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Distributed energy management for networked microgrids in a three-phase unbalanced distribution network

《能源前沿(英文)》 2023年 第17卷 第3期   页码 446-446 doi: 10.1007/s11708-022-0851-7

摘要: Owing to increased penetration of three-phase and single-phase microgrids, distributed energy resources (DERs), and responsive loads, the maintenance of a three-phase balance by distribution networks is a significant challenge. Existing literature on distributed energy management for networked microgrids generally neglects the distribution network or employs a simplified phase balanced distribution network; thus, these evaluations are not applicable. Further, the underlying mutual coupling between the different phases of distribution feeders results in a more challenging situation. To solve this issue, this study sought to propose distributed energy management based on a three-phase unbalanced distribution network. Various three-phase or single-phase microgrids, utility-owned DERs, and responsive loads were coordinated through iteratively adjusted price signals. Based on the price signals received, the microgrid controllers (MCs) and distribution management system (DMS) updated the schedules of the DERs and responsive loads under their jurisdiction separately. The price signals were then updated according to the generation-load mismatch at each node and distributed to the corresponding MCs and DMS for the next iteration. The iteration continued until a sufficiently small generation-load mismatch was achieved at all nodes, that is, a balanced generation and load at all nodes under the agreed price signals. Considering a three-phase unbalanced distribution network, the price signals were determined per phase per node. Overall, the proposed distributed energy management coordinates microgrids, utility-owned DERs, responsive loads with guaranteed network constraints, and preserves the privacy of microgrid customers. This distributed energy management method was further demonstrated through various case studies on a three-phase networked microgrid test system.

关键词: distributed optimization     energy management     networked microgrids     three-phase distribution network     distributed energy resources    

Aggravation of membrane fouling and methane leakage by a three-phase separator in an external anaerobic

Chao Pang, Chunhua He, Zhenhu Hu, Shoujun Yuan, Wei Wang

《环境科学与工程前沿(英文)》 2019年 第13卷 第4期 doi: 10.1007/s11783-019-1131-6

摘要:

The existence of three-phase separator did not affect COD removal in the EAnCMBR.

The existence of three-phase separator aggravated methane leakage of EAnCMBR.

The existence of three-phase separator aggravated membrane fouling rate of EAnCMBR.

Start-up of EAnCMBR equipped three-phase separator was slightly delayed.

关键词: Anaerobic membrane bioreactor     Three-phase separator     Membrane fouling     Methane leakage     Sludge property    

Performance investigation of artificial intelligence based controller for three phase four leg shunt

J. JAYACHANDRAN,R. MURALI SACHITHANANDAM

《能源前沿(英文)》 2015年 第9卷 第4期   页码 446-460 doi: 10.1007/s11708-015-0378-2

摘要: In this paper, the choice of power quality compensator is a DSTATCOM which constitutes a three phase four leg voltage source converter (VSC) with a DC capacitor. The control strategy proposed for the DSTATCOM is a neural network based one cycle control (OCC). This control strategy involves neural network block, digital circuits and linear elements, which eliminates the sensors required for sensing the load current and coupling inductor current in addition to the multiplier employed in the conventional method. The calculation of harmonic and reactive currents for the reference current generation is also eliminated, thus minimizing the complexity in the control strategy. The control strategy mitigates harmonic/reactive currents, ensures balanced and sinusoidal source current from the supply mains that are nearly in phase with the supply voltage, compensates neutral current, and maintains voltage across the capacitor under unbalanced source and load conditions. The performance of the DSTATCOM with the proposed artificial neural network (ANN) controllers is validated and investigated through simulations using Matlab software. The simulation results prove the efficacy of the proposed neural network based control strategy under varying source and load conditions.

