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Special Issue "Electric Power Systems Research 2019"

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "Electrical Power and Energy System".

Deadline for manuscript submissions: 31 December 2019.

Special Issue Editor

Guest Editor
Prof. Dr. Ying-Yi Hong

Department of Electrical Engineering, Chung Yuan Christian University, Taoyuan City, Taiwan
Website | E-Mail
Interests: smart grid; control and planning for microgrid; intelligent methods applied to power systems

Special Issue Information

Dear Colleagues,

Delivering a reliable power from a generation system through the transmission and distribution systems to the end-users is a main responsibility in a power grid utility. A power system is a large-scale and nonlinear system, which has a latent security, stablility or reliablility problem. Accordingly, the development of advanced technologies and innovative methods applied to the modern power system is crucial. Especially, distributed generation resources, energy storage system, electric vehicle, power electronics, and advanced control devices are addressed in a modern smart power system.

Electric Power Systems Research is a Special Issue in Energies for those who would like to publish original papers about the generation, transmission, distribution, and use of electrical energy. This Special Issue aims at presenting important results of work in electric power systems. The works can be applied research, development of new algorithms or components, original application of existing knowledge, or new facilities applied to power systems. This Special Issue received much attention in 2016, 2017, and 2018 and published many state-of-the-art studies, too.

Papers in the relevant area of Electric Power Systems Research, including but not limited to the following topics, are invited:

  1. Power system stability;
  2. Power system reliability;
  3. FACTS applied to power systems;
  4. Power system optimization;
  5. Intelligent methods applied to power system studies;
  6. Power market and demand response program;
  7. Control of generation systems;
  8. Operation of distribution systems;
  9. Control, operation, and planning of distributed generation resources;
  10. Control, operation, and planning of energy storage system and electric vehicle;
  11. Smart community with energy management systems;
  12. Microgrid and virtual power plant;
  13. Active distribution network;
  14. Harmonics/voltage power quality;
  15. Power system resiliency.

Prof. Dr. Ying-Yi Hong
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Stability
  • Reliability
  • Sustainability
  • Security

Published Papers (11 papers)

