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Power system reconfiguration and loss minimization for a distribution systems using “Catfish PSO” algorithm

K Sathish KUMAR,S NAVEEN

《能源前沿（英文）》 2014年第8卷第4期页码 434-442 doi: 10.1007/s11708-014-0313-y

摘要： One of the very important ways to save electrical energy in the distribution system is network reconfiguration for loss reduction. Distribution networks are built as interconnected mesh networks; however, they are arranged to be radial in operation. The distribution feeder reconfiguration is to find a radial operating structure that optimizes network performance while satisfying operating constraints. The change in network configuration is performed by opening sectionalizing (normally closed) and closing tie (normally opened) switches of the network. These switches are changed in such a way that the radial structure of networks is maintained, all of the loads are energized, power loss is reduced, power quality is enhanced, and system security is increased. Distribution feeder reconfiguration is a complex nonlinear combinatorial problem since the status of the switches is non-differentiable. This paper proposes a new evolutionary algorithm (EA) for solving the distribution feeder reconfiguration (DFR) problem for a 33-bus and a 16-bus sample network, which effectively ensures the loss minimization.

关键词： distribution system reconfiguration (DFR) power loss reduction catfish particle swarm optimization (catfish PSO) radial structure

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Constriction factor based particle swarm optimization for analyzing tuned reactive power dispatch

Syamasree BISWAS(RAHA), Kamal Krishna MANDAL, Niladri CHAKRABORTY

《能源前沿（英文）》 2013年第7卷第2期页码 174-181 doi: 10.1007/s11708-013-0246-x

摘要： The reactive power dispatch (RPD) problem is a very critical optimization problem of power system which minimizes the real power loss of the transmission system. While solving the said problem, generator bus voltages and transformer tap settings are kept within a stable operating limit. In connection with the RPD problem, solving reactive power is compensated by incorporating shunt capacitors. The particle swarm optimization (PSO) technique is a swarm intelligence based fast working optimization method which is chosen in this paper as an optimization tool. Additionally, the constriction factor is included with the conventional PSO technique to accelerate the convergence property of the applied optimization tool. In this paper, the RPD problem is solved in the case of the two higher bus systems, i.e., the IEEE 57-bus system and the IEEE 118-bus system. Furthermore, the result of the present paper is compared with a few optimization technique based results to substantiate the effectiveness of the proposed study.

关键词： real power loss minimization voltage stability constriction factor particle swarm optimization (PSO)

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Optimization of cold-end system of thermal power plants based on entropy generation minimization

《能源前沿（英文）》 2022年第16卷第6期页码 956-972 doi: 10.1007/s11708-021-0785-5

摘要： Cold-end systems are heat sinks of thermal power cycles, which have an essential effect on the overall performance of thermal power plants. To enhance the efficiency of thermal power plants, multi-pressure condensers have been applied in some large-capacity thermal power plants. However, little attention has been paid to the optimization of the cold-end system with multi-pressure condensers which have multiple parameters to be identified. Therefore, the design optimization methods of cold-end systems with single- and multi-pressure condensers are developed based on the entropy generation rate, and the genetic algorithm (GA) is used to optimize multiple parameters. Multiple parameters, including heat transfer area of multi-pressure condensers, steam distribution in condensers, and cooling water mass flow rate, are optimized while considering detailed entropy generation rate of the cold-end systems. The results show that the entropy generation rate of the multi-pressure cold-end system is less than that of the single-pressure cold-end system when the total condenser area is constant. Moreover, the economic performance can be improved with the adoption of the multi-pressure cold-end system. When compared with the single-pressure cold-end system, the excess revenues gained by using dual- and quadruple-pressure cold-end systems are 575 and 580 k$/a, respectively.

