The new reality of smart distribution systems with use of generation sources of small and medium sizes brings new challenges for the operation of these systems. The complexity and the large number of nodes requires us...The new reality of smart distribution systems with use of generation sources of small and medium sizes brings new challenges for the operation of these systems. The complexity and the large number of nodes requires use of methods which can reduce the processing time of algorithms such as power flow, allowing its use in real time. This paper presents a known methodology for calculating the power flow in three phases using backward/forward sweep method, and also considering other network elements such as voltage regulators, shunt capacitors and sources of dispersed generation of types PV （active power and voltage） and PQ （active and reactive power）. After that, new elements are introduced that allow the parallelization of this algorithm and an adequate distribution of work between the available processors. The algorithm was implemented using a multi-tiered architecture; the processing times were measured in many network configurations and compared with the same algorithm in the serial version.展开更多
在平抑光伏功率波动过程中,电池储能系统(battery energy storage system,BESS)因保持持续充、放电状态而导致寿命损耗较大。基于电池分组控制技术,提出考虑寿命延长的BESS平抑光伏分组功率分配办法。设计了食肉植物算法优化的改进雨流...在平抑光伏功率波动过程中,电池储能系统(battery energy storage system,BESS)因保持持续充、放电状态而导致寿命损耗较大。基于电池分组控制技术,提出考虑寿命延长的BESS平抑光伏分组功率分配办法。设计了食肉植物算法优化的改进雨流计数法,以获取光伏并网功率指令;利用小波包分解确定电池组数量及容量,同时根据设计的充、放电原则形成电池组的功率调节指令;进行电池组组别重置时,将BESS中诸多电池单元进行有序分配;提出二次功率分配策略,获取各电池单元的功率调节指令,二次分配时还应用了重复补发原则以最大限度跟踪功率调节指令,并保证组内电池单元荷电状态均衡。对所提功率分配方法进行了仿真验证,并与其他5种策略进行了对比,结果表明,所提功率分配方法实现了BESS对于功率调节指令的更好跟踪,降低了光伏并网功率波动率,延长了电池单元的使用寿命。展开更多
Accurate prediction of multiphase flowing bottom-hole pressure(FBHP)in wellbores is an important factor required for optimal tubing design and production optimization.Existing empirical correlations and mechanistic mo...Accurate prediction of multiphase flowing bottom-hole pressure(FBHP)in wellbores is an important factor required for optimal tubing design and production optimization.Existing empirical correlations and mechanistic models provide inaccurate FBHP predictions when applied to real-time field datasets because they were developed with laboratory-dependent parameters.Most machine learning(ML)models for FBHP prediction are developed with real-time field data but presented as black-box models.In addition,these ML models cannot be reproduced by other users because the dataset used for training the machine learning algorithm is not open source.These make using the ML models on new datasets difficult.This study presents an artificial neural network(ANN)visible mathematical model for real-time multiphase FBHP prediction in wellbores.A total of 1001 normalized real-time field data points were first used in developing an ANN black-box model.The data points were randomly divided into three different sets;70%for training,15%for validation,and the remaining 15%for testing.Statistical analysis showed that using the Levenberg-Marquardt training optimization algorithm(trainlm),hyperbolic tangent activation function(tansig),and three hidden layers with 20,15 and 15 neurons in the first,second and third hidden layers respectively achieved the best performance.The trained ANN model was then translated into an ANN visible mathematical model by extracting the tuned weights and biases.Trend analysis shows that the new model produced the expected effects of physical attributes on FBHP.Furthermore,statistical and graphical error analysis results show that the new model outperformed existing empirical correlations,mechanistic models,and an ANN white-box model.Training of the ANN on a larger dataset containing new data points covering a wider range of each input parameter can broaden the applicability domain of the proposed ANN visible mathematical model.展开更多
针对电动车辆的复杂行驶工况,提出一种基于雨流计数原理的实时预估钴酸锂电池健康状态(state of health,SOH)的建模方法。首先,开发了一种改进的实时雨流计数法,实现对不同放电深度(depth of discharge,DOD)下循环次数的统计分析;在此...针对电动车辆的复杂行驶工况,提出一种基于雨流计数原理的实时预估钴酸锂电池健康状态(state of health,SOH)的建模方法。首先,开发了一种改进的实时雨流计数法,实现对不同放电深度(depth of discharge,DOD)下循环次数的统计分析;在此基础上,提出一种利用等效充放电电流–荷电状态(state of charge,SOC)的包络面积,来评估每次循环中衰减因子的计算方法,并以不同循环次数下衰减因子的累加和来刻画电池的寿命衰减;最后,设计电池循环老化实验,验证了所提出方法可实现对随机充放电电流、DOD和循环次数下的电池SOH实时估计。展开更多
文摘The new reality of smart distribution systems with use of generation sources of small and medium sizes brings new challenges for the operation of these systems. The complexity and the large number of nodes requires use of methods which can reduce the processing time of algorithms such as power flow, allowing its use in real time. This paper presents a known methodology for calculating the power flow in three phases using backward/forward sweep method, and also considering other network elements such as voltage regulators, shunt capacitors and sources of dispersed generation of types PV （active power and voltage） and PQ （active and reactive power）. After that, new elements are introduced that allow the parallelization of this algorithm and an adequate distribution of work between the available processors. The algorithm was implemented using a multi-tiered architecture; the processing times were measured in many network configurations and compared with the same algorithm in the serial version.
