Power Distribution Research Articles

Techno-economic performance of different DC power distribution networks in official buildings based on a real-time analysis method

The integration of photovoltaic (PV) and energy storage systems into official buildings has garnered considerable attention, which are recognized as DC power sources. Notably, DC power can satisfy the majority of electrical demands in official buildings. The primary objective of this research is to enhance overall system efficiency by efficiently utilizing renewable energy through direct current (DC) power distribution compared to alternating current (AC) systems. This study proposes a techno-economic analysis framework to guide designers in selecting system configuration and voltage levels. The analysis covers various PV capacities, load compositions, and battery capacities, with the aim of optimizing power distribution efficiency and achieving a more competitive levelized cost of energy (LCOE). The proposed model integrates the dynamic efficiency of actual converters and wire gauges, enabling real-time computation of the energy supply–demand balance within the power distribution system, including associated conversion and transmission losses. The results indicate that conversion loss accounts for approximately 80% of the overall energy loss within power distribution networks. The implementation of DC power distribution significantly improves system efficiency and economic viability. Specifically, the DC375 system exhibits superior techno-economic performance in scenarios involving high PV and battery capacities. In scenarios with limited PV and battery capacity, the building power distribution system should employ a hybrid AC-DC topology to efficiently distribute the available PV output to building loads powered by DC

Safe deep reinforcement learning-assisted two-stage energy management for active power distribution networks with hydrogen fueling stations

In a power-hydrogen coupled integrated energy system (PHCIES), hydrogen fueling stations (HFSs) with solar photovoltaic (PV) systems are crucial devices to support hydrogen demand and maintain a stable and near-zero pollutant emission-based PHCIES operation by producing a pollutant-free hydrogen. However, optimal operation management of HFSs is challenging because the electrolyzers, compressor, hydrogen storage system (HSS), and fuel cell in HFSs are interconnected and change dynamically under various operational environments. To resolve this issue, this paper presents a safe deep reinforcement learning (DRL)-assisted two-stage framework that ensures a reliable and economical PHCIES operation. In the first stage, day-ahead operational schedules of stand-alone PV systems, PV-enabled HFSs, on-load tap changers, and capacitor banks with hourly resolution are coordinated to minimize the system operation cost, electricity arbitrage cost, PV curtailment cost, and real power loss by solving a Volt-VAR control (VVC) optimization problem. In the second stage, a safe DRL algorithm with a 15-min resolution is employed to minimize the real power loss and maximize the HFS profit by rescheduling the reactive power of stand-alone PV systems and real/reactive power and hydrogen of HFSs. The proposed self-tuning adaptive safety module integrated in the DRL method ensures no violations of HSS’ state-of-hydrogen (SOH) and voltage magnitude in the PHCIES during the training process. Numerical examples conducted on a PHCIES (IEEE 33-bus system coupled with two PV-enabled HFSs) demonstrate the effectiveness of the proposed framework in terms of training convergence, SOH/voltage violation, real power loss, and profit of HFSs.

A Comprehensive Study of Power Distribution Planning Perspectives: Modelling, Tools, Goals, and Criteria

A Comprehensive Study of Power Distribution Planning Perspectives: Modelling, Tools, Goals, and Criteria

A distributed double-layer control algorithm for medium voltage regulation and state of charge consensus of autonomous battery energy storage systems in distribution networks

The increasing integration of Distributed Generation (DG) based on Renewable Energy Sources (RES) in traditional distribution systems necessitates the adoption of smart grid strategies. These strategies rely heavily on energy storage actuation to manage the inherent variability of RES and ensure autonomous operation. This article presents a hierarchical digital control strategy for managing distribution power systems, utilizing Battery Energy Storage Systems (BESS) to regulate voltage amplitude and enhance overall behavior for efficient energy management. At the primary control level, operating at a minute-scale actuation rate, an integral voltage regulation loop determines the BESS power injection or consumption, refined by a fuzzy conditioning of signals that accounts for the state of charge and operational modes of each device. Laplacian and random switching secondary consensus control strategies, operating at a slower rate, ensure coordinated action among individual units. The convergence of these strategies is analytically validated using Lyapunov’s theory under idealized conditions. Extensive dynamic simulations over a 24-hour period demonstrate the proposed strategy’s effectiveness in improving power quality and coordinating voltage regulation, particularly in terms of enhancing the power factor and reducing the standard deviation of voltage and power variables over time in a coordinated manner.

