scholarly journals Automatic Identification and Importance Evaluation Technology of Power Transmission Section

2020 ◽  
Vol 213 ◽  
pp. 03036
Author(s):  
Yixuan Weng ◽  
Weizhe Ma ◽  
EnYan Xie ◽  
Hui Qi ◽  
Zhenxing Liu ◽  
...  
Keyword(s):  
Cross Section ◽  
Transmission Lines ◽  
Power Flow ◽  
Power Transmission ◽  
Power Grid ◽  
Stability Limit ◽  
Stability Margin ◽  
Automatic Identification ◽  
Flow State ◽  
The Impact

In theory, the cross section is the minimum cut set in the network. For the actual power grid, the transmission cross section is a collection of transmission lines between different regions, which is mainly used for power transmission to achieve the purpose of generating load balance. In this paper, a power grid zoning algorithm is proposed based on the topological structure characteristics and current operation state of the power grid, and the key transmission sections can be directly obtained without depending on the calculation of safety and stability margin. A practical system state partition model and key section sorting method are introduced, and a set of automatic identification method flow of key transmission sections of the system is established by searching for electrical betweenness. The importance of the transmission section is quantitatively evaluated from three angles: the margin from the stability limit, the hub position in the current power flow state, and the impact on the power grid after the power cut-off. The evaluation results can be used as a Reference for decision-making in the planning and reconstruction of the transmission section, safety monitoring, protection configuration, etc.

scholarly journals STUDY ON EFFECT OF UPFC DEVICE IN ELECTRICAL TRANSMISSION SYSTEM: POWER FLOW ASSESSMENT

2013 ◽  
pp. 70-74
Author(s):  
CH. CHENGAIAH ◽  
R.V.S. SATYANARAYANA ◽  
G.V. MARUTHESWAR MARUTHESWAR
Keyword(s):  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Power Transmission ◽  
Stability Limit ◽  
Transmission System ◽  
Real Time Control ◽  
Electrical Transmission ◽  
Transmission Systems ◽  
Time Control

The power transfer capability of electric transmission lines are usually limited by large signals ability. Economic factors such as the high cost of long lines and revenue from the delivery of additional power gives strong intensive to explore all economically and technically feasible means of raising the stability limit. On the other hand, the development of effective ways to use transmission systems at their maximum thermal capability. Fast progression in the field of power electronics has already started to influence the power industry. This is one direct out come of the concept of FACTS aspects, which has become feasible due to the improvement realized in power electronic devices in principle the FACTS devices should provide fast control of active and reactive power through a transmission line. The UPFC is a member of the FACTS family with very attractive features. This device can independently control many parameters. This device offers an alternative mean to mitigate transmission system oscillations. It is an important question is the selection of the input signals and the adopted control strategy for this device in order to damp power oscillations in an effective and robust manner. The UPFC parameters can be controlled in order to achieve the maximal desire effect in solving first swing stability problem. This problem appears for bulky power transmission systems with long transmission lines. In this paper a MATLAB Simulink Model is considered with UPFC device to evaluate the performance of Electrical Transmission System of 22 kV and 33kV lines. In the simulation study, the UPFC facilitates the real time control and dynamic compensation of AC transmission system. The dynamic simulation is carried out in conjunction with the N-R power flow solution sequence. The updated voltages at each N-R iterative step are interpreted as dynamic variables. The relevant variables are input to the UPFC controllers.

The Comparative Study on Influence on the Northeast China UHV Planning Power Grid Induced by Different Kind Geomagnetic Storms

2013 ◽  
Vol 330 ◽  
pp. 143-148
Author(s):  
Yan Cheng ◽  
Kai Rang Wang ◽  
Shu Min Sun ◽  
Hai Yang Ge ◽  
Guang Lei Li
Keyword(s):  
High Voltage ◽  
Transmission Lines ◽  
Power Flow ◽  
Geomagnetic Storms ◽  
Evaluation Model ◽  
Timing Analysis ◽  
Power Grid ◽  
Long Distance ◽  
The Impact ◽  
Ultra High Voltage