关键词: neural network     DSTATCOM     neutral current mitigation     total harmonic distortion (THD)     three phase four wire distribution system     unbalanced and/or distorted source    

An improved delta-star switching scheme for reactive power saving in three-phase induction motors

P. RAJA,N. KUMARESAN,M. SUBBIAH

《能源前沿(英文)》 2014年 第8卷 第3期   页码 364-370 doi: 10.1007/s11708-014-0324-8

摘要: It is proposed that a capacitor can be connected permanently across each phase winding of a three-phase induction motor along with the conventional delta-star switching, for further saving in VARh at reduced loads on the motor. The method of choosing a suitable value for the capacitor and the criteria to be adopted for calculating the power output at which the star to delta switching is to be made are also explained. The experimental results on a 3-phase, 4-pole, 415 V, 50 Hz, 3.3 kW induction motor verify the advantages in adding the capacitor to the phase winding of the motor. Compared to using only a single delta connected stator winding or a delta-star switching, the advantages of the proposed addition of a capacitor, are also demonstrated through a case study conducted on a 400 V, 250 kW motor. Any further improvement in grid side power factor can be achieved by employing a static synchronous compensator (STATCOM) of reduced VAR rating.

关键词: delta-star switching     induction motor     power factor     steady-state analysis    

考虑多孔电极内气液分布的数学模型

徐献芝,朱梅,杨基明

《中国工程科学》 2005年 第7卷 第8期   页码 36-40

摘要:

给出了多孔电极内不同气液分布形状的溶液欧姆定律;在单孔电极模型基础上定义了电化学反应的有效三相分界线长度概念,并给出了对应的计算方法;建立了基于多孔介质气液分布理论的一维电流和过电位数学模型,用数值迭代方法计算了沿电极面法线方向上的电流和过电位分布,分析了气体饱和度分布和有效三相分界线长度对它们的影响。

关键词: 多孔介质     过电位     单孔电极模型     三相界面     数学模型    

气体多孔电极反应微观机理及宏观现象的研究

朱梅,徐献芝,杨基明

《中国工程科学》 2005年 第7卷 第5期   页码 79-83

摘要:

提出多孔电极研究的新思路、新方法,探索电极反应的微观机理及宏观现象,试图为制造高效多孔电极提供理论参考。通过锌空气电池实验对比了立式多孔碳电极相对于传统多孔碳电极在放电中的优点。通过实验观察了三相界面的形成形态随时间变化的3个宏观过程,根据3个宏观过程对应的电化学过程定义了电极反应中所形成的2种有代表性的三相界面。分析了电解液在多孔电极中运动的微观机理并得出理想突变界面是气体电极的最佳工作状态的结论。

关键词: 多孔电极     三相界面     锌空气电池    

Thermodynamic models and energy distribution of single-phase heated surface in a boiler under unsteady

Xiyan GUO, Yongping YANG

《能源前沿(英文)》 2011年 第5卷 第1期   页码 69-74 doi: 10.1007/s11708-010-0117-7

摘要: A coal-fired power unit frequently operates under unsteady conditions; thus, in order to acquire scientific energy analysis of the unit, thermodynamic analysis of a single-phase heated surface in a boiler under such conditions requires investigation. Processes are analyzed, and distributions of energy and exergy are qualitatively revealed. Models for energy analysis, entropy analysis, and exergy analysis of control volumes and irreversible heat transfer processes are established. Taking the low-temperature superheater of a 610 t/h-boiler as an example, the distribution of energy, entropy production, and exergy is depicted quantitatively, and the results are analyzed.

关键词: thermodynamic model     energy distribution     boiler     unsteady conditions    

Estimation of distribution algorithm enhanced particle swarm optimization for water distribution network

