Power Configuration Research Articles

Optimized Power and Capacity Configuration Strategy of a Grid-Side Energy Storage System for Peak Regulation

The optimal configuration of the rated capacity, rated power and daily output power is an important prerequisite for energy storage systems to participate in peak regulation on the grid side. Economic benefits are the main reason driving investment in energy storage systems. In this paper, the relationship between the economic indicators of an energy storage system and its configuration is first analyzed, and the optimization objective function is formulated. Then, according to the objective limitations of the energy storage system configuration and operation, the constraints are formulated. A set of typical parameters is selected, and the CPLEX (IBM ILOG CPLEX Optimization Studio) solver is used in MATLAB to solve the optimal configuration results. Several sets of optimization results are obtained by taking different subjective coefficient β values, and the economic and social benefits of the optimization results are analyzed. When the economic benefits of the energy storage system are more important, the value of β needs to be smaller, such as a value of 1000. Conversely, when the peak-regulation effect is more important, the value of β should be larger. Finally, configuration results of the control groups are given, and the effect of optimizing the calculation for improving economic benefits is verified.

Optimal Configuration of Reactive Power in Distribution Network with Power Electronic Transformer

Traditional means of reactive power regulation are limited to adjusting the ratio of the On-Load Tap Changer or changing the access position of the reactive power compensation device and its access capacity. In order to save the cost of putting in reactive power compensation devices, this paper proposes to use the characteristics of the reactive power output function on both sides of the power electronic transformer to regulate the system reactive power distribution. For this purpose, a reactive power optimization model including distributed power supplies and power electronic transformers is constructed with the objectives of minimizing voltage excursions, maximizing voltage stability margins and minimizing active losses in the network. At the same time, based on the characteristics of decision variables, cross-feedback hybrid optimization algorithm is used to solve different types of variables, and an improved wolf pack algorithm using Tent chaotic map and Levy flight strategy is proposed to improve the solution efficiency of the algorithm. The experimental results conclude that the proposed model and algorithm are valid, and the algorithm has significant advantages in terms of model solution time and global search capability when compared with the traditional Wolf Pack algorithms and Particle Swarm Optimization algorithms.

Discourse, intersectionality, critique: theory, methods and practice

ABSTRACT For the past thirty years, Critical Discourse Studies has been consolidating as a form of linguistically-oriented, critical social research which is characterized by a deep interest in actual social issues and forms of inequality, such as racism, xenophobia, anti-Semitism and sexism, both in terms of the asymmetries between participants in discourse events and their unequal capacity to control how texts are produced, distributed and consumed. In parallel, since its coinage in Kimberlé Crenshaw's African American feminist critique of race and sex discrimination, intersectionality has been increasingly taken up on a global scale by scholars and practitioners alike, becoming a major feminist way of conceptualizing the relation between several forms of discrimination and oppression, to be analysed as simultaneous and multiplicative experiences. This Special Issue aims to enquire into the potential convergence between the critical discursive and intersectional approaches as theory, method and practice for the exploration of the crossroads of inequalities and oppression. This may contribute to the development of a critical research framework that enables the acknowledgment of the profound ways in which discursively, institutionally and/or structurally constructed sociocultural categorizations interact and produce different kinds of societal inequalities and unjust social relations. These, in turn, can be analysed in terms of the mutual and intertwined processes of resistance and transformation that arise out of them. Bringing together diverse contributions with a shared critical discursive and intersectional outlook, this Special Issue hopes to offer new theoretical and methodological insights for thinking through diversity in the light of present and future dynamics of inclusion, exclusion, and inequality. The six contributions operationalize the intersectional approach as theory, method and/or practice and incorporate it with a CDS perspective, providing a flavour of what a critical and intersectional discursive engagement with different and dynamic identity and power configurations on a global scale can achieve.

All Things Considered, Should Egalitarian Movements Accept Philanthropic Funding?

AbstractPhilanthropy is a contentious and often polarising topic within egalitarian social movements. There are good reasons for this. Philanthropy is reliant on the inequalities inherent in the capitalist system, is fundamentally at odds with democratic relationships, and can moderate or control the activities of recipients. This article therefore starts from the premise that philanthropy violates egalitarian ideals in very significant ways. However, it goes on to suggest that, absent a ruptural change that would drastically weaken the bases of philanthropic wealth, there is a strategic and contingent case for its selective use so long as it pushes existing configurations of power in more egalitarian directions. In making this case, the article draws primarily on the work of Wright (2010) but also on recent developments in the political theory of philanthropy. It calls for a critical literacy around philanthropy that combines an openness to experimentation with a clear-eyed sense of its significant risks. In this respect, it outlines specific conditions and strategies that movements should adopt if they pursue or accept philanthropic funding. Firstly, movements must deliberately articulate and actively defend their transformative vision, clarifying in the process the tactical place of philanthropy within this. Secondly, they must resist funder conditionalities, and preserve egalitarian modes of organising in the face of practices which undermine participatory ideals and threaten relations of care and solidarity. The article’s chief contribution is to integrate normative insights with lessons from the sociological literature on movement-philanthropy relations, for the sake of systematically untangling a live and troublesome issue within the praxis of radical movements.

