A Novel Pre-Dispatching Strategy of Power System under Extreme Weather

Pre-dispatch is an important way for distribution networks to cope with typhoon weather, enhance resilience and reduce economic losses. In order to accurately describe the faults and consequences of components’ failure in the distribution network, this paper establishes a pre-dispatch model to cope with typhoon weather based on line failures consequence analysis. First, Monte Carlo simulation is used to sample the typical fault scenarios of vulnerable lines. According to the location of switchgear, the distribution network is partitioned and a block breaker correlation matrix is established. Combined with the line fault status, a fault consequence model of distribution lines related to the pre-dispatching strategy is established. Then, the objective function is given to minimize the sum of the cost of the pre-dispatch operation and the power outage, and then establish a pre-dispatch model for the distribution network. In order to reduce the computational complexity, PH (Progressive Hedging) algorithm is used to solve the model. Finally, the IEEE-69 test system is used to analyze the effectiveness of the method. The results show that the proposed dispatching model can effectively avoid potential risks, reduce system economic losses and improve the resilience of power grids.

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Research on Single-Phase Grounding Fault in Distribution Networks with a DC Power Positioning Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.530-531.353 ◽

2014 ◽

Vol 530-531 ◽

pp. 353-356

Author(s):

Run Sheng Li

Keyword(s):

Power Distribution ◽

Single Phase ◽

Distribution Network ◽

Distribution Networks ◽

Power Distribution Network ◽

Power Outage ◽

Location Method ◽

Fault Resistance ◽

Ground Fault ◽

Positioning Method

Due to the high ground fault resistance and the complexity of power distribution network structure (such as too many nodes, branches and too long lines), adopting common traveling wave method and ac injection method can not effectively locate the single-phase grounding fault in the distribution network system.To solve above problems and determine the position of the point of failure prisely, this paper adopted the dc location method of injecting the dc signal from the point of failure under the power outage offline. This paper introduces the single phase dc method and the method of three phase dc, and the simulation shows that the dc location method is effective and feasible.

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Stochastic Planning and Operational Constraint Assessment of System-Customer Power Supply Risks in Electricity Distribution Networks

Sustainability ◽

10.3390/su13179579 ◽

2021 ◽

Vol 13 (17) ◽

pp. 9579

Author(s):

Mikka Kisuule ◽

Ignacio Hernando-Gil ◽

Jonathan Serugunda ◽

Jane Namaganda-Kiyimba ◽

Mike Brian Ndawula

Keyword(s):

Sequential Monte Carlo ◽

Network Reliability ◽

Distribution Network ◽

Integrated Approach ◽

Distribution Networks ◽

Test System ◽

Electricity Distribution ◽

Reliability Indices ◽

Operational Constraints ◽

The Impact

Electricity-distribution network operators face several operational constraints in the provision of safe and reliable power given that investments for network area reinforcement must be commensurate with improvements in network reliability. This paper provides an integrated approach for assessing the impact of different operational constraints on distribution-network reliability by incorporating component lifetime models, time-varying component failure rates, as well as the monetary cost of customer interruptions in an all-inclusive probabilistic methodology that applies a time-sequential Monte Carlo simulation. A test distribution network based on the Roy Billinton test system was modelled to investigate the system performance when overloading limits are exceeded as well as when preventive maintenance is performed. Standard reliability indices measuring the frequency and duration of interruptions and the energy not supplied were complemented with a novel monetary reliability index. The comprehensive assessment includes not only average indices but also their probability distributions to adequately describe the risk of customer interruptions. Results demonstrate the effectiveness of this holistic approach, as the impacts of operational decisions are assessed from both reliability and monetary perspectives. This informs network planning decisions through optimum investments and consideration of customer outage costs.

