A procedure for the instant-by-instant control of all the generation, or the so-called automatic generation control, of power pools is described. The multicomputer configuration formed by the multiplicity of individua...
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A procedure for the instant-by-instant control of all the generation, or the so-called automatic generation control, of power pools is described. The multicomputer configuration formed by the multiplicity of individual company computers present is utilised in the procedure. The method is an extension of the present basepoint-and-participation-factor approach used in the USA for the control of the generation in a single area. The paper first summarises the single-area method, and then presents the necessary multiarea theory; this is followed by the multiarea-dispatch algorithm and the procedure for the automatic generation control of power pools. It is shown that the hierarchy of multilevel control can be readily extended to a multiplicity of power pools or so-called ‘superpools’.
When charging or discharging electric vehicles, power losses occur in the vehicle and the building systems supplying the vehicle. A new use case for electric vehicles, grid services, has recently begun commercial oper...
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When charging or discharging electric vehicles, power losses occur in the vehicle and the building systems supplying the vehicle. A new use case for electric vehicles, grid services, has recently begun commercial operation. Vehicles capable of such application, called Grid-Integrated Vehicles, may have use cases with charging and discharging summing up to much more energy transfer than the charging only use case, so measuring and reducing electrical losses is even more important. In this study, the authors experimentally measure and analyze the power losses of a Grid-Integrated Vehicle system, via detailed measurement of the building circuits, power feed components, and of sample electric vehicle components. Under the conditions studied, measured total one-way losses vary from 12% to 36%, so understanding loss factors is important to efficient design and use. Predominant losses occur in the power electronics used for AC-DC conversion. The electronics efficiency is lowest at low power transfer and low state-of-charge, and is lower during discharging than charging. Based on these findings, two engineering design approaches are proposed. First, optimal sizing of charging stations is analyzed. Second, a dispatch algorithm for grid services operating at highest efficiency is developed, showing 7.0% to 9.7% less losses than the simple equal dispatch algorithm. (C) 2017 The Authors. Published by Elsevier Ltd.
In this study, we used the Disaggregation based on Physical And Theoretical scale Change (dispatch) algorithm under very wet soil conditions in Western Canada for the disaggregation of coarse resolution 40-km soil moi...
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In this study, we used the Disaggregation based on Physical And Theoretical scale Change (dispatch) algorithm under very wet soil conditions in Western Canada for the disaggregation of coarse resolution 40-km soil moisture derived from the Soil Moisture Ocean Salinity (SMOS) satellite. The algorithm relies on the Soil Evaporative Efficiency (SEE), which was estimated using the 1-km resolution data from the MODerate resolution Imaging Spectoradiometer (MODIS). The study aimed to: (i) evaluate dispatch under wet soil conditions, (ii) test the linearity/non-linearity of the relationship between soil moisture and SEE, and (iii) propose a more robust procedure to calibrate the SEE model under very wet soil conditions. The disaggregated soil moisture values were compared to 0-5 cm in situ measurements and the soil moisture derived from the L-MEB (L-band Microwave Emission of the Biosphere) model from airborne brightness temperature at 1.4 GHz collected during the Canadian Experiment for Soil Moisture in 2010 (CanEx-SM10) field campaign. The results show a correlation between 0.7 and 0.8 and bias values similar to 0 m(3)/m(3). The dispatch algorithm shows better disaggregation results under very wet soil conditions when a non-linear relationship is considered between SEE and soil moisture instead of a linear model. This is mainly due to the small variability of surface temperature inside the area covered by the SMOS pixel under very wet soil conditions, and the difficulty in accurately estimating the maximum soil temperature (Ts-max), which is a driving factor for SEE. A sensitivity analysis was conducted and it shows that the linear model performs well only if Ts-max can be determined more accurately. The possibility to determine Ts-max using high resolution MODIS data over a larger area than the SMOS pixel is examined and discussed in the paper. (C) 2015 Elsevier Inc. All rights reserved.
Taxi-passenger matching plays a crucial role in modern taxi systems. However, currently, the greedy mechanisms are widely adopted, which may limit the quality of services provided by the systems. In this paper, we fir...
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ISBN:
(纸本)9781538627266
Taxi-passenger matching plays a crucial role in modern taxi systems. However, currently, the greedy mechanisms are widely adopted, which may limit the quality of services provided by the systems. In this paper, we first formulate the taxi-passenger matching as a global optimization problem by considering the pickup rate and average waiting time of passengers. Then, we propose a parallel genetic algorithm to solve the problem. New operators, including initialization, crossover, and mutation, are designed specifically for the problem. In addition, we use a divide-and-conquer strategy for dimension reduction. The problem is divided into a number of sub-problems according to the geographical locations of passengers and taxis. Each sub-problem is then solved in a parallel way by a sub-component of our proposed algorithm. Experimental results validate the effectiveness and efficiency of the proposed algorithm. It is able to greatly enhance the quality of services provided by the taxi systems.
The integration of solar photovoltaic (PV) and electric vehicle (EV) systems offers a promising and sustainable solution to address the increasing energy demand, environmental pollution, and carbon emissions in the re...
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Taxi-passenger matching plays a crucial role in modern taxi systems. However, currently, the greedy mechanisms are widely adopted, which may limit the quality of services provided by the systems. In this paper, we fir...
详细信息
Taxi-passenger matching plays a crucial role in modern taxi systems. However, currently, the greedy mechanisms are widely adopted, which may limit the quality of services provided by the systems. In this paper, we first formulate the taxi-passenger matching as a global optimization problem by considering the pickup rate and average waiting time of passengers. Then, we propose a parallel genetic algorithm to solve the problem. New operators, including initialization, crossover, and mutation, are designed specifically for the problem. In addition, we use a divide-and-conquer strategy for dimension reduction. The problem is divided into a number of sub-problems according to the geographical locations of passengers and taxis. Each sub-problem is then solved in a parallel way by a sub-component of our proposed algorithm. Experimental results validate the effectiveness and efficiency of the proposed algorithm. It is able to greatly enhance the quality of services provided by the taxi systems.
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