Traction Power Systems Reliability Concepts

Joint Rail ◽  
2004 ◽  
Author(s):  
Sergo Sagareli
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electrical Energy ◽  
Total Power ◽  
Design Stage ◽  
Power Substation ◽  
Energy Deprivation ◽  
Power Systems Reliability ◽  
Traction Power

Reliability of a traction power system may be defined as its ability to continuously supply electrical power of adequate quality during sudden disturbances such as a short circuit or loss of system elements, while operating with a normal scheme configuration, or during scheduled maintenance and repairs, without causing safety hazards, train delays or public nuisance. While the utility power systems’ reliability may be expressed in outage minutes per year (or any other time period), which is calculated as a ratio of customers’ electrical energy deprivation to system’s total power capacity, for a traction power systems’ reliability evaluation, minutes of train delays caused by power interruption or relative values such as delay minutes per passenger-mile may be utilized. Considering the accelerated growth of traction power systems across the US in recent and coming years [1], creation of a reliability council similar to NERC [2] to develop reliability standards within the railroad industry may be highly beneficial: it could pull together statistical data on reliability from different railroads, analyze them, and develop guidelines and recommendations for optimal solutions to provide adequate reliability with the lowest cost possible. IEEE Traction Power Substation Committee and AREMA Committee 33 on Electrical Energy Utilization could initiate and lay groundwork for the creation of such a council. While most of the contingency situations may be predicted and counteracted on the design stage, only the real-life experience is the ultimate test for reliability. That’s why it is so important to keep and analyze records of any outages and contingencies encountered during traction power system operations. Records for these purposes may be provided by Multi-Purpose Relays [3] that become widely used in recently built substations. Classification of voltage events in future Standard may be based on the Institute of Electrical and Electronic Engineers Standard 1159-1995 “IEEE Recommended Practice for Monitoring Electric Power Quality” [4], classification of reliability events — according to NERC Planning Standards [2].

scholarly journals A Novel Methodology for Adaptive Coordination of Multiple Controllers in Electrical Grids

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1474
Author(s):  
Ruben Tapia-Olvera ◽  
Francisco Beltran-Carbajal ◽  
Antonio Valderrabano-Gonzalez ◽  
Omar Aguilar-Mejia
Keyword(s):  
Power Systems ◽  
Power System ◽  
Electric Power ◽  
Large Scale ◽  
Short Circuit ◽  
Dynamic Performance ◽  
Low Frequency ◽  
Electric Power System ◽  
Design Stage ◽  
Positive Interaction

This proposal is aimed to overcome the problem that arises when diverse regulation devices and controlling strategies are involved in electric power systems regulation design. When new devices are included in electric power system after the topology and regulation goals were defined, a new design stage is generally needed to obtain the desired outputs. Moreover, if the initial design is based on a linearized model around an equilibrium point, the new conditions might degrade the whole performance of the system. Our proposal demonstrates that the power system performance can be guaranteed with one design stage when an adequate adaptive scheme is updating some critic controllers’ gains. For large-scale power systems, this feature is illustrated with the use of time domain simulations, showing the dynamic behavior of the significant variables. The transient response is enhanced in terms of maximum overshoot and settling time. This is demonstrated using the deviation between the behavior of some important variables with StatCom, but without or with PSS. A B-Spline neural networks algorithm is used to define the best controllers’ gains to efficiently attenuate low frequency oscillations when a short circuit event is presented. This strategy avoids the parameters and power system model dependency; only a dataset of typical variable measurements is required to achieve the expected behavior. The inclusion of PSS and StatCom with positive interaction, enhances the dynamic performance of the system while illustrating the ability of the strategy in adding different controllers in only one design stage.

scholarly journals Architectural and functional classification of smart grid solutions

2019 ◽  
Vol 2 (S1) ◽  
Author(s):  
Friederike Wenderoth ◽  
Elisabeth Drayer ◽  
Robert Schmoll ◽  
Michael Niedermeier ◽  
Martin Braun
Keyword(s):  
Smart Grid ◽  
Power Systems ◽  
Power System ◽  
Power Distribution ◽  
Hierarchical Architecture ◽  
Distribution Grid ◽  
Active System ◽  
System Operation ◽  
Power System Operation