Designing Educational and Home Computers in State Socialism: The Polish and Czechoslovak Experience

Abstract This article investigates the design of two comparable microcomputers that were built under state socialism in neighboring countries: Poland (Elwro Junior) and Czechoslovakia (Didaktik Gama). Both computers were “clones” of the highly popular British ZX Spectrum computer. In our article, we discuss the decisions that informed the design of the local “clones” of the British computer, and how both endeavors were supposed to solve specific problems identified by the communities involved in their design. We argue that different configurations of power—in which the actors that took part in the design of both computers were embedded—were the primary reason why these similar products, the ZX Spectrum clones, were “scripted” in a substantially different manner. The Junior was designed as an “educational computer” envisaged as an aid to schooling, while the Gama was a more flexible “home computer.” Our investigation focuses on how their designers projected, or “scripted,” possible forms of computer use, and who they imagined would be the users of these machines. We also compare both computers with the high-profile One Laptop Per Child project to demonstrate the wider relevance of our study and the usefulness of our investigative toolset to the intersection of design studies and science and technology studies.

Managing economies, managing nature: Industry and regulation of fisheries in the post-war Soviet Union and Norway

In the aftermath of the Second World War, states across the world sought to expand industrial fishing to both feed and employ their populations. This article examines the structure of the post-war fishing political economies in two countries separated by the Cold War divide: the Soviet Union and Norway. Their political-economic organization and governing ideologies differed, yet many of the goals and objectives of resource management were similar. The mechanisms to enforce regulation, however, were widely divergent, reflecting varying configurations of state power and social control.

Towards a US-led Networked Interregional Architecture for the Indo-Pacific?

The Biden administration’s approach to the Indo-Pacific strategy represents the latest and most ambitious incarnation of the ‘new multilateralism’—an institutional redesign that seeks to respond to unprecedented changes in and challenges to the US-led international order. This article sheds light on the conceptual underpinnings, structural features, and development of the strategy. It shows how ‘entrepreneurial’ Japanese diplomacy, US coalition-building, Transatlantic policy convergences, and the galvanizing effects of the Russian invasion of Ukraine have combined to shape the contours of the strategy and endow it with a sense of common purpose. It brings into sharp focus the US strategy’s reliance on the creation, strengthening, and leveraging of informal institutional configurations of power and cooperation. And it highlights some of the factors that might result in this approach ultimately proving to be more of a triumph of structure and process than of concrete substance and accomplishment.

Real-Time 59.2 Tb/s Unrepeated Transmission Over 201.6 km Using Ultra-Wideband SOA as High-Power Booster

Ultrawide-bandwidth (UWB) optical amplification covering C+L bands over 102 nm is implemented by using a seamless semiconductor optical amplifier (SOA) as a high-power booster with a maximum output power of 24.4 dBm as well as a hybrid scheme of pre-amplification, which combines backward distributed Raman pumping with SOA. In order to provide understanding of the transmission performance of SOA, we perform a thorough SOA characterization. By applying different total input powers, we have measured the output spectrum shape and power. In addition, the dependence of the gain on the driving current is also shown. The SOA noise figure is also analyzed for the case of a single channel input. Using the characterized SOA and employing real-time transponders, supporting two different modulation formats: 400 Gb/s PDM-16QAM and 200 Gb/s PDM-QPSK, a total real-time throughput of 59.2 Tb/s has been achieved over an unrepeated transmission span of 201.6 km-long pure silica core fiber (PSCF). Three different configurations of the output power of SOA booster are compared, which demonstrates an improvement of 17% in total throughput when increasing the SOA output power from 21 dBm to 24.4dBm. Our results show the advantages and benefits of high-power SOA boosters for UWB amplification.