Adult Educational Cross-Cultural Kids: Identities of Im(mobility) Across Sociolinguistic Spaces

ABSTRACT This article explores the notion of multilingual spaces as sites of (de)legitimization and of the construction of (un)belonging by analyzing the lived experiences of six Hong Kong adult educational cross-cultural kids (AECCK) (i.e., adults who have spent their formative years attending schools founded on and run by a cultural base different from their home or local language), and reports representative narratives from three focal AECCK’s. The study focuses on the way the AECCKs’ identities were constructed as they were positioned as perpetual foreigners across different spaces and times, from the sociolinguistic spaces in which they grew up and the spaces that they encountered abroad. Findings show that even the economically and educationally privileged may also encounter linguistic spaces where they are delegitimized—unequal distribution of power can occur in any multilingual spaces. This study highlights the importance of fostering greater inclusivity in spaces of multilingualism in promoting the wellbeing of all multilinguals.

On the Relationship Between the Banded Hiss Distribution and Plasmapause Location: A Survey of Van Allen Probes Observations

AbstractThe plasmapause is the outer boundary of the plasmasphere and plays a crucial role in the propagation of plasma waves. We statistically investigate the relationship between the distribution of banded hiss and plasmapause locations. Wave power distributions of banded hiss are analyzed in terms of two ways: (a) the distance away from the plasmapause (ΔL) and (b) the equatorial distance away from the Earth. Statistical results show both bands of banded hiss have larger wave powers and occurrence rates near the plasmapause. The frequencies of two banded hiss waves both decrease discernably with increasing L‐shell at most magnetic local time sectors and geomagnetic activities, but remain nearly constant with increasing ΔL. The highly consistent distribution suggests both bands may be generated in the plume region. The correlation between banded hiss waves and plasmapause locations sheds new light on the generation mechanisms of banded hiss waves.

Advanced transient switching and coordinated power control strategies for flexible interconnection of multiple microgrids

Multiple microgrid (MG) distribution systems are facing challenges owing to variations in the operational statuses of the individual MGs, which experience voltage and current fluctuations during transient interconnections. The impedances of the interconnecting lines further exacerbate the unevenness of power distribution among the MGs, hence threatening the operational stability of the system. To achieve flexible and seamless interconnections between multiple MGs, we fully analyzed the interconnected structures and operation modes of the MGs; then, we designed a transient switching control method based on investigation of the transient interconnection processes to ensure smooth transition of the MGs. Additionally, to balance the power distribution among the interconnected MGs, a voltage–current-based coordinated power control strategy was synthesized using advanced synchronized fixed-frequency technology. Simulation case studies were conducted, and the results indicate that the proposed coordinated power control scheme effectively facilitated instantaneous interconnections between the isolated regions, thereby avoiding voltage disturbances and current surges. Furthermore, it efficiently equalized and distributed the output power from the distributed energy sources, thereby enhancing the operational flexibilities and stabilities of the MGs and distribution system.

Research on cross regional green certificate bilateral distributed robust trading strategy based on Bayesian theory.

