With the raising of requirement of power grid operation to voltage control and reactive power management level, automatic voltage control (AVC) becomes a hot spot in the research. Due to the constraints in the managem...
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With the raising of requirement of power grid operation to voltage control and reactive power management level, automatic voltage control (AVC) becomes a hot spot in the research. Due to the constraints in the management mode, the applied research of AVC is hitherto a blank in North America power grids. An AVC system, which is suitable to special management modes of a certain interconnected power grid in Northeast U. S. and can meet the demand of on-line operation, is designed and implemented. In the designed system, phase shifter models are added into power flow modules and during the computation of control strategy by optimal power flow (OPF) the static security constraints after the assumed faults are considered. Both the data and assessment results of long-term on-line trail-operation show that the reactive power and voltage level of the interconnected power grid can be improved by applying the designed AVC system, and both security and economy of the interconnected power grid can be enhanced.
power flow exhibits uncertainty when power injections randomly fluctuate. The variables of power flow problem are correlated through the constraints set forth by power flow equations. Affine arithmetic can effectively...
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Advanced applications of energy storage system comprise load shifting, isolated island operation, frequency regulation and reactive support, etc. There are already algorithms and control strategies for advanced applic...
Advanced applications of energy storage system comprise load shifting, isolated island operation, frequency regulation and reactive support, etc. There are already algorithms and control strategies for advanced applications, but still lack an independent supporting software platform. This paper concentrates on the structure and realization of software platform for advanced application of large-scale energy storage system, including demand analysis, software architecture and module design, user interface and functionality development. An easy to operate and expand software platform, with a beautiful graphical user interface and support for visualization of data, was designed and implemented.
The analysis and simulation of power system are becoming more and more challenging as the complexity of system topology and components has been increased. In this paper, a hybrid parallel algorithm is proposed for the...
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The analysis and simulation of power system are becoming more and more challenging as the complexity of system topology and components has been increased. In this paper, a hybrid parallel algorithm is proposed for the real-time electromagnetic transient simulation (EMTS) of integrated powersystems containing multiphase machines. The proposed algorithm is com- posed of a novel network partition method called component level parallelization and the Multi-Area Thevenin Equivalent (MATE) method, which extends the flexibility of the network partition in parallel simulation. Moreover, several methods are developed to enhance the efficiency of the communication and computation. powersystems with up to 410 single-phase elec- trical nodes and 336 switches are simulated in a time step of 50 ~ts to validate the proposed algorithm.
The smart grid is attracting more and more attention in electrical engineering for its promising ***,huge challenges also exist in the implementations of the smart grid,such as high penetration of renewable energy res...
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The smart grid is attracting more and more attention in electrical engineering for its promising ***,huge challenges also exist in the implementations of the smart grid,such as high penetration of renewable energy resources,low carbon electricity and cyber-physical security,*** this paper,the latest progress of some research focuses and advance technologies in the development of smart grid is reviewed.
Due to the power electronic devices in doubly fed induction generators (DFIG), it is very time consuming to simulate the electromagnetic transients of DFIG using its detailed model. Thus it is necessary to have approp...
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ISBN:
(纸本)9781629936017
Due to the power electronic devices in doubly fed induction generators (DFIG), it is very time consuming to simulate the electromagnetic transients of DFIG using its detailed model. Thus it is necessary to have appropriately simplified model of DFIG that maintains desirable accuracy. In this paper, the piecewise averaged model of PWM converters is introduced and applied to the modelling of DFIG. The proposed model divides the simulation time interval into switching periods and recalculates the averaged state equations of PWM converters in each switching cycle. In addition, a predictorcorrector based EMTP algorithm is designed to iteratively solve the model. Instead of treating switching events at the time points when they happen, the new algorithm solves all the switching instants in a switching cycle at the same time, which avoids frequency modification of the system conductance matrix and speeds up EMT simulations of DFIG. simulation results of a single-machine infinity bus system with a DFIG show that the proposed model and algorithm can achieve satisfactory accuracy and efficiency.
We calculated energy-related carbon emissions from Beijing's production and household sectors in 1995, 2000, 2005, and 2009 based on the default carbon-emission coefficients provided by the Intergovernmental Panel...
We calculated energy-related carbon emissions from Beijing's production and household sectors in 1995, 2000, 2005, and 2009 based on the default carbon-emission coefficients provided by the Intergovernmental Panel on Climate Change (IPCC). Taking 1995–2000, 2000–2005, and 2005–2009 as the study periods, we decomposed the effects of changes in carbon emissions resulting from eight causal factors using the logarithmic mean divisia index method: economic activity and population size, which reflect the change in socioeconomic activity; energy intensity and energy consumption per capita, which reflect the change in the intensity of energy use; and economic structure, the urban and rural population distribution structure, and the energy mix of the production and household sectors, which reflect structural changes. We found that in all three study periods, the changes in economic activity, population size, and energy consumption per capita stimulated emissions, whereas the changes in energy intensity, the urban and rural population distribution structure, and the energy mix of the production and household sectors decreased emissions. In contrast, changes in the economic structure decreased emissions in the first and third periods, and increased emissions in the second period. Our results clearly indicate that under current practices, carbon emissions will increase as a result of rapid growth of the economy, the population, and the energy consumption per capita. In the future, the main routes to reduce carbon emissions will be to adjust the economic structure and energy mix, and to reduce the energy intensity of each sector.
This paper proposes a simple universal index for on-line quantitative assessment of flame stability. The proposed index has a dynamic range of [0, 1] and is designed by combining the dynamic characteristics of seven p...
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This paper proposes a simple universal index for on-line quantitative assessment of flame stability. The proposed index has a dynamic range of [0, 1] and is designed by combining the dynamic characteristics of seven parameters extracted from flame images in HSI color space. It assesses the flame stability in terms of color, geometry and luminance. Experiments were carried out on a 9MW th heavy-oil-fired combustion test facility. The impact of the swirl vanes on the stability of a heavy oil flame is investigated. The results obtained demonstrate the effectiveness of the proposed approach to quantitative flame stability assessment.
To coordinately consider the economy and security of the system during reactive voltage control, a multi-objective reactive power optimization model is proposed. Apart from the conventional economic objective, the new...
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With the background park lighting application, and based on the characteristics of advanced devices in the system, this paper studies the photovoltaic (PV) light emitted diode (LED) lighting system in three main aspec...
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