Energy exergy and economic evaluation of a CCHP configuration powered by CPVT collectors dynamically

This study presents a dynamic simulation of a combined cooling, heating, and power (CCHP) configuration powered by concentrating photovoltaic thermal (CPVT) collectors. The desired configuration comprises CPVT collectors, a phase change material (PCM) storage tank, an organic Rankine cycle (ORC), an absorption chiller, and heat exchangers. The evaluation has been carried out for a residential building using EES, MATLAB, and TRNSYS software. Moreover, an auxiliary heater has been used to provide the thermal energy of the desired configuration in case of low or no solar irradiation. The desired configuration has been evaluated from energy, exergy, and economic points of view during the warm months of the year (May to September). Also, the influences of key parameters of the desired system such as the CPVT area, CPVT flow rate, and PCM melting temperature on the performance of the desired configuration have been examined. The results indicate that the solar fraction enhances by about 161 % when the CPVT area changes from 100 m2 to 400 m2. Also, CPVT has found to be the main contributor to exergy destruction, accounting for 49% of the total. The maximum energy and exergy efficiencies of the desired configuration are obtained at the CPVT area of 400 m2 with values of 72.26 % and 79.03 % respectively. On the other hand, the lowest payback period occurs at 100 m2 with value of 11 years.

Parametric study of DBD plasma actuator for heat transfer enhancement in flow over a flat plate at low Reynolds numbers

The present study intends to find the optimal configurations of Dielectric-Barrier-Discharge (DBD) plasma actuators to augment the thermo-hydraulic performance in air flow over a flat plate at low Reynolds numbers. A range of parametric studies are conducted to determine the impact of the major contributing variables; Reynolds number, voltage frequency, and the applied voltage of the DBD actuator, on the heat transfer. This study reports that in the presence of plasma actuation, the factor of enhancement (Num/Num0) achieves about 3.76. Results show that reducing the Reynolds number and raising the frequency and applied voltage of the DBD actuator improve the factor of enhancement. Furthermore, the plasma system thermal efficiency (PSTE) to achieve the optimized electric power consumption and heat transfer augmentation is introduced as the rate of increase of enhancement factor to the rate of increase of consumed electric power. The frequency and applied voltage for the DBD actuator are used as the design variables to find the optimum configurations. Optimum electric power consumption and configurations of DBD plasma actuator based on Reynolds number are determined. Results also show that Vapp = 10.5 kV and f = 5 kHz conditions for DBD plasma actuator is much beneficial than the other configurations in the presence of low Reynolds number external flow. This study's findings will benefit designers in developing high-performance heat transfer.

Research on power configuration scheme of parallel hybrid oil-electric power system for tilt- rotor UAV

The tilt-rotor UAV is a new type of unmanned aerial vehicle that has both the hovering capability of a rotary-wing UAV and the high-speed cruising flight capability of a fixed- wing UAV. Through the tilting system of the UAV, different working states can be switched: during the take-off and landing phases, the rotor axis is perpendicular to the ground, thus realizing aerial hovering, forward and backward flight and side flight. In the cruise flight phase, the rotor axis is perpendicular to the flight direction, thus achieving the flight attitude of a fixed-wing aircraft. The hybrid power system is a composite power system that combines fuel power with electrical power. By applying the oil-electric hybrid power system on the tilt-rotor UAV, it can combine the advantages of long range and long range of fuel power and low noise and pollution of electric power. In this paper, the tilt-rotor UAV parallel oil-electric hybrid power system power configuration scheme is studied. Firstly, the three operating modes of the oil-electric hybrid power system are introduced, including hybrid drive, drive charging and pure oil drive. The power requirements of the tilt-rotor UAV in vertical takeoff and landing, fixed-wing cruise and other flight phases are calculated, and the correspondence between the UAV flight status and the hybrid power system operation mode is established according to the working characteristics of the tilt-rotor UAV and the hybrid power system operation mode. The power configuration method for each flight phase is finally determined, and the process of the overall power configuration realization of the threshold value is described in detail.

SOCIAL DISTANCE AND VIETNAMESE TRADITIONAL ART DECORATION

The goal of this analysis is to apply the Systemic Functional Linguistics theory (SFL) to analyze social distance and visual sign in the context of Vietnamese art decoration. Based on the concept of social semiotics, social distance between interactants in this analysis is analyzed through a register description of tenor system within the context of situation. From a social point of view, this analysis applies the five lines of human thought based on Bogardus divided into motivational relevancies, including (i) human life, (ii) the natural world, (iii) mythology, (iv) philosophy, (v) religion, and (vi) culture and tradition, to describe the relationship between context of situation and meaning interpretation of Vietnamese traditional art decoration. The findings suggest that social distance generally plays an important role among interactants through Vietnamese traditional art decoration and functional meaning interpretation. The findings further suggest that the tenor system reflects some levels of social distance through a configuration of power, contact, and affective involvement of language usage. As a result, the levels of social distance could be realized by functional and social meaning interpretation, called socio-functional meaning system, through three perspectives: (i) art interpretation and art appreciation, (ii) social beliefs, faiths, and respect, and (iii) features and properties of art decoration. Some benefits of this study can be applied to other fields of human communication such as film, advertising, and art aesthetics.