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Research

Open AccessArticle
Intelligent Classification Method for Grid-Monitoring Alarm Messages Based on Information Theory
Energies 2019, 12(14), 2814; https://doi.org/10.3390/en12142814
Received: 31 May 2019 / Revised: 13 July 2019 / Accepted: 16 July 2019 / Published: 22 July 2019
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Abstract
Alarm messages for grid monitoring are an important way to supervise the operation of power grids. Since the use of alarm messages is increasing exponentially due to the continuous expansion of the scale of power grids, a processing method for alarm messages based [...] Read more.
Alarm messages for grid monitoring are an important way to supervise the operation of power grids. Since the use of alarm messages is increasing exponentially due to the continuous expansion of the scale of power grids, a processing method for alarm messages based on statistics is proposed in this study. Entropy theory in information theory is introduced into the calculation of information value in power-grid alarming. By means of multiple entropy definitions, an evaluation index system for information value is constructed. Based on the analytic hierarchy process (AHP), various alarm-message entropies are used as indices to comprehensively assess the information value and level of each alarm message. Finally, an example is given to illustrate the effectiveness and practicality of the proposed method. This study provides a new idea for the intelligent classification of alarm messages. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
Application of Ordinal Optimization to Reactive Volt-Ampere Sources Planning Problems
Energies 2019, 12(14), 2746; https://doi.org/10.3390/en12142746
Received: 2 July 2019 / Revised: 15 July 2019 / Accepted: 16 July 2019 / Published: 17 July 2019
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Abstract
Reactive volt-ampere sources planning is an effort to determine the most effective investment plan for new reactive sources at given load buses while ensuring appropriate voltage profile and satisfying operational constraints. Optimization of reactive volt-ampere sources planning is not only a difficult problem [...] Read more.
Reactive volt-ampere sources planning is an effort to determine the most effective investment plan for new reactive sources at given load buses while ensuring appropriate voltage profile and satisfying operational constraints. Optimization of reactive volt-ampere sources planning is not only a difficult problem in power systems, but also a large-dimension constrained optimization problem. In this paper, an ordinal optimization-based approach containing upper and lower level is developed to solve this problem efficiently. In the upper level, an ordinal search (OS) algorithm is utilized to select excellent designs from a candidate-design set according to the system’s structural information exploited from the simulations executed in the lower level. There are five stages in the ordinal search algorithm, which gradually narrow the design space to search for a good capacitor placement pattern. The IEEE 118-bus and IEEE 244-bus systems with four load cases are employed as the test examples. The proposed approach is compared with two competing methods; the genetic algorithm and Tabu search, and a commercial numerical libraries (NL) mixed integer programming tool; IMSL Numerical Libraries. Experimental results illustrate that the proposed approach yields an outstanding design with a higher quality and efficiency for solving reactive volt-ampere sources planning problem. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
Harmonic Stability Analysis for Multi-Parallel Inverter-Based Grid-Connected Renewable Power System Using Global Admittance
Energies 2019, 12(14), 2687; https://doi.org/10.3390/en12142687
Received: 20 June 2019 / Revised: 8 July 2019 / Accepted: 10 July 2019 / Published: 12 July 2019
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Abstract
Multi-parallel grid-connected voltage source inverters (VSIs) are widely applied in the fields of renewable energy, energy storage, harmonic suppression, etc. However, these inverters may cause harmonic stability problems due to the interactions among the grid-connected inverters through the grid impedance, which can seriously [...] Read more.
Multi-parallel grid-connected voltage source inverters (VSIs) are widely applied in the fields of renewable energy, energy storage, harmonic suppression, etc. However, these inverters may cause harmonic stability problems due to the interactions among the grid-connected inverters through the grid impedance, which can seriously threaten system stability. The impedance-based stability criterion provides an effective tool for analyzing harmonic instability issues and can be divided into two types, namely, a ratio type and a sum type. Based on the existing studies of the sum-type criterion, this paper further proposes a new sum-type form based on the global admittance from the PCC to assess system stability through frequency-domain analysis. This global admittance-based stability criterion can be used not only to analyze system stability, but also to reveal the influence of each VSI unit on system stability with a lower computational burden and provide guidance for resonance suppression, especially in the case of a large number of grid-connected inverters and asymmetric inverter parameters. Finally, a MATLAB/Simulink model and 400 kVA/400 V experimental platform consisting of six grid-connected VSIs were established, and the corresponding results are presented to verify the effectiveness of the proposed method. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
Nature-Inspired Whale Optimization Algorithm for Optimal Coordination of Directional Overcurrent Relays in Power Systems
Energies 2019, 12(12), 2297; https://doi.org/10.3390/en12122297
Received: 14 May 2019 / Revised: 10 June 2019 / Accepted: 12 June 2019 / Published: 16 June 2019
Cited by 1 | PDF Full-text (5240 KB) | HTML Full-text | XML Full-text
Abstract
In power systems protection, the optimal coordination of directional overcurrent relays (DOCRs) is of paramount importance. The coordination of DOCRs in a multi-loop power system is formulated as an optimization problem. The main objective of this paper is to develop the whale optimization [...] Read more.
In power systems protection, the optimal coordination of directional overcurrent relays (DOCRs) is of paramount importance. The coordination of DOCRs in a multi-loop power system is formulated as an optimization problem. The main objective of this paper is to develop the whale optimization algorithm (WOA) for the optimal coordination of DOCRs and minimize the sum of the operating times of all primary relays. The WOA is inspired by the bubble-net hunting strategy of humpback whales which leads toward global minima. The proposed algorithm has been applied to six IEEE test systems including the IEEE three-bus, eight-bus, nine-bus, 14-bus, 15-bus, and 30-bus test systems. Furthermore, the results obtained using the proposed WOA are compared with those obtained by other up-to-date algorithms. The obtained results show the effectiveness of the proposed WOA to minimize the relay operating time for the optimal coordination of DOCRs. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
