The Application of the Minimum Cut Sets in Reliability Evaluation of Power Transmission and Transformation System

2012 ◽  
Vol 463-464 ◽  
pp. 1175-1181 ◽  
Author(s):  
Jing Cai ◽  
Fang Li ◽  
Ning An ◽  
Jing Jing Lu ◽  
Lu Sun
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Power Transmission ◽  
Evaluation Process ◽  
Practical Method ◽  
Reliability Evaluation ◽  
Minimum Cut ◽  
Transformation System ◽  
Minimum Path ◽  
Schedule Repair

As an important part of power systems, power transmission and transformation system involves various equipments, complicated structure and operation modes, and its reliability level has a significant influence on the reliability of the whole system. The paper proposes a practical method for reliability evaluation of power transmission and transformation system based on minimum cut sets. The algorithm, based on topological structure and reliability data without power flow, analyses the reliability of system by different voltage grades. In each voltage grade analysis, the method resolves minimum path sets by depth first search method, gets minimum cut sets, and calculates reliability index. The method considers three states involved normal operating, schedule repair and fault repair, and it makes the evaluation process much more reasonable and effective as it resolves branch-node mixed cut sets. The paper verifies the effectiveness of the algorithm by the test of IEEE-RTS 79 system

scholarly journals Optimal Sizing and Spatial Allocation of Storage Units in a High-Resolution Power System Model

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3365 ◽  
Author(s):  
Lukas Wienholt ◽  
Ulf Müller ◽  
Julian Bartels
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Power Flow ◽  
Optimal Power Flow ◽  
Power Transmission ◽  
Renewable Generation ◽  
Large Power ◽  
Transmission Grid ◽  
Storage Units

The paradigm shift of large power systems to renewable and decentralized generation raises the question of future transmission and flexibility requirements. In this work, the German power system is brought to focus through a power transmission grid model in a high spatial resolution considering the high voltage (110 kV) level. The fundamental questions of location, type, and size of future storage units are addressed through a linear optimal power flow using today’s power grid capacities and a generation portfolio allowing a 66% generation share of renewable energy. The results of the optimization indicate that for reaching a renewable energy generation share of 53% with this set-up, a few central storage units with a relatively low overall additional storage capacity of around 1.6 GW are required. By adding a constraint of achieving a renewable generation share of at least 66%, storage capacities increase to almost eight times the original capacity. A comparison with the German grid development plan, which provided the basis for the power generation data, showed that despite the non-consideration of transmission grid extension, moderate additional storage capacities lead to a feasible power system. However, the achievement of a comparable renewable generation share provokes a significant investment in additional storage capacities.

scholarly journals Operation and Challenges of Multi-Infeed LCC–HVDC System: Commutation Failure, AC/DC Power Flow, and Voltage Stability

2021 ◽  
Vol 11 (18) ◽  
pp. 8637
Author(s):  
Bilawal Rehman ◽  
Atiq ur Rehman ◽  
Waqar Ahmad Khan ◽  
Irfan Sami ◽  
Jong-Suk Ro
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Voltage Stability ◽  
Power Transmission ◽  
Voltage Source ◽  
Future Research ◽  
Long Distance ◽  
Hvdc System ◽  
Dc Power ◽  
Commutation Failure

This paper presents a detailed analysis of commutation failure, AC/DC power flow, and voltage stability of multi-infeed high-voltage direct current (HVDC). The use of HVDC power transmission technology has become common in modern power systems. During the past two decades, HVDC technology has been extensively used for long-distance bulk power transmission to remote areas. Throughout the world, the demand for power has drastically increased in recent years due to industrialization; such situations make HVDC an economic candidate because the distance between power generation plants and load areas is significantly very long. The line-commutated converter (LCC) technology-based HVDC system is well more mature than other available conversion schemes (i.e., voltage source converters), and it is widely used in high-power projects. China had approximately 50 HVDC–LCC links in 2020, and a single LCC-based link with the highest capacity is 12 GW. The installation of several HVDC links in an existing power network has led to a situation where two or more HVDC links terminate in the electric vicinity of each other’s AC network or even in same AC busbar. Such scenarios are termed multi-infeed HVDC system. Multi-infeed HVDC systems bring various challenges related to voltage stability, local and concurrent commutation failure, and AC/DC power flow. Here, the literature available on these phenomena of LCC-based HVDC is discussed for future research. The assumptions and drawbacks of various techniques used for investigating the mentioned phenomena are also highlighted.

scholarly journals Effective Utilization of Transmission Line Capacity in a Meshed Network with Series Capacitor Upto its Thermal Limit

2020 ◽  
Vol 8 (6S) ◽  
pp. 9-13
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Line ◽  
Power Flow ◽  
Power Transmission ◽  
Power Delivery ◽  
Thermal Limit ◽  
Effective Utilization ◽  
Generation Cost ◽  
Series Capacitor