关键词： cold-end system entropy generation minimization optimization economic analysis genetic algorithm (GA)

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Power fluctuation and power loss of wind turbines due to wind shear and tower shadow

Binrong WEN, Sha WEI, Kexiang WEI, Wenxian YANG, Zhike PENG, Fulei CHU

《机械工程前沿（英文）》 2017年第12卷第3期页码 321-332 doi: 10.1007/s11465-017-0434-1

摘要：

The magnitude and stability of power output are two key indices of wind turbines. This study investigates the effects of wind shear and tower shadow on power output in terms of power fluctuation and power loss to estimate the capacity and quality of the power generated by a wind turbine. First, wind speed models, particularly the wind shear model and the tower shadow model, are described in detail. The widely accepted tower shadow model is modified in view of the cone-shaped towers of modern large-scale wind turbines. Power fluctuation and power loss due to wind shear and tower shadow are analyzed by performing theoretical calculations and case analysis within the framework of a modified version of blade element momentum theory. Results indicate that power fluctuation is mainly caused by tower shadow, whereas power loss is primarily induced by wind shear. Under steady wind conditions, power loss can be divided into wind farm loss and rotor loss. Wind farm loss is constant at 3α(3α−1)R²/(8H²). By contrast, rotor loss is strongly influenced by the wind turbine control strategies and wind speed. That is, when the wind speed is measured in a region where a variable-speed controller works, the rotor loss stabilizes around zero, but when the wind speed is measured in a region where the blade pitch controller works, the rotor loss increases as the wind speed intensifies. The results of this study can serve as a reference for accurate power estimation and strategy development to mitigate the fluctuations in aerodynamic loads and power output due to wind shear and tower shadow.

关键词： wind turbine wind shear tower shadow power fluctuation power loss

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Optimal operation of energy at hydrothermal power plants by simultaneous minimization of pollution and

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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Comparison of optimal capacitor placement methods in radial distribution system with load growth and ZIP load model

Veera Venkata Satya Naryana MURTY, Ashwani KUMAR

《能源前沿（英文）》 2013年第7卷第2期页码 197-213 doi: 10.1007/s11708-013-0249-7

摘要： In this paper, a combined power loss sensitivity (PLS) index-based approach is proposed to determine the optimal location of the capacitors in the radial distribution system (RDS) based on the real and reactive combined loss sensitivity index, as capacitor placement not only reduces real power loss with voltage profile improvement but also reduces reactive power loss due to the reactive power compensation in the network. The results have been obtained with the existing methods of power loss index (PLI) and index vector (IV) method for comparison. Besides, the optimal placement has been obtained with the proposed method as well as existing methods and the total kVar support has been obtained. In addition, the results of net cost savings for the 10-, 34-, and 69-bus systems are obtained for comparison. Moreover, the results have been obtained for a large system of 85 buses to validate the results with combined sensitivity based approach. Furthermore, the load growth factor has been considered in the study which is essential for the planning and expansion of the existing systems, whereas the impact of the realistic load model as ZIP load model has been considered for the study of all the systems.

关键词： load growth load models reactive power compensation radial distribution system power loss index (PLI) power loss sensitivity (PLS) index vector (IV)

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Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough

Honglun YANG, Qiliang WANG, Jingyu CAO, Gang PEI, Jing LI

《能源前沿（英文）》 2020年第14卷第4期页码 867-881 doi: 10.1007/s11708-020-0707-y

摘要： This paper proposes a comprehensive thermodynamic and economic model to predict and compare the performance of concentrated solar power plants with traditional and novel receivers with different configurations involving operating temperatures and locations. The simulation results reveal that power plants with novel receivers exhibit a superior thermodynamic and economic performance compared with traditional receivers. The annual electricity productions of power plants with novel receivers in Phoenix, Sevilla, and Tuotuohe are 8.5%, 10.5%, and 14.4% higher than those with traditional receivers at the outlet temperature of 550°C. The levelized cost of electricity of power plants with double-selective-coated receivers can be decreased by 6.9%, 8.5%, and 11.6%. In Phoenix, the optimal operating temperature of the power plants is improved from 500°C to 560°C by employing a novel receiver. Furthermore, the sensitivity analysis of the receiver heat loss, solar absorption, and freeze protection temperature is also conducted to analyze the general rule of influence of the receiver performance on power plants performance. Solar absorption has a positive contribution to annual electricity productions, whereas heat loss and freeze protection temperature have a negative effect on electricity outputs. The results indicate that the novel receiver coupled with low melting temperature molten salt is the best configuration for improving the overall performance of the power plants.