Abstract Historically, the power distribution grid was a passive system with limited control capabilities. Due to its increasing digitalization, this paradigm has shifted: the passive architecture of the power system itself, which includes cables, lines, and transformers, is extended by a communication infrastructure to become an active distribution grid. This transformation to an active system results from control capabilities that combine the communication and the physical components of the grid. It aims at optimizing, securing, enhancing, or facilitating the power system operation. The combination of power system, communication, and control capabilities is also referred to as a “smart grid”. A multitude of different architectures exist to realize such integrated systems. They are often labeled with descriptive terms such as “distributed,” “decentralized,” “local,” or “central." However, the actual meaning of these terms varies considerably within the research community.This paper illustrates the conflicting uses of prominent classification terms for the description of smart grid architectures. One source of this inconsistency is that the development of such interconnected systems is not only in the hands of classic power engineering but requires input from neighboring research disciplines such as control theory and automation, information and telecommunication technology, and electronics. This impedes a clear classification of smart grid solutions. Furthermore, this paper proposes a set of well-defined operation architectures specialized for use in power systems. Based on these architectures, this paper defines clear classifiers for the assessment of smart grid solutions. This allows the structural classification and comparison between different smart grid solutions and promotes a mutual understanding between the research disciplines. This paper presents revised parts of Chapters 4.2 and 5.2 of the dissertation of Drayer (Resilient Operation of Distribution Grids with Distributed-Hierarchical Architecture. Energy Management and Power System Operation, vol. 6, 2018).

scholarly journals Composed Index for the Evaluation of the Energy Security of Power Systems: Application to the Case of Argentina

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3998
Author(s):  
Sergio Fuentes ◽  
Roberto Villafafila-Robles ◽  
Eduardo Lerner
Keyword(s):  
Power Systems ◽  
Power System ◽  
Fossil Fuel ◽  
Energy Systems ◽  
Electrical Energy ◽  
Multidimensional Index ◽  
Policy Makers ◽  
Sustainable Systems ◽  
Security Index ◽  
Evaluation Of Policies

Energy transitions’ trend towards sustainable systems has prompted energy systems to shift from being fossil-fuel-based to rely on renewable energy. These transitions have led the power system to occupy the center of modern infrastructures, so assuring its security has become a priority for policy makers. This work presents a tool based on a multidimensional index, the Power System Security Index (PSIx), for the evaluation of policies affecting the security of the supply of electrical energy. The developed frame is applied to the current power system of Argentina, and it is compared to the system in year 2002. Availability of resources and infrastructure are the strengths of the country, while economic, governability, and research, development and innovation spheres leave room for improvement. The further incorporation of more economies to the study would substantially enrich the statistical analysis of the results.

Electrical Faults in Power Systems

2016 ◽  
pp. 1-11
Author(s):  
Abdelkader Abdelmoumene ◽  
Hamid Bentarzi
Keyword(s):  
Fault Detection ◽  
Power Systems ◽  
Power System ◽  
System Analysis ◽  
Electrical Equipment ◽  
Correct Classification ◽  
Power System Analysis ◽  
Electrical Faults

The identification and classification of electrical faults have a great importance in power system analysis. They help in the dimensioning and the adequate choice of electrical equipment, especially, for protective and interrupting devices. This chapter describes the various faults undergone by the power system and removes some ambiguities causing confusions and difficulties for the correct classification of faults. Once the faults terminologies are well understood and properly assessed; they can be used efficiently to develop enhanced algorithms dedicated to fault detection, classification, isolation and diagnostics.

scholarly journals Model and Analysis of Integrating Wind and PV Power in Remote and Core Areas with Small Hydropower and Pumped Hydropower Storage

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3459 ◽  
Author(s):  
Xianxun Wang ◽  
Lihua Chen ◽  
Qijuan Chen ◽  
Yadong Mei ◽  
Hao Wang
Keyword(s):  
Power Systems ◽  
Power System ◽  
Thermal Power ◽  
Power Production ◽  
Total Power ◽  
Energy Integration ◽  
Small Hydropower ◽  
Peak Period ◽  
Renewable Power ◽  
Core Areas

