In this paper, the problem of grid-to-vehicle energy exchange between a smart grid and plug-in electric vehicle groups (PEVGs) is studied using a noncooperative Stackelberg game. In this game, on the ...one hand, the smart grid, which acts as a leader, needs to decide on its price so as to optimize its revenue while ensuring the PEVGs' participation. On the other hand, the PEVGs, which act as followers, need to decide on their charging strategies so as to optimize a tradeoff between the benefit from battery charging and the associated cost. Using variational inequalities, it is shown that the proposed game possesses a socially optimal Stackelberg equilibrium in which the grid optimizes its price while the PEVGs choose their equilibrium strategies. A distributed algorithm that enables the PEVGs and the smart grid to reach this equilibrium is proposed and assessed by extensive simulations. Further, the model is extended to a time-varying case that can incorporate and handle slowly varying environments.
This paper proposes a new integrated control scheme for large-scale wind turbine generators (WTG) incorporated with a battery energy storage system (BESS). The primary goal is to improve the ...dispatchability of wind power over a wide range. The proposed controller consists of switching feedback controllers for WTG equipped with BESS management and is developed to systematically govern both systems for optimal regulation while ensuring safe operation within defined limits. A scenario-based switching logic is recommended to coordinate the hybrid systems, and a three-layer WTG controller is devised using a gain-scheduled control method. The suggested controller's performance is evaluated through simulation case studies, particularly in dealing with wind forecast errors (WFE) in the short-term dispatch scheme. To assess the proposed controller's effectiveness, a comparison is made against a baseline controller in three criteria: standard deviation (STD), mean (X) and an integral absolute error (IAE). These criteria help to evaluate the energy mismatch concerning the reference power command. The results are presented to elucidate the effectiveness of the proposed controller in regulating WTG-BESS throughout the entire operating region using a real wind profile from a wind farm in Australia. The findings show that the proposed approach has significant potential to enhance performance, leading to vastly improved wind power dispatch compared to the baseline approach.
Transmission of signals using multiple antennas can significantly improve the energy efficiency of a wireless network, and the proper alignment of the transmitted signals' phases at the receiver is ...one of the key factors so this efficiency improvement can be realized. In a time-varying channel, due to the relative motion between the transmitters and the receiver, the development of a scheme that guarantees such alignment is very challenging. In this paper, considering a distributed transmit beamforming scenario, an algorithm to achieve such phase alignment of signals in a time-varying channel is proposed. A simple formula is derived, which can be adopted by each transmitter to compute its beamforming weight's phase, and it is shown that the use of this perturbation results in a significant improvement in terms of speed of convergence at the receiver. With simulation it is shown that, using the proposed scheme, the transmitted signals' phase aligned at the receiver 33% faster than the one-bit feedback scheme. The average theoretical bit error rate is achieved 50% faster relative to the one-bit feedback scheme with on average 18% less number of antennas at the transmitter.
In this paper, a game theoretic scheme is proposed to study power control in a multi-source (transmitting to multiple clusters) wireless sensor network. A game where each sensor chooses it's transmit ...power independently to achieve a target signal to interference plus noise ratio (SINR) at the master sensor in the receiving cluster is analyzed. It is shown that the game has a Nash equilibrium and it is unique under certain constraints. Numerical results are provided to show the effectiveness of the proposed game considering distance-dependent attenuation with various path loss exponents.
In this paper, utilizing data funneling and distributed beamforming, we propose a novel cooperative cross-layer transmission scheme to reduce the transmit energy of sensor nodes while communicating ...over long distances in a wireless sensor network. We show that the proposed transmission scheme requires less transmit energy, compared to direct beamforming and direct single link transmission, to achieve the same symbol error probability (SEP) at the receiver. Considering battery energy consumption, we show that our proposed transmission scheme is capable of increasing the life time of sensor nodes that need to communicate over long distances. We also show improved performance in terms of a routing metric.
