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Pragmatic multi-stage simulated annealing for optimal placement of synchrophasor measurement units in

Pathirikkat GOPAKUMAR,M. JAYA BHARATA REDDY,Dusmata Kumar MOHANTA

《能源前沿（英文）》 2015年 第9卷 第2期   页码 148-161 doi: 10.1007/s11708-015-0344-z

摘要： Conventional power grids across the globe are reforming to smart power grids with cutting edge technologies in real time monitoring and control methods. Advanced real time monitoring is facilitated by incorporating synchrophasor measurement units such as phasor measurement units (PMUs) to the power grid monitoring system. Several physical and economic constraints limit the deployment of PMUs in smart power grids. This paper proposes a pragmatic multi-stage simulated annealing (PMSSA) methodology for finding the optimal locations in the smart power grid for installing PMUs in conjunction with existing conventional measurement units (CMUs) to achieve a complete observability of the grid. The proposed PMSSA is much faster than the conventional simulated annealing (SA) approach as it utilizes controlled uphill and downhill movements during various stages of optimization. Moreover, the method of integrating practical phasor measurement unit (PMU) placement conditions like PMU channel limits and redundant placement can be easily handled. The efficacy of the proposed methodology has been validated through simulation studies in IEEE standard bus systems and practical regional Indian power grids.

关键词： phasor measurement units (PMUs)     pragmatic PMU placement     simulated annealing (SA)     western region Indian power grid (WRIPG)    

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Optimal placement of PMUs for the smart grid implementation in Indian power grid—A case study

Pathirikkat GOPAKUMAR, G. Surya CHANDRA, M. Jaya Bharata REDDY, Dusmata Kumar MOHANTA

《能源前沿（英文）》 2013年 第7卷 第3期   页码 358-372 doi: 10.1007/s11708-013-0257-7

摘要： Efficient utilization of energy resources is essential for a developing country like India. The concept of smart grid (SG) can provide a highly reliable power system with optimized utilization of available resources. The present Indian power grid requires revolutionary changes to meet the growing demands and to make the grid smarter and reliable. One of the important requirements for SG is the instantaneous monitoring of the voltage, current and power flows at all buses in the grid. The traditional monitoring system cannot satisfy this requirement since they are based on nonlinear power flow equations. Synchro-phasor-measurement devices like phasor measurement units (PMUs) can measure the phasor values of voltages at installed buses. Consequently, the currents passing through all branches connected to that bus can be computed. Since the voltage phasor values at the neighboring buses of a bus containing the PMU can be estimated using Ohm’s law, it is redundant to install PMUs at all the buses in a power grid for its complete observability. This paper proposes the optimal geographical locations for the PMUs in southern region Indian power grid for the implementation of SG, using Integer Linear Programming. The proposed optimal geographical locations for PMU placement can be a stepping stone for the implementation of SG in India.

关键词： phasor measurement units (PMUs)     smart grid (SG)     southern region Indian power grid (SRIPG)     integer linear programming (ILP)    

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Optimal redundant placement of PMUs in Indian power grid — northern, eastern and north-eastern regions

Pathirikkat GOPAKUMAR, G. Surya CHANDRA, M. Jaya Bharata REDDY, Dusmata Kumar MOHANTA

《能源前沿（英文）》 2013年 第7卷 第4期   页码 413-428 doi: 10.1007/s11708-013-0274-6

摘要： Effective utilization of renewable energy sources and efficient management of electric energy are essential for any developing countries like India. This can be envisioned through the implementation of concepts of smart grid (SG). One of the key requisites for SG implementation is that the grid should be completely observable. Renovation of conventional Indian power grid to a SG necessitates incorporation of the phasor measurement units (PMUs) in the present power grid measurement and monitoring system. Since the cost of PMU is high and any bus containing a PMU makes the neighboring connected buses observable, optimal placement of PMUs is very important for complete observability of the grid. This paper proposes optimal redundant geographical locations in the northern, eastern and north-eastern regions of Indian power grid for PMU placement. The PMUs installed in these geographical locations will make the grid completely observable and maintain the observability under the conditions of failure of some PMUs or branch outages. Integer linear programming has been used for finding the optimal PMU locations. The results proposed in this paper can be a stepping stone for revamping the Indian power grid to a SG ensuring complete observability during different contingency conditions.