Small hydropower (SHP) and pumped hydropower storage (PHS) are ideal members of power systems with regard to integrating intermittent power production from wind and PV facilities in modern power systems using the high penetration of renewable energy. Due to the limited capacity of SHP and the geographic restrictions of PHS, these power sources have not been adequately utilized in multi-energy integration. On the one hand, rapidly increasing wind/PV power is mostly situated in remote areas (i.e., mountain and rural areas) and is delivered to core areas (i.e., manufacturing bases and cities) for environmental protection and economic profit. On the other hand, SHP is commonly dispersed in remote areas and PHS is usually located in core areas. This paper proposes a strategy to take advantage of the distribution and regulation features of these renewable energy sources by presenting two models, which includes a remote power system model to explore the potential of SHP to smooth the short-term fluctuations in wind and PV power by minimizing output fluctuations as well as a core power system model to employ PHS to shift the surplus power to the peak period by maximizing the income from selling regenerated power and minimizing output fluctuations. In the proposed first model, the cooperative regulation not only dispatches SHP with a reciprocal output shape to the wind/PV output to smooth the fluctuations but also operates the reservoir with the scheduled total power production by adjusting its output in parallel. The results of a case study based on a municipal power system in Southwestern China show that, with the proposed method, SHP can successfully smooth the short-term fluctuations in wind and PV power without influencing the daily total power production. Additionally, SHP can replace the thermal power production with renewable power production, smooth the thermal output, and further reduce the operation costs of thermal power. By storing the surplus power in the upper reservoir and regenerating the power during the peak period, PHS can obtain not only the economic benefit of selling the power at high prices but also the environmental benefit of replacing non-renewable power with renewable power. This study provides a feasible approach to explore the potential of SHP and PHS in multi-energy integration applications.

scholarly journals Studi Analisa Pengaruh Total Harmonic Distortion (THD) terhadap Rugi-Rugi, Efisiensi, dan Kapasitas Kerja Transformator pada Penyulang Kerobokan

2019 ◽  
Vol 6 (2) ◽  
pp. 121
Author(s):  
I Putu Adi Wirajaya ◽  
I Wayan Rinas ◽  
I Wayan Sukerayasa
Keyword(s):  
Power System ◽  
Measurement Method ◽  
Harmonic Distortion ◽  
Electrical Energy ◽  
Work Capacity ◽  
Total Power ◽  
Power Losses ◽  
Distribution Transformers ◽  
Direct Measurement Method ◽  
Electrical Loads

Kerobokan feeder supply electrical energy in the area of Kerobokan. This feeder supplies 67 distribution transformers that serve a variety of customers with nonlinier electrical loads. Nonlinier electrical loads cause harmonics which adversely affect customers and power system equipment, especially distribution transformers. In Kerobokan feeder, only 3 (4.5%) of the 67 transformers has THDi content that according with the IEEE 519-2014 standard and 64 (95.5%) of the 67 transformers has a high THDi content and exceed the IEEE 519-2014 standard. For this reason, the power losses, efficiency, and work capacity of the transformer are analyzed due to the effect of THDi. This study uses a direct measurement method in all transformers in the Kerobokan feeder and simulation on the ETAP Powerstation program. The results of the analysis showed that total power losses without being affected by THDi for all transformers were 49.4 kW and after being affected by THDi were 591.71 kW. The highest THDi content is in the KA 0992 transformer is 24.8% which results in an increased in power losses is 12.02 kW or 12.02% of its capacity and a decreased in efficiency is 12.66% and has a decreased in work capacity is 19.9%. While the smallest THDi content is found in the DB 449 transformer is 6.8% which results in an increased in power losses is 2.2 kW or 0.88% of its capacity and a decreased efficiency is 1.01% and has a decreased in work capacity is 2.7%.

A Novel Fused Converter for Hybrid Power Systems

2014 ◽  
Vol 984-985 ◽  
pp. 744-749
Author(s):  
W. Margaret Amutha ◽  
Renugadevi ◽  
V. Rajini
Keyword(s):  
Wind Speed ◽  
Power Systems ◽  
Power System ◽  
Rural Areas ◽  
Power Flow ◽  
Electrical Energy ◽  
Hybrid Power System ◽  
Hybrid Power ◽  
Different Seasons ◽  
Continuous Power

—Hybrid power system consists of different sources of electrical energy with different operating times during different seasons. Deployment of a hybrid power system is expected in rural areas. Supplying remote load systems such as rural telephony, hospitals, military etc.., where continuous power supply is required, can be realized with the combination of wind and solar power. The proposed topology is designed for telecom load which uses dual input dc-dc fused converter for combining solar and wind energy sources. For the further research and improvements in the proposed fused converter topology, it is necessary to know in detail the power flow from solar and wind sources to the load or to storage battery depending on different seasons. For various wind speed with constant solar irirradiation and, for various solar irirradiations with constant wind speed, the power flow of the hybrid power system is simulated and presented. The same topology is investigated for different switching frequencies (10 kHz and 20 kHz), using MATLAB/SIMULINK, and the efficiencies are calculated.