Along with the UHV construction scheme, China will form a large number of transmission lines which have the characteristics of the ultra-high voltage, large-capacity, long-distance. Because the UHV power grid transmission line parameters and the structure of the grid and the transformer are different from the other power net, Geomagnetic storms will affect the UHV power grid more, the work have important significance to the assessment of the ultra-high voltage power grid level and influence. The impact of different storms on the grid are also different .Based on the power flow mechanism of the GIC, different data and network parameters of geomagnetic storms, the evaluation model of the GIC is established ,we assess the result of the GIC induced by the geomagnetic storms happened on November 2004 and December 2006 in the 2020 planning ultra-high voltage power grid, find out the greatest impact transformer substation and the timing analysis results of the grid compare the different impact of different storm.. The comparison of the analysis results is helpful for understanding the different kind geomagnetic storms and the regional features of GIC.

New aspects of power grid facilities personnel workplaces electromagnetic environment

2020 ◽  
Vol 60 (9) ◽  
pp. 569-574
Author(s):  
Nina B. Rubtsova ◽  
Sergey Yu. Perov ◽  
Olga V. Belaya ◽  
Tatiana A. Konshina
Keyword(s):  
Transmission Lines ◽  
Power Transmission ◽  
Power Grid ◽  
Spectral Characteristics ◽  
Ground Level ◽  
Frequency Characteristics ◽  
Frequency Range ◽  
Electromagnetic Environment ◽  
Limit Values ◽  
Special Assessment

Introduction. Electromagnetic safety of power grid facilities staff requires the exclusion of electromagnetic fields (EMF) harmful effects. EMF is evaluated by 50 Hz electric and magnetic fields (EF and MF) values in the framework of working conditions special assessment, and very rarely the analysis of the electromagnetic environment (EME) is carried out in depth. The aim of the study - EME hygienic assessment of power grid EHV facilities personnel workplace with adequate 50 Hz EF and MF levels evaluation as well as the analysis of EF and MF in the frequency range from 5 Hz to 500 Hz amplitude-frequency characteristics. Materials and methods. 50 Hz EF and MF values assessment was carried out on open switchgears (S) of substations and within sanitary breaks of 500 and 750 kV overhead power transmission lines (OTL). Measurements along to OTL trasses was performed using matrix-based method. Measurements and analysis of EF and MF values in 5-500 Hz frequency range amplitude-frequency characteristics were performed in the territory of 500 and 750 kV S. Results. Power frequency 50 Hz measurements results at 500 and 750 kV S ground-level personnel workplaces showed the presence of an excess of permissible limit values by EF intensity and the absence of an excess by MF. The measured EF values within 500 and 750 kV OTL sanitary gaps require limiting the working time of linemen due to the excess of the hygienic norms for full work shift, while the MP levels were almost completely within the standard values for persons not occupationally connected with electrical installations maintenance. MF and EE frequency range from 50 Hz to 500 Hz spectral characteristics analysis showed that 3rd harmonic percentage does not exceed 2.5% for EF and 6% for MF of the main level, the level of the 5th harmonic does not exceed 1% for EF and 3.5% for MF, the level of the 7th harmonic does not exceed 0.2% for EF and 0.8% for MF. These data show despite its low levels the contribution of MF different harmonics in a possible adverse impact on humane than EF corresponding harmonics. Conclusions. There was the confirmation of the previously justified use of the "matrix" scheme for of EF and MF values measurement along OTL routes. The relevance of to EF and MF all frequency components expos ure assessing possible health risk in extremely high voltage S territories and under OTL, based on international recommendations due to the lack of sanitary regulations in the Russian Federation for >50 Hz-30 kHz EF and MF, is shown.