关键词： phasor measurement unit (PMU)     smart grid (SG)     Indian power grid     northern region Indian power grid (NRIPG)     eastern region Indian power grid (ERIPG)     north-eastern region Indian power grid (NERIPG)     redundancy     integer linear programing (ILP)    

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Distribution and potential ecological risk of heavy metals in the typical eco-units of Haihe River Basin

Jingling LIU,Tao YANG,Qiuying CHEN,Feng LIU,Binbin WANG

《环境科学与工程前沿（英文）》 2016年 第10卷 第1期   页码 103-113 doi: 10.1007/s11783-014-0686-5

摘要： The distribution and characteristics of seven heavy metals in sediments located in the typical ecological units (eco-units) (e.g., rivers, lakes, and estuaries) of Haihe River Basin were analyzed. The Hakanson potential ecological risk index was used for ecological risk assessment. The results indicated that the concentration scales of As, Hg, Cr, Cd, Pb, Cu, and Zn in the eco-units were 2.08 to 24.80 mg·g , 0.01 to 1135.50 mg·g , 28.70 to 152.73 mg·g , 0.03 to 195765.83 mg·g , 8.65 to 157.82 mg·g , 6.47 to 178.61 mg·g , and 21.09 to 1076.25 mg·g , respectively. The maximum concentrations of Hg, Cd, and Zn showed higher levels than other water bodies around the world. Hg and Cd have high concentrations in Zhangweinanhe River (1135.50 and 195765.83 mg·g , respectively) and Haihe Estuary (790.50 and 548.47 mg·g , respectively). According to the ecological factor, Cd and Hg showed very strong ecological risks. The seven heavy metals, namely, Cd, Hg, As, Cr, Pb, Cu, and Zn, exhibited ecological risk levels in descending order. Based on the potential ecological risk index, Luanhe River and Baiyangdian Lake had moderate ecological risks, whereas every site in Zhangweinanhe River and Haihe Estuary had substantial risk levels. The risk order of the typical eco-units are as follows: Zhangweinan River (2278345.68)>Estuary (161914.74)>Luanhe River (191.54)>Baiyangdian Lake (120.95). These results provided a scientific basis for water environment improvement and risk management of the Haihe River Basin.

关键词： Haihe River Basin     ecological risk     eco-units     heavy metals    

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Reliability prediction and its validation for nuclear power units in service

Jinyuan SHI,Yong WANG

《能源前沿（英文）》 2016年 第10卷 第4期   页码 479-488 doi: 10.1007/s11708-016-0425-7

摘要： In this paper a novel method for reliability prediction and validation of nuclear power units in service is proposed. The equivalent availability factor is used to measure the reliability, and the equivalent availability factor deducting planed outage hours from period hours and maintenance factor are used for the measurement of inherent reliability. By statistical analysis of historical reliability data, the statistical maintenance factor and the undetermined parameter in its numerical model can be determined. The numerical model based on the maintenance factor predicts the equivalent availability factor deducting planed outage hours from period hours, and the planed outage factor can be obtained by using the planned maintenance days. Using these factors, the equivalent availability factor of nuclear power units in the following 3 years can be obtained. Besides, the equivalent availability factor can be predicted by using the historical statistics of planed outage factor and the predicted equivalent availability factor deducting planed outage hours from period hours. The accuracy of the reliability prediction can be evaluated according to the comparison between the predicted and statistical equivalent availability factors. Furthermore, the reliability prediction method is validated using the nuclear power units in North American Electric Reliability Council (NERC) and China. It is found that the relative errors of the predicted equivalent availability factors for nuclear power units of NERC and China are in the range of –2.16% to 5.23% and –2.15% to 3.71%, respectively. The method proposed can effectively predict the reliability index in the following 3 years, thus providing effective reliability management and maintenance optimization methods for nuclear power units.

