Power System Architecture Research Articles

Enhancing Renewable Energy-Grid Integration by Optimally Placed FACTS Devices: The Nigeria Case Study

Integrating renewable energy sources into existing power grids presents considerable challenges, especially with the intermittency of wind and solar power. This issue is particularly acute in developing countries like Nigeria, where grid infrastructure is often weak, significantly limiting the potential for RE penetration. This study explores strategies to enhance RE integration in Nigeria by employing Flexible Alternating Current Transmission System (FACTS) devices. By leveraging the reactive-power sensitivity index through modal analysis, the optimal location for the FACTS device can be determined. Analysis of the Nigerian power grid demonstrates that the deployment of FACTS devices, specifically Static Synchronous Compensators (STATCOMs), can increase the penetration limit of RE by 40%. This enhancement allows for the integration of an additional 152 MW of wind energy without compromising system stability. The findings underscore the potential of FACTS devices to improve voltage profiles and overall grid stability, thereby facilitating a higher integration of renewable energy sources into weak grids without necessitating substantial changes to the existing power system architecture. This solution can help Nigeria and other countries with similar infrastructure challenges to overcome their renewable energy integration hurdles and transition towards a more sustainable, reliable, and resilient energy mix, paving the way for a cleaner and greener future.

Hybrid energy storage systems for high power spacecraft missions

This work aims to analyze the feasibility of utilizing hybrid storage systems to enable the operation of high-power payloads during eclipse periods. The main objective of the study is to reach possible configurations with the same performance as traditional designs, but with reduced mass and/or volume, or to maintain the mass and volume while increasing the peak power capabilities. The proposed solution involves the use of supercapacitors and high-energy lithium-ion cells, with the former serving to meet peak loads and the latter supplying the mean power needs. Additionally, a simple architecture for the electrical power system is proposed, and the sizing equations for the supercapacitors and lithium-ion cells are derived from the governing power and energy balance equations. The results allow well-founded decision-making process on the suitability of the hybrid configuration based on the peak power demand and its duration, as well as the mean power demand during eclipse operations.

Intelligent agents for advanced power system protection schemes

This study explores the incorporation of intelligent agents to improve power system safety, using several computational models including machine learning, rule-based systems, neural networks, and fuzzy logic. The research assesses the effectiveness and efficiency of these agents in promptly identifying, categorizing, and responding to faults in the power system architecture using empirical analysis. The results demonstrate the higher performance of agents based on neural networks, with an average improvement in fault prediction accuracy of 38% compared to systems based on rules. Furthermore, the evaluation of power system devices demonstrates a direct relationship between greater voltage ratings and increased expenses for both installation and maintenance, underscoring their crucial importance within the system. An examination of fault severity reveals that greater severity failures have a direct and significant influence on system downtime. These problems lead to longer interruptions, which emphasizes the need of implementing effective fault management systems. Intelligent agents' actions have different costs and reaction times. Actions based on neural networks have lower average costs and shorter response times, demonstrating their cost-effectiveness and efficiency in addressing faults. The study of percentage change highlights the importance of using various kinds of intelligent agents and higher-rated devices. This research offers insights into performance differences and the consequences for optimizing protection measures. This research provides a thorough understanding of how intelligent agents may enhance power system protection. It also offers guidance for future improvements in creating power grid infrastructures that are robust, dependable, and adaptable.

LCA of a Proton Exchange Membrane Fuel Cell Electric Vehicle Considering Different Power System Architectures

Fuel cell electric vehicles are a promising solution for reducing the environmental impacts of the automotive sector; however, there are still some key points to address in finding the most efficient and less impactful implementation of this technology. In this work, three electrical architectures of fuel cell electric vehicles were modeled and compared in terms of the environmental impacts of their manufacturing and use phases. The three architectures differ in terms of the number and position of the DC/DC converters connecting the battery and the fuel cell to the electric motor. The life cycle assessment methodology was employed to compute and compare the impacts of the three vehicles. A model of the production of the main components of vehicles and fuel cell stacks, as well as of the production of hydrogen fuel, was constructed, and the impacts were calculated using the program SimaPro. Eleven impact categories were considered when adopting the ReCiPe 2016 midpoint method, and the EF (adapted) method was exploited for a final comparison. The results highlighted the importance of the converters and their influence on fuel consumption, which was identified as the main factor in the comparison of the environmental impacts of the vehicle.