Xuewei QI,Ke LI,Walter D. POTTER

《环境科学与工程前沿(英文)》 2016年 第10卷 第2期   页码 341-351 doi: 10.1007/s11783-015-0776-z

摘要: The optimization of a water distribution network (WDN) is a highly nonlinear, multi-modal, and constrained combinatorial problem. Particle swarm optimization (PSO) has been shown to be a fast converging algorithm for WDN optimization. An improved estimation of distribution algorithm (EDA) using historic best positions to construct a sample space is hybridized with PSO both in sequential and in parallel to improve population diversity control and avoid premature convergence. Two water distribution network benchmark examples from the literature are adopted to evaluate the performance of the proposed hybrid algorithms. The experimental results indicate that the proposed algorithms achieved the literature record minimum (6.081 M$) for the small size Hanoi network. For the large size Balerma network, the parallel hybrid achieved a slightly lower minimum (1.921M?) than the current literature reported best minimum (1.923M?). The average number of evaluations needed to achieve the minimum is one order smaller than most existing algorithms. With a fixed, small number of evaluations, the sequential hybrid outperforms the parallel hybrid showing its capability for fast convergence. The fitness and diversity of the populations were tracked for the proposed algorithms. The track record suggests that constructing an EDA sample space with historic best positions can improve diversity control significantly. Parallel hybridization also helps to improve diversity control yet its effect is relatively less significant.

关键词: particle swarm optimization (PSO)     diversity control     estimation of distribution algorithm (EDA)     water distribution network (WDN)     premature convergence     hybrid strategy    

Residence time distribution and modeling of the liquid phase in an impinging stream reactor

Xingjun WANG, Xianhui HU, Lishun HU, Guangsuo YU, Fuchen WANG,

《化学科学与工程前沿(英文)》 2010年 第4卷 第3期   页码 353-359 doi: 10.1007/s11705-009-0262-x

摘要: Based on some experimental investigations of liquid phase residence time distribution (RTD) in an impinging stream reactor, a two-dimensional plug-flow dispersion model for predicting the liquid phase RTD in the reactor was proposed. The calculation results of the model can be in good agreement with the experimental RTD under different operating conditions. The axial liquid dispersion coefficient increases monotonously with the increasing liquid flux, but is almost independent of gas flux. As the liquid flux and the gas flux increase, the liquid dispersion coefficient of center-to-wall decreases. The axial liquid dispersion coefficient is much larger than that of center-to-wall, which indicates that the liquid RTD is dominated mainly by axial liquid dispersion in the impinging stream reactor.

关键词: RTD     liquid dispersion     reactor     liquid     independent    

Data-driven distribution network topology identification considering correlated generation power of distributed

《能源前沿(英文)》 2022年 第16卷 第1期   页码 121-129 doi: 10.1007/s11708-021-0780-x

摘要: This paper proposes a data-driven topology identification method for distribution systems with distributed energy resources (DERs). First, a neural network is trained to depict the relationship between nodal power injections and voltage magnitude measurements, and then it is used to generate synthetic measurements under independent nodal power injections, thus eliminating the influence of correlated nodal power injections on topology identification. Second, a maximal information coefficient-based maximum spanning tree algorithm is developed to obtain the network topology by evaluating the dependence among the synthetic measurements. The proposed method is tested on different distribution networks and the simulation results are compared with those of other methods to validate the effectiveness of the proposed method.

关键词: power distribution network     data-driven     topology identification     distributed energy resource     maximal information coefficient    

Numerical simulation of three-dimensional gas/liquid two-phase flow in a proton exchange membrane fuel

ZHUGE Weilin, ZHANG Yangjun, LAO Xingsheng, CHEN Xiao, MING Pingwen

《能源前沿(英文)》 2007年 第1卷 第3期   页码 305-310 doi: 10.1007/s11708-007-0044-4

摘要: Investigation into the formation and transport of liquid water in proton exchange membrane fuel cells (PEMFCs) is the key to fuel cell water management. A three-dimensional gas/liquid two-phase flow and heat transfer model is developed based on the multiphase mixture theory. The reactant gas flow, diffusion, and chemical reaction as well as the liquid water transport and phase change process are modeled. Numerical simulations on liquid water distribution and its effects on the performance of a PEMFC are conducted. Results show that liquid water distributes mostly in the cathode, and predicted cell performance decreases quickly at high current density due to the obstruction of liquid water to oxygen diffusion. The simulation results agree well with experimental data.

