CRII: CPS: Architecture and Distributed Computation in the Networked Control Paradigm: An Autonomous Grid Example

该提案将建立一个框架，用于开发在网络控制系统(NCS)环境中运行的分布式网络物理系统。具体关注的是这样一种应用，其中，由于物理系统的巨大规模，计算和通信挑战是独一无二的，并且系统元素之间的通信包括潜在的重大损失和延迟。电网就是一个例子，它包括大规模部署分布式和联网的相量测量单元(PMU)和风能资源。尽管已经在理论层面上对网络控制系统中数据丢失和延迟的影响进行了大量的建模和分析，但它们对网络物理系统行为的影响却鲜有人关注。因此，过去对“智能电网”所做的许多研究过度简化了模型的“物理”部分，从而忽视了存在于模型的维度和电网动态的异质性核心的关键计算挑战。在理解网络控制系统中不确定因素(例如带宽限制、丢包、迷失方向、延迟、信号丢失等)的影响方面仍存在明显差距。交叉耦合有风电场的大型电网中的不确定性(例如，风能的变化性、故障和非线性、拓扑变化等)。关于电网的可靠运行。为了应对这些挑战，该项目将首次开发一个建模框架，通过NCS、分布式计算和包括分布式风力发电资源的大型电网的联合仿真来发现迄今未知的交互作用。最重要的是，它通过频域抽象解决了分布式计算中的挑战，并提出了两种在丢包过程中稳定网格的新技术。更广泛的影响在于更深入地了解智能电网中延迟和中断的影响。这将使能源传输资产得到更好的利用，并改善可再生能源的整合。该项目将促进妇女参与STEM学科，并将包括与当地美洲原住民部落社区大学进行外联。该项目将使用一种适用于各种CP的方法，加深对网络延迟和丢弃的影响的基本了解。它将通过对电网的代表性亚暂态模型的充分性研究以及通信网络中的分组丢弃的吉尔伯特模型的表示来实现对智能电网的变革性广域测量系统的研究。最重要的是，提出了频域抽象的基本概念，包括平衡截断和最优Hankel范数逼近，以显著降低分布式计算的负担。最后，提出了一种新的减少副本的方法和一种改进的卡尔曼滤波方法，以解决遇到丢包时使用风电场控制来稳定电网的问题。

This proposal will establish a framework for developing distributed Cyber-Physical Systems operating in a Networked Control Systems (NCS) environment. Specific attention is focused on an application where the computational, and communication challenges are unique due to the sheer size of the physical system, and communications between system elements include potential for significant losses and delays. An example of this is the power grid which includes large-scale deployment of distributed and networked Phasor Measurement Units (PMUs) and wind energy resources. Although, much has been done to model and analyze the impact of data dropouts and delay in NCS at a theoretical level, their impact on the behavior of cyber physical systems has received little attention. As a result much of the past research done on the `smart grid' has oversimplified the `physical' portion of the model, thereby overlooking key computational challenges lying at the heart of the dimensionality of the model and the heterogeneity in the dynamics of the grid. A clear gap has remained in understanding the implications of uncertainties in NCS (e.g. bandwidth limitations, packet dropout, packet disorientation, latency, signal loss, etc.) cross-coupled with the uncertainties in a large power grid with wind farms (e.g. variability in wind power, fault and nonlinearity, change in topology etc.) on the reliable operation of the grid. To address these challenges, this project will, for the first time, develop a modeling framework for discovering hitherto unknown interactions through co-simulation of NCS, distributed computing, and a large power grid included distributed wind generation resources. Most importantly, it addresses challenges in distributed computation through frequency domain abstractions and proposes two novel techniques in grid stabilization during packet dropout. The broader impact lies in providing deeper understanding of the impact of delays and dropouts in the Smart Grid. This will enable a better utilization of energy transmission assets and improve integration of renewable energy sources. The project will facilitate participation of women in STEM disciplines, and will include outreach with local Native American tribal community collegesThis project will develop fundamental understanding of impact of network delays and drops using an approach that is applicable to a variety of CPS. It will enable transformative Wide-Areas Measurement Systems research for the smart grid through modeling adequacy studies of a representative sub-transient model of the grid along with the representation of packet drop in the communication network by a Gilbert model. Most importantly, fundamental concepts of frequency domain abstraction including balanced truncation and optimal Hankel-norm approximation are proposed to significantly reduce the burden of distributed computing. Finally, a novel `reduced copy' approach and a `modified Kalman filtering' approach are proposed to address the problem of grid stabilization using wind farm controls when packet drop is encountered.