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A Hybrid Optimization Approach for Power Loss Reduction and DG Penetration Level Increment in Electrical Distribution Network

Energies ◽

10.3390/en13226008 ◽

2020 ◽

Vol 13 (22) ◽

pp. 6008

Author(s):

Teketay Mulu Beza ◽

Yen-Chih Huang ◽

Cheng-Chien Kuo

Keyword(s):

Power Loss ◽

Distribution Network ◽

Distribution Networks ◽

Test System ◽

Base Case ◽

Optimization Approach ◽

Loss Reduction ◽

Voltage Profile ◽

Electrical Distribution ◽

Power Loss Reduction

The electrical distribution system has experienced a number of important changes due to the integration of distributed and renewable energy resources. Optimal integration of distributed generators (DGs) and distribution network reconfiguration (DNR) of the radial network have significant impacts on the power system. The main aim of this study is to optimize the power loss reduction and DG penetration level increment while keeping the voltage profile improvements with in the permissible limit. To do so, a hybrid of analytical approach and particle swarm optimization (PSO) are proposed. The proposed approach was tested on 33-bus and 69-bus distribution networks, and significant improvements in power loss reduction, DG penetration increment, and voltage profile were achieved. Compared with the base case scenario, power loss was reduced by 89.76% and the DG penetration level was increased by 81.59% in the 69-bus test system. Similarly, a power loss reduction of 82.13% and DG penetration level increment of 80.55% was attained for the 33-bus test system. The simulation results obtained are compared with other methods published in the literature.

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Voltage Stability Analysis in Medium-Voltage Distribution Networks Using a Second-Order Cone Approximation

Energies ◽

10.3390/en13215717 ◽

2020 ◽

Vol 13 (21) ◽

pp. 5717

Author(s):

Oscar Danilo Montoya ◽

Walter Gil-González ◽

Andrés Arias-Londoño ◽

Arul Rajagopalan ◽

Jesus C. Hernández

Keyword(s):

Distributed Generation ◽

Optimal Power Flow ◽

Voltage Stability ◽

Distribution Network ◽

Distribution Networks ◽

Test System ◽

Second Order ◽

Voltage Distribution ◽

Medium Voltage ◽

Second Order Cone

This paper addresses the voltage stability margin calculation in medium-voltage distribution networks in the context of exact mathematical modeling. This margin calculation is performed with a second-order cone (SOCP) reformulation of the classical nonlinear non-convex optimal power flow problems. The main idea around the SOCP approximation is to guarantee the global optimal solution via convex optimization, considering as the objective function the λ-coefficient associated with the maximum possible increment of the load consumption at all the nodes. Different simulation cases are considered in one test feeder, described as follows: (i) the distribution network without penetration of distributed generation; (ii) the distribution network with penetration of distributed generation; and (iii) the distribution grid with capacitive compensation. Numerical results in the test system demonstrated the effectiveness of the proposed SOCP approximation to determine the λ-coefficient. In addition, the proposed approximation is compared with nonlinear tools available in the literature. All the simulations are carried out in the MATLAB software with the CVX package and the Gurobi solver.

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Stochastic Planning and Operational Constraint Assessment of System-Customer Power Supply Risks in Electricity Distribution Networks

10.20944/preprints202107.0679.v1 ◽

2021 ◽

Author(s):

Mikka Kisuule ◽

Ignacio Hernando-Gil ◽

Jonathan Serugunda ◽

Jane Namaganda-Kiyimba ◽

Mike Brian Ndawula

Keyword(s):

Sequential Monte Carlo ◽

Network Reliability ◽

Distribution Network ◽

Integrated Approach ◽

Distribution Networks ◽

Test System ◽

Electricity Distribution ◽

Reliability Indices ◽

Operational Constraints ◽

The Impact

Electricity distribution network operators face several operational constraints in the provision of safe and reliable power given that investments for network area reinforcement must be commensurate with improvements in network reliability. This paper provides an integrated approach for assessing the impact of different operational constraints on distribution network reliability by incorporating component lifetime models, time-varying component failure rates as well as the monetary cost of customer interruptions in an all-inclusive probabilistic methodology that applies a time-sequential Monte Carlo simulation. A test distribution network based on the Roy Billinton test system is modelled to investigate the system performance when overloading limits are exceeded as well as when preventive maintenance is performed. Standard reliability indices measuring the frequency and duration of interruptions, and the energy not supplied are complemented with a novel monetary reliability index. The comprehensive assessment includes not only average indices but also their probability distributions to adequately describe the risk of customer interruptions. Results demonstrate the effectiveness of this holistic approach as the impacts of operational decisions are assessed from both reliability and monetary perspectives. This informs network planning decisions through optimum investments and consideration of customer outage costs.