Power system networks are becoming interconnected for the purpose of power delivery to decrease the overall power generation cost. With insufficient control, the power systems become more complicated to function and less secure. The economics of AC power transmission have always forced the planning engineers to transmit as much power as possible through a given transmission line. The smaller and thermally limited lines are crowded in many networks while other higher capacity lines run well below their thermal maximum. When series capacitors are introduced in the higher voltage cables, power may be transferred from the overloaded lines, maximizing the use of the existing line as well as complementing the performance of the power system. In this paper, a three-line meshed power system network with different thermal line limits is considered for the purpose of showing effective utilization of line network for maximum power flow through the intended line with series capacitor compensation. The simulations are performed by using PowerWorld simulator confirms the addition of series capacitor increases the power transfer through the line up to its thermal limit

scholarly journals A minimization model of the power shortage of electric power systems with regard to the restrictions on controlled sections

2021 ◽  
pp. 95-120
Author(s):  
Dmitry Iakubovsky ◽  
◽  
Dmitry Krupenev ◽  
Denis Boyarkin ◽  
◽  
...  
Keyword(s):  
Power Systems ◽  
Mathematical Models ◽  
Electric Power ◽  
Power Flow ◽  
Power Transmission ◽  
Electric Power Systems ◽  
Variable Number ◽  
Electric Power System ◽  
Active Power Flow ◽  
Adequacy Assessment

A steady trend towards the development of electric power systems leads to their continuous enlargement and sophistication. As a result, new ways of their control appear. In this regard, the existing models and complexes for adequacy assessment may work inadequately and ineffectively in terms of the obtained results adequacy. To assess the current state of the existing models and complexes, we reviewed and analyzed the domestic and foreign software and computer systems. In particular, we considered mathematical models of minimizing the power shortage. This work is based on the problem of modifying mathematical models of minimizing the power shortage used in adequacy assessment of the electric power systems of one of the complexes under consideration. As a modification of mathematical models, it is proposed to exclude the existing method of using the line capacities and start use correct accounting for the maximum permissible active power flow in controlled sections. The experimental part reflected in the paper concerns the testing of options for models to minimize the power shortage, as well as the proposed modifications on various systems, including those consisting of three and seven reliability zones with a variable number of controlled sections and power lines included in them. The results of the study have shown that the proposed modifications are efficient and can be used in the future. The authors also obtained the most adequate results in terms of the physical laws of electric power system operation due to the model of minimizing the power shortage with quadratic losses which takes into account the limitations of power transmission over controlled sections.

scholarly journals Enhanced High Performance Power Compensation Methodology by IPFC Using PIGBT-IDVR

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Subramanian Arumugom ◽  
Marimuthu Rajaram
Keyword(s):  
Power Systems ◽  
Distributed System ◽  
High Speed ◽  
High Performance ◽  
Power Flow ◽  
Reactive Power ◽  
Power Transmission ◽  
Dynamic Voltage Restorer ◽  
Voltage Restorer ◽  
Dynamic Voltage

Currently, power systems are involuntarily controlled without high speed control and are frequently initiated, therefore resulting in a slow process when compared with static electronic devices. Among various power interruptions in power supply systems, voltage dips play a central role in causing disruption. The dynamic voltage restorer (DVR) is a process based on voltage control that compensates for line transients in the distributed system. To overcome these issues and to achieve a higher speed, a new methodology called the Parallel IGBT-Based Interline Dynamic Voltage Restorer (PIGBT-IDVR) method has been proposed, which mainly spotlights the dynamic processing of energy reloads in common dc-linked energy storage with less adaptive transition. The interline power flow controller (IPFC) scheme has been employed to manage the power transmission between the lines and the restorer method for controlling the reactive power in the individual lines. By employing the proposed methodology, the failure of a distributed system has been avoided and provides better performance than the existing methodologies.

scholarly journals ON THE SIMULATION OF MODES ОF ELECTRIC POWER SYSTEMS WITH FACTS

2017 ◽  
Vol 60 (4) ◽  
pp. 341-351
Author(s):  
E. D. Halilov
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Power Flow ◽  
Power Transmission ◽  
Electric Power Systems ◽  
Active Power ◽  
Operating Conditions ◽  
Electrical Networks ◽  
Facts Devices

Power flow control is an important task of development of electric power systems. It is necessary to reduce the power loss, improve the reliability and quality of power supply and increase the power transmission. Currently, on the basis of modern power electronics effective FАСТS devices for flexible control of power system operation modes have been developed. FАСТS devices are able to simultaneously influence the voltage, the reactance, the angle between the voltages. As it is known, the calculations of the established modes of electric systems are the most frequently performed tasks at all the territorial and time levels of control and planning operations. These calculations are significant by themselves, being also an integral part of software systems of calculation of losses of power and energy in electrical networks, calculation of optimal modes and also sustainability. The need for multiple mode calculation imposes high requirements to the methods of calculation of the established modes in real time in terms of performance and reliability of the results of the solution being obtained under operating conditions of electric power systems. In traditional calculations of the established modes of electrical networks, shunt reactors, current-limiting reactors, capacitor banks, longitudinal compensation devices were accounted in the simulation as passive elements. In regard with the introduction of FACTS devices in power systems, there is an arising need to develop appropriate algorithms and implement them in the form of software for analyzing and controlling the established modes of power systems. The methodology and software for calculation of the established modes of electric networks with consideration of FACTS devices have been developed. The software makes it possible to obtain practically acceptable solutions in three outer iterations. Based on the results of numerical simulation of modes of the power system of the “Azerenergy” JSC it was determined that the application of FACTS devices can significantly increase the transmission line active power, improve voltage levels and reduce losses of active power. The dependences of flows and power losses on the control parameter of FACTS devices have been derived. 