Optimal reconciliation of hierarchical wind power forecasts of correlated wind farms

Wind power forecasts of widely distributed wind farms in a spatial hierarchy are required at different hierarchical levels of power system architecture for various operational decisions. Accurate hierarchical forecasts necessitate aggregation consistency across hierarchy i.e. lower-level forecasts summate precisely to higher-level forecasts. Aggregation consistency substantially improves through optimal reconciliation of forecasts. Reconciliation can further improve forecast accuracy by incorporating spatial correlation among wind farms in the hierarchy. However, covariance matrix formed in reconciliation observes matrix order to increase manifold while including correlation. Estimation of such high-dimensional matrix is computationally complex. Additionally, aggregation of estimation errors leads to poor estimation accuracy. Moreover, in this reconciliation process, covariance matrix based on the observed data is non-invertible as the number of predictors usually happens to be larger than sample size. This work proposes MinT(Shrink) estimator for covariance matrix estimation for such systems. This estimator captures correlation among wind farms while shrinks off-diagonal elements of covariance matrix toward zero to alleviate computational complexity of high-dimensional matrix. It also provides invertible covariance matrix by employing shrinkage parameter λ. Case study presents efficacy of considering spatial correlation in hierarchical wind power forecasts in terms of improved forecast accuracy at all hierarchy levels and time horizons.

Dynamic modelling, simulation, and control of hybrid power systems for escort tugs and shuttle tankers

The maritime industry targeted shipping decarbonization over the past few years for achieving stakeholders’ expectations and also to abide by the environmental global agenda. For that, increasing energy efficiency and reducing pollutant gas emissions are key objectives. Thus, alternatives, such as hybrid power systems and the use of alternative fuels, emerge as promising solutions to meet stakeholders’ and society’s expectations. This paper proposes hybrid power system architectures for an escort tug and for a shuttle tanker, which are vessels largely used in the oil and gas sector. We analyze different control strategies of these systems, namely Rule-Based method, Equivalent Consumption Minimization Strategy (ECMS), Adaptive-ECMS and Model Predictive Control (MPC), using numerical modeling and simulations, comparing their performance with those of traditional power systems. The most efficient designs showed reductions in fuel consumption of up to 18.9% for tugs, and 2% for shuttle tankers.

A review of the different power system architecture at the district level and its analysis

The new power system at the station level is the phased product of the large-scale and high-proportion penetration development of wind and solar new energy. The source network load storage system with the station area as the smallest adjustable unit is constructed by using energy storage +. Different from the traditional substation area system, the architecture of the new power system at the substation area level becomes extremely complex due to the change of access terminal attributes, interaction relationship and various business types. In order to systematically describe the new power system architecture at the station district level, this paper first combs and summarizes the relevant literature at home and abroad, and summarizes the literature related to the current substation District, wind and new energy access and energy storage system regulation. Secondly, from the perspectives of demand differences, common functional requirements and non functional requirements, the requirements of station area level new power system under different application scenarios are classified and analyzed in detail. Then, a new power system for different scenarios is designed, which is divided into local equipment layer, edge control layer, station management layer and centralized control layer from bottom to top, and the functions of each layer are described in detail. Taking Zhangjiajie scenery storage and charging comprehensive energy demonstration project as an example, this paper expounds the ways of terminal data access, transmission and visualization under the framework of Taiwan district level new power system, so as to provide reference for the networking of other similar projects. Finally, the research contents of this paper are summarized, and the contents that need further research in the future are prospected.