关键词: diffusion     gas/liquid two-phase     management     exchange     transfer    

Energy distribution between liquid hydrogen and liquid oxygen temperatures in a Stirling/pulse tube refrigerator

《能源前沿(英文)》 2023年 第17卷 第4期   页码 516-526 doi: 10.1007/s11708-022-0844-6

摘要: A two-stage gas-coupled Stirling/pulse tube refrigerator (SPR), whose first and second stages respectively involve Stirling and pulse tube refrigeration cycles, is a very promising spaceborne refrigerator. The SPR has many advantages, such as a compact structure, high reliability, and high performance, and is expected to become an essential refrigerator for space applications. In research regarding gas-coupled regenerative refrigerator, the energy flow distribution between the two stages, and optimal phase difference between the pressure wave and volume flow, are two critical parameters that could widely influence refrigerator performance. The effects of displacer displacement on the pressure wave, phase difference, acoustic power distribution, and inter-stage cooling capacity shift of the SPR have been investigated experimentally. Notably, to obtain the maximum first-stage cooling capacity, an inflection point in displacement exists. When the displacer displacement is larger than the inflection point, the cooling capacity could be distributed between the first and second stages. In the present study, an SPR was designed and manufactured to work between the liquid hydrogen and liquid oxygen temperatures, which can be used to cool small-scale zero boil-off systems and space detectors. Under appropriate displacer displacement, the SPR can reach a no-load cooling temperature of 15.4 K and obtain 2.6 W cooling capacity at 70 K plus 0.1 W cooling capacity at 20 K with 160 W compressor input electric power.

关键词: Stirling/pulse tube refrigerator     displacer displacement     space application     phase shift     energy distribution    

Planning and analysis of the demonstration project of the MVDC distribution network in Zhuhai

Lu QU, Zhanqing YU, Qiang SONG, Zhichang YUAN, Biao ZHAO, Dawei YAO, Jianfu CHEN, Yao LIU, Rong ZENG

《能源前沿(英文)》 2019年 第13卷 第1期   页码 120-130 doi: 10.1007/s11708-018-0599-2

摘要: The DC distribution system is an important development direction of the distribution system, which can improve the reliability and the quality of the power supply, and support the new energy, the energy storage, the electric vehicles, and the flexible access of AC and DC loads to grid. To realize the demonstration application of the DC distribution technology, China’s first demonstration project of the medium voltage DC distribution network will be built in Zhuhai, Guangdong Province to support the construction of the city energy internet. First, this paper analyzes the demand of the DC distribution network project, and puts forward the construction content and construction target. Then, it designs and analyzes the electrical connection mode, system operation mode, and startup and shutdown mode of the DC distribution network, and proposes the overall project construction plan. Finally, it conducts the specific project design and analysis, which mainly include the selection of equipment such as inverters, DC transformers and DC circuit breakers, the design and analysis of the DC control and protection system, the design and analysis of the over-voltage protection and the configuration scheme of the lightning arrester, and analysis of the system transient characteristics. The design and analysis of the engineering program is a combination of China’s distribution network engineering practice and technical characteristics, which lays a solid foundation for the advancement of the DC power distribution technology in China, and has reference value and demonstration effect for the design and construction of other projects.

关键词: MVDC distribution network     DC solid state transformer     DC circuit breaker     modular multilevel converter    

A novel power system reconfiguration for a distribution system with minimum load balancing index using

K. Sathish KUMAR, T. JAYABARATHI

《能源前沿(英文)》 2012年 第6卷 第3期   页码 260-265 doi: 10.1007/s11708-012-0196-8

摘要: In this paper, the objective of minimum load balancing index (LBI) for the 16-bus distribution system is achieved using bacterial foraging optimization algorithm (BFOA). The feeder reconfiguration problem is formulated as a non-linear optimization problem and the optimal solution is obtained using BFOA. With the proposed reconfiguration method, the radial structure of the distribution system is retained and the burden on the optimization technique is reduced. Test results are presented for the 16-bus sample network, the proposed reconfiguration method has effectively decreased the LBI, and the BFOA technique is efficient in searching for the optimal solution.