Waves of Structural Deglobalization: A World-Systems Perspective

Structural globalization has been both a cycle and an upward trend as periods of greater global integration have been followed by periods of deglobalization on a long-term stair-step toward the greater connectedness of humanity. Since 2008, the world-system may once again be entering another phase of structural deglobalization as the contradictions of capitalist neoliberalism, environmental degradation and uneven development have provoked different kinds of anti-globalization populism, rivalry among contending powers, trade wars and policies and social movements intended to mitigate the effects of anthropogenic climate change. This plateauing and possible downturn in economic connectedness is occurring in the context of U.S. hegemonic decline and the emergence of a more multipolar configuration of economic and political power among states. The combination of greater communications connectivity and greater awareness of North/South inequalities, as well as destabilizing conflicts and climate change, have provoked waves of refugee migrations and political reactions against immigrants. The result has been a period of chaos that is similar in some ways (but different in others) from what occurred during the last half of the 19th century and the first half of the 20th century. This study investigates the question of whether the world-system is indeed once again entering another period of economic deglobalization and compares the current period with what happened in the 19th and 20th centuries to specify the similarities and the differences. We conclude that, based on changes in the level of economic connectedness since 2008, it is still too soon to tell for sure if the world-system is entering another period of deglobalization, but the important similarities between the recent period and earlier periods of deglobalization make it likely that the system is now in another deglobalization or plateau phase.

A Second Cold War? Explaining Changes in the American Discourse on China: Evidence from the Presidential Debates (1960-2020).

The online version contains supplementary material available at 10.1007/s11366-023-09857-z.

Energy Independence of a Small Office Community Powered by Photovoltaic-Wind Hybrid Systems in Widely Different Climates

Hybrid renewable energy systems are an optimal solution for small energy communities’ energy supply. One of the critical issues is the strong correlation of these systems with outdoor climatic conditions. The goal is to make local communities increasingly energy independent. To this end, an in-depth analysis of the behaviour of hybrid photovoltaic (PV)–wind systems powering small office communities in 48 locations around the world characterized by widely varying climates was conducted. System sizes, assumed to be stand-alone or grid-connected, were varied, for a total of 343 system power configurations. Highest satisfied load fraction (SLF) values are obtained with a significant predominance of PV over wind; the trend is more pronounced in dry and continental climates (zones B and D according to the Köppen climate classification). The utilization factor (UF) values of 1 are rarely reached and never in the wind-only or PV-only configurations. In all climates, the grid energy interaction factor (GEIF) values of zero are never reached but come very close. The benefit-cost ratio (BCR) of grid-connected systems is significantly higher than stand-alone systems.

A comprehensive review of grid-connected solar photovoltaic system: Architecture, control, and ancillary services

The installed capacity of solar photovoltaic (PV) based generating power plants has increased significantly in the last couple of decades compared to the various renewable energy sources (VRES). As a result, the increased penetration of solar PV-based generating units leads to several issues related to power quality, system stability, and reliability. In view of these concerns, various international standards and grid codes have been amended to address such critical issues. Therefore, most solar PV-based generating units have undergone several changes in operational and control structure. Subsequently, varieties of solar PV configurations and control structures have been proposed by several researchers to augment the desired operational features. This paper presents a comprehensive review of various solar PV configurations, control strategies, and ancillary services with multifunctional features within this context. The utilization and benefits of various configurations and their practical aspects have been discussed thoroughly for all the configurations and architectures. Apart from this, the control aspects of grid-connected solar PV systems are categorized into two important segments, namely, a) DC-side control and b) AC-side control. This article covers the important features, utilization, and significant challenges of this controller and summarizes the advanced control techniques available in the literature. Further, the various control techniques have been compared concerning different operational parameters, such as controller gains, duties, and selector quantities in tabular form with ready references. Furthermore, the concerns related to power quality, stability, and reliability of various techniques have been included for understanding the applicability of grid-connected PV systems. In the end, a detailed comparison of some available industrial inverters concerning their power ratings, voltage ratings, configurations, and advanced functions incorporated are also presented, which will help the researchers, academicians, and practicing engineers.