Suggestion of a New Protection Scheme for a Transmission System Equipped with a Thyristor-Controlled Series Capacitor
Energies 2019, 12(12), 2250; https://doi.org/10.3390/en12122250
Received: 3 May 2019 / Revised: 1 June 2019 / Accepted: 10 June 2019 / Published: 12 June 2019
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Abstract
A thyristor-controlled series capacitor (TCSC) is employed to a transmission line in order to enhance the usable capacity of the present as well as upgraded lines, improve system stability, reduce losses, and improve power flow control capability. However, in an abnormal situation, the [...] Read more.
A thyristor-controlled series capacitor (TCSC) is employed to a transmission line in order to enhance the usable capacity of the present as well as upgraded lines, improve system stability, reduce losses, and improve power flow control capability. However, in an abnormal situation, the TCSC may transit from the existing operation mode to the other mode according to its control system and protection strategy. There is much difference in the impedance of the TCSC between each mode. This threatens the reliability of the conventional protection system, especially the distance relay, that works based on the measurement of line impedance. In this paper, we suggest a new protection scheme for a distance relay of a transmission line equipped with a TCSC. In the suggested method, in order to mitigate the effect of the TCSC in the fault loop, the TCSC injected voltage is subtracted from the measured phase voltage before supplying the voltage signal to the distance relay. The suggested scheme was verified by a real time digital simulator (RTDS)-based closed-loop test bed of a protective relay. The effect of the TCSC in the fault loop was completely mitigated. The distance relay works properly with the suggested scheme. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
Energy Management Optimization and Voltage Evaluation for Residential and Commercial Areas
Energies 2019, 12(9), 1811; https://doi.org/10.3390/en12091811
Received: 3 April 2019 / Revised: 5 May 2019 / Accepted: 8 May 2019 / Published: 13 May 2019
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Abstract
In most smart grids, load management techniques are required to handle multiple loads of several types. This paper studies decentralized demand-side management (DSM) in a grid with different types of appliances in two service areas: one with many residential households, and one bus [...] Read more.
In most smart grids, load management techniques are required to handle multiple loads of several types. This paper studies decentralized demand-side management (DSM) in a grid with different types of appliances in two service areas: one with many residential households, and one bus with commercial customers. Each building runs an individual optimal DSM to reschedule the usage time of its flexible appliances to reduce its electric energy cost at a manageable sacrifice of inconvenience according to the forecasted time-varying electricity price. Using the developed model, we examined the effectiveness of decentralized DSM by comparing its performance on the operation status of the grid in terms of electricity cost saving, rooftop photovoltaic (PV) utilization efficiency, voltage fluctuation, power loss, voltage rises, and reverse power flows, which can easily be seen at the commercial load bus. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
Novel Protection Scheme considering Tie Switch Operation in an Open-Loop Distribution System using Wavelet Transform
Energies 2019, 12(9), 1725; https://doi.org/10.3390/en12091725
Received: 4 April 2019 / Revised: 19 April 2019 / Accepted: 3 May 2019 / Published: 7 May 2019
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Abstract
Loop power distribution systems are gaining increasing attention due to improvements in the reliability of the power supply and the connection of distributed generation. With loop distribution systems, there is the possibility of mal-operation of the protection relay because of the existence of [...] Read more.
Loop power distribution systems are gaining increasing attention due to improvements in the reliability of the power supply and the connection of distributed generation. With loop distribution systems, there is the possibility of mal-operation of the protection relay because of the existence of the tie switch and bi-directional current injection. In this paper, we propose a novel protection scheme considering the tie switch operation in the open loop power distribution system using wavelet transform. We analyze the possibility of mal-operation of the protection relay as a result of the normal load current after tie switch operation and analyze the characteristics of the normal load current and fault current injection after tie switch operation. Using these results, a new index is proposed to distinguish the normal load current and fault current, and a novel protection scheme based on this new index is proposed. The proposed method is modeled using an electromagnetic transients program and MATLAB, and the various simulations are performed according to the tie switch position, the fault location, and the success or failure of the fault section separation. From the simulation results, we can confirm that the normal load current and the fault current after tie switch operation can be accurately distinguished and the protection relay can accurately operate at only fault conditions. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
A Simplified Model of Coaxial, Multilayer High-Temperature Superconducting Power Cables with Cu Formers for Transient Studies
Energies 2019, 12(8), 1514; https://doi.org/10.3390/en12081514
Received: 1 April 2019 / Revised: 16 April 2019 / Accepted: 17 April 2019 / Published: 22 April 2019
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Abstract
Bypassing transient current through copper (Cu) stabilizer layers reduces heat generation and temperature rise of high-temperature superconducting (HTS) conductors, which could protect HTS cables from burning out during transient conditions. The Cu layer connected in parallel with HTS tape layers impacts current distribution [...] Read more.
