Power System Technology Research Articles

High-temperature superconductor-based power and propulsion system architectures as enablers for high power missions

The increasing competitiveness of electric propulsion systems (EPS) for primary spacecraft propulsion has paved the way for higher payload mass fractions by offering significantly higher specific impulses than chemical systems. Concurrently, High-Temperature Superconductors (HTS) have reached an unprecedented level of industrial maturity in recent years, and considering their low masses, compactness, and high current densities, they offer the potential to act as a disruptive technology in several spaceflight applications such as power management systems, re-entry and radiation shielding as investigated in the EU-funded MEESST project, as well as EPS. In the latter case, efforts are already ongoing to develop an HTS-enhanced Applied-Field Magnetoplasmadynamic (AF-MPD) thrusters for high power mission applications. The Tsiolkovsky equation infers that the payload mass fraction increases indefinitely with increased Specific Impulse (Isp), however, in the case of electric propulsion, the dependence of thrust on the available power complicates this issue when transfer time is a primary driver. Here, the Tsiolkovsky equation becomes inadequate and considering a non-dimensional version of the Tsiolkovsky equation in terms of the mission ΔV and transfer time, the EPS thrust efficiency, and the specific mass of the power system becomes necessary. This paper first discusses the recent advances in HTS and their suitability for spaceflight, before reviewing The development of power system technologies is reviewed and a conceptual power system architecture incorporating HTS is presented. These technologies are analysed using a non-dimensional Tsiolkovsky approach and their impacts on the overall payload mass fraction are assessed. For high-power missions (>100 kW), the use of HTS is shown to have a highly beneficial impact on the mass of the power system. Correspondingly, this enables higher payload mass fractions achievable at increased specific impulse operation, thus strengthening the case for high-power, high-Isp EPS technologies such as AF-MPDT.

Analytical approach for adequacy assessment of cyber–physical multi-microgrid distribution systems with distributed generation

In recent years, there has been a marked increase in the deployment of information and communication technologies (ICTs) in power systems. ICTs impart a cyber-physical nature to power systems, and though they improve the power system performance in various respects, they themselves are prone to random failures. With even more extensive penetration of ICTs expected to strongly characterise the future power systems, it is imperative to systematically study the impact of failures in cyber-physical power systems on the adequacy of power systems. With this as backdrop, the paper presents a novel analytical approach to study the impact of failure of various control layers and the cyber links between them on the adequacy of multi-microgrid distribution systems consisting of distributed generation resources such as wind and solar units. The main adequacy index of interest is Expected Energy Not Served, based on which the interruption costs can be computed. A case study is presented where the developed methodology is applied to a multi-microgrid distribution system where four different operation modes are realisable—normal, joint, islanding, and shutdown modes. The results are validated against those of a recently developed Monte Carlo simulation approach.

Analysis on Application of Relay Protection Technology in Power System

Analysis on Application of Relay Protection Technology in Power System

Optimal Placement and Operation of FACTS Technologies in a Cyber-Physical Power System: Critical Review and Future Outlook

With the current transitioning and increasing complexity of power systems owing to the continuous integration of distributed generators (DGs) and Flexible AC Transmission Systems (FACTS), power system quality and security studies have extended to incorporate the impacts of these technologies. This paper presents a review of the operation and reliability impacts of FACTS technologies in improving power quality and security in modern Cyber-Physical Power Systems (CPPS). While introducing DG to the power system helps to decentralize the network for easy accessibility and enhances clean energy system, it creates new challenges such as harmonics, voltage instability, and frequency distortion. These challenges can be tackled with FACTS devices which are flexible and dynamic smart electronic controllers used to stabilize power system parameters to improve power quality and reliability. This paper examines the current state-of-the-art optimization techniques and artificial intelligence and/or computational techniques for optimal placement and operation of FACTS devices. This review highlights the generational advancement of FACTS technologies and the different objectives of optimal placement and operation of these devices. Moreover, the concept of CPPS is discussed with the potential utilization of distribution-FACTS (D-FACTS) devices for network security. Furthermore, a bibliometric analysis was carried out to show research trend of FACTS utilization. The result presents future trajectories for power utility industries and researchers interested in power system optimization and the application of FACTS technologies in smart power system networks. Some of the significant findings leads to proposed demand-side management for placement of DGs and FACTS technologies as a more strategic optimal system sizing to minimize cost. It was also concluded that future design of FACTS/D-FACTS devices must consider and appreciate interactions with the automated systems of CPPS to enhance effective integration. To this end, design modification of the operational configuration of these devices with sensors for real-time synchronized control and interaction with other CPPS technologies is an area that requires more research attention in the future.

