The improved weighted-least-square model was used for state simulation of water distribution networks. And DFP algorithm was applied to get the model solution. In order to fit DFP algorithm,the initial model was trans...The improved weighted-least-square model was used for state simulation of water distribution networks. And DFP algorithm was applied to get the model solution. In order to fit DFP algorithm,the initial model was transformed into a non-constrained optimization problem using mass conservation. Then,through one dimensional optimization and scale matrix establishment,the feasible direction of iteration was obtained,and the values of state variables could be calculated. After several iterations,the optimal estimates of state variables were worked out and state simulation of water distribution networks was achieved as a result. A program of DFP algorithm is developed with Delphi 7 for verification. By running on a designed network,which is composed of 55 nodes,94 pipes and 40 loops,it is proved that DFP algorithm can quickly get the convergence. After 36 iterations,the root mean square of all nodal head errors is reduced by 90.84% from 5.57 to 0.51 m,and the maximum error is only 1.30 m. Compared to Marquardt algorithm,the procedure of DFP algorithm is more stable,and the initial values have less influences on calculation accuracy. Therefore,DFP algorithm can be used for real-time simulation of water distribution networks.展开更多
直流潮流控制器是解决环网式直流配电网的线路潮流不完全可控的有效技术手段。然而,现有方法未能充分发掘其在故障限流中的潜力。该文建立了三有源桥串并联潮流控制器(triple active bridge power flow controller,TAB-PFC)的故障模量...直流潮流控制器是解决环网式直流配电网的线路潮流不完全可控的有效技术手段。然而,现有方法未能充分发掘其在故障限流中的潜力。该文建立了三有源桥串并联潮流控制器(triple active bridge power flow controller,TAB-PFC)的故障模量分析模型,提出一种基于TAB-PFC的双极直流配电网主动限流策略。首先阐述了TAB-PFC的限流原理,提出基于TAB-PFC的主动限流控制策略。然后对TAB-PFC不同故障阶段进行建模,并计及极间互感构建含TAB-PFC的双极直流配电网故障模量等效模型。在此基础上,分析不同参数对TAB-PFC的限流能力的影响,为其参数选取提供依据。在MATLAB/Simulink搭建了含TAB-PFC的双极直流配电网模型,验证了所提主动限流策略的有效性及故障等效电路模型和参数分析的正确性。展开更多
高比例新能源接入使配电网具备一定的主动电压支撑能力,可通过调节公共连接点无功功率,实现输配协同电压调控。然而,新能源出力波动及输配耦合效应加剧了电压失稳过程的复杂性,给短期电压稳定(short-term voltage stability,STVS)评估...高比例新能源接入使配电网具备一定的主动电压支撑能力,可通过调节公共连接点无功功率,实现输配协同电压调控。然而,新能源出力波动及输配耦合效应加剧了电压失稳过程的复杂性,给短期电压稳定(short-term voltage stability,STVS)评估带来挑战。为此,提出计及输配协同的STVS数据驱动评估方法,首先,区别于传统评估中将配电网简化为不可控等值负荷,构建计及配电网主动电压支撑能力的系统时域仿真拓展模型,基于优化方法量化支撑能力并嵌入时域仿真,反映其对电压稳定的影响。其次,基于该模型与历史数据,构建以系统量测量为输入、稳定性状态为输出的训练数据集,训练卷积神经网络(convolutional neural network,CNN)实现STVS在线评估。相比于现有基于深度学习的STVS评估,提出了基于关键节点电压的输入-输出变量降维提取方法,可显著减少训练数据量,提升学习效率。算例仿真结果验证了所提方法在STVS评估和电压失稳程度量化方面的有效性。展开更多
基金Project(IRT0853) supported by Changjiang Scholars and Innovative Research Team in UniversityProject(DB03086) supported by Talents Fund of Xi’an University of Architecture and TechnologyProject(50978213) supported by National Natural Science Foundation
文摘The improved weighted-least-square model was used for state simulation of water distribution networks. And DFP algorithm was applied to get the model solution. In order to fit DFP algorithm,the initial model was transformed into a non-constrained optimization problem using mass conservation. Then,through one dimensional optimization and scale matrix establishment,the feasible direction of iteration was obtained,and the values of state variables could be calculated. After several iterations,the optimal estimates of state variables were worked out and state simulation of water distribution networks was achieved as a result. A program of DFP algorithm is developed with Delphi 7 for verification. By running on a designed network,which is composed of 55 nodes,94 pipes and 40 loops,it is proved that DFP algorithm can quickly get the convergence. After 36 iterations,the root mean square of all nodal head errors is reduced by 90.84% from 5.57 to 0.51 m,and the maximum error is only 1.30 m. Compared to Marquardt algorithm,the procedure of DFP algorithm is more stable,and the initial values have less influences on calculation accuracy. Therefore,DFP algorithm can be used for real-time simulation of water distribution networks.
文摘直流潮流控制器是解决环网式直流配电网的线路潮流不完全可控的有效技术手段。然而,现有方法未能充分发掘其在故障限流中的潜力。该文建立了三有源桥串并联潮流控制器(triple active bridge power flow controller,TAB-PFC)的故障模量分析模型,提出一种基于TAB-PFC的双极直流配电网主动限流策略。首先阐述了TAB-PFC的限流原理,提出基于TAB-PFC的主动限流控制策略。然后对TAB-PFC不同故障阶段进行建模,并计及极间互感构建含TAB-PFC的双极直流配电网故障模量等效模型。在此基础上,分析不同参数对TAB-PFC的限流能力的影响,为其参数选取提供依据。在MATLAB/Simulink搭建了含TAB-PFC的双极直流配电网模型,验证了所提主动限流策略的有效性及故障等效电路模型和参数分析的正确性。
文摘高比例新能源接入使配电网具备一定的主动电压支撑能力,可通过调节公共连接点无功功率,实现输配协同电压调控。然而,新能源出力波动及输配耦合效应加剧了电压失稳过程的复杂性,给短期电压稳定(short-term voltage stability,STVS)评估带来挑战。为此,提出计及输配协同的STVS数据驱动评估方法,首先,区别于传统评估中将配电网简化为不可控等值负荷,构建计及配电网主动电压支撑能力的系统时域仿真拓展模型,基于优化方法量化支撑能力并嵌入时域仿真,反映其对电压稳定的影响。其次,基于该模型与历史数据,构建以系统量测量为输入、稳定性状态为输出的训练数据集,训练卷积神经网络(convolutional neural network,CNN)实现STVS在线评估。相比于现有基于深度学习的STVS评估,提出了基于关键节点电压的输入-输出变量降维提取方法,可显著减少训练数据量,提升学习效率。算例仿真结果验证了所提方法在STVS评估和电压失稳程度量化方面的有效性。
