Developing hydrogen-integrated energy systems (HIES) represents a cutting-edge strategy for harnessing renewable energy (RE). However, the inherent unpredictability and variability of RE significantly increase the ope...
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To monitor the condition of online power apparatus accurately and provide appropriate guidance on their maintenance,a fundamental ultra-high frequency(UHF) database of partial discharges corresponding to different typ...
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To monitor the condition of online power apparatus accurately and provide appropriate guidance on their maintenance,a fundamental ultra-high frequency(UHF) database of partial discharges corresponding to different types of defects is presented for the observation of insulation state of gas insulated switchgear(GIS).In order to imitate the defects in a GIS online,five types of typical partial discharge(PD) sources(*** metal,protrusion,bouncing particles,void in spacer,and particle on the surface of solid insulation) were designed and fabricated.A wideband UHF sensor and an amplifier were applied to obtain UHF *** on the characteristics of the five different defects,nine meaningful parameters which were independent of the phase of the applied voltage were extracted from the PD samples and then *** this paper,Fisher discriminant analysis(FDA),a pattern recognition algorithm,was applied for the purpose of classifying the *** this way,there was no need to set complicated parameters and kernel function,and the total discrimination accuracy of test samples was 97.6%.It indicates that based on the nine especial parameters,the typical defects in GIS can be identified exactly by means of *** the analysis method could be possibly regarded as a universal classification method.
This paper presents a game-theoretic method to predict microgrid(MG) development tendency in China. As many distribution generators(DGs) are integrated in distribution systems, analysis of MG formation necessity is co...
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This paper presents a game-theoretic method to predict microgrid(MG) development tendency in China. As many distribution generators(DGs) are integrated in distribution systems, analysis of MG formation necessity is conducted from the aspect of DGs. In order to maximize the profit brought by DGs and to earn money from arbitrage, it may be necessary for customers to combine their DGs and loads and to construct an MG to obtain maximal control ability. A game model is built to emulate trading between MGs and the distribution system based on MG powercontrol, in which both trading profit and outage cost are considered for each MG. Nash equilibrium(NE) is calculated, and sensitivities of NE to some boundary conditions are studied. The results show that variable MG trading prices with appropriate net generation cost(i.e., DG generation cost minus government subsidy price) may encourage the growth of MGs. Government subsidies, generation costs, and trading prices may also affect DG use, and therefore they may impact customer motivation to build MGs.
作者：
Ziyuan TENGMinfang HANFuel Cell and Energy Storage Center
Department of Energy and Power EngineeringState Key Laboratory of Control and Simulation of Power Systems and Generation EquipmentTsinghua UniversityBeijing 100084China
Energy is important for human survival and *** September 2020,the Chinese government announced that“China aims to have their CO_(2) emissions peak before 2030 and achieve carbon neutrality before 2060.”As China’s r...
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Energy is important for human survival and *** September 2020,the Chinese government announced that“China aims to have their CO_(2) emissions peak before 2030 and achieve carbon neutrality before 2060.”As China’s reformation and opening-up proceeds into its fifth decade,this new vision for its future is in line with that of the world’s major economies in terms of the need to reach net zero emissions globally by the mid-21stcentury[1].However,coal-fueled thermal powergeneration is currently dominant and accounts for more than 70%of the total amount of power generated in China,making it the world’s largest energy consumer and carbon *** on the country’s domestic resources,namely the abundance of coal and scarcity of oil and gas,it would be difficult to fundamentally change this coal-based energy structure in the short *** 2021,the global total energy sector was responsible for 36.3 Gt of CO_(2) emissions,including approximately 12 Gt from China,which thus accounts for one-third of the total global emissions[2].The demand for efficiency,energy savings,and emissions reduction in the powergeneration industry has become increasingly *** need has arisen to enhance ways in which to use coal cleanly and efficiently,reduce the consumption thereof,and replace coal with other forms of *** addition,carbon emissions need to be lowered by promoting the adoption of alternative powergeneration technologies that are more energy *** would require transformation away from coal power and the exploration of clean,efficient,flexible,and safe forms of energy as the main future development directions[3].
With the increasing penetration of renewable energy resources(RESs), the uncertainties of volatile renewable generations significantly affect the powersystem operation. Such uncertainties are usually modeled as stoch...