To ensure the effective implementation of the compulsory green certificate transaction in China, a multi-participant cross-regional green certificate bilateral transaction model considering the relevant technical characteristics of the unit is proposed to solve the problems such as the mismatch between the supply and demand of green certificates and the reduction of the transaction plan by the grid operation constraints in the current green certificate transaction. To mobilize the initiative of participants, the model adopts the bilateral transaction of free negotiation. To balance the interests of transaction participants, the paper analyzes the complex interaction of multi participants in cross-regional bilateral transactions by using cooperative game theory. Simultaneously, the model considers multiple uncertainties among participants and takes into account the correlation of photovoltaic power in multiple periods. Based on the distributed robust theory, the multivariate nonlinear model and mixed-effect model of Bayesian are proposed to construct the fuzzy sets of the probability distribution for wind and photovoltaic power. On this basis, the paper analyzes the strategic behaviors of multi participants affected by uncertainty factors in the cross-regional green certificate bilateral trade through a numerical example, and quantitatively analyzes the sensitivity of each participant's transaction plan affected by uncertainty factors. The results show that the degree of competition will affect the strategic behavior and income of the participants, and the full cooperation mode can not only avoid the risk of fluctuations in the transaction price and transaction power within the alliance but also stabilize the supply and demand of green certificate transactions.

The Consequences of Reunifications in Chinese History: The Founding of the Sui vs. the Founding of the Song

Although all reunifications in Chinese history can be conceptualized as adhering on the surface to similar patterns, in fact each was the consequence of a complex assortment of contingent circumstances. Moreover, the particularities of the founding years of a dynasty had a wide-ranging impact on subsequent historical development. This article compares the circumstances and process of the founding of the Sui to the circumstances and process of the founding of the Song in order to show how differences between them might explain the very different political cultures of the Sui-Tang period as compared to the Song period. Thus, the pre-dynastic size of the north Chinese elite and patterns of inter-state interactions had repercussions on the subsequent geographic distribution of political power. In addition, distinct strategies of political legitimation at the inception of each of the two dynasties help account for strikingly different attitudes concerning the relationship between the past and the present, as well as the desirability of transformative and fundamental sociopolitical change.

Improving the Energy Efficiency of a Power Distribution Network by Loss Reduction: A Case Study in Rural 11 Kv Feeder

Improving the Energy Efficiency of a Power Distribution Network by Loss Reduction: A Case Study in Rural 11 Kv Feeder

Institutions matter: The role of institutions in the relationship between decision-making power and contraceptive autonomy.

Several academic papers have shown that the distribution of household decision-making power has a positive influence on women's contraceptive autonomy. This paper considers the role of the social or institutional environment (as captured by place of residence) in ameliorating or contributing to this relationship. Our study focuses on the context of Nigeria, a country with diverse gender norms and religious practices, often determined by geographic location. For example, Western common law is more prevalent in the southern Nigeria, while Sharia law is largely practiced in the North of the country. The analysis uses the Performance and Monitoring for Action (PMA) dataset (2019-2020), and analysis is done using logistic regressions. We find evidence that the relationship between household decision-making power and contraceptive autonomy is mediated by institutions (city). More specifically, we show that in Lagos-a state characterised by the increasing empowerment of women-women have more contraceptive autonomy as they gain decision-making power in the household. The opposite is true in Kano-household decision-making power has no bearing on contraceptive autonomy.

The Contestation of National Adaptation Policies in Indonesia

Indonesia actively supports the United Nations Framework Convention on Climate Change to achieve the Global Goal on Adaptation by setting ambitious climate change adaptation pledges in its Nationally Determined Contributions. This paper explores the implementation of those adaptation commitments within a polycentric governance structure in Indonesia. There is a debate about whether polycentric institutions help or hinder the effectiveness of adaptation outcomes. The question remains, why is the implementation of climate change adaptation policies in Indonesia ineffective? This paper argues that the contestation between the National Development Planning Agency and the Ministry of Environment and Forestry, as two dominant ministries in adaptation, has beset the polycentric structure of adaptation governance in Indonesia and resulted in ineffective adaptation policy implementation. Moreover, the polycentric adaptation governance is ineffective because Indonesia is still facing problems in coordination, collaboration, policy learning, leadership, resource distribution, and dispersion of power.