A Tale of Two Entities

2021 ◽  
Vol 2 (2) ◽  
pp. 1-21
Author(s):  
Hossam ElHussini ◽  
Chadi Assi ◽  
Bassam Moussa ◽  
Ribal Atallah ◽  
Ali Ghrayeb
Keyword(s):  
Power Flow ◽  
Power Grid ◽  
Communication Protocols ◽  
Charging Infrastructure ◽  
Electric Vehicle Charging ◽  
Public Data ◽  
Simulation Based ◽  
Charging Stations ◽  
The Impact ◽  
Ev Charging

With the growing market of Electric Vehicles (EV), the procurement of their charging infrastructure plays a crucial role in their adoption. Within the revolution of Internet of Things, the EV charging infrastructure is getting on board with the introduction of smart Electric Vehicle Charging Stations (EVCS), a myriad set of communication protocols, and different entities. We provide in this article an overview of this infrastructure detailing the participating entities and the communication protocols. Further, we contextualize the current deployment of EVCSs through the use of available public data. In the light of such a survey, we identify two key concerns, the lack of standardization and multiple points of failures, which renders the current deployment of EV charging infrastructure vulnerable to an array of different attacks. Moreover, we propose a novel attack scenario that exploits the unique characteristics of the EVCSs and their protocol (such as high power wattage and support for reverse power flow) to cause disturbances to the power grid. We investigate three different attack variations; sudden surge in power demand, sudden surge in power supply, and a switching attack. To support our claims, we showcase using a real-world example how an adversary can compromise an EVCS and create a traffic bottleneck by tampering with the charging schedules of EVs. Further, we perform a simulation-based study of the impact of our proposed attack variations on the WSCC 9 bus system. Our simulations show that an adversary can cause devastating effects on the power grid, which might result in blackout and cascading failure by comprising a small number of EVCSs.

scholarly journals Solar PV Grid Power Flow Analysis

2019 ◽  
Vol 11 (6) ◽  
pp. 1744 ◽  
Author(s):  
Qais Alsafasfeh ◽  
Omar Saraereh ◽  
Imran Khan ◽  
Sunghwan Kim
Keyword(s):  
Power System ◽  
Power Flow ◽  
Power Grid ◽  
Load Flow ◽  
Small Scale ◽  
Solar Pv ◽  
Voltage Fluctuation ◽  
Power Sources ◽  
Pv Grid ◽  
The Impact

As the unconstrained integration of distributed photovoltaic (PV) power into a power grid will cause changes in the power flow of the distribution network, voltage deviation, voltage fluctuation, and so on, system operators focus on how to determine and improve the integration capacity of PV power rationally. By giving full consideration to the static security index constraints and voltage fluctuation, this paper proposes a maximum integration capacity optimization model of the PV power, according to different power factors for the PV power. Moreover, the proposed research analyzes the large-scale PV grid access capacity, PV access point, and multi-PV power plant output, by probability density distribution, sensitivity analysis, standard deviation analysis, and over-limit probability analysis. Furthermore, this paper establishes accessible capacity maximization problems from the Institute of Electrical and Electronics Engineers (IEEE) standard node system and power system analysis theory for PV power sources with constraints of voltage fluctuations. A MATLAB R2017B simulator is used for the performance analysis and evaluation of the proposed work. Through the simulation of the IEEE 33-node system, the integration capacity range of the PV power is analyzed, and the maximum integration capacity of the PV power at each node is calculated, providing a rational decision-making scheme for the planning of integrating the distributed PV power into a small-scale power grid. The results indicate that the fluctuations and limit violation probabilities of the power system voltage and load flow increase with the addition of the PV capacity. Moreover, the power loss and PV penetration level are influenced by grid-connected spots, and the impact of PV on the load flow is directional.

scholarly journals Overview of Oman Power Transmission System and Protection Schemes for Effective Energy Management in Smart Grid Operations

2021 ◽  
Vol 9 ◽  
Author(s):  
Saif Al Omairi ◽  
Marya Al Balushi ◽  
Kenneth E. Okedu
Keyword(s):  
Smart Grid ◽  
Energy Management ◽  
Power Flow ◽  
Power Transmission ◽  
New Technology ◽  
Power Grid ◽  
Transmission System ◽  
Effective Energy ◽  
Peak Voltage ◽  
High Level

