Further Investigation of the Impacts of Cold Load Pickup on Design and Operation of Electric Power Distribution Systems

Pahwa 在配电系统中，由于冷负荷拾取，在长时间停电之后的电力恢复导致负荷比正常负荷高得多。 除了初始瞬变之外，冷负载拾取期间的负载具有可以是正常负载的2至5倍的持久分量，并且可以持续几个小时。 持久的组件主要是由于损失的多样性，在循环类型的负载，如空调，冰箱等，因为公用事业公司希望利用现有的资产，以最大程度上，冷负荷皮卡是一个重要的问题，在配电系统的设计和运行。 PI在1994年获得了国家科学基金会的一个项目（奖号9311257）的资金，从操作和设计的角度来调查冷负荷拾取对配电系统的影响。 研究了配电网分步恢复最优分段顺序的确定方法。 此外，系统设计，以确定最佳数量的分段器和变电站Transformer的最佳尺寸所需的系统进行了研究。 基于该研究发表了三篇期刊论文和三篇会议论文。 本研究还形成了一位博士的部分论文。学生和博士另一个学生的论文。 提交该提案是为了申请资金，以进一步调查冷负荷对配电系统的影响。 具体而言，该研究将解决1）修改的Transformer负载模型，2）进一步调查的最佳恢复序列，3）包括更好的模型，变压器的成本和中断的成本在优化问题，4）包括电压降和馈线容量约束的优化问题，和5）有关的问题，估计的冷负荷拾取模型参数。 该研究为配电自动化与配电系统设计的集成奠定了基础。 到目前为止，配电自动化主要是从系统运行的角度来讨论的。 然而，作为配电自动化的结果，将需要设计配电系统的新方法。 新的设计应有效地利用自动化，同时保持系统成本低。 随着配电自动化渗透率的提高，新的设计程序将成为配电系统设计的一个组成部分。 由于公用事业目前正在发生的变化，这些问题将在未来得到更多的关注。 这些变化将导致公用事业环境的重组，在这种环境下，配电公司将被要求更有效地管理其资产。 该项目将为研究生攻读博士学位提供一个新的机会。学位和接受培训，在配电系统领域以及在各种数学和计算技术。 这项研究的结果也将是非常有用的PI融入研究型课程。

ECS-9721447 Pahwa Restoration of power after an extended outage in a distribution system results in load much higher than normal load due to cold load pickup. In addition to initial transients, the load during cold load pickup has an enduring component that can be 2 to 5 times normal load and may last for several hours. The enduring component is mainly due to loss of diversity in the cycling type of loads, such as air conditioners, refrigerator etc. Since utilities would like to utilize the existing assets to the maximum extent, cold load pickup is an important issue in design and operation of distribution systems. The PI received funding for a project (Award Number 9311257) in 1994 from the National Science Foundation to investigate the impacts of cold load pickup on distribution systems from both operation and from design points of view. Techniques for determination of the optimal sequence of sections for step-by-step restoration of distribution systems were investigated. Also, system design to determine the optimal number of sectionalizers and the optimal size of substation transformer needed for the system was investigated. Three journal papers and three conference papers were published based on the research. The research also formed partial dissertation of one Ph.D. student and full Ph.D. dissertation of another student. This proposal is being submitted to request funding for further investigation of the impacts of cold load pickup on distribution systems. Specifically, the research will address 1) modification of the transformer loading model, 2) further investigation of the optimal restoration sequence, 3) inclusion of better models for cost of transformers and cost of interruption in the optimization problem, 4) inclusion of voltage drop and feeder capacity constraints in the optimization problem, and 5) issues related to estimation of the cold load pickup model parameters. The proposed research lays a foundation for integration of distribution automation into design of distribution systems. So far distribution automation has mostly been discussed from the point of view of system operation. However, as a result of distribution automation, new methods of designing distribution systems will be needed. The new designs should utilize automation effectively and at the same time keep the system cost low. As the penetration of distribution automation increases, the new design procedures will become an integral part of distribution system design. These issues will gather more attention in the future due to the changes that are taking place presently in the utility business. These changes will result in the restructured utility environment under which the distribution companies will be required to manage their assets more efficiently and effectively. The proposed project will offer a novel opportunity for a graduate student to pursue the Ph.D. degree and receive training in the field of distribution systems as well as in various mathematical and computational techniques. The results of this research also will be extremely useful for the PI for integration into research-based courses.