State-of-the-Art Review on Shipboard Microgrids: Architecture, Control, Management, Protection, and Future Perspectives

Shipboard microgrids (SBMGs) are becoming increasingly popular in the power industry due to their potential for reducing fossil-fuel usage and increasing power production. However, operating SBMGs poses significant challenges due to operational and environmental constraints. To address these challenges, intelligent control, management, and protection strategies are necessary to ensure safe operation under complex and uncertain conditions. This paper provides a comprehensive review of SBMGs, including their classifications, control, management, and protection, as well as the most recent research statistics in these areas. The state-of-the-art SBMG types, propulsion systems, and power system architectures are discussed, along with a comparison of recent research contributions and issues related to control, uncertainties, management, and protection in SBMGs. In addition, a bibliometric analysis is performed to examine recent trends in SBMG research. This paper concludes with a discussion of research gaps and recommendations for further investigation in the field of SBMGs, highlighting the need for more research on the optimization of SBMGs in terms of efficiency, reliability, and cost-effectiveness, as well as the development of advanced control and protection strategies to ensure safe and stable operation.

Single-Inductor Multiple-Input–Multiple-Output Converter for CubeSats Electric Power System

State-of-the-art CubeSat electric power system (EPS) architectures employ multiple dc-dc converters to regulate the load voltage and maximize the solar energy harvest. However, this leads to the use of multiple bulky inductors in the CubeSat EPS which is much constrained by strict volume and weight restrictions. With the aim of achieving smaller EPS footprint, this paper presents a new single-inductor based multiple-input multiple-output (MIMO) converter for CubeSat EPS. The operational principles of the proposed converter and its steady-state analysis are discussed, and converter modeling is performed. A control strategy is developed to achieve voltage regulation of the CubeSat loads and maximum power point tracking (MPPT) for the PV panels under a wide-range of irradiation conditions. An experimental prototype based on the 1U CubeSat specifications is developed to validate the performance of the proposed MIMO converter.

Design rules to establish a credible More‐Electric Engine baseline power architecture concept

AbstractThe More‐Electric Engine (MEE), with its electrified engine auxiliary systems and increased multi‐shaft power offtake, is likely to become an increasingly central aspect of future More‐Electric Aircraft. Consequently, lightweight but resilient electrical power architectures are needed for these future MEE applications. However, whilst a range of MEE architectures exist in the research literature, no effective baseline architecture or standardised feature identification has been proposed to specifically address their unique design requirements. Accordingly, any underpinning technology‐focused research for critical MEE subsystems may ultimately have a reduced effectiveness without this credible baseline. Based on comprehensive design analyses, preliminary design requirements and anticipated operational modes, this article proposes key design rules for the formation of the first generic baseline MEE electrical power system architecture concept. Guidance is provided on features such as the number of power generation systems, the number and topologies of distribution channels, type of power conversion, essential load redundancy, and the location of emergency power supply. This article also provides full transparency of the design process so that key decision points can be revisited to capture application‐specific requirements and updates to certification requirements.

Current Trends in Electric Vehicle Charging Infrastructure; Opportunities and Challenges in Wireless Charging Integration

Nowadays, the imperative need for the reduction of Greenhouse Gas (GHG) emissions leads to the wider adoption of environmentally friendly transportation means. As a result, various policies underpinning the Electric Vehicle (EV) deployment are legislated globally, and several technical advances contributing to the electrification of the transportation sector are pursued. In this paper, a comprehensive overview of the current status of the infrastructure utilized for the realization of both conductive and contactless (wireless) charging of an EV battery is conducted. Furthermore, the issue of EV integration in conventional distribution networks, as well as in future power system architectures, is discussed in detail. Particular focus is given to wireless (i.e., inductive) charging. A detailed presentation of the respective standards and charging levels, as well as the magnetic couplers and the compensation network configurations, is carried out. Moreover, innovative concepts such as dynamic and quasi-dynamic wireless charging, as well as future challenges and opportunities, are presented and discussed. Finally, smart control and communication techniques applicable to EV charging are presented in the context of the future Internet of Energy (IoE) concept.

