A larger number of uncertain factors in energy systems influence their evolution.Owing to the complexity of energy system modeling,incorporating uncertainty analysis to energy system modeling is essential for future e...A larger number of uncertain factors in energy systems influence their evolution.Owing to the complexity of energy system modeling,incorporating uncertainty analysis to energy system modeling is essential for future energy system planning and resource allocation.This study focusses on long-term energy system optimization model.The important uncertain parameters in the model are analyzed and divided into policy,economic,and technical factors.This study specifically addresses the challenges related to carbon emission reduction and energy transition.It involves collecting and organizing relevant research on uncertainty analysis of long-term energy systems.Various energy system uncertainty modeling methods and their applications from the literature are summarized in this review.Finally,important uncertainty factors and uncertainty modeling methods for long-term energy system modeling are discussed,and future research directions are proposed.展开更多
Far from the Madding Crowd is one of the most eminent works of British writer Thomas Hardy. In the novel, Hardy set amounts of uncertain factors such as death, love, and coincidence to push the development of the nove...Far from the Madding Crowd is one of the most eminent works of British writer Thomas Hardy. In the novel, Hardy set amounts of uncertain factors such as death, love, and coincidence to push the development of the novel, figures' destiny and characteristics.展开更多
Since the joint actuator of the space robot executes the control instructions frequently in the harsh space environment,it is prone to the partial loss of control effectiveness(PLCE)fault.An adaptive fault-tolerant co...Since the joint actuator of the space robot executes the control instructions frequently in the harsh space environment,it is prone to the partial loss of control effectiveness(PLCE)fault.An adaptive fault-tolerant control algorithm is designed for a space robot system with the uncertain parameters and the PLCE actuator faults.The mathematical model of the system is established based on the Lagrange method,and the PLCE actuator fault is described as an effectiveness factor.The lower bound of the effectiveness factors and the upper bound of the uncertain parameters are estimated by an adaptive strategy,and the estimated value is fed back to the control algorithm.Compared with the traditional fault-tolerant algorithms,the proposed algorithm does not need to predetermine the lower bound of the effectiveness factor,hence it is more in line with the actual engineering application.It is proved that the algorithm can guarantee the stability of the closed-loop system based on the Lyapunov function method.The numerical simulation results show that the proposed algorithm can not only compensate for the uncertain parameters,but also can tolerate the PLCE actuator faults effectively,which verifies the effectiveness and superiority of the control scheme.展开更多
Demand response(DR)is a practical solution to overcoming the challenges posed by the volatility and intermit tency of the renewable generation in power systems.Industrial electricity demand is growing rapidly,which ma...Demand response(DR)is a practical solution to overcoming the challenges posed by the volatility and intermit tency of the renewable generation in power systems.Industrial electricity demand is growing rapidly,which makes the DR po tential estimation of industrial user critical for the DR imple mentation.In this paper,a unified model for estimating DR po tential in the production processes of aluminum,cement,and steel is proposed on the basis of their unique operational char acteristics.Firstly,considering the typical characteristic con straints of different industrial users,a DR potential estimation model is developed to capture typical industrial user response behavior under various operational and economic factors.The proposed estimation model is further refined to account for the uncertain and subjective factors present in the actual estima tion environment.Secondly,a virtual data acquisition method is introduced to obtain the private virtual parameters required in the estimation process.Then,an industrial user participation threshold is presented to determine whether industrial users may participate in DR at a given time with consideration of their response characteristics.The industrial users may not al ways act with perfect rationality,and the response environment remains uncertain.In addition,the subjective factor in this pa per includes the proposed threshold and the bounded rationali ty.Finally,an improved DR potential estimation model is pro posed to reduce the difficulties in the actual estimation process.The simulation results validate the effectiveness of the proposed estimation model and the improved DR potential estimation model across multiple cases.展开更多
To avoid the aerodynamic performance loss of airfoil at non-design state which often appears in single point design optimization, and to improve the adaptability to the uncertain factors in actual flight environment, ...To avoid the aerodynamic performance loss of airfoil at non-design state which often appears in single point design optimization, and to improve the adaptability to the uncertain factors in actual flight environment, a two-dimensional stochastic airfoil optimization design method based on neural networks is presented. To provide highly efficient and credible analysis, four BP neural networks are built as surrogate models to predict the airfoil aerodynamic coefficients and geometry parameter. These networks are combined with the probability density function obeying normal distribution and the genetic algorithm, thus forming an optimization design method. Using the method, for GA（W）-2 airfoil, a stochastic optimization is implemented in a two-dimensional flight area about Mach number and angle of attack. Compared with original airfoil and single point optimization design airfoil, results show that the two-dimensional stochastic method can improve the performance in a specific flight area, and increase the airfoil adaptability to the stochastic changes of multiple flight parameters.展开更多
机会约束规划主要用来处理含多个随机变量的复杂约束问题,由于虚拟电厂存在大量不确定因素,包括可再生能源输出功率波动、负荷预测误差、机组故障停运等,采用机会约束规划建模能够很好地描述由随机变量带来的不确定性。该文建立基于机...机会约束规划主要用来处理含多个随机变量的复杂约束问题,由于虚拟电厂存在大量不确定因素,包括可再生能源输出功率波动、负荷预测误差、机组故障停运等,采用机会约束规划建模能够很好地描述由随机变量带来的不确定性。该文建立基于机会约束规划的虚拟电厂(virtual power plant,VPP)经济调度模型。该模型以最大化虚拟电厂经济效益为目标、旋转备用约束为机会约束,利用随机模拟和遗传算法结合的混合算法进行求解。针对机会约束规划处理中所伴随的失负荷风险,建立风险量化指标,讨论不同控制场景、不同置信水平及不同风险系数下VPP调度决策所面临的风险水平,探讨虚拟电厂调度过程中经济性与风险性之间的平衡关系,以期为机会约束规划中最佳置信水平的选择提供参考。展开更多
基金supported by Global Energy Interconnection Group Co.,Ltd.:Assessment of China’s carbon neutrality implementation path and simulation research on policy tool combination(SGGEIG00JYJS2200059).