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With the increasing penetration of renewable energy resources(RESs), the uncertainties of volatile renewable generations significantly affect the powersystem operation. Such uncertainties are usually modeled as stochastic variables obeying specific distributions by neglecting the temporal correlations. Conventional approaches to hedge the negative effects caused by such uncertainties are thus hard to pursue a trade-off between computation efficiency and optimality. As an alternative, the theory of stochastic process can naturally model temporal correlation in closed forms. Attracted by this feature, our research group has been conducting thorough researches in the past decade to introduce stochastic processes within renewable powersystems. This paper summarizes our works from the perspective of both the frequency domain and the time domain, provides the tools for the analysis and control of powersystems under a unified framework of stochastic processes, and discusses the underlying reasons that stochastic process-based approaches can perform better than conventional approaches on both computational efficiency and optimality. These work may shed a new light on the research of analysis, control and operation of renewable power ***, this paper outlooks the theoretic developments of stochastic processes in future’s renewable powersystems.
A small electrical explosion of wire （EEW） setup for nanopowder production is constructed. It consists of a low inductance capacitor bank of 2 μF–4 μF typically charged to 8 kV–30 kV, a triggered gas switch, and...
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A small electrical explosion of wire （EEW） setup for nanopowder production is constructed. It consists of a low inductance capacitor bank of 2 μF–4 μF typically charged to 8 kV–30 kV, a triggered gas switch, and a production chamber housing the exploding wire load and ambient gas. With the EEW device, nanosize powders of titanium oxides, titanium nitrides, copper oxides, and zinc oxides are successfully synthesized. The average particle size of synthesized powders under different experimental conditions is in a range of 20nm–80nm. The pressure of ambient gas or wire vapor can strongly affect the average particle size. The lower the pressure, the smaller the particle size is. For wire material with relatively high resistivity, such as titanium, whose deposited energy Wd is often less than sublimation energy W s due to the flashover breakdown along the wire prematurely ending the Joule heating process, the synthesized particle size of titanium oxides or titanium nitrides increases with overheat coefficient k （k = W d /Ws ） increasing.
With the rapid development of renewable energies,especially wind power,how to manage unexpected generation variations economically and reliably in dispatch has become crucial for modern power *** address this issue,th...
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ISBN:
(纸本)9781479900305
With the rapid development of renewable energies,especially wind power,how to manage unexpected generation variations economically and reliably in dispatch has become crucial for modern power *** address this issue,this paper presents an affine disturbance feedback robust dispatch(ADF-RD) methodology for powersystems with large scale wind power integration in the framework of adjustable robust optimization(ARO).This methodology divides the dispatching process into pre-dispatch and ***-dispatch decision immunizes against all possible realizations of uncertainties in a set,while re-dispatch which can be regarded as a feedback will be adaptively adjusted using an affine function with respect to the realized uncertainty in real *** ADF-RD methodology is applied to an hourly ahead dispatch(HAD) *** effectiveness and efficiency of the proposed ADF-RD methodology are demonstrated by numerical experiments carried on a five-bus system.
The dynamic properties between torsional and bending vibrations of a vertical mass unbalanced rotor are described. The equation of rotor system motion is obtained by Lagrangian dynamics without considering the externa...
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ISBN:
(纸本)9784883254194
The dynamic properties between torsional and bending vibrations of a vertical mass unbalanced rotor are described. The equation of rotor system motion is obtained by Lagrangian dynamics without considering the external actuating forces and torque, shows coupling effect and nonlinear interaction between the rotor system bending and torsional vibrations. An attempt of theoretical analysis and numerical simulation is made to reveal dynamic characteristics of a rotor system. Theoretical analysis of the rotor dynamic equations based on perturbation theory indicates that at stable state of vibration the coupled effect on the rotor system is nonexistent and the bending vibration becomes equal amplitude with shafting speed at stable vibration state. While the torsional vibration keeps on attenuating until it stops. In addition, the numerical simulation results to the dynamic equations, show that coupled torsional and bending vibrations are induced by mass eccentricity, and coupled effect can only be found in vibration initial state of the rotor system. Other numerical simulation results are consistent with the theoretical analysis.
Surface discharge of oil paper insulation is one of the insulation defects in converter transformers. However, the mechanism of surface discharge in oil paper insulation remains unclear. A novel method of surface disc...
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Applying co-simulation technology is a very important trend in power electronics simulation, which can make full use of the merits of different software to improve the efficiency of building up a system. In this paper...
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