ◽  
pp. 11-19
Author(s):  
František Janíček ◽  
Martin Mucha ◽  
Karol Česnek ◽  
Jozef Kováčik
Keyword(s):  
Control Unit ◽  
Simulation Software ◽  
Transient Phenomena ◽  
Controlled Switching ◽  
Transient Electromagnetic ◽  
Statistical Frequency

Controlled Switching of the T402 Transformer in the Križovany 400kV Substation The paper deals with simulating the circumstances of switching surge and trigger current at switching-in of the T402 autotransformer recently installed in Križovany, with the tests conducted by means of ATP (Alternative Transient Program) simulation software for simulating transient electromagnetic phenomena. The target has been to determine temporal curves for the most critical surge instances against earth and between the phases and the curves for trigger current with and without surge limiters connected, and to determine by means of simulations the size and statistical frequency of switching surges and based on a controlled switching simulation, to describe the elimination of transient phenomena during the process and in reference to the simulations and to operating manual for the PSD02 Siemens control unit, suggest the required configuration settings for the unit.

Impacts of Diverting Potential Difference on Armored Cables in Substations

2014 ◽  
Vol 986-987 ◽  
pp. 931-935
Author(s):  
Li Chen
Keyword(s):  
Dielectric Breakdown ◽  
Simulation Software ◽  
Potential Difference ◽  
Insulation Material ◽  
Grid Simulation ◽  
Transient Electromagnetic ◽  
Grounding Grid ◽  
Large Current ◽  
Electrical Tree ◽  
Grounding Grids

To reduce the interference on communication equipments caused by transient electromagnetic field of switching operation, the shields of cables are connected to grounding grid on both sides in the substations grounding designs. However, when the substation is stroke by lightning or shorted, the huge potential difference called diverting potential difference between the cable core and the shield is generated, which can easily destroy insulation of cables, even producing electrical tree or dielectric breakdown in insulation material. Moreover, the large current flowing through the shield of cables will cause personnel accidents and equipment damages. In this paper, the electric model of cables is established using grounding grid simulation software—CEDGS. The way diverting potential difference changes influenced by grounding grids, soil and other parameters is analyzed. Measures to reduce diverting potential difference are proposed for providing a theoretical basis of construction in practice.

Transient Electromagnetic Phenomena–Standardization and EMC Requirements–Mitigation Techniques

2018 ◽  
pp. 211-247
Author(s):  
Eleni P. Nicolopoulou ◽  
Panagiotis K. Papastamatis
Keyword(s):  
Design Procedure ◽  
Design Guidelines ◽  
International Standards ◽  
Space Application ◽  
Transient Phenomena ◽  
Spacecraft Charging ◽  
Transient Electromagnetic ◽  
Mitigation Techniques

In this chapter, the spacecraft charging effects that lead to ESD events, as well as the associated immunity testing required, are presented in detail and compared to the human-induced discharges, mainly simulated by most commercial ESD generators. Additionally, design guidelines for mitigating the effects of these ESD occurrences, essential for every space application designer, are discussed. Finally, the measurement requirements, as well as the test setups, regarding the immunity testing to power leads transients are described thoroughly. This chapter aims at reviewing the current international standards and the recent bibliography, summarizing and commenting on the EMC requirements, regarding the transient phenomena, pinpointing the differentiations of these standards and their effects on the design procedure and testing creditability.

scholarly journals Synchronous Study of Ferroresonance and Inrush Current Phenomena and their Related Reasons in Ground Power Networks

2010 ◽  
Vol 27 (1) ◽  
pp. 82-87 ◽  
Author(s):  
Amin Akrami ◽  
Mohammad Ghaderi ◽  
Saeed Ghadi
Keyword(s):  
Power Transformers ◽  
Inrush Current ◽  
Power Networks ◽  
Transient Phenomena ◽  
Controlled Switching ◽  
Inrush Currents ◽  
Very High ◽  
Inductive Reactance

Synchronous Study of Ferroresonance and Inrush Current Phenomena and their Related Reasons in Ground Power NetworksEnergizing the power transformers usually results in flowing very high inrush currents. This harmful current can be minimized using controlled switching and considering the value of residual flux. But nowadays, developing the ground power networks results in high increment of ferroresonance phenomenon occurrence due to the line' capacitance reactance and nonlinear inductive reactance of power transformer's core. In this study, these transient phenomena and their cause have studied synchronously.

