Any physical or electrical disturbance affects the performance of the electric power system. Therefore, advanced emergency control techniques that would adjust disrupted power fow to an acceptable operating state would make the system more resilient to malicious attacks. Particularly important is the development of improved tools and strategies that allow a more nuanced real-time treatment of which loads are and are not served during restoration.
Reducing the impact of an attack (and its consequences) involves developing and using advanced network technologies and control features at both the bulk power system level and the distribution system level. Distributed energy resources could also play a signifcant role in minimizing power disruptions to customers, powering critical services and facilities, and facilitating restoration. Several concepts in this area involve the expanded use of combined heat and power technology, distributed generation, and micro-grids. Such technologies already are in use but not fully deployed. However, considerable research focused on hardware, control systems, control policy, and the impacts of alternative regulatory arrangements is needed to enable resolution of technical and regulatory impediments to integrate such resources into the overall system.
The extended loss of electric supply due to a malicious attack could have a signifcant impact on several interdependent civilian infrastructure systems,2including water treatment and pumping facilities, sewage treatment plants, transportation, communication systems, gas pipelines, and traffc control systems. Although studies have qualitatively evaluated the impact of the loss of power supply on specifc systems, they have not, for the most part, considered all interdependent systems collectively. Moreover, in most regions, efforts have not been made to investigate and model the impacts of a long-term curtailment of the electricity supply. A critical aspect of system interdependencies is that offcial policies will be needed to coordinate these systems, establish hierarchies in terms of responsibilities and control following an attack, enunciate a clear public message, and continuously update information in a coordinated fashion.
The need for a well-coordinated, automatic or semiautomatic plan for restoring the electric system after a coordinated malicious attack has been a topic of intense discussion in the electric power industry. North American Electric Reliability Council (NERC) guidelines require every region to have such a plan. Automating recovery to reduce the possibility of human error, however, is an enormous task requiring signifcant investment in research toward developing techniques to coordinate various options and develop decision-making tools.
This section discusses a wide range of specifc technologies for which R&D is promising. They are grouped into eight technology areas according to how they will beneft the power system.
Increasing the power fow capacity of transmission lines can increase security because it provides greater ability to bypass a damaged line in delivering power from generating stations to load centers.
The transfer capability of some transmission circuits can be increased by raising the operating voltage and reconfgur-ing conductors into a more compact arrangement on existing rights-of-way.
New, recently developed conductors having composite cores or using aluminum alloys have higher current-carrying capability than conductors in general use. Under high rates of power fow, they have less mechanical sag at high temperatures because of lower thermal expansion as compared to typical conductors with steel cores. Reducing the sag of a loaded line allows greater loading of lines, although increased thermal capacity, if not used properly, can place more stress on the power system.
High-temperature Superconducting Cables
High-temperature superconducting cables can potentially carry three to fve times as much current as conventional cables of the same size, but considerably more research is required before these cables can be made technically successful and ready for widespread use. Although initial assessments indicate that such cables are very complex and expensive special-purpose devices with limited applications, they nonetheless deserve consideration.
New composite materials that are inherently insulating and corrosion-resistant could potentially replace metals in the support structures for substations and transmission lines and could also allow for reconfguring existing rights-of-way to increase power fow. Many complex issues still have to