scholarly journals A Thermal Rating Calculation Approach for Wind Power Grid-Integrated Overhead Lines

Energies ◽  
2018 ◽  
Vol 11 (6) ◽  
pp. 1523 ◽  
Author(s):  
Mengxia Wang ◽  
Mingqiang Wang ◽  
Jinxin Huang ◽  
Zhe Jiang ◽  
Jinyan Huang
Keyword(s):  
Power Systems ◽  
Wind Power ◽  
Transmission Lines ◽  
Power Flow ◽  
Power Transmission ◽  
Wind Farms ◽  
Utilization Efficiency ◽  
Power Transmission Lines ◽  
Overhead Lines ◽  
Wind Power Integration

Currently, the rapid increase in wind power integration in power systems is resulting in an increasing power flow in the grid-integrated power transmission lines of wind farms. The wind power curtailment caused by the current limits (thermal ratings) of the wind power integration overhead lines (WPIOLs) is becoming increasingly common. Aiming at this issue, the influence of conductor heating on the loss of tensile strength (LOTS) and sag of a WPIOL was analyzed in this paper. Then a decision model is proposed for the thermal ratings of WPIOLs, which regards the minimized wind power curtailment as objective and introduces permissible cumulative LOTS and sag of the conductor as constraints. Based on this model, the thermal rating for a WPIOL can be decided to ensure the expected service life of the conductor and safe clearance. In addition, case studies are used to demonstrate that the proposed approach is capable of improving the conservatism of conventional thermal rating calculation and reducing the wind power curtailment by improving the utilization efficiency of WPIOLs.

scholarly journals Contingency Analysis of Fault and Minimization of Power System Outage using Fuzzy Controller

2019 ◽  
Vol 9 (1) ◽  
pp. 4111-4115
Keyword(s):  
Power Systems ◽  
Power System ◽  
Transmission Line ◽  
Power Flow ◽  
Power Transmission ◽  
Fuzzy Controller ◽  
Transmission System ◽  
Load Flow ◽  
Contingency Analysis ◽  
Additional Advantage

In power systems, voltage stability perform the major role in design and its operation. Major system failures are occur due to voltage variability and breakdown. To meet and compensate the rising power demand of regular usage in modern trends, transmission networks are enormously loaded which create the voltage instability. Contingency analysis is a recognized energy managing tool. It calculate the violation in the transmission line. In this paper a computational controller fuzzy system is suggested to handle the transmission line outage and overload in other branch kind of problems in Power system. The efficiency of power transmission system with fuzzy controller is inveterate by computation of various parameters of transmission bus under different loading situations. For the contingency analysis the transmission power flow several methods have been developed. Fast Decoupled load flow program is the effective method which provides a fast and effective solution to the contingency analysis in the transmission system and also it is incorporate with matrix alteration formula which gives additional advantage for the system.

scholarly journals Which Neural Network to Choose for Post-Fault Localization, Dynamic State Estimation, and Optimal Measurement Placement in Power Systems?

2021 ◽  
Vol 4 ◽  
Author(s):  
Andrei Afonin ◽  
Michael Chertkov
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Power Transmission ◽  
Fault Localization ◽  
Dynamic State ◽  
Linear Ordinary Differential Equations ◽  
Measurement Placement ◽  
Dynamic State Estimation ◽  
Measurement Units ◽  
Fault State

We consider a power transmission system monitored using phasor measurement units (PMUs) placed at significant, but not all, nodes of the system. Assuming that a sufficient number of distinct single-line faults, specifically the pre-fault state and the (not cleared) post-fault state, are recorded by the PMUs and are available for training, we first design a comprehensive sequence of neural networks (NNs) locating the faulty line. Performance of different NNs in the sequence, including linear regression, feed-forward NNs, AlexNet, graph convolutional NNs, neural linear ordinary differential equations (ODEs) and neural graph-based ODEs, ordered according to the type and amount of the power flow physics involved, are compared for different levels of observability. Second, we build a sequence of advanced power system dynamics–informed and neural ODE–based machine learning schemes that are trained, given the pre-fault state, to predict the post-fault state and also, in parallel, to estimate system parameters. Finally, third and continuing to work with the first (fault localization) setting, we design an (NN-based) algorithm which discovers optimal PMU placement.

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