This article presents an overview of the transmission system and protection schemes employed in the national power grid of Oman. The technical design requirements considering the percentage of allowable limits for the different transmission voltage levels in the power grid of Oman were considered based on the electrical standards and grid codes of Oman. Also, the protection and fault requirements based on relay settings and backup protection were some of the factors considered in this study. More so, the power flow, peak, and off-peak voltage profiles of the main interconnection and Dhofar transmission systems were analyzed in detail, considering projections for 2021 and 2025, respectively, for effective energy management and smart grid operations. The current protection equipment of the power grid of Oman was evaluated, and some improvement schemes were proposed considering the implementation of the new technology for smart grid operation. The continuous investment in the transmission system of the Oman power grid and the use of updated protection technology would lead to the enhancement of the performance of the Oman transmission system to reach a high-level power transmission availability.

scholarly journals Evaluating the Impact of Pre-clustering and Class Imbalance on Solar Flare Forecasting

2018 ◽  
Author(s):  
Mirelle C. Bueno ◽  
Guilherme P. Coelho ◽  
Ana Estela A. Da Silva ◽  
André L. S. Gradvohl
Keyword(s):  
Machine Learning ◽  
Solar Flare ◽  
Transmission Lines ◽  
Solar Flares ◽  
Power Transmission ◽  
Class Imbalance ◽  
The Sun ◽  
Power Transmission Lines ◽  
Short Circuits ◽  
The Impact

Among the phenomena that occur on the surface of the Sun, solar flares may cause several damages, from short circuits in power transmission lines to complete interruptions in telecommunications systems. In order to mitigate these effects, many works have been dedicated to the proposal of mechanisms capable of predicting the occurrence of solar flares. In this context, the present work sought to evaluate two aspects related to machine learning-based solar flare forecasting: (i) the impact of class imbalance in training datasets on the performance of the predictors; and (ii) whether the incorporation of a pre-clustering step prior to the classifiers training contributes to a better prediction.

scholarly journals Power System Security with Contingency Technique by using SSSC & UPFC

2019 ◽  
Vol 8 (2S11) ◽  
pp. 772-777
Keyword(s):  
Power System ◽  
Phase Angle ◽  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Power Transmission ◽  
Electrical Power ◽  
Unified Power Flow Controller ◽  
Electrical Power System ◽  
Power Requirement

Now days’ electrical power requirement has enlarged expanding as expansion & restructuring of electrical power system (PS) for generation & transmission in power sector is critically limited due to current resources & environmental circumstances. As outcome, approximately of corridors of power transmission overhead lines are greatly loaded & congested. Also major issue of power system voltage stability becomes power transfer restricted and capability issue. A Modern power electronics technology FATCS considered device Static Synchronous Series Compensator (SSSC) is VSC demanded series FACTS equipment. Unified power flow controller (UPFC) is to manage power flow (PF), voltage magnitude & phase angle. In this research paper suggested to maintain voltage magnitude as well as PF of faulty lines. The consequence of mutation of PS parameters like voltage, phase angle, active power, reactive power, & overall power factor with & without SSSC & UPFC have also incorporated. Assessment of PS safety is essential in society to expand customs to sustain system functions when one or more components fail. A PS is "secure" when it can defy loss of one or more ingredients & still go on working without major problems. The Contingency event investigation technique is taken to identify electrical node PF in faulty transmission lines (TL). The Performance of PS has been tested on IEEE 14-Bus System.

scholarly journals The Influence of Decentralized Wind Power on the Characteristics of Distribution Network

2021 ◽  
Vol 261 ◽  
pp. 01037
Author(s):  
Ruomeng Jiang
Keyword(s):  
Wind Power ◽  
Power Flow ◽  
Large Scale ◽  
Power Grid ◽  
Distribution Network ◽  
Flow Distribution ◽  
Voltage Level ◽  
Negative Impacts ◽  
The Impact ◽  
Planning And Operation

This paper expounds the influence of decentralized wind power on the characteristics of distribution network. Through analysis, it can be concluded that after installing an appropriate amount of decentralized wind power, the voltage level of load bus can be improved. The power flow distribution will be changed, and the network loss of the power grid will be reduced. The decentralized wind power has also brought about negative impacts, such as voltage flicker and harmonics, the impact on the scope and direction of protection of relay protection, and greater uncertainty in the planning and operation of regional power grid. The analysis above provides some theoretical guidance for the large-scale development of decentralized wind power in the future.

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