Electric Power Grid Modernization

传统的交流电力系统构成了电能产生/传输/输送的主要基础设施，是基于20世纪中期的集中发电、控制和运营概念和策略。这种遗留系统在满足21世纪当前和未来的需求方面表现出固有的局限性。原因是(i)发电类型和特性的变化，例如风能和太阳能的深度渗透；（ii）对更高程度的安全性、弹性和可靠性的需求，例如，防止因自然（甚至人为）灾害造成的故障和停电；以及（iii）对电力市场民主化的需求日益增加，以促进客户的参与。这些导致了电网现代化的一系列活动，主要基于(i)传感和测量的大规模利用，（ii）储能系统的电网整合，以及（iii）新颖的操作、控制和潮流概念/策略。从传统电网向现代化电网转变的主要驱动因素是不断增长的供需侧机会，以及信息通信技术（ict）和电力电子设备和系统（如用于集成交流电力系统的高压直流（HVDC）系统）在技术和经济上的可行性。在不久的将来，即到2025年，现代化电网的主要目标是降低(1)停电的成本，(2)储备边际，(3)清洁能源整合的成本。

The legacy AC power system constitutes the main infrastructure for generation/transmission/delivery of the electrical energy, and is based on the mid-20th century centralized generation, control, and operational concepts and strategies. This legacy system exhibits inherent limitations to meet the current and the future requirements of the 21th century. The reasons are (i) changing mix of types and characteristics of generation, e.g., high-depth of penetration of wind and solar power, (ii) the need for higher degree of security, resiliency and reliability, e.g., to prevent failures and blackouts due to natural (and even man-made) disasters , and (iii) the increasing demand for democratization of the electricity market to facilitate customers' participation. These have resulted in a portfolio of activities under the umbrella of grid modernization which is primarily based on (i) massive utilization of sensing and measurement, (ii) grid-integration of energy storage systems, and (iii) novel operation, control and power flow concepts/strategies. The main drivers behind this transformation from the legacy- to the modernized-grid are the growing supply- and demand-side opportunities, and the technical and economical viability of the information and communication technologies (ICTs) and power electronic based apparatus and systems, e.g., high-voltage direct-current (HVDC) systems, for integration in AC power systems. The main objective of a modernized-grid in the near future, i.e., by 2025, is to reduce the costs of (i) power outage, (ii) reserve margin, and (iii) clean energy integration. This discovery grant program focuses on the R&D of novel control, power flow, and operational strategies to enable transition process from the legacy infrastructure to the modernized grid. The enabling technologies for the envisioned R&D program include (i) the overlay HVDC transmission network based on the use of voltage-sourced converter (VSC) configurations and (ii) ICTs for sensing, measurement, control and protection. The VSC-HVDC system forms an integral part of the legacy AC grid and serves as the physical layer to realize the envisioned control, power flow, and the operational strategies in its host AC system and enable the functionalities that are required to modernized the AC grid. The overall AC grid and the overlay VSC-HVDC system also will be equipped with ICTs for coordinated sensing, monitoring, measurement and communications. The ICT-based cyber layer also compliments the infrastructure for wide-area control/protection of the host AC system. The outcome of this research program provides the basis for (i) large-scale integration of renewable resources, (ii) efficient spatial/temporal transfer of bulk power as the economy of generation/demand dictates, (iii) prevention of cascaded events/failures, and (iv) integration of multi-microgrids in the legacy grid.