Equal Power Distribution Research Articles

Carrier Rotation Strategies for Equal Power Distributions in Cascaded H-Bridge Multilevel Inverters

AbstractMulticarrier pulse width modulation (MC-PWM) techniques such as Level-shifted PWM (LS-PWM) and Phase-shifted PWM (PS-PWM) are the popular methods to control the output voltage of Multilevel Inverters (MLIs). The advantage of LS-PWM techniques over PS-PWMs is that they produce better harmonic profile, but the un-equal power distribution problem of LS-PWMs imposes limitation to their usage in high power and medium voltage applications. For achieving the equal conduction periods and to evenly distribute the power among different cells, carrier rotation should be employed in LS-PWM. This paper proposes two rotation schemes introduced to LS-PWM for producing the collective benefit of equal power distribution from PS-PWM and better harmonic profile from LS-PWM. MATALB/Simulink has been used to create simulation models and the experimental validations are performed by a hardware setup using dSPACE-DS1104 R&D Controller board. Furthermore, experimental results of device conduction periods, conduction losses of individual cells, total harmonic distortions (THDs) and fundamental output voltages have been measured. The effectiveness of proposed methods are verified by comparing the obtained results with traditional MC-PWM techniques.

Indigenous Epistemologies, Worldviews, and Theories of Power

The current project aims to identify and explore concepts of power from an Indigenous understanding. The topic of power is informed by vast literature that reaches back into the beginnings of western philosophy. The conceptions that result are based on a western worldview that does not incorporate cultural differences. An Indigenous theory of power can be used to inform strategies toward achieving a more equal distribution of power, and encourage successful Indigenous-settler reconciliation. Within the academic setting, Indigenous scholars are developing Indigenous research initiatives aimed at decolonizing methodologies and achieving intellectual self-determination (Smith, 2012, p.120). Utilizing a decolonization framework saturated with reflexivity, Indigenous research methods in conversation with grounded theory will be applied to identify an Indigenous worldview of power. Researcher reflexivity, relationships with community and research-based support systems are requisite to a decolonization research framework (Smith, 1999, p.138). Data collection will occur at M’Chigeeng First Nation and the Chief of that community has been recruited as community partner to this project. Together we aim to answer Indigenous questions to improve Indigenous lives with research based on standards for how we should structure our relationships with each other and with all of creation (Wilson, 2001, p.177). Indigenous research methods combined grounded theory allows the project to bridge worldviews, while allowing for relationships to guide the process. A literature analysis, interviews, sharing circles and review of historical records will be used.

Teaching Physical Activity—a Matter of Health and Equality?

ABSTRACTThe aim of this study is to understand the mechanisms supporting equality and social health in physical activity (PA) practices by analysing didactic choices. Social health is understood as equal distribution of power. Thereby, a healthy PA practice needs to be inclusive. 3 PA activities are analysed as cases. Issues of inclusion and exclusion are scrutinized. The analysis shows how the power in PA classes may be reallocated by didactic choices and tools such as the teaching content, the rules, the organization, and the leader attitude. Additionally, to increase the possibilities of conducting healthy PA teaching in physical education and health (PEH), humane values need to take precedence before the competitive sport logic governed by a scientific paradigm.

Capacity Analysis of MIMO in Non-Uniform Nakagami Channel with Linear Receiver

ABSTRACTMultiple-input–multiple-output (MIMO) systems have emerged as a promising solution to provide high data rate wireless services in a rich scattering environment. This paper deals with the performance analysis of the MIMO system in correlated non-uniform phase distributed Nakagami-m channel with linear receiver. Authors have considered spatial diversity scheme i.e, vertical bell laboratories layered space-time (V-BLAST) systems in correlated MIMO Nakagami-m fading channels with equal power distribution among the transmitter side antennas. Also, they consider that the channel state information (CSI) is available only at the receiver. The paper presents a detailed analysis of the channel capacity in correlated and uncorrelated channel condition and validated the result with appropriate mathematical model. The effect of Doppler shift and Nakagami-m fading parameter m on the channel ergodic and outage capacity has been analyzed here.

IMPROVING INNOVATION CAPABILITIES BY COOPERATION: EXAMINING EFFECTS OF CORE NETWORK MANAGEMENT FUNCTIONS AND RELATIONAL MECHANISMS IN THE INDUSTRIAL GOODS SECTOR

For companies, cooperation represents a way to innovate more effectively. Within this respect, past literature stresses the importance of core network management functions and relational mechanisms for the effectiveness of interorganisational cooperation. However, it is still unclear whether and how core network management functions and relational mechanisms improve a firm’s innovation capability from interorganisational cooperation. Based on data of 154 industrial companies, the results from structural equation modelling provide evidence that core network management functions significantly enhance innovation capability improvement of individual firms by interorganisational cooperation. Furthermore, both formal and informal relational mechanisms partially mediate the impact of core network management functions on innovation capability improvement. With regard to informal relational mechanisms, companies should foster trust, guarantee equal power distribution and ascribe high importance to their cooperation. With regard to formal relational mechanisms, companies should provide organisational support to their cooperation, continuously share knowledge with their partners and also meet and communicate on regular basis.

