This letter proposes a novel hybrid component and configuration model for combined-cycle gas turbines(CCGTs) participating in independent system operator(ISO) markets. The proposed model overcomes the inaccuracy issue...This letter proposes a novel hybrid component and configuration model for combined-cycle gas turbines(CCGTs) participating in independent system operator(ISO) markets. The proposed model overcomes the inaccuracy issues in the current configuration-based model while retaining its simple and flexible bidding framework of configuration-based models. The physical limitations—such as minimum online/offline time and ramping rates—are modeled for each component separately, and the cost is calculated with the bidding curves from the configuration modes. This hybrid mode can represent the current dominant bidding model in the unit commitment problem of ISOs while treating the individual components in CCGTs accurately. The commitment status of the individual components is mapped to the unique configuration mode of the CCGTs. The transitions from one configuration mode to another are also modeled. No additional binary variables are added, and numerical case studies demonstrate the effectiveness of this model for CCGT units in the unit commitment problem.展开更多
基金supported by the U.S.Department of Energy under Contract No.DE-AC36-08GO28308 with Alliance for Sustainable Energy,LLC,the Manager and Operator of the National Renewable Energy LaboratoryU.S.Department of Energy Office of Energy Efficiency and Renewable Energy Wind Energy Technologies Office
文摘This letter proposes a novel hybrid component and configuration model for combined-cycle gas turbines(CCGTs) participating in independent system operator(ISO) markets. The proposed model overcomes the inaccuracy issues in the current configuration-based model while retaining its simple and flexible bidding framework of configuration-based models. The physical limitations—such as minimum online/offline time and ramping rates—are modeled for each component separately, and the cost is calculated with the bidding curves from the configuration modes. This hybrid mode can represent the current dominant bidding model in the unit commitment problem of ISOs while treating the individual components in CCGTs accurately. The commitment status of the individual components is mapped to the unique configuration mode of the CCGTs. The transitions from one configuration mode to another are also modeled. No additional binary variables are added, and numerical case studies demonstrate the effectiveness of this model for CCGT units in the unit commitment problem.
文摘针对目前腰部医学图像处理较少涉及分割并量化分析软组织的现状,提出一种腰部核磁共振图像(magnet-ic resonance imaging,MRI)中椎间盘分割及定量分析的算法:首先用改进的基于独立分量分析的主动外观模型(in-dependent component analysis based active appearance model,ICA-AAM)分割椎体,并基于最小描述长度(minimumdescription length,MDL)准则获得腰部弯曲曲线;利用上述分割结果,结合椎间盘成像特点和局部图像灰度投影,进一步实现基于马尔科夫随机场(Markov random field,MRF)的椎间盘快速无监督分割;通过分割结果判断并定量计算椎间盘突出程度。实验表明该算法快速有效,可以辅助医生诊断、治疗腰椎间盘突出等疾病。