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Enhancing Integrated Power and Water Distribution Networks Seismic Resilience Leveraging Microgrids

Sustainability ◽

10.3390/su12062167 ◽

2020 ◽

Vol 12 (6) ◽

pp. 2167 ◽

Cited By ~ 1

Author(s):

Javad Najafi ◽

Ali Peiravi ◽

Amjad Anvari-Moghaddam

Keyword(s):

Power Distribution ◽

Water Distribution ◽

Distribution Network ◽

Water Distribution Network ◽

Distribution Networks ◽

Power Distribution Network ◽

Proposed Model ◽

Resilience Index ◽

The Cost ◽

Water Pumps

An earthquake, as one of the natural disasters, can damage vital infrastructures including the power distribution network (PDN) and water distribution network (WDN). The dependency of WDN on PDN is the other challenge that can be highlighted after the earthquake. In this paper, the resilience improvement planning of integrated PDN and WDN against earthquakes is solved through stochastic programming. Power lines and substation hardening in PDN and water pipes rehabilitation with better material are the candidate strategies to minimize the expected inaccessibility value of loads to power and water as the resilience index and to minimize the cost of strategies. The proposed model is tested on the modified IEEE 33-bus PDN with a designed WDN and its performance is evaluated under different cases where the impacts of using distributed generations (DG) in PDN, equipping the water pumps to back-up generators, and the value of loads accessibility to water on the system resilience are investigated.

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A Novel Machine Learning-Based Short-Circuit Current Prediction Method for Active Distribution Networks

Energies ◽

10.3390/en12193793 ◽

2019 ◽

Vol 12 (19) ◽

pp. 3793 ◽

Cited By ~ 1

Author(s):

Zheng ◽

Wang ◽

Jiang ◽

Keyword(s):

Distribution Systems ◽

Large Scale ◽

Short Circuit ◽

Distribution Network ◽

Prediction Method ◽

Short Circuit Current ◽

Distribution Networks ◽

Test System ◽

High Penetration ◽

Active Distribution Networks

The traditional mechanism models used in short-circuit current calculations have shortcomings in terms of accuracy and speed for distribution systems with inverter-interfaced distributed generators (IIDGs). Faced with this issue, this paper proposes a novel data-driven short-circuit current prediction method for active distribution systems. This method can be used to accurately predict the short-circuit current flowing through a specified measurement point when a fault occurs at any position in the distribution network. By analyzing the features related to the short-circuit current in active distribution networks, feature combination is introduced to reflect the short-circuit current. Specifically, the short-circuit current where IIDGs are not connected into the system is treated as the key feature. The accuracy and efficiency of the proposed method are verified using the IEEE 34-node test system. The requirement of the sample sizes for distribution systems of different scale is further analyzed by using the additional IEEE 13-node and 69-node test systems. The applicability of the proposed method in large-scale distribution network with high penetration of IIDGs is verified as well.

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Increasing Electric Vehicle Penetration Using Smart Switching and Emergency Uprating

Frontiers in Energy Research ◽

10.3389/fenrg.2021.672721 ◽

2021 ◽

Vol 9 ◽

Author(s):

Shuran Liu ◽

Meng Cheng ◽

Qinhao Xing ◽

Yizhe Jiang ◽

Qianliang Xiang ◽

...