Selective Harmonic Elimination in Multi-level Inverters with Series-Connected Transformers with Equal Power Ratings

This study applies the selective harmonic elimination (SHE) technique to design and operate a regulated AC/DC/AC power supply suitable for maritime military applications and underground trains. The input is a single 50/60 Hz AC voltage, and the output is a 400 Hz regulated voltage. The switching angles for a multi-level inverter and transformer turns ratio are determined to operate with special connected transformers with equal power ratings and produce an almost sinusoidal current. As a result of its capability of directly controlling harmonics, the SHE technique is applicable to apparatus with congenital immunity to specific harmonics, such as series-connected transformers, which are specially designed to equally share the total load power. In the present work, a single-phase 50/60 Hz input source is rectified via a semi-controlled bridge rectifier to control DC voltage levels and thereby regulate the output load voltage at a constant level. The DC-rectified voltage then supplies six single-phase quazi-square H-bridge inverters, each of which supplies the primary of a single-phase transformer. The secondaries of the six transformers are connected in series. Through off-line calculation, the switching angles of the six inverters and the turns ratios of the six transformers are designed to ensure equal power distribution for the transformers. The SHE technique is also employed to eliminate the higher-order harmonics of the output voltage. A digital implementation is carried out to determine the switching angles. Theoretical results are demonstrated, and a scaled-down experimental 600 VA prototype is built to verify the validity of the proposed system.

A Multiagent-Based Tool for the Simulation of Social Production and Management of Urban Ecosystems: A Case Study on San Jerónimo Vegetable Garden - Seville, Spain

The concept of social production and management of urban ecosystems may be understood as the generation of new physical or relational situations, by constructing, transforming or eliminating physical and/or relational objects or ensuring the fulfillment of their social and environmental functions. This includes the citizen participation in the process of urban planning and transformation, forming a network structured and supported by tools allowing the equal distribution of power in the decision making. The SJVG-MAS Project addresses, in an interdisciplinary approach, the development of computational tools based on Multiagent Systems (MAS) for the simulation of the social production and management processes that occur in urban ecosystems, in particular, the San JerA³nimo Vegetable Garden project (Spain). In this paper, we present a MAS-based simulation tool developed in JaCaMo. We conceived a 5-dimensional BDI-like agent social system composed of the agents' population, the social organization, the environment, the interactional/communication and the regulatory structures.

Capacity Enhancement with Joint Subchannel and Power Allocation Scheme for OFDMA Femtocell Networks

Efficient power and subchannel allocation methods are required for orthogonal frequency division multiple access (OFDMA) based femtocell networks to improve the capacity of the system. This paper considers a joint subchannel and power allocation algorithm with capacity maximization for downlink of an OFDMA based femtocell networks. In the proposed algorithm subchannel allocation is first performed based on signal to interference plus noise ratio (SINR) of the channel with equal power distribution. Then for enhancing capacity with optimal power allocation, successive convex approximation (SCA) based power optimization is adopted. The effect of Arithmetic geometric mean (AGM) approximation with SCA on power optimization is also investigated. The optimal power is subsequently distributed by water-filling algorithm.

Asymmetric out-of-plane power distribution in a two-dimensional photonic crystal nanocavity.

Conventional air-bridge two-dimensional photonic crystal (2D-PhC) nanocavities emit light with an equal power distribution for upward and downward out-of-plane directions. Some applications, however, require concentration of the radiation in a preferred direction. In this Letter, we design a 2D-PhC nanocavity that radiates dominantly into one of the out-of-plane directions with a narrow far-field distribution. Our design is based on a conventional air-bridge L3 photonic crystal nanocavity. The asymmetric out-of-plane power distribution is achieved solely by adding periodic shallow holes on the slab surface, which also function as a second-order grating for the directional beaming.

People, Planet, Power: Toward a New Social Settlement

This article presents proposals for a new social settlement – a framework for deciding how people live together and what they expect from government, now and for the future. The proposed settlement has three goals: social justice, environmental sustainability, and a more equal distribution of power. To achieve these goals we have identified a set of objectives too often ignored in mainstream debates: achieving prosperity without depending on economic growth; shifting investment and action upstream to prevent harm rather than coping with the consequences; strengthening the “core economy” of unpaid work, everyday wisdom, and social connections; and fostering solidarity and an understanding of how individuals depend on each other to achieve shared goals. The article draws on a report from the New Economics Foundation, which focuses on the United Kingdom but offers a framework for developing policy and practice that may be useful in other countries, especially in the developed world.