IMPACT OF THE SMART GRID SYSTEM ON THE NATIONAL ENERGY NETWORK

Modern power system technologies offer the integration of renewable energy in electricity grids, intelligent metering, bidirectional communication between power generation units and the central control system for energy production and consumption, prevention of power outages, sustainable and safe energy sources, and energy security. Moreover, the modern energy system requires control, measurement and cybersecurity of energy processes at every point of the grid.
 The infrastructure of the national networks of many countries is very old and includes classic technologies of production, transmission and distribution of electricity. In addition, the controllability and managebility of these systems are also unsatisfactory. On the other hand, Smart Grid technologies include sophisticated tools to monitor and control the power system in both directions from power plants to end users or vice versa so that vulnerabilities can be identified in advance and the necessary measures taken. In addition, the smart grid system offers monitoring and management of electricity from production to the end user, as well as provides smart accounting, integration of renewable energy into the grid. Morover, the efficient use of energy sources with minimal losses and minimal illegal use is also addressed in smart grid technology. This article highlights the impact of smart grid technologies on national power grids and offers some useful suggestions for transforming their classic power grid system into a Smart Grid grid system.
 Transforming the classic network into an intelligent one fills its own business areas and provides increased efficiency, loss reduction, flexible price for consumers, safe and stable electricity, as well as reliable and digital infrastructure.
 As a result, building a Smart Grid is a complex task, starting with a detailed quantification of system requirements, determining the actual goals and the levels of operation needed to achieve them. This research will be an effective and efficient tool for researchers, engineers, transmitter operators and distributors to transform the classical national energy system into an intelligent energy system.

Applications of Blockchain Technology in Modern Power Systems: A Brief Survey

In the context of modern power system development to support the evolution towards green energy and carbon-neutral emission goals, many existing problems and even challenges demand new technical solutions. In recent years, decentralized blockchain technology has been employed to address some problems in power systems, and many papers have been published. In this paper, the concept of blockchain is first introduced. A brief survey of the existing publications regarding the applications of blockchain in power systems, including power system dispatching, microgrid operation, energy trading, electricity trading settlement, transmission, and distribution system operation, is then carried out. In addition, several application scenarios of blockchain technology in power systems are also introduced. Through the discussion, we found that we still need to weigh the advantages and disadvantages, overcome its leakage, and bring its value into play if we apply blockchain technology in modern power systems in support of zero carbon goals.

Evaluation of false data injection attacks on automatic generation control considering wind power dynamics

The automatic generation control (AGC) system is a crucial control system based on information and communication technology in interconnected power systems. However, the dependence on cyber systems has increased the risk of false data injection attacks (FDIAs) against AGC systems. Furthermore, as the penetration level of wind power increases, an AGC dynamic framework incorporating wind stochastic modeling should be developed, and the impact of FDIAs on AGC considering wind power penetrations should also be evaluated. This paper proposes an evaluation method of the impact of FDIAs on AGC considering wind power penetrations. First, a linearized analysis framework is developed, in which the network model is considered due to its geographical smoothing effects. Then, stochastic differential equations (SDEs) are employed to model wind power and load temporal uncertain behaviors, and the overall system dynamics under different FDIA types are also proposed. Finally, the proposed methodology is illustrated via a 4-area practical AGC system. The simulation results show the effects of different types of attacks on the AGC system considering wind power penetrations and demonstrate that the existing evaluation frameworks may overestimate FDIA effects and wind power fluctuation and corresponding system inertia reduction may help the attacker to cause system instability.