Bypassing transient current through copper (Cu) stabilizer layers reduces heat generation and temperature rise of high-temperature superconducting (HTS) conductors, which could protect HTS cables from burning out during transient conditions. The Cu layer connected in parallel with HTS tape layers impacts current distribution among layers and variations of phase resistance in either steady-state or transient conditions. Modeling the multilayer HTS power cable is important for transient studies. However, existing models of HTS power cables have only proposed HTS cables without the use of a Cu-former layer. To overcome this problem, the authors proposed a multilayer HTS power cable model that used a Cu-former layer in each phase for transient study. It was observed that resistance of the HTS conductor increased significantly in the transient state due to a quenching phenomenon, which made the transient current mainly flow into the Cu-former layers. Since resistance of the Cu-former layer has a significant impact on the transient current, detailed modeling of the Cu-former layer is described in this study. The feasibility of the developed HTS cable model is evaluated in the PSCAD/EMTDC program. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
Risk Based Maintenance in the Hydroelectric Power Plants
Energies 2019, 12(8), 1502; https://doi.org/10.3390/en12081502
Received: 21 March 2019 / Revised: 16 April 2019 / Accepted: 17 April 2019 / Published: 20 April 2019
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Abstract
In this study, maintenance planning problem is handled in one of the hydroelectric power plants which directly affect Turkey’s energy supply security with a fifth share in the total generation. In this study, a result is obtained by taking into consideration the multi-objective [...] Read more.
In this study, maintenance planning problem is handled in one of the hydroelectric power plants which directly affect Turkey’s energy supply security with a fifth share in the total generation. In this study, a result is obtained by taking into consideration the multi-objective and multi-criteria structure of the maintenance planning in the hydroelectric power plants with thousands of complex equipment and the direct effect of this equipment on uninterrupted and low-cost electricity generation. In the first stage, the risk levels of the equipment in terms of the power plant are obtained with the combination of AHP (Analytical Hierarchy Process) and TOPSIS (technique for order preference by similarity to ideal solution) which are frequently used in the literature due to their advantages. Department-based maintenance plans of all equipment for periodic and revision maintenance strategies are formed by integrating these values into the time allocated for maintenance and the number of employees constraints. As a result of the application of this methodology which is designed for the first time in the literature with the integration of multi-criteria decision-making methods for the maintenance planning problem in a hydroelectric power plant, all elements that prevent the sustainable energy supply in the power plant are eliminated. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
Short-Term Load Dispatching Method for a Diversion Hydropower Plant with Multiple Turbines in One Tunnel Using a Two-Stage Model
Energies 2019, 12(8), 1476; https://doi.org/10.3390/en12081476
Received: 13 March 2019 / Revised: 13 April 2019 / Accepted: 15 April 2019 / Published: 18 April 2019
Cited by 1 | PDF Full-text (2587 KB) | HTML Full-text | XML Full-text
Abstract
Short-term load dispatching (STLD) for a hydropower plant with multiple turbines in one tunnel (HPMTT) refers to determining when to startup or shutdown the units of different tunnels and scheduling the online units of each tunnel to obtain optimal load dispatch while simultaneously [...] Read more.
Short-term load dispatching (STLD) for a hydropower plant with multiple turbines in one tunnel (HPMTT) refers to determining when to startup or shutdown the units of different tunnels and scheduling the online units of each tunnel to obtain optimal load dispatch while simultaneously meeting the hydraulic and electric system constraints. Modeling and solving the STLD for a HPMTT is extremely difficult due to mutual interference between units and complications of the hydraulic head calculation. Considering the complexity of the hydraulic connections between multiple power units in one tunnel, a two-phase decomposition approach for subproblems of unit-commit (UC) and optimal load dispatch (OLD) is described and a two-stage model (TSM) is adopted in this paper. In the first stage, an on/off model for the units considering duration constraints is established, and the on/off status of the units and tunnels is determined using a heuristic searching method and a progressive optimal algorithm. In the second stage, a load distribution model is established and solved using dynamic programming for optimal load distribution under the premise of the on/off status of the tunnel and units in the first stage. The proposed method is verified using the load distribution problem for the Tianshengqiao-II reservoir (TSQII) in dry season under different typical load rates. The results meet the practical operation requirements and demonstrate the practicability of the proposed method. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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Open AccessArticle
Adaptive Phasor Estimation Algorithm Based on a Least Squares Method
Energies 2019, 12(7), 1387; https://doi.org/10.3390/en12071387
Received: 11 March 2019 / Revised: 2 April 2019 / Accepted: 7 April 2019 / Published: 10 April 2019
PDF Full-text (3007 KB) | HTML Full-text | XML Full-text
Abstract
This paper proposes an adaptive phasor estimation algorithm based on a least square method that can suppress the adverse effect of an exponentially decreasing DC offset component in a phasor estimation process. The proposed algorithm is composed of three stages: a basic least [...] Read more.
This paper proposes an adaptive phasor estimation algorithm based on a least square method that can suppress the adverse effect of an exponentially decreasing DC offset component in a phasor estimation process. The proposed algorithm is composed of three stages: a basic least squares model, a time constant calculation, and an adaptive least squares model. First, we use the basic least squares model to estimate the parameter of the DC offset component in the fault current signal. This model is designed to incorporate fundamental frequency, and harmonic and constant components. Second, we use the estimated parameter to calculate the time constant of the DC offset component. Third, we redesign a least squares model that incorporates fundamental frequency, harmonic components, and exponential function of the DC offset component. Since this model incorporates the exponential function of the DC offset component contained in the fault current signal, it estimates the phasor of the correct fundamental frequency component without influence of the DC offset component. We evaluated the performance of the proposed algorithm using computer generated signals and EMTP simulation signals. The evaluation results show that the proposed algorithm can effectively suppress the adverse influence of the exponentially decaying DC offset component. Full article
(This article belongs to the Special Issue Electric Power Systems Research 2019)
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