In this paper a distributed transmit beamforming technique is proposed for time-varying wireless communication channels that improves the signal gain at the receiving terminal, and thus yielding an ...enhanced signal-to-interference-plus-noise ratio. In this regard, a two-bit feedback algorithm, with considerable gains in terms of received signal strength (RSS), is proposed for optimizing the phase synchronization of signals beamformed from distributed transmitters towards a moving receiver. It is shown that the proposed scheme can successfully capture the impact of time-varying wireless channels on the transmitted signals with reasonable accuracy such that an improved RSS is achieved at the receiver. Numerical experiments show that the proposed two-bit feedback scheme achieves an improved average RSS of about 37.9% and 29.7%, relative to the existing one-bit scheme and the improved one-bit feedback scheme respectively. Results also show that the proposed scheme requires a significantly reduced number of antennas to achieve an RSS equivalent to that of the one-bit feedback schemes.
In this paper an efficient energy curtailment scheme is studied, which enables the power users of a smart grid network to decide on the reduction in energy supplied to them in the event of a power ...outage in the system. Considering the advantages of a two-way communications infrastructure for any future smart grid, a non-cooperative generalized Nash game is proposed where the players are users of power in the network. They adopt a strategy to choose the amount of reduction in energy supplied to them based on their energy requirements so as to minimize the total cost incurred to the system due to the power outage (i.e., social optimality). The game is modeled as a variational inequality problem, and it is shown that the socially optimum solution is obtained at the variational equilibrium of the energy curtailment game. An algorithm that enables the users to efficiently reach this equilibrium is proposed. Simulation results show that the proposed game yields an improvement of about 15% on average, in terms of average total cost reduction, compared to a standard equal power curtailment scheme.
In this study we have investigated the effects of variation of silicon substrate thickness on the gain of integrated antennas in on-chip wireless interconnect system. The antennas were fabricated on ...silicon wafer and the excitation was applied horizontally. Simulation of the test structure has been carried out using ANSOFT High Frequency Structure Simulation (HFSS) program employing the three dimensional finite element methods. A simple analytical model is also developed, using ground reflection (two ray) model to predict the gain in various thicknesses of silicon substrate. Results obtained from the analytic model and simulated data are presented here for comparison.
A fuelling success: High‐quality aromatic fuel additives can be produced directly from solid biomass feedstocks by catalytic fast pyrolysis in a single catalytic reactor at short residence times. ...High heating rates and catalyst‐to‐feed ratios are needed to ensure that pyrolized biomass compounds enter the pores of the ZSM5 catalyst and that thermal decomposition is avoided. Product selectivity is a function of the active site and pore structure of the catalyst.
The evolution in microgrid technologies as well as the integration of electric vehicles (EVs), energy storage systems (ESSs), and renewable energy sources will all play a significant role in ...balancing the planned generation of electricity and its real-time use. We propose a real-time decentralized demand-side management (RDCDSM) to adjust the real-time residential load to follow a preplanned day-ahead energy generation by the microgrid, based on predicted customers' aggregate load. A deviation from the predicted demand at the time of consumption is assumed to result in additional cost or penalty inflicted on the deviated customers. To develop our system, we formulate a game with mixed strategy which in the first phase (i.e., prediction phase) allows each customer to process the day ahead raw predicted demand to reduce the anticipated electricity cost by generating a flattened curve for its forecasted future demand. Then, in the second stage (i.e., allocation phase), customers play another game with mixed strategy to mitigate the deviation between the instantaneous real-time consumption and the day-ahead predicted one. To achieve this, customers exploit renewable energy and ESSs and decide optimal strategies for their charging/discharging, taking into account their operational constraints. RDCDSM will help the microgrid operator to better deal with uncertainties in the system through better planning its day-ahead electricity generation and purchase, thus increasing the quality of power delivery to the customer. We evaluate the performance of our method against a centralized allocation and an existing decentralized EV charge control noncooperative game method both of which rely on a day ahead demand prediction without any refinement. We run simulations with various microgrid configurations, by varying the load and generated power, and compare the outcomes.
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