The Architecture Optimization and Energy Management Technology of Aircraft Power Systems: A Review and Future Trends

With the development of More/All-Electric Aircraft, especially the progress of hybrid electrical propulsion or electrical propulsion aircraft, the problem of optimizing the energy system design and operation of the aircraft must be solved regarding the increasing electrical power demand-limited thermal sink capability. The paper overviews the state of the art in architecture optimization and an energy management system for the aircraft power system. The basic design method for power system architecture optimization in aircraft is reviewed from the multi-energy form in this paper. Renewable energy, such as the photo-voltaic battery and the fuel cell, is integrated into the electrical power system onboard which can also make the problem of optimal energy distribution in the aircraft complex because of the uncertainty and power response speed. The basic idea and research progress for the optimization, evaluation technology, and dynamic management control methods of the aircraft power system are analyzed and presented in this paper. The trend in optimization methods of engineering design for the energy system architecture in aircraft was summarized and derived from the multiple objective optimizations within the constraint conditions, such as weight, reliability, safety, efficiency, and characteristics of renewable energy. The cost function, based on the energy efficiency and power quality, was commented on and discussed according to different power flow relationships in the aircraft. The dynamic control strategies of different microgrid architectures in aircraft are compared with other methods in the review paper. Some integrated energy management optimization strategies or methods for electrical propulsion aircraft and more electric aircraft were reviewed. The mathematical consideration and expression of the energy optimization technologies of aircraft were analyzed and compared with some features and solution methods. The thermal and electric energy coupling relationship research field is discussed with the power quality and stability of the aircraft power system with some reference papers. Finally, the future energy interaction optimization problem between the airport microgrid and electric propulsion aircraft power system was also discussed and predicted in this review paper. Based on the state of the art technology development for EMS and architecture optimization, this paper intends to present the industry’s common sense and future trends on aircraft power system electrification and proposes an EMS+TMS+PHM to follow in the electrified aircraft propulsion system architecture selection

Vacuum Switching Technology for Future of Power Systems

• China pledged to achieve carbon neutrality in 2060 at COP21. • Vacuum is a preferred alternative to SF 6 in switching in future power systems. • Fast vacuum circuit breaker can interrupt a fault current in the first half-cycle. • Fast vacuum switching technology is promising for accurate controlled switching. • Future power systems could benefit from the application of fast vacuum switches. • Vacuum switching technology is changing the future of power systems. Even though switching in vacuum is a technology with almost 100 years of history, its recent developments are still changing the future of power transmission and distribution systems. First, current switching in vacuum is an eco-friendly technology compared to switching in SF 6 gas, which is the strongest greenhouse gas according to the Kyoto Protocol. Vacuum, an eco-friendly natural medium, is promising for reducing the usage of SF 6 gas in current switching in transmission voltage. Second, switching in vacuum achieves faster current interruption than existing alternating current (AC) switching technologies. A vacuum circuit breaker (VCB) that uses an electromagnetic repulsion actuator is able to achieve a theoretical limit of AC interruption, which can interrupt a short-circuit current in the first half-cycle of a fault current, compared to the more common three cycles for existing current switching technologies. This can thus greatly enhance the transient stability of power networks in the presence of short-circuit faults, especially for ultra- and extra-high-voltage power transmission lines. Third, based on fast vacuum switching technology, various brilliant applications emerge, which are benefiting the power systems. They include the applications in the fields of direct current (DC) circuit breakers (CBs), fault current limiting, power quality improvement, generator CBs, and so forth. Fast vacuum switching technology is promising for controlled switching technology in power systems because it has low variation in terms of opening and closing times. With this controlled switching, vacuum switching technology may change the “gene” of power systems, by which power switching transients will become smoother.

Recurrent neural network with density-based clustering for group pattern detection in energy systems

This research explores a new direction in power system technology and develops a new framework for pattern group discovery from large power system data. The efficient combination between the recurrent neural network and the density-based clustering enables to find the group patterns in the power system. The power system data is first collected in multiple time series data and trained by the recurrent neural network to find simple patterns. The simple patterns are then studied, and analyzed with the density-based clustering algorithm to identify the group of patterns. The solution was analyzed in two case studies (pattern discovery and outlier detection) specifically for power systems. The results show the advantages of the proposed framework and a clear superiority compared to state-of-the-art approaches, where the average correlation in group pattern detection is 90% and in group outlier detection more than 80% of both true-positive and true-negative rates.