scholarly journals Simulation Verification of Overcurrent Protection Operation in Power Networks Integrating Renewable Energy Sources in Energy Communities

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2193
Author(s):  
Mateusz Szablicki ◽  
Piotr Rzepka ◽  
Adrian Halinka
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Power System ◽  
Renewable Energy Sources ◽  
Design Stage ◽  
Energy Sources ◽  
Power System Protection ◽  
System Protection ◽  
Energy Community ◽  
Digital Protection

This publication discusses the risks of further use of classical overcurrent protections in modern power systems. The increasing penetration of renewable energy sources has caused a lot of challenges, among other things, the development of energy communities that balance local generation and consumption. Usually the interconnection line between the energy community and power systems are only used to balance the shortage or overflow of energy. As a result, most of the time these connections can be low loaded. Such a state can cause incorrect operation of power system protection approached, because the current level values are smaller than the required activation level for the protections. This article presents the potential incorrect operation of digital power system protection with overcurrent function. The obtained simulation results clearly show that the correctness of protection operation is strongly dependent on the level load of lines and the parameters and structure of the protection decision algorithms. These problems occur during low load line periods because these were not taken into account during the classical digital protection design stage. In the future this can cause problems with the fulfillment of the basic protection requirements of stability, speed, sensitivity. This publication suggests extra problems for power system protection research.

scholarly journals Solar PV Placement and Sizing for Line Stability Enhancement and Optimal Operating Cost

2019 ◽  
Vol 9 (1) ◽  
pp. 3585-3593
Keyword(s):  
Power Systems ◽  
Power System ◽  
Voltage Stability ◽  
Reactive Power ◽  
Cost Minimization ◽  
Operating Cost ◽  
System Stability ◽  
Total Power ◽  
Solar Pv ◽  
Stability Enhancement

Nowadays, many countries have started to implement and installed solar photovoltaic (PV). The initial designs of existing power systems were not integrating with any renewable energy (RE) including PV. So, the small scale PV may not have any effect on these power systems. However, integrating large scale PV might raise several power quality issues including power system stability. Power system stability has become major attention where the main focus is on voltage stability.Voltage stability is related on electrical grid capacity to balance the Total Power of Demand (PD) and Total Power generated by Generator (Pgtt). Instability of the voltage can cause inability of the power system to meet the demand of reactive power. The lack of reactive power will cause instability in the power system.This paper present optimal placement and sizing of PV for stability enhancement and operating cost minimization. In this research, reactive power has gradually increased and Fast Voltage Stability Index (FVSI) is applied to analyze voltage stability. PV is applied to stabilize voltage stability of the power system. Economic Load Dispatch (ELD) is conducted to determine the optimal cost and loss. DEIANT is conducted to optimize the total cost and the total loss after solar PV implementation. Simulation result indicates the effectiveness of the proposed technique for stability enhancement and operating cost minimization.

scholarly journals Assessment of the Impacts of Climate Change on Power Systems: The Italian Case Study

2021 ◽  
Vol 11 (24) ◽  
pp. 11821
Author(s):  
Giuseppe Marco Tina ◽  
Claudio F. Nicolosi
Keyword(s):  
Climate Change ◽  
Power Systems ◽  
Power System ◽  
Electrical Energy ◽  
Meteorological Variables ◽  
System Transformation ◽  
Change Models ◽  
Italian Case ◽  
Wide Range ◽  
The Impact

Climate change due to the greenhouse effect will affect meteorological variables, which in turn will affect the demand for electrical energy and its generation in coming years. These impacts will become increasingly important in accordance with the increasing penetration of renewable, non-programmable energy sources (e.g., wind and solar). Specifically, the speed and amplitude of power system transformation will be different from one country to another according to many endogenous and exogenous factors. Based on a literature review, this paper focuses on the impact of climate change on the current, and future, Italian power system. The paper shows a wide range of results, due not just to the adopted climate change models used, but also to the models used to assess the impact of meteorological variables on electricity generation and demand. Analyzing and interpreting the reasons for such differences in the model results is crucial to perform more detailed numerical analyses on the adequacy and reliability of power systems. Concerning Italian future scenarios, the double impact of uncertainties in national policies and changes in power plant productivity and demand, has been considered and addressed.

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