Organic Community Leadership: An Integrated Perspective

Community, characterised by reciprocity and mutuality, represents one of the fundamental bases upon which society is built. Community leadership is a distinct leadership style that refers to civic-minded individuals who voluntarily and organically self-organise and devote their efforts towards leading issues of importance within their communities. This organic community leadership is a ‘collective relational phenomenon’ that is favoured in dynamic environments; the voluntary action of people within a community can help tackle community challenges at scale, with speed, and result in grassroot innovations. Despite its positive role in society, community leadership faces additional challenges to leadership in organisational settings, including understanding the spatial boundaries of a domain which spans different social fields, fostering linkages among groups where there is no formal authorisation, being receptive to varying ideologies, capabilities, and divergent viewpoints to foster collaboration, and managing unequal power distribution and divergent political agendas. The above opportunities and challenges posed by community leadership has meant that the past few decades have seen growing attention placed on the study of community leadership. Gaps remain in the body of knowledge in supporting the effective execution of community leadership. Authors argue that the leadership literature remains fragmented, many leadership frameworks/models remain agnostic of context, and there is a need for improved understanding of where and by whom leadership is enacted. Most studies to date concentrate on discrete aspects of the community leadership sphere. A more integrated perspective on organic community leadership is needed. Based on a SLR, this paper presents an integrated framework for organic community leadership. The framework emphasises human agency and fostering the collective efficacy of a broad coalition of community stakeholders to work towards a common purpose. It recognises the legitimisation process of emerging leaders and key leader behavioural considerations, framed within the context of fostering an appropriate environment for community cohesion, collaboration, and action. Thus, this paper takes a step towards providing a more holistic stance on the community leadership phenomenon.

AN ANALYSIS ON THE 2015 TÜRKİYE AND RUSSIA AIRCRAFT CRISIS: COMPELLENCE, DETERRENCE AND BALANCING

It is possible to state that as a discipline, international security studies have developed within the framework of the realist paradigm and during the period of the Cold War. It is established that the field of security studies, which places a particular emphasis on the role of military power and states in international politics, is consequently designated as strategic studies. In this context, studies on coercion strategies have been implemented focusing on states’ power. On the other hand, power distribution and balance of power in the system along with the ascend of neorealism have been underlined. In this study, the aircraft crisis taking approximately nine months between Turkish-Russian relationship has been examined utilizing both coercion (deterrence and compellence) and balancing strategies. The objective of the study is to clarify the agreement between Türkiye and Russia from the perspective of aforementioned strategies, perception of actors and cost-benefit calculations. In this qualitative case study, the process tracing method was used to reveal the cause-and-effect relationship between variables in a clear and definitive manner. In addition, document analysis technique was used to collect the data. It is concluded that given the estimated exorbitant costs to both parties at the conclusion of the crisis, the parties involved reached an agreement to conclude the crisis.

The Growth of Cross‐Border Regions Toward “Two Countries, One Park”: A Case Study of the Mohan–Boten Cross‐Border Cooperation Zone

ABSTRACTCross‐border regions have been the frontier areas of regional and subregional cooperation, the development of which involves the interaction of multiple scales and various agents. Existing studies focus mainly on cross‐border economic cooperation but pay less attention to issues such as urban construction and community development, which may lead to the neglect of the interests of local communities in the development of cross‐border regions. Based on a case study of the Mohan–Boten Cross‐border Cooperation Zone (CCZ), this study argues for the integrated development toward “Two Countries, One Park” through the functional integration of urban planning, industrial investment, public services, and community development. The study finds that the success of the “Two Countries, One Park” pattern relies on the coordination of multi‐scalar governance and multi‐agent cooperation, whereas the “scale paradox” caused by the asymmetric distribution of power and responsibility among different governance scales and the relevant agents is a major hindrance to functional integration and cross‐border cooperation. Addressing the “scale paradox” is, therefore, crucial for successful cross‐border development.

Design Study for a Superconducting High-Power Fan Drive for a Long-Range Aircraft

New aerodynamic aircraft concepts enable the storage of volumetric liquid hydrogen (LH2). Additionally, the low temperatures of LH2 enable technologies such as the superconductivity of electrical fan drives and power distribution components. An increased power density of the onboard wiring harness and the electrical machine can be expected. The highest system efficiency and the smallest fuel and tank weight will be achieved with a highly efficient energy conversion by the fuel cell from LH2 to electrical energy. This publication shows a comprehensive study for cryogenic fan drives based on experimental-driven tape superconductor investigations, mission profile-based considerations, design analyses of superconducting electrical machines, and studies of the cooling concepts. A cryogenic system cannot be considered without a feasible cooling concept. Here, an approach with a safe He-based cooling system is proposed, using the LH2 flow to the fuel cell as a heat sink for the losses in the electrical system.