Research on Energy Storage Technology in the New Energy Power System

Research on Energy Storage Technology in the New Energy Power System

Preface

We are glad to introduce you that the 2022 International Conference on Green Energy and Power Systems(ICGEPS 2022) was successfully held from 14 to 16 January, 2022. Considering worldwide travel restriction and the impact of COVID-19, ICGEPS 2022 was carried out in the form of virtual conference to avoid personnel gatherings. Because most participants were still highly enthusiastic about participating in this conference, we chose to carry out ICGEPS 2022 via online platform according to the original schedule instead of postponing it.The conference aimed to provide a platform for experts and scholars to discuss the global development of green energy and power-related technologies, thus promoting the sustainable development of energy. Meanwhile, we also held a technical seminar on energy sustainable development and technologies for clean energy innovation as well as green energy development. Welcome experts and scholars in related fields to contribute actively and take time to attend the conference.This scientific event brings together more than 120 national and international researchers in Green Energy and Power Systems. On top of the local participants coming from different national universities, international participants are also registered from different countries, namely Iran, Ethiopia, Ukraine and Malaysia. During the conference, the conference model was divided into three sessions, including oral presentations, keynote speeches, and online Q&A discussion. In the first part, some scholars, whose submissions were selected as the excellent papers, were given about 5-10 minutes to perform their oral presentations one by one. Then in the second part, keynote speakers were each allocated 30-45 minutes to hold their speeches.In the second part, we invited five professors as our keynote speakers. Prof. Zhiyuan Zhu, Southwest University, performed a speech: Self-powered 3D integrated microsystem and artificial intelligence. And then we had Prof. Pan Hui, Institute of Applied Physics and Materials Engineering, Department of Physics and Chemistry, Faculty of Science and Technology, University of Macau. He presented an insightful speech: Design and Fabrication of Electrocatalysts for Water Oxidization. Prof. Zainal Kadir, Faculty of Engineering, University Putra Malaysia, Malaysia, performed a speech: Future Grid Optimisation Through Innovative Technologies. Prof. Chris Mi, San Diego State University, USA. He delivered a wonderful speech: Cost-Effective Integration of Second-Life EV Batteries with Solar PV Systems for Commercial Buildings. Prof. Steivan Defilla, our finale keynote speaker, from Tianjin University. Their insightful speeches had triggered heated discussion in the third session of the conference. Every participant praised this conference for disseminating useful and insightful knowledge.The proceedings are a compilation of the accepted papers and represent an interesting outcome of the conference. Topics include but are not limited to the following areas: Power Systems, Energy and Development Technology and more related topics. All the papers have been through rigorous review and process to meet the requirements of International publication standard.We would like to acknowledge all of those who supported ICGEPS 2022. The help and contribution of each individual and institution was instrumental in the success of the conference. In particular, we would like to thank the organizing committee for its valuable inputs in shaping the conference program and reviewing the submitted papers.The Committee of ICGEPS 2022 Lists of title Committee member, Conference General Chair, Organizing Committee (In no particular order), Technical Program Committee (In no particular order) are available in this Pdf.

A general model of optimal energy storage operation in the market conditions

In liberalized electricity markets, energy storage devices, especially those with high capacity, can generate income through multiple services. In this paper, a general model of energy storage operation, suitable for different optimizations and comparisons of various storage technologies in market-oriented power systems, is presented. The objective function maximizes the possible income of storage units (based on the daily operation cycle) earned from energy arbitration and several ancillary services, considering various constraints and market rules for service providers. The mixed integer linear programming (MILP) optimization technique is used to solve the objective function. In numerical examples, the optimal operation modes and possible incomes for typical battery and typical pumped storage hydropower plant (PSHP), using the achieved electricity market prices of energy and the ancillary services (regulation-up, regulation-down and spinning reserve services) in one year, were compared. The influence of the efficiency coefficient, as well as the influence of various PSHP inflows on storage policy, were investigated. The proposed model has proven robust and applicable for various analyses of storage unit operations. The performed numerical calculations have shown that with the decreasing of storage device efficiency coefficient, the incomes generated through ancillary services become more significant.

Power system security simulation technologies: engineering safety, network security and cyber-physical integrated security

Power system security simulation technologies study system behaviors via simulation experiments or numerical calculations to deal with security threats such as system faults and external attacks. With the wide application of information technologies such as automatic control, network communication, and artificial intelligence, the power system has developed into a cyber-physical system (CPS), where the physical and information systems are deeply coupled. Faults caused by physical damage or network attacks are interrelated in the power system and can spread across domains, resulting in new security threats. Therefore, power system security simulation is facing new challenges. This paper reviewed the security incidents that have significantly impacted the power system and analyzed the requirement and development of security simulation technologies for power systems from three dimensions: engineering security, network security, and cyber-physical integrated security. Therefore, the representative security simulation testbeds were classified and summarized. Moreover, the challenges and development trends of the power system security simulation technologies were explored.