关键词： nuclear power units in service     reliability     reliability prediction     equivalent availability factors    

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Implementation and performance evaluation of advance metering infrastructure for Borneo-Wide Power Grid

Mujahid TABASSUM,Manas K. HALDAR,Duaa Fatima S. KHAN

《能源前沿（英文）》 2020年 第14卷 第1期   页码 192-211 doi: 10.1007/s11708-016-0438-2

摘要： In this paper, a supervisory computer network for Borneo-Wide Power Grid system have been proposed and implemented, which includes a renewable power generation and advanced metering infrastructure. An Internet-based communication network running on multiprotocol label switching (MPLS) has been implemented for a smart power grid, with the addition of the renewable energy monitoring system. The centralized supervisory control and data acquisition systems (SCADA) are replaced by a wide area monitoring system(WAMS) comprising of a phasor measurement unit (PMU). The implemented communication network used advanced metering infrastructure that operates on worldwide interoperability for microwave access (WiMAX), wireless fidelity (Wi-Fi) and low power Wi-Fi, which are proposed for the distribution systems of Sarawak Energy. The proposed wide area network (WAN) is simulated using OPNET Modeler and the results are compared with the existing WAN used by Sarawak Energy.

关键词： renewable energy     multiprotocol label switching (MPLS)     power grid     phasor measurement unit (PMU)     supervisory control and data acquisition systems (SCADA)     wide area monitoring system (WAMS)     worldwide interoperability for microwave access (WiMAX)     synchronous digital hierarchy (SDH)    

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density measurement for plastic injection molding via ultrasonic technology

《机械工程前沿（英文）》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0714-2

摘要： Density variation during the injection molding process directly reflects the state of plastic melt and contains valuable information for process monitoring and optimization. Therefore, in-situ density measurement is of great interest and has significant application value. The existing methods, such as pressure−volume−temperature (PVT) method, have the shortages of time-delay and high cost of sensors. This study is the first to propose an in-situ density measurement method using ultrasonic technology. The analyses of the time-domain and frequency-domain signals are combined in the proposed method. The ultrasonic velocity is obtained from the time-domain signals, and the acoustic impedance is computed through a full-spectral analysis of the frequency-domain signals. Experiments with different process conditions are conducted, including different melt temperature, injection speed, material, and mold structure. Results show that the proposed method has good agreement with the PVT method. The proposed method has the advantages of in-situ measurement, non-destructive, high accuracy, low cost, and is of great application value for the injection molding industry.

关键词： ultrasonic measurement     melt density     in-situ measurement     injection molding    

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Capacity limitation of nuclear units in grid based on analysis of frequency regulation

Yiping DAI, Pan JIANG, Lin GAO, Weimin KAN, Xiaoqing XIAO, Ge JIN

《能源前沿（英文）》 2012年 第6卷 第2期   页码 148-154 doi: 10.1007/s11708-012-0174-1

摘要： The increasing capacity of nuclear units in power grid poses threat to system stability and security. Load disturbance may cause overspeed of the units and trigger the overspeed protection controller (OPC). Repeating actions of valves have a strong impact on the security of the equipment and may result in a collapse of the power system. Based on the analysis of frequency regulation, mathematic models for nuclear units in the grid are established in this paper to simulate the dynamic process when load disturbance occurs. The critical action of the OPC is proposed as the constraint of safe operation for the units. The relationship between different styles of frequency regulation and the allowable capacity of the nuclear units in the grid is discussed. This research can help to estimate the capacity limitation of nuclear units in the grid.

关键词： nuclear units capacity     overspeed     primary frequency control (PFC)     second frequency control (SFC)    

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Optimal operation of energy at hydrothermal power plants by simultaneous minimization of pollution and costs using improved ABC algorithm

Homayoun EBRAHIMIAN,Bahman TAHERI,Nasser YOUSEFI

《能源前沿（英文）》 2015年 第9卷 第4期   页码 426-432 doi: 10.1007/s11708-015-0376-4

摘要： The aim of this paper is simultaneous minimization of hydrothermal units to reach the best solution by employing an improved artificial bee colony (ABC) algorithm in a multi-objective function consisting of economic dispatch (ED) considering the valve-point effect and pollution function in power systems in view of the hot water of the hydro system. In this type of optimization problem, all practical constraints of units were taken into account as much as possible in order to comply with the reality. These constraints include the maximum and minimum output power of units, the constraints caused by the balance between supply and demand, the impact of pollution, water balance, uneven production curve considering the valve-point effect and system losses. The proposed algorithm is applied on the studied system, and the obtained results indifferent operating conditions are analyzed. To investigate in various operating conditions, different load profiles in 12 h are taken into account. The obtained results are compared with those of the other methods including the genetic algorithm (GA), the Basu technique, and the improved genetic algorithm. Fast convergence is one of this improved algorithm features.