关键词： concentrated solar power parabolic trough receiver heat loss solar energy annual performance

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Loss coefficient of nitrogenous non-point source pollution under various precipitation conditions

CHENG Hongguang, HAO Fanghua, REN Xiyan, YANG Shengtian, XIONG Wen, LEI Shaoping

《环境科学与工程前沿（英文）》 2008年第2卷第2期页码 230-235 doi: 10.1007/s11783-008-0043-7

摘要： In this study, calibrations of non-point source (NPS) pollution models are performed based on Black River basin historical real-time runoff data, sedimentation record data, and NPS sources survey information. The concept of NPS loss

关键词： information concept non-point historical real-time sedimentation

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Mechanism on minimization of excess sludge in oxic-settling-anaerobic (OSA) process

WANG Jianfang, ZHAO Qingliang, JIN Wenbiao, LIN Jikan

《环境科学与工程前沿（英文）》 2008年第2卷第1期页码 36-43 doi: 10.1007/s11783-008-0001-4

摘要： The oxic-settling-anaerobic (OSA) process is a promising wastewater treatment technique for efficiently reducing sludge production and improving the stability of process operation. In this paper, the possible factors of sludge reduction such as sludge decay, uncoupled metabolism, and anaerobic oxidation with low sludge production were discussed in the OSA process. It has been confirmed that sludge decay is the decisive cause in the OSA process, accounting for 66.7% of sludge production reduction. Sludge decay includes hydrolysis and acidogenesis of dead microorganisms and particle organic carbon adsorbed in sludge floc and endogenous metabolism. By batch experiments, it has been proven that there is energetic uncoupling in the OSA system since microorganisms were exposed to alternative anaerobic and aerobic environment. It accounts for about 7.5% of sludge production reduction. Soluble chemical oxygen demand (SCOD) released from the anaerobic sludge tank in the OSA process was used as the substrate for cryptic growth. The substrate was used for anoxic denitrifying, anaerobic phosphorus release, sulfate reduction, and methane production. These anaerobic reactions in the sludge anaerobic tank have lower sludge production than in the aerobic oxidation when equivalent SCOD is consumed, which may lead to approximately 23% of sludge reduction in the OSA process. It has been concluded that multiple causes resulted in the minimization of excess sludge in the OSA system. The microbial community structure and diversity of sludge samples from the CAS (conventional activated sludge) and OSA systems were investigated by 16 SrDNA PCR-DG-DGGE (polymerase chain reaction-double gradient-denaturing gradient gel electrophoresis). DGGE profile and cluster analysis showed more abundant species in the OSA system contrasting to microbial communities in the CAS system.

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Real-time simulation platform for photovoltaic system with a boost converter using MPPT algorithm in

Geethanjali PURUSHOTHAMAN, Vimisha VENUGOPALAN, Aleena Mariya VINCENT

《能源前沿（英文）》 2013年第7卷第3期页码 373-379 doi: 10.1007/s11708-013-0272-8

摘要： Recently, real-time simulation of renewable energy sources are indispensible for evaluating the performance of the maximum power point tracking (MPPT) controller, especially in the photovoltaic (PV) system in order to reduce cost in the testing phase. Nowadays, real time PV simulators are obtained by using analog and/or digital components. In this paper, a real-time simulation of a PV system with a boost converter was proposed using only the digital signal processor (DSP) processor with two DC voltage sources to emulate the temperature and irradiation in the PV system. A MATLAB/Simulink environment was used to develop the real-time PV system with a boost converter into a C-program and build it into a DSP controller TMS320F28335. Besides, the performance of the real-time DSP-based PV was tested in different temperature and irradiation conditions to observe the P-V and V-I characteristics. Further, the performance of the PV with a boost converter was tested at different temperatures and irradiations using MPPT algorithms. This scheme was tested through simulation and the results were validated with that of standard conditions given in the PV data sheets. Implementation of this project helped to attract more researchers to study renewable energy applications without real sources. This might facilitate the study of PV systems in a real-time scenario and the evaluation of what should be expected for PV modules available in the market.