The Control and Simulation of Plug-In Parallel Hybrid Electrical City Bus

2013 ◽  
Vol 278-280 ◽  
pp. 1631-1634
Author(s):  
Yun Yun Yang ◽  
Sen Wu ◽  
Zheng Ce Cao
Keyword(s):  
Fuel Economy ◽  
Simulation Analysis ◽  
Control Unit ◽  
Simulation Software ◽  
State Of Charge ◽  
City Bus ◽  
Parallel Hybrid ◽  
Electrical Vehicle ◽  
Battery State Of Charge ◽  
Two Parameter

Take the Plug-in Parallel Hybrid Electrical Vehicle as research object, matching with the parameter of its power system. Then designs a two—parameter fuzzy control unit for torque split between engine and electric motor. The input parameters are the torque needs of the drive system and the battery State Of Charge. Doing the simulation analysis in the simulation software ADVISOR, the results show that the control strategy has improved the dynamic property and fuel economy of the vehicle effectively.

The velocity regulation of power consumption with traffic lights for electric vehicles

2019 ◽  
Vol 233 (9) ◽  
pp. 2312-2322
Author(s):  
Qingwu Liu ◽  
Hongwen He
Keyword(s):  
Power Consumption ◽  
Travel Time ◽  
Electricity Consumption ◽  
Control Unit ◽  
Simulation Software ◽  
Traffic Information ◽  
Level Control ◽  
Long Distance ◽  
Traffic Lights ◽  
Traffic Conditions

Traffic conditions, especially at traffic crossings, have a great impact on the power consumption of vehicles. Regulating velocity using the information between vehicles and traffic systems can decrease the power consumption. This article mainly focuses on an electric vehicle equipped with radar sensors, which can get the traffic information from upto a 100-m-long distance between the controlled vehicle and the traffic lights. Using the information gathered from sensors, the top-level control unit regulates the velocity aiming at lower power consumption. When traveling through crossings, two different traffic conditions are discussed. For the first condition, no other vehicles run between the controlled vehicle and the traffic lights. Only the traffic lights information is considered. For the second condition, the controlled vehicle follows other vehicles to go through the crossing. The information of the nearest front vehicle and traffic lights is taken into consideration. In summary, the traffic lights information, including the controlled vehicle current state, the traffic lights remaining time, and the velocity and distance of the nearest former vehicle (for the second condition) are sent to the top-level control unit. Then, the control unit calculates a velocity list, which will be sent to the vehicle control unit. A simulation is conducted using a traffic simulation software named “Simulation of Urban Mobility” to verify the algorithm. The simulation results indicate that the energy efficiency is improved. For the first condition, the travel time is reduced by 8.27%, and the power consumption is reduced by 18.7%. For the second condition, the power consumption is reduced by 2.96%. Finally, for a 5.8-km driving cycle containing both conditions, the travel time is reduced by 6.9% and electricity consumption is reduced by 9.51%.

scholarly journals Research on Characteristic Recognition and Dangerous Prevention While Mining through Collapse Column of Pansan Minefield,China

2021 ◽  
Author(s):  
Haitao Xu ◽  
hui yang ◽  
Wenbin Sun ◽  
Lingjun Kong ◽  
Peng Zhang
Keyword(s):  
Coal Seam ◽  
Water Inrush ◽  
Coal Pillar ◽  
Simulation Software ◽  
Coal Seams ◽  
Transient Electromagnetic ◽  
Working Face ◽  
Electromagnetic Detection ◽  
Floor Failure ◽  
Collapse Column

Abstract In order to find out the characteristics of geological isomer exposed in the mining process of 12318 working face in Pansan Mine and grasp its influence law on subsequent coal seams mining, the isomer was firstly determined as the collapse column by means of 3D seismic, transient electromagnetic detection, SYT detection and other methods, and its development characteristics, conductivity and water enrichment were identified.Then FLAC3D numerical simulation software was used to analyze the characteristics of vertical stress and plastic failure zone in different coal seams during mining.Finally, by comparing the ultimate failure depth of floor and the thickness of waterproof layer in the process of each coal seam directly pushing through the collapse column, the risk of water inrush and the prevention are analyzed.The results show that the exposed geological isomer is characterized by weak water-rich collapse column.Under the influence of the mining of the previous coal seam and the activation of the collapse column, the subsequent coal seam is in the low stress area before mining, which increases the floor failure and causes the activation of the collapse column more easily during mining.Coal 5# and 4# can be directly pushed through the collapse column, and coal pillar of sufficient width should be left for coal 1# to prevent the collapse column from activating water inrush.