关键词： practical constraints of units     pollution function     inlet steam valve     up-ramp rate of units     improved ABC algorithm    

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Energy conservation in China’s coal-fired power industry by installing advanced units and organized phasing

Weiliang WANG, Junfu LYU, Zheng LI, Hai ZHANG, Guangxi YUE, Weidou NI

《能源前沿（英文）》 2019年 第13卷 第4期   页码 798-807 doi: 10.1007/s11708-019-0633-z

摘要： Coal-fired power is the main power source and the biggest contributor to energy conservation in the past several decades in China. It is generally believed that advanced technology should be counted on for energy conservation. However, a review of the decline in the national average net coal consumption rate (NCCR) of China’s coal-fired power industry along with its development over the past few decades indicates that the up-gradation of the national unit capacity structure (including installing advanced production and phasing out backward production) plays a more important role. A quantitative study on the effect of the unit capacity structure up-gradation on the decline in the national average NCCR suggests that phasing out backward production is the leading factor for the decline in the NCCR in the past decade, followed by the new installation, whose sum contributes to approximately 80% of the decline in the national average NCCR. The new installation has an effective affecting period of about 8 years, during which it would gradually decline from a relatively high value. Since the effect of phasing out backward production may remain at a certain degree given a continual action of phasing out backward capacity, it is suggested that the organized action of phasing out backward production should be insisted on.

关键词： coal-fired power     energy conservation     net coal consumption rate     new installation     phasing out backward production     unit capacity structure    

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Occurrence and migration of microplastics and plasticizers in different wastewater and sludge treatment units

《环境科学与工程前沿（英文）》 2022年 第16卷 第11期 doi: 10.1007/s11783-022-1577-9

摘要：

● Reduce the quantifying MPs time by using Nile red staining.

关键词： Microplastics     Municipal wastewater treatment plant     Phthalate esters     Thermal hydrolysis    

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High risk factors for pulmonary fungous infection in intensive care units of neurosurgery

ZHU Wenyu, TAN Liping, CHEN Xiangfeng, HUANG Qiang, LAN Qing

《医学前沿（英文）》 2007年 第1卷 第3期   页码 299-303 doi: 10.1007/s11684-007-0057-8

摘要： By analyzing the high risk factors for pulmonary fungous infection in intensive care units of neurosurgery, the strategy of early diagnosis and treatment was explored. According to the domestic diagnostic standard on pulmonary fungous infection, clinical data on 58 patients with the infection in our department were analyzed. One hundred and seventeen strains of fungi were separated from the 58 cases. Candidiasis was the most frequent type, accounting for 92.3% of the cases. Conditions such as the severity of primary diseases, long-time coma, long-term use of broad-spectrum antibiotic, abuse of glucocorticoid, the open airway, and some invasive intubations, may be regarded as high risk factors for pulmonary fungous infection. Fluconazole showed good clinical effects on the treatment of fungous infection. To eliminate these high risk factors, early diagnosis and the use of prophylactic antifungal agents can help reduce the incidence of pulmonary fungous infection.

关键词： seventeen     incidence     glucocorticoid     broad-spectrum antibiotic     Candidiasis    

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Inhibition character of crotonaldehyde manufacture wastewater on biological acidification

《环境科学与工程前沿（英文）》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1403-9

摘要：

• The inhibition of the main organic pollutions in CMW was demonstrated.