文摘A larger number of uncertain factors in energy systems influence their evolution.Owing to the complexity of energy system modeling,incorporating uncertainty analysis to energy system modeling is essential for future energy system planning and resource allocation.This study focusses on long-term energy system optimization model.The important uncertain parameters in the model are analyzed and divided into policy,economic,and technical factors.This study specifically addresses the challenges related to carbon emission reduction and energy transition.It involves collecting and organizing relevant research on uncertainty analysis of long-term energy systems.Various energy system uncertainty modeling methods and their applications from the literature are summarized in this review.Finally,important uncertainty factors and uncertainty modeling methods for long-term energy system modeling are discussed,and future research directions are proposed.
文摘Far from the Madding Crowd is one of the most eminent works of British writer Thomas Hardy. In the novel, Hardy set amounts of uncertain factors such as death, love, and coincidence to push the development of the novel, figures' destiny and characteristics.
基金supported by the National Natural Science Foundation of China(11372073,11072061)
文摘Since the joint actuator of the space robot executes the control instructions frequently in the harsh space environment,it is prone to the partial loss of control effectiveness(PLCE)fault.An adaptive fault-tolerant control algorithm is designed for a space robot system with the uncertain parameters and the PLCE actuator faults.The mathematical model of the system is established based on the Lagrange method,and the PLCE actuator fault is described as an effectiveness factor.The lower bound of the effectiveness factors and the upper bound of the uncertain parameters are estimated by an adaptive strategy,and the estimated value is fed back to the control algorithm.Compared with the traditional fault-tolerant algorithms,the proposed algorithm does not need to predetermine the lower bound of the effectiveness factor,hence it is more in line with the actual engineering application.It is proved that the algorithm can guarantee the stability of the closed-loop system based on the Lyapunov function method.The numerical simulation results show that the proposed algorithm can not only compensate for the uncertain parameters,but also can tolerate the PLCE actuator faults effectively,which verifies the effectiveness and superiority of the control scheme.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BK20230953)the Joint Funds of the National Natural Science Foundation of China(No.U2066601)the National Natural Science Foundation of China(No.52277088).
文摘Demand response(DR)is a practical solution to overcoming the challenges posed by the volatility and intermit tency of the renewable generation in power systems.Industrial electricity demand is growing rapidly,which makes the DR po tential estimation of industrial user critical for the DR imple mentation.In this paper,a unified model for estimating DR po tential in the production processes of aluminum,cement,and steel is proposed on the basis of their unique operational char acteristics.Firstly,considering the typical characteristic con straints of different industrial users,a DR potential estimation model is developed to capture typical industrial user response behavior under various operational and economic factors.The proposed estimation model is further refined to account for the uncertain and subjective factors present in the actual estima tion environment.Secondly,a virtual data acquisition method is introduced to obtain the private virtual parameters required in the estimation process.Then,an industrial user participation threshold is presented to determine whether industrial users may participate in DR at a given time with consideration of their response characteristics.The industrial users may not al ways act with perfect rationality,and the response environment remains uncertain.In addition,the subjective factor in this pa per includes the proposed threshold and the bounded rationali ty.Finally,an improved DR potential estimation model is pro posed to reduce the difficulties in the actual estimation process.The simulation results validate the effectiveness of the proposed estimation model and the improved DR potential estimation model across multiple cases.
文摘To avoid the aerodynamic performance loss of airfoil at non-design state which often appears in single point design optimization, and to improve the adaptability to the uncertain factors in actual flight environment, a two-dimensional stochastic airfoil optimization design method based on neural networks is presented. To provide highly efficient and credible analysis, four BP neural networks are built as surrogate models to predict the airfoil aerodynamic coefficients and geometry parameter. These networks are combined with the probability density function obeying normal distribution and the genetic algorithm, thus forming an optimization design method. Using the method, for GA（W）-2 airfoil, a stochastic optimization is implemented in a two-dimensional flight area about Mach number and angle of attack. Compared with original airfoil and single point optimization design airfoil, results show that the two-dimensional stochastic method can improve the performance in a specific flight area, and increase the airfoil adaptability to the stochastic changes of multiple flight parameters.
文摘机会约束规划主要用来处理含多个随机变量的复杂约束问题,由于虚拟电厂存在大量不确定因素,包括可再生能源输出功率波动、负荷预测误差、机组故障停运等,采用机会约束规划建模能够很好地描述由随机变量带来的不确定性。该文建立基于机会约束规划的虚拟电厂(virtual power plant,VPP)经济调度模型。该模型以最大化虚拟电厂经济效益为目标、旋转备用约束为机会约束,利用随机模拟和遗传算法结合的混合算法进行求解。针对机会约束规划处理中所伴随的失负荷风险,建立风险量化指标,讨论不同控制场景、不同置信水平及不同风险系数下VPP调度决策所面临的风险水平,探讨虚拟电厂调度过程中经济性与风险性之间的平衡关系,以期为机会约束规划中最佳置信水平的选择提供参考。