Keyword(s):

Network Performance ◽

Negative Impact ◽

Network Reliability ◽

Distribution Network ◽

Distribution Networks ◽

Test System ◽

Evaluation Framework ◽

Reliability Performance ◽

The Impact

One of the key challenges facing distribution network operators today is the expected increase in electric vehicles. The increased load from EV charging will result in distribution assets becoming “thermally overloaded” due to higher operating temperatures. In addition to the issue of increased load, we have a limited understanding of the behavior and performance of the distribution assets and their potential to accept the increased load. It has been well acknowledged that EVs increase the network loading level, leading to a reduced system reliability performance. These results have not been quantified in a realistic case study, including actual cable rating and design properties. To address this gap, this paper proposes a novel methodology in the existing power network reliability evaluation framework, which quantifies the impact of different EV penetration levels on distribution network reliability, and the thermal performance of distribution cables. Novel approaches using smart switching technology and emergency uprating are proposed to reduce the peak power demand caused by EVs, in order to reinforce the reliability of the grid and to boost the maximum allowable EV penetration in the distribution networks. The methodology was applied using a case study on the modified EV-integrated RBTS (Roy Billinton Test System) bus four distribution network. The results showed that the negative impact of EVs on network performance can be mitigated by the implementation of smart switching technology. The peak demand under contingencies can also be accepted by the cables though emergency uprating. The frequency and duration of EV demand interruption was also significantly reduced. Thus, a higher EV penetration can be accommodated.

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Impact of distributed power generation on protection coordination in distribution network

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v23.i3.pp1271-1280 ◽

2021 ◽

Vol 23 (3) ◽

pp. 1271

Author(s):

Zineb El Idrissi ◽

Faissal El Mariami ◽

Abdelaziz Belfqih ◽

Touria Haidi

Keyword(s):

Negative Impact ◽

Short Circuit ◽

Distribution Network ◽

Distribution Networks ◽

Power Grids ◽

Distributed Power Generation ◽

Distributed Generators ◽

Electric Power Sector ◽

Coordination Systems ◽

The Impact

<p>In the whole world and especially in Morocco, the electric power sector faces significant challenges and the demand for energy is increasing as fossil fuel sources are disappearing. Moreover, the high cost of construction of large production plants and the obligation to reduce greenhouse gas emissions are among the factors pushing the energy sector to integrate distributed generators DGs based on renewable energies into power grids. However, the integration of these generators increased the values of short-circuit currents in the network, which poses a real threat to the existing protection coordination systems in the distribution network. The aim of this article is to bring together in a single platform all available research addressing the issue of protection coordination in the presence of DGs in the distribution network, in order to help researchers identify future scope. This paper presents a review of the impact of distributed generators on the protection coordination of distribution networks. The solutions proposed in the literature, to mitigate the negative impact of DGs, have been investigated in detail, along with the limitations of these proposed techniques.</p>

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A study on appropriate investment of pipeline rehabilitation for water distribution network

Water Science & Technology Water Supply ◽

10.2166/ws.2005.0019 ◽

2005 ◽

Vol 5 (2) ◽

pp. 31-38

Author(s):

A. Asakura ◽

A. Koizumi ◽

O. Odanagi ◽

H. Watanabe ◽

T. Inakazu

Keyword(s):

Monte Carlo Simulation ◽

Monte Carlo ◽

Water Supply ◽

Water Distribution ◽

Ad Hoc ◽

Distribution Network ◽

Water Distribution Network ◽

Distribution Networks ◽

Optimal Basis ◽

Model Case

In Japan most of the water distribution networks were constructed during the 1960s to 1970s. Since these pipelines were used for a long period, pipeline rehabilitation is necessary to maintain water supply. Although investment for pipeline rehabilitation has to be planned in terms of cost-effectiveness, no standard method has been established because pipelines were replaced on emergency and ad hoc basis in the past. In this paper, a method to determine the maintenance of the water supply on an optimal basis with a fixed budget for a water distribution network is proposed. Firstly, a method to quantify the benefits of pipeline rehabilitation is examined. Secondly, two models using Integer Programming and Monte Carlo simulation to maximize the benefits of pipeline rehabilitation with limited budget were considered, and they are applied to a model case and a case study. Based on these studies, it is concluded that the Monte Carlo simulation model to calculate the appropriate investment for the pipeline rehabilitation planning is both convenient and practical.

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