关键词: bacterial foraging optimization algorithm (BFOA)     distribution system     network reconfiguration     load balancing index (LBI)     radial network    

Two-phase early prediction method for remaining useful life of lithium-ion batteries based on a neuralnetwork and Gaussian process regression

《能源前沿(英文)》 doi: 10.1007/s11708-023-0906-4

摘要: Lithium-ion batteries (LIBs) are widely used in transportation, energy storage, and other fields. The prediction of the remaining useful life (RUL) of lithium batteries not only provides a reference for health management but also serves as a basis for assessing the residual value of the battery. In order to improve the prediction accuracy of the RUL of LIBs, a two-phase RUL early prediction method combining neural network and Gaussian process regression (GPR) is proposed. In the initial phase, the features related to the capacity degradation of LIBs are utilized to train the neural network model, which is used to predict the initial cycle lifetime of 124 LIBs. The Pearson coefficient’s two most significant characteristic factors and the predicted normalized lifetime form a 3D space. The Euclidean distance between the test dataset and each cell in the training dataset and validation dataset is calculated, and the shortest distance is considered to have a similar degradation pattern, which is used to determine the initial Dual Exponential Model (DEM). In the second phase, GPR uses the DEM as the initial parameter to predict each test set’s early RUL (ERUL). By testing four batteries under different working conditions, the RMSE of all capacity estimation is less than 1.2%, and the accuracy percentage (AP) of remaining life prediction is more than 98%. Experiments show that the method does not need human intervention and has high prediction accuracy.

关键词: lithium-ion batteries     RUL prediction     double exponential model     neural network     Gaussian process regression (GPR)    

标题 作者 时间 类型 操作

Distributed energy management for networked microgrids in a three-phase unbalanced distribution network

期刊论文

Aggravation of membrane fouling and methane leakage by a three-phase separator in an external anaerobic

Chao Pang, Chunhua He, Zhenhu Hu, Shoujun Yuan, Wei Wang

期刊论文

Performance investigation of artificial intelligence based controller for three phase four leg shunt

J. JAYACHANDRAN,R. MURALI SACHITHANANDAM

期刊论文

An improved delta-star switching scheme for reactive power saving in three-phase induction motors

P. RAJA,N. KUMARESAN,M. SUBBIAH

期刊论文

考虑多孔电极内气液分布的数学模型

徐献芝,朱梅,杨基明

期刊论文

气体多孔电极反应微观机理及宏观现象的研究

朱梅,徐献芝,杨基明

期刊论文

Thermodynamic models and energy distribution of single-phase heated surface in a boiler under unsteady

Xiyan GUO, Yongping YANG

期刊论文

Estimation of distribution algorithm enhanced particle swarm optimization for water distribution network

Xuewei QI,Ke LI,Walter D. POTTER

期刊论文

Residence time distribution and modeling of the liquid phase in an impinging stream reactor

Xingjun WANG, Xianhui HU, Lishun HU, Guangsuo YU, Fuchen WANG,

期刊论文

Data-driven distribution network topology identification considering correlated generation power of distributed

期刊论文

Numerical simulation of three-dimensional gas/liquid two-phase flow in a proton exchange membrane fuel

ZHUGE Weilin, ZHANG Yangjun, LAO Xingsheng, CHEN Xiao, MING Pingwen

期刊论文

Energy distribution between liquid hydrogen and liquid oxygen temperatures in a Stirling/pulse tube refrigerator

期刊论文

Planning and analysis of the demonstration project of the MVDC distribution network in Zhuhai

Lu QU, Zhanqing YU, Qiang SONG, Zhichang YUAN, Biao ZHAO, Dawei YAO, Jianfu CHEN, Yao LIU, Rong ZENG

期刊论文

A novel power system reconfiguration for a distribution system with minimum load balancing index using

K. Sathish KUMAR, T. JAYABARATHI

期刊论文

Two-phase early prediction method for remaining useful life of lithium-ion batteries based on a neuralnetwork and Gaussian process regression

期刊论文