Electromagnetic Transients

2021 ◽  
pp. 226-263
Author(s):  
Eleni P. Nicolopoulou ◽  
Panagiotis K. Papastamatis ◽  
Ioannis F. Gonos
Keyword(s):  
Standardized Testing ◽  
Design Guidelines ◽  
International Standards ◽  
Electromagnetic Transients ◽  
Space Systems ◽  
Transient Phenomena ◽  
Testing Procedures ◽  
Physical Mechanisms ◽  
Transient Electromagnetic ◽  
Electromagnetic Disturbances

This chapter aims at presenting the current international standards and the recent bibliography regarding the transient phenomena associated with space systems, with emphasis on the EMC requirements. The first section of the chapter focuses on the description of the physical mechanisms causing transient electromagnetic phenomena in space. The second section reviews the procedures proposed for testing the immunity of space equipment against these transients, as described in the current space standards and in recent bibliography as non-standardized testing procedures. Finally, the last section investigates possible mitigation approaches and design guidelines against these electromagnetic disturbances, essential for every space system designer.

scholarly journals Research on Simplified Model of AC/DC Hybrid Microgrid for Fault Analysis

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 358 ◽  
Author(s):  
Tianliang Yao ◽  
Zhiwei Li ◽  
Jiping Qu ◽  
Zhaoxiong Li ◽  
Qi Zhao ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Power Flow ◽  
Simulation Software ◽  
Fault Analysis ◽  
Simplified Model ◽  
Power Electronic ◽  
Acceptable Error ◽  
Electromagnetic Transient ◽  
Hybrid Microgrid ◽  
Transient Electromagnetic

The AC/DC hybrid microgrid, which takes into account the access requirements of AC and DC sources and loads, optimizes the structure of traditional distribution networks. The application of power electronic transformers as the core of its energy management, with electrical isolation and accurate control of the voltage, current and power flow by the control system, enables the microgrid to achieve a more flexible and stable transmission mode. Because the power electronic transformer combines the power electronic device and the high-frequency transformer, its frequent switching causes the electromagnetic transient simulation to take too long. Therefore, by simplifying control loops and converters, this paper proposes a simplified model for the microgrid system power flow and the dynamic response under exposure to a fault. The mathematical model equivalent simplification method is used in this paper. This method is concise and efficient and does not rely on the performance of a computer or change the program algorithm of the software. The simplified model was built based on PSCAD (Power System Computer Aided Design) simulation software and was carried out under short circuit fault conditions to verify its validity. The comparison of the simulation’s time consumption and accuracy shows that model simplification can significantly improve the simulation speed, with an acceptable error rate, and its dynamic response maintains good consistency with that of the detailed electromagnetic transient model. Therefore, it can be applied to the transient electromagnetic simulation fault analysis of the AC/DC hybrid microgrid.

Design of Transient Electromagnetic Signal Acquisition System Based on FPGA

2014 ◽  
Vol 602-605 ◽  
pp. 2184-2187 ◽  
Author(s):  
Bo Peng ◽  
Guang Min Sun ◽  
De Qun Zhao
Keyword(s):  
Real Time ◽  
Data Storage ◽  
Dynamic Range ◽  
Control Unit ◽  
Acquisition System ◽  
Electromagnetic Signal ◽  
Signal Acquisition ◽  
Dual Channel ◽  
Transient Electromagnetic ◽  
Field Programmable

An acquisition system applying in transient electromagnetic method (TEM) receiver has been designed in this paper. The accuracy of acquisition has been improved by using a floating-point A/D with high input dynamic range, which is composed of programmable gain amplifiers (PGA) and a dual-channel 16 bit resolution ADC. The real-time performance can be ensured by using a field-programmable gate arrays (FPGA) as the main control unit to control ADC, PGA, data storage and communication interface. By integrating a soft core CPU, Nios II, in FPGA, the complexity of circuit design was decreased, and the work efficiency of system was improved. This system, which has good performance of real-time and high integration level, can meet the needs of TEM signal acquisition.

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