Design of a delay dependent wide area damping controller using Cyber–Physical Power System architecture

With the wide application of information and communication technology in power grids, the integration and collaboration of information networks and physical grid have become an essential feature of the smart grid, constituting a typical power information physical system. However, information network has communication time delay problem, which tends to deteriorate the system controller performance or even counter-tune, leading to system instability. To effectively reduce low-frequency oscillation of the wide-area interconnected grid and overcome the negative impact of the communication network’s delay problem, a delay dependent Wide Area Damping Controller(WADC) is designed using cyber–physical power system architecture. First, we establish a power information physical system simulation platform based on Object linking and embedding for Process Control (OPC) technology, implementing the joint operation of the power system simulation tool DIgSILENT and the information system simulation tool MATLAB. The platform can effectively respond to the system’s information system and physical system interaction effects during simulation. Then, to compensate for communication delays in the power information physical system, this paper proposes a new WADC strategy that uses a Model Predictive Controller (MPC) to generate control commands and an adaptive time delay compensator to compensate for the random communication delays generated in the communication. Finally, a case study with various uncertainties and through the interference test of a four-machine system and 39 bus system, the proposed control strategy is proposed.

The Possibility of Using Superconducting Magnetic Energy Storage/Battery Hybrid Energy Storage Systems Instead of Generators as Backup Power Sources for Electric Aircraft

The annual growth rate of aircraft passengers is estimated to be 6.5%, and the CO2 emissions from current large-scale aviation transportation technology will continue to rise dramatically. Both NASA and ACARE have set goals to enhance efficiency and reduce the fuel burn, pollution, and noise levels of commercial aircraft. However, such radical improvements require radical solutions. With the current traditional aircraft designs based on gas turbines or piston engines, these goals are infeasible. Small-scale aircraft have successfully proven emission reductions using energy storage systems, such as Alice aircraft. This paper involves an investigation of the possibility of using superconducting magnetic energy storage (SMES)/battery hybrid energy storage systems (HESSs) instead of generators as backup power sources to improve system efficiency and reduce emissions. Two different power system architectures of electric aircraft (EA) were compared in terms of reliability and stability in a one-generator failure scenario. As weight is crucial in EA designs, the weights of the two systems were compared, including the generators and energy storage systems. The two EA systems were built in Simulink/MATLAB to compare their reliability and stability. With the currently available technologies, based on the energy density of 250 Wh/kg for lithium-ion batteries and a power density of 8.8 kW/kg for generators, the use of the generators as backup sources proved more efficient than the use of HESS. The break-even point was observed at 750 Wh/kg for battery energy density. Any value more than the 750 Wh/kg energy density makes HESS lighter and more efficient than generators.

Short-term day-ahead photovoltaic output forecasting using PCA-SFLA-GRNN algorithm

The work of forecasting solar power is becoming more crucial with directives to regulate the quality of the power and increase the system’s reliability as photovoltaic (PV) sites are being integrated into the architecture of power systems at an increasing rate. This study proposes a metaheuristic model for short-term photovoltaic power forecasting that includes shuffled frog leaping algorithm (SFLA), principal component analysis (PCA), and generalized regression neural network (GRNN). In this model, GRNN is implemented to analyze the input parameters after the dimension reduction process, and its parameters get optimized with the help of the SFLA, which has the advantage of fast convergence speed as well as searching ability, whereas PCA techniques are implemented to diminish the dimension of meteorological conditions. This hybrid model achieves day-ahead short-term forecasting, as shown in an experimental case of a Bhadla Solar Park installed in Gujarat, India. The accuracy of the proposed model obtained a mean absolute error (nMAE) of 2.3325, and a root mean square error (RMSE) of 129.425. Similarly, the error in forecasting obtained by the proposed method results in nMAE = 2.977 and RMSE = 160.92. The output results obtained surpassed all other hybrid models used for comparison in this study.

A Bilevel Optimization Model Based on Edge Computing for Microgrid.

With the continuous progress of renewable energy technology and the large-scale construction of microgrids, the architecture of power systems is becoming increasingly complex and huge. In order to achieve efficient and low-delay data processing and meet the needs of smart grid users, emerging smart energy systems are often deployed at the edge of the power grid, and edge computing modules are integrated into the microgrids system, so as to realize the cost-optimal control decision of the microgrids under the condition of load balancing. Therefore, this paper presents a bilevel optimization control model, which is divided into an upper-level optimal control module and a lower-level optimal control module. The purpose of the two-layer optimization modules is to optimize the cost of the power distribution of microgrids. The function of the upper-level optimal control module is to set decision variables for the lower-level module, while the function of the lower-level module is to find the optimal solution by mathematical methods on the basis of the upper-level and then feed back the optimal solution to the upper-layer. The upper-level and lower-level modules affect system decisions together. Finally, the feasibility of the bilevel optimization model is demonstrated by experiments.