Research on Multiuser Scheduling Algorithm Based on the Frobenius-Norm of Channel Matrix

In MU-MIMO system when a base station sometimes has not enough resources to satisfy the service application from each user, we should arrange to communicate selectively for a certain number of users according to some appropriate method, i.e. multiuser scheduling. Given necessary channel state information this paper investigated the relationship between the norm of channel matrix and channel quality and studied multiuser scheduling algorithm typically based on the Frobenius-norm of channel matrix which was simulated respectively for equal power distribution and water-filling power distribution in MU-MIMO system model. The simulation result showed that at the same transmitted signal-to-noise ratio (SNR) such scheduling algorithm could be able to lower the bit error rate (BER) effectively and improve the receive capability in comparison to random scheduling.

Numerical investigation on cascaded 1 × 3 photonic crystal power splitter based on asymmetric and symmetric 1 × 2 photonic crystal splitters designed with flexible structural defects.

We propose a photonic crystal slab-based 1 × 3 power splitter with high output transmission and equal power distribution. It is designed by cascading an asymmetric 1 × 2 power splitter and a symmetric 1 × 2 power splitter. Desired equal power splitting is achieved by introducing and optimizing the splitting region of the 1 × 2 power splitters with flexible structural defects. Simulations were carried out by using 3-D Finite Difference Time Domain method showing equal normalized power distributions of 29.6%, 28.9% and 30.5% at 1550 nm optical wavelength. In addition, equal power splitting also takes place at 1561 nm.

English

This paper presents a new control technique to regulate the capacitor voltage in cascaded multilevel inverters. Without requiring transformers, the scheme proposed here allows the use of a single dc power source with the remaining n − 1 dc sources being capacitors. This paper focuses mainly to achieve an effective capacitor voltage regulation with the Phase shift modulation and energy storage using Ultra-capacitors as they have higher power density, higher efficiency, longer life and greater cycling capability in cascaded multilevel inverters. It shows hope to reduce the voltage ripple of the capacitors, which leads to higher power conversion efficiency with equal power distribution, reduces the initial cost, and complexity hence it is apt for industrial applications. In this paper a 5-level cascaded multilevel inverter with induction motor drive is considered. Finally, the simulation results validate the concept of this topology.

English

This paper presents a new control technique to meet the grid codes in cascaded multilevel inverters. In this paper a new selective harmonic mitigation (SHM-PWM) technique to produce waveforms with low switching frequency without compromising waveform quality, which is capable of meeting grid codes even under non equal dc link voltages. In this paper by maintaining voltage balancing and reducing the total harmonic distortion we can achieve the enhancement of power quality with unequal dc sources. This paper also focuses on the method to enhance the power quality of individual cells which leads to higher power conversion efficiency with equal power distribution. This reduces the initial cost, and complexity hence it is apt for industrial applications. Simulation work is done using the MATLAB software and experimental results have been presented to validate the theory.

English

This paper presents a new control technique to regulate the capacitor voltage in cascaded multilevel inverters. Without requiring transformers, the scheme proposed here allows the use of a single dc power source with the remaining n − 1 dc sources being capacitors, which can achieve an effective role on harmonic elimination while generating the ideal output voltage. This paper focuses mainly to achieve an effective capacitor voltage regulation, and the effect of power factor on capacitor voltage regulation with the Phase shift modulation. The main advantages of this paper are to eliminate the harmonics, high-quality output power due to its high number of output levels. It shows hope to reduce the voltage ripple of the capacitors, which leads to higher power conversion efficiency with equal power distribution, reduces the initial cost, and complexity hence it is apt for industrial applications. Simulation work is done using the MATLAB software and experimental results have been presented to validate the theory.

Optimal Electrical Power Distribution Among Coexisting OFDM-Based Signals in LR-PONs: Theoretical and Experimental Analyses