文摘在平抑光伏功率波动过程中,电池储能系统(battery energy storage system,BESS)因保持持续充、放电状态而导致寿命损耗较大。基于电池分组控制技术,提出考虑寿命延长的BESS平抑光伏分组功率分配办法。设计了食肉植物算法优化的改进雨流计数法,以获取光伏并网功率指令;利用小波包分解确定电池组数量及容量,同时根据设计的充、放电原则形成电池组的功率调节指令;进行电池组组别重置时,将BESS中诸多电池单元进行有序分配;提出二次功率分配策略,获取各电池单元的功率调节指令,二次分配时还应用了重复补发原则以最大限度跟踪功率调节指令,并保证组内电池单元荷电状态均衡。对所提功率分配方法进行了仿真验证,并与其他5种策略进行了对比,结果表明,所提功率分配方法实现了BESS对于功率调节指令的更好跟踪,降低了光伏并网功率波动率,延长了电池单元的使用寿命。
文摘Accurate prediction of multiphase flowing bottom-hole pressure(FBHP)in wellbores is an important factor required for optimal tubing design and production optimization.Existing empirical correlations and mechanistic models provide inaccurate FBHP predictions when applied to real-time field datasets because they were developed with laboratory-dependent parameters.Most machine learning(ML)models for FBHP prediction are developed with real-time field data but presented as black-box models.In addition,these ML models cannot be reproduced by other users because the dataset used for training the machine learning algorithm is not open source.These make using the ML models on new datasets difficult.This study presents an artificial neural network(ANN)visible mathematical model for real-time multiphase FBHP prediction in wellbores.A total of 1001 normalized real-time field data points were first used in developing an ANN black-box model.The data points were randomly divided into three different sets;70%for training,15%for validation,and the remaining 15%for testing.Statistical analysis showed that using the Levenberg-Marquardt training optimization algorithm(trainlm),hyperbolic tangent activation function(tansig),and three hidden layers with 20,15 and 15 neurons in the first,second and third hidden layers respectively achieved the best performance.The trained ANN model was then translated into an ANN visible mathematical model by extracting the tuned weights and biases.Trend analysis shows that the new model produced the expected effects of physical attributes on FBHP.Furthermore,statistical and graphical error analysis results show that the new model outperformed existing empirical correlations,mechanistic models,and an ANN white-box model.Training of the ANN on a larger dataset containing new data points covering a wider range of each input parameter can broaden the applicability domain of the proposed ANN visible mathematical model.
文摘针对电动车辆的复杂行驶工况,提出一种基于雨流计数原理的实时预估钴酸锂电池健康状态(state of health,SOH)的建模方法。首先,开发了一种改进的实时雨流计数法,实现对不同放电深度(depth of discharge,DOD)下循环次数的统计分析;在此基础上,提出一种利用等效充放电电流–荷电状态(state of charge,SOC)的包络面积,来评估每次循环中衰减因子的计算方法,并以不同循环次数下衰减因子的累加和来刻画电池的寿命衰减;最后,设计电池循环老化实验,验证了所提出方法可实现对随机充放电电流、DOD和循环次数下的电池SOH实时估计。