A Brief Review of Power Quality Issues Emerged due to Modernization of Power System Infrastructure

The architecture of power systems is evolving daily due to technological advancements aimed at reducing energy consumption and improving the environment. However, this improvement in the architecture of the network has affected the quality of the electricity and is producing several problems associated with the quality of power supplied. In a broad sense, the recent standard procedures for power generation, transmission and distribution are the root cause of the recently discovered problems with power quality. Investigating these problems is essential to accurately forecast the stochastic impacts on today network's functioning and locate the best remedy for these problems. This study includes a discussion on quality challenges that evolved due to modernization in the infrastructure of power network and an evaluation of the latest solutions presented in the literature to overcome those difficulties. This paper also makes recommendations for the future scope of research that should be done to address these new power quality problems.

A multi‐layer framework for energy efficiency assessment of shore‐to‐ship fast charging systems including onshore batteries

This paper proposes a three-layer framework for energy efficiency evaluation of Shore-to-Ship Charging (S2SC) systems using load-dependent loss models of the components. The considered S2SC system is supplied by the grid but is also supported by On-Shore Batteries (OSB). The presented approach is then used to investigate the impact of the specific design and operational parameters on energy efficiency. Power system architectures for three general S2SC solutions for ac, dc, and inductive charging are defined and compared in terms of energy efficiency. Operational parameters are also considered in the analysis, namely, the grid power ratio, determining the load sharing between the grid and the OSB, as well as the OSB charging profile. A case study is performed with peak charging power of 1 MW, and the most efficient S2SC solutions are identified for both ac- and dc-based onboard power systems. Moreover, it is shown that charging OSB with the highest available power from the grid between the charging breaks would often lead to higher energy efficiency than the maximum utilization of the available charging time. Field data from a real S2SC system is used to verify the estimated energy efficiency by the proposed framework. The analysis of the real case S2SC is then extended to include and verify a projected OSB.

Rapid reconstruction modelling method of civil aircraft power system based on power flow topology

Aircraft power system is one of the most important systems, that ensures the normal power consumption of electrical equipment. The design and evaluation of power supply architecture are important parts of aircraft power system design. This paper introduces a rapid reconstruction modeling method of civil aircraft power system based on power flow topology and verifies this modeling method with MATLAB/Simulink and LABVIEV simulation. Simulation results are of great significance to the evaluation of aircraft power system architecture.

Powertrain Design and Energy Management Strategy Optimization for a Fuel Cell Electric Intercity Coach in an Extremely Cold Mountain Area

Facing the challenge that the single-motor electric drive powertrain cannot meet the continuous uphill requirements in the cold mountainous area of the 2022 Beijing Winter Olympics, the manuscript adopted a dual-motor coupling technology. Then, according to the operating characteristics and performance indicators of the fuel cell (FC)–traction battery hybrid power system, the structure design and parameter matching of the vehicle power system architecture were carried out to improve the vehicle’s dynamic performance. Furthermore, considering the extremely cold conditions in the Winter Olympics competition area and the poor low-temperature tolerance of core components of fuel cell electric vehicles (FCEV) under extremely cold conditions, such as the reduced capacity and service life of traction batteries caused by the rapid deterioration of charging and discharging characteristics, the manuscript proposed a fuzzy logic control-based energy management strategy (EMS) optimization method for the proton exchange membrane fuel cell (PEMFC), to reduce the power fluctuation, hydrogen consumption and battery charging/discharging times, and at the same time, to ensure the hybrid power system meets the varying demand under different conditions. In addition, the performance of the proposed approach was investigated and validated in an intercity coach in real-world driving conditions. The experimental results show that the proposed powertrain with an optimal control strategy successfully alleviated the fluctuation of vehicle power demand, reduced the battery charging/discharging times of traction battery, and improved the energy efficiency by 20.7%. The research results of this manuscript are of great significance for the future promotion and application of fuel cell electric coaches in all climate environments, especially in an extremely cold mountain area.

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.