A Proposal of a Scheduled Operation Method for VPP Consisting of PV and Battery to Reduce Output Suppression

The renewable energy resources such as the photovoltaic generation and the wind turbine generation are rapidly being introduced. In order to compensate the surplus and shortage of those output, the energy storage system such as the battery is expected to become the key technology in the future power system. In this paper, we focus on the scheduled operation of the virtual power plant (VPP) which is composed by distributed photovoltaic generations and the battery. The battery was installed to reduce the imbalance of the generated output from the scheduled output caused by the forecast error in our previous study. As the additional role for the battery, when the transmission system operator commands the upper limit of the VPP output, charging the surplus output over the upper limit is taken into consideration. The annual computational simulation of the VPP operation is implemented to show the effectiveness of the proposed method. To evaluate the performance, the accumulated value of the imbalance, the output suppression, the generated output and discharge are calculated.

Operation Status Monitoring of Transmission Tower in Power System based on Data Fusion

This paper studies the application of data fusion technology in power system to solve some difficult problems in this complex energy system. A transmission tower identification and bird nest detection method based on corner, line, color and shape features is proposed. Through LSD (Line Segment Detection) and Harris corner detection method, the straight line segment and corner point in the image are extracted respectively. Combined with triangle method, the actual tilt angle of tower is measured; According to the nesting rule of birds in transmission towers, the basic unit segmentation algorithm of transmission towers is proposed, and the basic unit segmentation of transmission towers is realized by using the local maximum of the target pixel row statistical histogram. The algorithm proposed in this paper can effectively solve the problems of on-line measurement of tilt angle of transmission tower and on-line detection of bird's nest, which will lay a theoretical foundation for on-line monitoring of transmission tower status.

Simulation of freight trains with up to three traction units in radio communication

Paper reports the main results of a systematic study on longitudinal train dynamics (LTD) of long freight trains, equipped with radio communication. The simulation results have been used to prepare an experimental test campaign to test the Distributed Power System (DPS) technology. The simulations refer to up/down and level track and they compare the LTD of trains with and without DPS, for different train operations and radio link conditions. The DPS technology is proved (by simulations and test) to be a very effective way to increase the efficiency of future freight trains.

Perspectives on Future Power System Control Centers for Energy Transition

Today's power systems are seeing a paradigm shift under the energy transition, sparkled by the electrification of demand, digitalisation of systems, and an increasing share of decarbonated power generation. Most of these changes have a direct impact on their control centers, forcing them to handle weather-based energy resources, new interconnections with neighbouring transmission networks, more markets, active distribution networks, micro-grids, and greater amounts of available data. Unfortunately, these changes have translated during the past decade to small, incremental changes, mostly centered on hardware, software, and human factors. We assert that more transformative changes are needed, especially regarding humancentered design approaches, to enable control room operators to manage the future power system. This paper discusses the evolution of operators towards continuous operation planners, monitoring complex time horizons thanks to adequate real-time automation. Reviewing upcoming challenges as well as emerging technologies for power systems, we present our vision of a new evolutionary architecture for control centers, both at backend and frontend levels. We propose a unified hypervision scheme based on structured decision-making concepts, providing operators with proactive, collaborative, and effective decision support.

An Overview on Reliability Analysis and Evaluation Methods Applied to Smart Grids

The reliability can be defined as to carry out predefined requirements in a predefined duration. The importance of reliability analysis increases day by day as the customers become more conscious about a product or service which they buy. The application area of reliability analysis is very wide. Any product\ system or service including smart grids can be subject of the reliability analysis. As power system technology and computer science improving, the concept of smart grids begins to take part in our lives. Therefore, it is very essential to make reliability analysis for smart grids. In this paper, reliability analysis methods applied to smart grids are focused on and the classifications in reliability analysis have been explained. Besides, distribution networks reliability concept and different methods such as simulation and analytical approaches to assess the reliability have been introduced. The applications of these methods on smart grids are well explained. In addition to these, smart grids and conventional grid is compared. Different approaches such as tree analysis, failure mode effect analysis, Markov process and Monte Carlo simulation methods are carried out with wind turbines.

Emerging Technologies in Power Systems

Recently, renewable energy resources have been connected to the power system to reduce carbon emissions worldwide [...]