关键词： Crotonaldehyde manufacture wastewater     Biological acidification     Volatile fatty acids     Inhibition     Toxic units    

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A measurement system for thin elastohydrodynamic lubrication films

WANG Xuefeng, GUO Feng, YANG Peiran

《机械工程前沿（英文）》 2007年 第2卷 第2期   页码 193-196 doi: 10.1007/s11465-007-0032-8

摘要： An elastohydrodynamic lubrication (EHL) film measurement system using multi-beam interferometry is introduced in this paper. The measurement principle and the instrumentation are discussed. A simple and efficient method is suggested to obtain the fringe order of measured points. It is demonstrated that the presented measurement system can provide continuous measurement of lubricating films from nano to micro scales at a nano-level resolution, and can be used to investigate ultra-thin EHL films and tiny variations in EHL films.

关键词： instrumentation     continuous measurement     elastohydrodynamic lubrication     ultra-thin     measurement    

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扩大乙烯装置原料来源的思考与实践

曹湘洪

《中国工程科学》 2001年 第3卷 第5期   页码 35-43

摘要：

从烃类原料裂解制乙烯的裂解性能和烃类馏份馏程及组成相关研究结果出发，提出了与世界乙烯原料轻质化的大趋势不同的扩大乙烯原料来源的思路：大庆原油的重馏份油即常三、减一线油和减二、减三线油酮苯脱蜡副产的蜡下油可以作乙烯原料。总结了该原料性能测试、模拟裂解炉评价及工业装置上应用的结果，证明该原料裂解时有较高的乙烯收率，也能保证裂解炉较长的运行周期，有明显的经济效益。

关键词： 乙烯     原料     来源    

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标题 作者 时间 类型 操作

Pragmatic multi-stage simulated annealing for optimal placement of synchrophasor measurement units in

Pathirikkat GOPAKUMAR,M. JAYA BHARATA REDDY,Dusmata Kumar MOHANTA

期刊论文

Optimal placement of PMUs for the smart grid implementation in Indian power grid—A case study

Pathirikkat GOPAKUMAR, G. Surya CHANDRA, M. Jaya Bharata REDDY, Dusmata Kumar MOHANTA

期刊论文

Optimal redundant placement of PMUs in Indian power grid — northern, eastern and north-eastern regions

Pathirikkat GOPAKUMAR, G. Surya CHANDRA, M. Jaya Bharata REDDY, Dusmata Kumar MOHANTA

期刊论文

Distribution and potential ecological risk of heavy metals in the typical eco-units of Haihe River Basin

Jingling LIU,Tao YANG,Qiuying CHEN,Feng LIU,Binbin WANG

期刊论文

Reliability prediction and its validation for nuclear power units in service

Jinyuan SHI,Yong WANG

期刊论文

Implementation and performance evaluation of advance metering infrastructure for Borneo-Wide Power Grid

Mujahid TABASSUM,Manas K. HALDAR,Duaa Fatima S. KHAN

期刊论文

density measurement for plastic injection molding via ultrasonic technology

期刊论文

Capacity limitation of nuclear units in grid based on analysis of frequency regulation

Yiping DAI, Pan JIANG, Lin GAO, Weimin KAN, Xiaoqing XIAO, Ge JIN

期刊论文

Optimal operation of energy at hydrothermal power plants by simultaneous minimization of pollution and costs using improved ABC algorithm

Homayoun EBRAHIMIAN,Bahman TAHERI,Nasser YOUSEFI

期刊论文

Energy conservation in China’s coal-fired power industry by installing advanced units and organized phasing

Weiliang WANG, Junfu LYU, Zheng LI, Hai ZHANG, Guangxi YUE, Weidou NI

期刊论文

Occurrence and migration of microplastics and plasticizers in different wastewater and sludge treatment units

期刊论文

High risk factors for pulmonary fungous infection in intensive care units of neurosurgery

ZHU Wenyu, TAN Liping, CHEN Xiangfeng, HUANG Qiang, LAN Qing

期刊论文

Inhibition character of crotonaldehyde manufacture wastewater on biological acidification

期刊论文

A measurement system for thin elastohydrodynamic lubrication films

WANG Xuefeng, GUO Feng, YANG Peiran

期刊论文

扩大乙烯装置原料来源的思考与实践

曹湘洪

期刊论文