设计了一种基于模块化多电平型固态变压器(modular multilevel converter-solid state transformer,MMC-SST)的新型直流微网架构,可最大限度地适应新能源的接入,提高系统的电能质量,真正实现能量的双向按需传输和动态平衡使用。首先,详...设计了一种基于模块化多电平型固态变压器(modular multilevel converter-solid state transformer,MMC-SST)的新型直流微网架构,可最大限度地适应新能源的接入,提高系统的电能质量,真正实现能量的双向按需传输和动态平衡使用。首先,详细分析了基于MMC-SST的新型直流微网的系统结构,并给出了MMC-SST主电路拓扑;然后,对MMC-SST各级的控制策略和直流微网子系统能量管理算法进行了优化设计,使MMC-SST能够按照给定的功率因数运行,并具有比传统控制方式更快的瞬态响应速度和更强的鲁棒性,实现了直流微网子系统的灵活、经济、可靠运行;最后,通过搭建基于MMC-SST的新型直流微网子系统的简化计算机仿真平台,进行综合仿真验证了提出的架构和控制策略的可行性和有效性。展开更多
In this paper, we propose a new smooth function that possesses a property not satisfied by the existing smooth functions. Based on this smooth function, we discuss the existence and continuity of the smoothing path fo...In this paper, we propose a new smooth function that possesses a property not satisfied by the existing smooth functions. Based on this smooth function, we discuss the existence and continuity of the smoothing path for solving the P0 function nonlinear complementarity problem (NCP). Using the characteristics of the new smooth function, we investigate the boundedness of the iteration sequence generated by the non-interior continuation methods for solving the P0 function NCP under the assumption that the solution set of the NCP is nonempty and bounded. We show that the assumption that the solution set of the NCP is nonempty and bounded is weaker than those required by a few existing continuation methods for solving the NCP.展开更多
针对现有固态变压器拓扑结构存在的局限性及控制方法的不足,本文提出了一种模块化多电平型固态变压器(MMC solid state transformer,MMC-SST),并相应介绍了一种内模控制(internal model control,IMC)实现方法.首先分析了MMC-SST系统拓...针对现有固态变压器拓扑结构存在的局限性及控制方法的不足,本文提出了一种模块化多电平型固态变压器(MMC solid state transformer,MMC-SST),并相应介绍了一种内模控制(internal model control,IMC)实现方法.首先分析了MMC-SST系统拓扑与运行特性,建立了同步旋转坐标系下MMC-SST输入级和输出级的数学模型;然后根据内模控制的特性,将内模电流内环与PI电压外环相结合,构造出新的双闭环控制结构,实现对MMC-SST输入级和输出级的控制;最后,基于Matlab/Simulink建立了MMC-SST系统仿真模型,在网侧电压波动、负荷突变和网侧功率因数变化多种工况进行了性能测试,结果表明,本文提出的基于内模控制的MMC-SST能够按照给定的功率因数运行,并且具有电压、电流动态响应快、抗负载扰动能力强等特点.展开更多
A trust region algorithm for equality constrained optimization is proposed, which is a nonmonotone one in a certain sense. The augmented Lagrangian function is used as a merit function. Under certain conditions, the g...A trust region algorithm for equality constrained optimization is proposed, which is a nonmonotone one in a certain sense. The augmented Lagrangian function is used as a merit function. Under certain conditions, the global convergence theorems of the algorithm are proved.展开更多
In this paper, we present a trust region algorithm for bound constrained minimization. Under milder conditions, we prove the global convergence of the main algorithm. It is also proved that the correct active set can ...In this paper, we present a trust region algorithm for bound constrained minimization. Under milder conditions, we prove the global convergence of the main algorithm. It is also proved that the correct active set can be identified in a finite number of iterations if strict complementarity slackness condition holds, and so the proposed algorithm reduces finally to an unconstrained minimization method in a finite number of iterations, allowing a fast asymptotic rate of convergence.展开更多
文摘设计了一种基于模块化多电平型固态变压器(modular multilevel converter-solid state transformer,MMC-SST)的新型直流微网架构,可最大限度地适应新能源的接入,提高系统的电能质量,真正实现能量的双向按需传输和动态平衡使用。首先,详细分析了基于MMC-SST的新型直流微网的系统结构,并给出了MMC-SST主电路拓扑;然后,对MMC-SST各级的控制策略和直流微网子系统能量管理算法进行了优化设计,使MMC-SST能够按照给定的功率因数运行,并具有比传统控制方式更快的瞬态响应速度和更强的鲁棒性,实现了直流微网子系统的灵活、经济、可靠运行;最后,通过搭建基于MMC-SST的新型直流微网子系统的简化计算机仿真平台,进行综合仿真验证了提出的架构和控制策略的可行性和有效性。
基金the National Natural Science Foundation of China (Grant Nos. 19871016 and 19731001).
文摘In this paper, we propose a new smooth function that possesses a property not satisfied by the existing smooth functions. Based on this smooth function, we discuss the existence and continuity of the smoothing path for solving the P0 function nonlinear complementarity problem (NCP). Using the characteristics of the new smooth function, we investigate the boundedness of the iteration sequence generated by the non-interior continuation methods for solving the P0 function NCP under the assumption that the solution set of the NCP is nonempty and bounded. We show that the assumption that the solution set of the NCP is nonempty and bounded is weaker than those required by a few existing continuation methods for solving the NCP.
文摘针对现有固态变压器拓扑结构存在的局限性及控制方法的不足,本文提出了一种模块化多电平型固态变压器(MMC solid state transformer,MMC-SST),并相应介绍了一种内模控制(internal model control,IMC)实现方法.首先分析了MMC-SST系统拓扑与运行特性,建立了同步旋转坐标系下MMC-SST输入级和输出级的数学模型;然后根据内模控制的特性,将内模电流内环与PI电压外环相结合,构造出新的双闭环控制结构,实现对MMC-SST输入级和输出级的控制;最后,基于Matlab/Simulink建立了MMC-SST系统仿真模型,在网侧电压波动、负荷突变和网侧功率因数变化多种工况进行了性能测试,结果表明,本文提出的基于内模控制的MMC-SST能够按照给定的功率因数运行,并且具有电压、电流动态响应快、抗负载扰动能力强等特点.
基金Project supported by the National Natural Science Foundation of China and Postdoctoral Foundation of China.
文摘A trust region algorithm for equality constrained optimization is proposed, which is a nonmonotone one in a certain sense. The augmented Lagrangian function is used as a merit function. Under certain conditions, the global convergence theorems of the algorithm are proved.
文摘In this paper, we present a trust region algorithm for bound constrained minimization. Under milder conditions, we prove the global convergence of the main algorithm. It is also proved that the correct active set can be identified in a finite number of iterations if strict complementarity slackness condition holds, and so the proposed algorithm reduces finally to an unconstrained minimization method in a finite number of iterations, allowing a fast asymptotic rate of convergence.