Reduction of losses in electric power distribution system–dynamic reconfiguration case study

Reduction of losses in electric power distribution system–dynamic reconfiguration case study

Intelligent fault diagnosis in power distribution networks using LSTM-DenseNet network

This paper introduces a novel fault diagnosis method that combines DenseNet and Long Short-Term Memory (LSTM) networks. The DenseNet utilizes its unique dense block structure to detect subtle variations in three-phase voltage and zero-sequence current signals. In addition, the Squeeze-and-Excitation (SE) module is introduced in DenseNet. The SE module enhances DenseNet's feature representation by adapting the importance of each channel in the feature map. Furthermore, integrating the LSTM model enables capturing time-domain features of fault signals, enhancing the analysis of waveform changes and trends. These extracted features are subsequently fused in a cascaded manner, leveraging the strengths of both approaches to obtain a more comprehensive information representation. To better explain the capability of feature extraction in each part of the model, t-distributed Stochastic Neighbor Embedding (t-SNE) method is used for visual analysis. The proposed method is evaluated using two distribution network models, namely the 10 kV and IEEE34 networks, in simulation. The verification results indicate that the proposed method achieves exceptionally high accuracy in fault identification for both tested distribution network models, with rates of 99.87 % and 99.82 %, respectively, while also demonstrating robust performance in noisy environments. This performance surpasses that of other related methods, underscoring the enhanced effectiveness of our approach.

An Analysis of Case Study Utilizing Distributed Power Flow Controllers Which Improves and Mitigates Power Quality

Abstract—Providing high-quality electrical power should be taken into consideration in light of the rising demand for electricity and the rise in non-linear loads in power systems. This research examines power quality concerns related to voltage sag and swell and uses a distributed power flow controller (DPFC) to reduce voltage deviation and enhance power quality. A novel FACTS device, the DPFC shares structural similarities with the unified power flow controller (UPFC). Despite UPFC, DPFC separates the three-phase series converter into many single-phase series dispersed converters via the line and removes the common dc-link between the shunt and series converters. A DPFC located in a single-machine infinite bus power system with two parallel transmission lines is included in the case study. The MATLAB/Simulink environment was to model the system. The simulation findings that are shown confirm that DPFC may raise power quality.

Characterising the power spectrum dynamics of the non-REM to REM sleep transition.

The transition from non-rapid eye movement (NREM) to rapid eye movement (REM) sleep is considered a transitional or intermediate stage (IS), characterised by high amplitude spindles in the frontal cortex and theta activity in the occipital cortex. Early reports in rats showed an IS lasting from 1 to 5 s, but recent studies suggested a longer duration of this stage of up to 20 s. To further characterise the IS, we analysed its spectral characteristics on electrocorticogram (ECoG) recordings of the olfactory bulb (OB), primary motor (M1), primary somatosensory (S1), and secondary visual cortex (V2) in 12 Wistar male adult rats. By comparing the IS with consolidated NREM/REM epochs, our results reveal that the IS has specific power spectral patterns that fall out of the NREM and REM sleep state power distribution. Specifically, the main findings were that sigma (11-16 Hz) power in OB, M1, S1, and V2 increased during the IS compared with NREM and REM sleep, which started first in the frontal part of the brain (OB -54 s, M1 -53 s) prior to the last spindle occurrence. The beta band (17-30 Hz) power showed a similar pattern to that of the sigma band, starting -54 s before the last spindle occurrence in the M1 cortex. Notably, sigma infraslow coupling (~0.02 Hz) increased during the IS but occurred at a slower frequency (~0.01 Hz) compared with NREM sleep. Thus, we argue that the NREM to REM transition contains its own local spectral profile, in accordance with previous reports, and is more extended than described previously.