关键词： photovoltaic (PV) module digital signal processor (DSP) controller power electronic converter real-time simulation

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Real drive cycles analysis by ordered power methodology applied to fuel consumption, CO

Pol Masclans Abelló, Vicente Medina Iglesias, M. Antonia de los Santos López, Jesús Álvarez-Flórez

《环境科学与工程前沿（英文）》 2021年第15卷第1期 doi: 10.1007/s11783-020-1296-z

摘要： Abstract • New method named CAbOP is presented based on ordering data according to power. • Three emission models are used and their emission results compared. • Emissions data are analyzed in real driving cycles under CAbOP criteria. • Methodology to collect data and reconstruct lost data in real urban driving cycles. In this work three fuel consumption and exhaust emission models, ADVISOR, VT-MICRO and the European Environmental Agency Emission factors, have been used to obtain fuel consumption (FC) and exhaust emissions. These models have been used at micro-scale, using the two signal treatment methods presented. The manuscript presents: 1) a methodology to collect data in real urban driving cycles, 2) an estimation of FC and tailpipe emissions using some available models in literature, and 3) a novel analysis of the results based on delivered wheel power. The results include Fuel Consumption (FC), CO2, NOx and PM10 emissions, which are derived from the three simulators. In the first part of the paper we present a new procedure for incomplete drive cycle data treatment, which is necessary for real drive cycle acquisition in high density cities. Then the models are used to obtain second by second FC and exhaust emissions. Finally, a new methodology named Cycle Analysis by Ordered Power (CAbOP) is presented and used to compare the results. This method consists in the re-ordering of time dependant data, considering the wheel mechanical power domain instead of the standard time domain. This new strategy allows the 5 situations in drive cycles to be clearly visualized: hard breaking zone, slowdowns, idle or stop zone, sustained speed zone and acceleration zone. The complete methodology is applied in two real drive cycles surveyed in Barcelona (Spain) and the results are compared with a standardized WLTC urban cycle.

关键词： Cycle Analysis by Ordered Power (CAbOP) Micro and macro models Real drive cycle NO_x/PM₁₀/CO₂ emissions Wheel mechanical power domain Worldwide Harmonized Light-Duty Vehicles Test Cycle (WLTC)

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Robust design approach to the minimization of functional performance variations of products and systems

J. ZHANG, H. DU, D. XUE, P. GU

《机械工程前沿（英文）》 2021年第16卷第2期页码 379-392 doi: 10.1007/s11465-020-0607-1

摘要： Functional performance variations of products and systems are often used to measure the qualities of products and systems considering the changes in the design parameter values caused by uncertainties. A robust design approach has been developed in this research to minimize the functional performance variations considering the design parameter uncertainties by identifying the boundaries of the functional performance variations through optimization. In this work, a mathematical model is developed to describe the relationships among functional performance, design configurations and parameters, and design parameter uncertainties. A multi-level optimization model is established to identify: (1) The optimal design configuration, (2) the optimal values of design parameters, and (3) the boundaries of functional performance variations. Sensitivity analysis considering the impact of parameter uncertainties on functional performance variation boundaries has also been conducted. A case study on the design of a truss system has been conducted. Case study results show that the sensitivities of functional performance variation boundaries to the design parameter uncertainties can be reduced significantly using the new robust design approach.

关键词： product design robust design design optimization uncertainties

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Real prospects for the development of power technologies based on renewable energy sources in Poland

Sławomir DYKAS, Artur SZYMAŃSKI, Xiaoshu CAI

《能源前沿（英文）》 2017年第11卷第2期页码 168-174 doi: 10.1007/s11708-017-0474-6

摘要： In Poland more than 40% of the power units have been operating for over 40 years now and more than 10% are over 50 years old, which indicates a high degree of decrease in the value of the energy sector. An analysis of the energy market shows that every year a new power plant should be built with a capacity of 1000 MW to ensure the national energy security. An energy market research indicates that in Poland the structure of energy production is changing in recent years—the share of fossil (solid) fuels in electricity and heat production was approximately 88% in 2009, while in 2004 it reached 93%. According to the analysis of the market, it can be seen that conventional energy, mainly based on coal and lignite, has been the most important segment of the sector for a long time.?In this paper the prospects for the development of power technologies based on renewable energy sources (RES) in Poland are presented.