Tipu and the Turks: An Islamicate Embassy in the Age of British Expansion

AbstractIn 1786, several hundred subjects of Tipu Sultan (r. 1782–99), ruler of the kingdom of Mysore in southern India, travelled to the Ottoman Empire on a diplomatic mission. This essay revisits the embassy's travels, and travails, across Eurasia and the Indian Ocean by drawing attention to a rich cache of administrative documents. I suggest that this collection, hitherto unexamined, can illuminate some significant aspects of diplomatic conduct and procedure in Islamicate Eurasia, yet underexplored. The essay accordingly highlights such overlooked themes as the bureaucratic complexities that were involved in long-distance ambassadorial tours, the role ceremonials played in elite intercourse, and the myriad ways in which material culture mediated interstate exchanges. While its significance lies also in how it decentres a dominant scholarly focus on encounters between Europe and its others, scrutiny of this collection, I additionally argue, can enhance historical understanding of how reciprocal relations between Islamicate polities transformed due to growing European influence. As contemporary configurations of imperial power changed in both South Asia and the Middle East, the Mysore-Ottoman embassy hence at once reflected and anticipated the advent of European—and more specifically, British—hegemony in non-European diplomatic contexts.

Challenging war traditions: humanitarian discourse and the nuclear prohibition treaty

Abstract This article interrogates the humanitarian discourse and the emergence of the new Treaty on the Prohibition of Nuclear Weapons (TPNW). Often acknowledged as decisive for adopting the TPNW, the humanitarian discourse is considered vital to stigmatizing nuclear weapons and their purported deterrence value. However, the literature has not thoroughly examined the mechanisms through which speaking in humanitarian terms enabled proponents of the TPNW to exercise agency, failing to appreciate the complex discursive practices sustaining power relations in nuclear politics. This article introduces a theoretical framework that can help us make sense of these complexities, while illuminating additional ways through which the humanitarian discourse contributed to the TPNW. Using a feminist post-structuralist lens, I argue that the humanitarian discourse enabled small and middle-power states to challenge war traditions that sustain dominant configurations of power in nuclear politics. Upon speaking in humanitarian terms, these states destabilized the ongoing reiteration of the protector/protected dichotomy that has placed non-nuclear states in a position of subordination. The article draws attention to how dominant assumptions of the masculine and feminine shape global politics, while advancing theoretical tools to help us grasp and seize possibilities for policy innovation and change.

A safety check method to maximize the effective reserve by optimizing the power of the tie-line in the power market

To ensure the stability of the electricity spot market and the safety of the provincial and regional power systems, a safety check method is proposed to maximize the effective reserve resources in the power system by optimizing the power of each tie-line. This safety check method accurately models the tie-line equipment and the effective reserve resources and is coupled with each constraint of the electricity spot market clearing model to form a safety check algorithm to optimize the power of tie-line power. The model involved in this paper is a linear model, which has a clear implementation method in practical dispatching applications. Through this method, the power configuration scheme of each tie-line to meet the electricity spot market constraints can be obtained, and the safety check results have the executability of the power market. The rationality and feasibility of the safety check algorithm results are verified by simulating the provincial-scale electricity spot market. According to the simulation results, this method can release effective reserve resources and provide more guarantees for the safe operation of the power grid. In addition, this method can save up to 4.9% of the total operation cost of the power system and improve the dispatching economy of the power system. This method is of great significance to ensure the safe operation of the power system and the day-ahead market and real-time market scheduling in the actual power spot system. In addition, this method also has great guiding significance for the analysis of the actual reserve situation of the power market after the event.

Optimization of combined heat and power cogeneration via modification of low-pressure regenerative system with absorption heat exchanger

The large exergy loss during heat transfer is a key problem for the combined heat and power cogeneration. Instead of the traditional heat source coming from high-grade extracted steam at the outlet of the intermediate-pressure turbine, a novel combined heat and power configuration is proposed for large heat demand by modifying the low-pressure regenerative system. By adding a new LP unit with sufficient extracted flow and heat exchange, a part of the heat source from high-grade extracted steam at the outlet of the intermediate-pressure turbine is replaced by low-grade extracted steam within the LP turbine, avoiding the off-design operation of the LP turbine in the traditional combined heat and power configuration. In addition, the new combined heat and power configuration is optimized by introducing an absorption heat exchanger. The absorption heat exchanger lowers the return temperature of the PHS, which further reduces the energy grade of the heat source. The thermodynamic results show that the electric efficiency of the novel combined heat and power configuration is increased by 4.24% in total at a given heat demand of 241.37 MW. Exergetic results reveal that the exergy loss of two heat exchange links is drastically reduced from 30.47 MW and 26.04 MW to 8.80 MW and 11.81 MW respectively. An economic analysis of the new CHP configuration indicates that the dynamic payback period counteracting the investment increment is only 2.15 years, and the net present value increment over a 25-year period can reach $55.818 million.