Since the examination paper generated with computer by the algorithms of random and backtracking takes on inferior quality and inefficient, and the question of generating examination paper with computer has the charac...Since the examination paper generated with computer by the algorithms of random and backtracking takes on inferior quality and inefficient, and the question of generating examination paper with computer has the character of multi-ob-jective because of the index system metrics, the genetic algorithm with multi-objective strategy optimization is proposed to solve this problem. Mapping the index system to multi-objective functions and optimizing the computing with multi-objective strategy are employed in the algorithm. The genetic algorithm experiment based on the multi-objective strategy optimization shows that the result has the advantages getting tradeoff between performance and quality, and having the ability to tune the performance and quality to meet the user’s requirements.展开更多
以风光为代表的新能源具有出力不确定性、波动性,聚合新能源发电资源的虚拟电厂(virtual power plant,VPP)在优化调度时难以避免VPP实际出力与调度计划间的偏差,进而导致VPP运营风险增加,收益降低。提出了考虑新能源不确定性风险的VPP...以风光为代表的新能源具有出力不确定性、波动性,聚合新能源发电资源的虚拟电厂(virtual power plant,VPP)在优化调度时难以避免VPP实际出力与调度计划间的偏差,进而导致VPP运营风险增加,收益降低。提出了考虑新能源不确定性风险的VPP双层调度策略。首先,建立了考虑VPP内部资源聚合效益的上层模型;其次,针对新能源出力不确定性,采用条件风险价值量化虚拟电厂调度风险,建立了考虑VPP收益和风险的下层多目标调度模型;最后,通过算例验证了调度模型的有效性,能够为VPP提供兼顾收益与风险的调度辅助决策。展开更多
该文以混合型二极管箝位型三电平双有源桥(neutral point clamped hybrid three-level dual active bridge,HN3L-DAB)变换器为研究对象。相比于两电平DAB变换器,HN3L-DAB的三电平结构引入中间电平,增加了控制自由度,从而更灵活地控制电...该文以混合型二极管箝位型三电平双有源桥(neutral point clamped hybrid three-level dual active bridge,HN3L-DAB)变换器为研究对象。相比于两电平DAB变换器,HN3L-DAB的三电平结构引入中间电平,增加了控制自由度,从而更灵活地控制电感电流。文中首先分析NH3L-DAB的工作原理,推导出各器件动作时的电感电流值以及各工作模式的功率传输函数。在此基础上,针对一类输入高电压、输出大电流场合的应用需求,结合NH3L-DAB变换器的软开关特性,提出了高效率多目标优化调制策略,旨在同时减小导通损耗和开关损耗,兼顾实现高电压侧零电压开通、大电流侧零电流关断、降低电感电流有效值。最后搭建实验平台进行实验,在不同工况下验证三电平DAB变换器拓扑方案的可行性和多目标优化调制策略的有效性。展开更多
文摘Since the examination paper generated with computer by the algorithms of random and backtracking takes on inferior quality and inefficient, and the question of generating examination paper with computer has the character of multi-ob-jective because of the index system metrics, the genetic algorithm with multi-objective strategy optimization is proposed to solve this problem. Mapping the index system to multi-objective functions and optimizing the computing with multi-objective strategy are employed in the algorithm. The genetic algorithm experiment based on the multi-objective strategy optimization shows that the result has the advantages getting tradeoff between performance and quality, and having the ability to tune the performance and quality to meet the user’s requirements.
文摘以风光为代表的新能源具有出力不确定性、波动性,聚合新能源发电资源的虚拟电厂(virtual power plant,VPP)在优化调度时难以避免VPP实际出力与调度计划间的偏差,进而导致VPP运营风险增加,收益降低。提出了考虑新能源不确定性风险的VPP双层调度策略。首先,建立了考虑VPP内部资源聚合效益的上层模型;其次,针对新能源出力不确定性,采用条件风险价值量化虚拟电厂调度风险,建立了考虑VPP收益和风险的下层多目标调度模型;最后,通过算例验证了调度模型的有效性,能够为VPP提供兼顾收益与风险的调度辅助决策。
文摘该文以混合型二极管箝位型三电平双有源桥(neutral point clamped hybrid three-level dual active bridge,HN3L-DAB)变换器为研究对象。相比于两电平DAB变换器,HN3L-DAB的三电平结构引入中间电平,增加了控制自由度,从而更灵活地控制电感电流。文中首先分析NH3L-DAB的工作原理,推导出各器件动作时的电感电流值以及各工作模式的功率传输函数。在此基础上,针对一类输入高电压、输出大电流场合的应用需求,结合NH3L-DAB变换器的软开关特性,提出了高效率多目标优化调制策略,旨在同时减小导通损耗和开关损耗,兼顾实现高电压侧零电压开通、大电流侧零电流关断、降低电感电流有效值。最后搭建实验平台进行实验,在不同工况下验证三电平DAB变换器拓扑方案的可行性和多目标优化调制策略的有效性。