A method is proposed to determine the theoretical optimal electrical power distribution (OEPD) among several orthogonal frequency division multiplexing (OFDM)-based signals transmitted in coexistence in radio-over-fiber. The method is based on a theoretical analysis, which takes into account the influence of the frequency-dependent loss of the channel and individual bandwidth and performance requirements of the signals on the performance of the signals. The method is experimentally validated for a bundle of five coexisting OFDM-based signals, which are used to deliver a quintuple-play service to each user in a wavelength division multiplexing long-reach passive optical network (LR-PON). The theoretical and experimental OEPDs are obtained, and the discrepancy between them is assessed. When the system parameters are set for best performance, the discrepancy does not exceed 10% in six of the seven transmission scenarios considered, indicating that the effect of nonlinear distortion on the OEPD can usually be neglected. More importantly, for fiber lengths close to the maximum transmission reach [situations in which it is more relevant to optimize the electrical power distribution (EPD)], the proposed method provides accurate estimates of the OEPD. Using the OEPDs, the provision of five OFDM-based signals in coexistence is experimentally demonstrated. Specifically, using 16- and 4-quadrature amplitude modulation (QAM) in the fixed Internet access service enables network reaches up to 122 km and more than 130 km of standard single-mode fiber, respectively. Compared with a reference EPD (equal power distribution among the coexisting signals), the use of the OEPDs results in an improvement of 20 and 28 km in the network reaches using 16- and 4-QAM in the fixed Internet service, respectively.

Energy-Efficient Resource Allocation in OFDM Systems With Distributed Antennas

In this paper, we develop an energy-efficient resource-allocation scheme with proportional fairness for downlink multiuser orthogonal frequency-division multiplexing (OFDM) systems with distributed antennas. Our aim is to maximize energy efficiency (EE) under the constraints of the overall transmit power of each remote access unit (RAU), proportional fairness data rates, and bit error rates (BERs). Because of the nonconvex nature of the optimization problem, obtaining the optimal solution is extremely computationally complex. Therefore, we develop a low-complexity suboptimal algorithm, which separates subcarrier allocation and power allocation. For the low-complexity algorithm, we first allocate subcarriers by assuming equal power distribution. Then, by exploiting the properties of fractional programming, we transform the nonconvex optimization problem in fractional form into an equivalent optimization problem in subtractive form, which includes a tractable solution. Next, an optimal energy-efficient power-allocation algorithm is developed to maximize EE while maintaining proportional fairness. Through computer simulation, we demonstrate the effectiveness of the proposed low-complexity algorithm and illustrate the fundamental tradeoff between energy- and spectral-efficient transmission designs.

Power Quality Enhancement Of Miso Converter For Combined Upqc And Photovoltaic Array

The people in the industrial and residential areas have in the need of the equal power distribution. Proposed system is dealt with the enhancement of power quality generation. This proposed system also deals with the voltage distortion and sag in the industrial and residential areas, which is mainly due to the heavy loads. The voltage sag or distortion can be compensated by implementing the proposed system which includes the combination of UPQC and photo voltaic array, the general working of the UPQC is to increase the voltage in the heavy load condition i.e., the compensation volt age is given to the transmission lines and the role of the photo voltaic array system is that the solar energy is converted into the electrical energy, the generated energy will be in DC form. It is mandatory to note that the photo voltaic array unit is connected through the DC-DC converter (ex: chopper) which has the Multi Input Single Output (MISO) in a link which is in the DC form, this is further connected to the UPQC, the photo voltaic arrays gives the energy to operate the UPQC. The system is based on the theory of instantaneous power. Finally the MATLAB software is used to check efficiency of the system by help of simulation, Thus this system is an efficient method for compensating the voltage sag and the voltage distortion with the improvement of the power quality and to develop the power generation for the betterment of future generation.

基于联合优化函数选择最优中继的研究

该文介绍了基于联合优化函数进行最优中继选择的算法，并采用最优功率分配机制对源与中继进行功率的合理分配。总功率一定条件下，与采用的等功率分配机制相比，最优功率分配机制功率更合理地分配功率，节点网络寿命更长。MATLAB仿真结果表明采用最优功率分配机制的联合优化函数选择的中继，通信性能较好。This paper introduces the optimal relay selection algorithm based on joint optimization function, and it applies the optimal power distribution mechanism which can allocate the source and relay power reasonably. Under condition that the total power is limited, the proposed optimal power distribution mechanism, compared with the equal power distribution mechanism, can make the power distribution more effective, and nodes in the network have a longer lifetime. The simulation results based on MATALAB show that the relay, which uses the optimal power distribution mechanism based on the joint optimization function, has a better performance.

A pluralistic perspective on the intractability of the International Joint Commission's Lake Ontario-St. Lawrence River study

As environmental public participation has become increasingly mandated worldwide, its advantages and disadvantages have been widely documented. This article uses qualitative analysis of documentation and interviews with 40 participants in a US–Canadian International Joint Commission water management controversy. It demonstrates how ambiguity and diffuse power—that is, two characteristics of organizational pluralism—revealed in communication and governance contribute to the challenges of resolving the 13-year controversy. The article adds to the literature that has largely focused on power disparities between governing or managing organizations and stakeholders and makes recommendations for addressing situations involving organizational and scientific ambiguity as well as relatively equal distribution of power. Copyright © 2013 John Wiley & Sons, Ltd.