关键词： renewable energy sources energy sector energy mix Poland

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Review of recent advances of polymer based dielectrics for high-energy storage in electronic power devices

Wenjie Sun, Jiale Mao, Shuang Wang, Lei Zhang, Yonghong Cheng

《化学科学与工程前沿（英文）》 2021年第15卷第1期页码 18-34 doi: 10.1007/s11705-020-1939-4

摘要： Polymer-based dielectric capacitors are widely-used energy storage devices. However, although the functions of dielectrics in applications like high-voltage direct current transmission projects, distributed energy systems, high-power pulse systems and new energy electric vehicles are similar, their requirements can be quite different. Low electric loss is a critical prerequisite for capacitors for electric grids, while high-temperature stability is an essential pre-requirement for those in electric vehicles. This paper reviews recent advances in this area, and categorizes dielectrics in terms of their foremost properties related to their target applications. Requirements for polymer-based dielectrics in various power electronic equipment are emphasized, including high energy storage density, low dissipation, high working temperature and fast-response time. This paper considers innovations including chemical structure modification, composite fabrication and structure re-design, and the enhancements to material performances achieved. The advantages and limitations of these methods are also discussed.

关键词： dielectric capacitors polymer-based dielectrics energy density dielectric loss working temperature frequency response

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Dynamic characteristics and improved MPPT control of PV generator

Houda BRAHMI, Rachid DHIFAOUI

《能源前沿（英文）》 2013年第7卷第3期页码 342-350 doi: 10.1007/s11708-013-0242-1

摘要： This paper presents a mathematical model of photovoltaic (PV) module and gives a strategy to calculate online the maximum power point (MPP). The variation of series and shunt resistor are taken into account in the model and are dynamically identified using the Newton-Raphson algorithm. The effectiveness of the proposed model is verified by laboratory experiments obtained by implementing the model on the dSPACE DS1104 board.

关键词： modeling of photovoltaic (PV) generator maximum power point tracking (MPPT) estimation parameters real time controller

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标题作者时间类型操作

Power system reconfiguration and loss minimization for a distribution systems using “Catfish PSO” algorithm

K Sathish KUMAR,S NAVEEN

期刊论文

Constriction factor based particle swarm optimization for analyzing tuned reactive power dispatch

Syamasree BISWAS(RAHA), Kamal Krishna MANDAL, Niladri CHAKRABORTY

期刊论文

Optimization of cold-end system of thermal power plants based on entropy generation minimization

期刊论文

Power fluctuation and power loss of wind turbines due to wind shear and tower shadow

Binrong WEN, Sha WEI, Kexiang WEI, Wenxian YANG, Zhike PENG, Fulei CHU

期刊论文

Optimal operation of energy at hydrothermal power plants by simultaneous minimization of pollution and

Homayoun EBRAHIMIAN,Bahman TAHERI,Nasser YOUSEFI

期刊论文

Comparison of optimal capacitor placement methods in radial distribution system with load growth and ZIP load model

Veera Venkata Satya Naryana MURTY, Ashwani KUMAR

期刊论文

Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough

Honglun YANG, Qiliang WANG, Jingyu CAO, Gang PEI, Jing LI

期刊论文

Loss coefficient of nitrogenous non-point source pollution under various precipitation conditions

CHENG Hongguang, HAO Fanghua, REN Xiyan, YANG Shengtian, XIONG Wen, LEI Shaoping

期刊论文

Mechanism on minimization of excess sludge in oxic-settling-anaerobic (OSA) process

WANG Jianfang, ZHAO Qingliang, JIN Wenbiao, LIN Jikan

期刊论文

Real-time simulation platform for photovoltaic system with a boost converter using MPPT algorithm in

Geethanjali PURUSHOTHAMAN, Vimisha VENUGOPALAN, Aleena Mariya VINCENT

期刊论文

Real drive cycles analysis by ordered power methodology applied to fuel consumption, CO

Pol Masclans Abelló, Vicente Medina Iglesias, M. Antonia de los Santos López, Jesús Álvarez-Flórez

期刊论文

Robust design approach to the minimization of functional performance variations of products and systems

J. ZHANG, H. DU, D. XUE, P. GU

期刊论文

Real prospects for the development of power technologies based on renewable energy sources in Poland

Sławomir DYKAS, Artur SZYMAŃSKI, Xiaoshu CAI

期刊论文

Review of recent advances of polymer based dielectrics for high-energy storage in electronic power devices

Wenjie Sun, Jiale Mao, Shuang Wang, Lei Zhang, Yonghong Cheng

期刊论文

Dynamic characteristics and improved MPPT control of PV generator

Houda BRAHMI, Rachid DHIFAOUI

期刊论文

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