Recent research has explored the potential for distributed, consumer-based equipment to participate in control action seeking to improve grid dynamic performance. Renewable resources are displacing synchronous generators, reducing the electrically coupled rotating inertia supplied to the system as a percentage of generation. However, this loss may be mitigated by feedback control emulating the dynamics of rotating inertia and so-called "emulated inertia" control may be implemented in distributed, consumer-based resources. The case study presented illustrates that emulated inertia feedback is also extremely well-suited to subversion by a cyberattacker. In particular, local inertia-emulating feedback can create wide-area instabilities with only slight modification of feedback parameters. The amount of affected load can be relatively modest and the attacker can "target" particular generators, producing oscillations that would likely trip rate-of-change-of-frequency protective relays within one minute. The authors believe this scenario is particularly troubling, because it is likely that distributed consumer-based control systems will lack the strong cybersecurity protection afforded large generation resources.

Large technological systems have many modes of failure – some mundane, others exotic, some with dire consequences. Failures resulting in death and environmental degradation spring easily to mind: Chernobyl, Bhopal, Deepwater Horizon. As a large technological system, the U.S. electric power infrastructure experienced failures during major Northeast blackouts in 1965 and 2003, when large areas were ...

The intrinsic electromechanical coupling of power and frequency across a power system creates the possibility of indirect cyber-physical attacks, where the attack's impact occurs at locations far removed from the intrusion point. The work here explores this vulnerability, demonstrating mechanisms by which an attacker could cause system-wide unstable oscillations and trips of generators, by an attack altering only local control characteristics of customer loads. This extends previous work on malicious control in generator governor control loops in three ways. First, the fidelity and size of the study system is improved, with each generator represented via detailed models in a non-linear dynamic simulation. Second, we study an increasingly plausible attack, in which loads (prior to attack) are enlisted to enhance system stability through the exercise of emulated inertia control. Finally, the work demonstrates methodologies which an attacker might employ to choose the generator(s) targeted to experience large oscillations (and tripping through protective relay action) and the locations, where compromised control systems would have greatest impact. Nonlinear simulation results indicate that malicious control destabilizes the power system, with targeted generators experiencing large magnitude oscillations, and probable tripping of rate of change of frequency protective relays. These results are demonstrated as robust over variations in parameters, topology, and loading.

Methods to modify power system dynamics through the addition of synthetic inertia have gained increasing research attention over the past several years. Many researchers justify this focus by implicitly assuming that adding inertia increases a system's stability, and only focusing on the frequency nadir as a measure of performance. In this paper, we draw attention to the fact that adding synthetic inertia to a power system may not always increase the system stability when considering overall small signal behavior. We apply two different sets of dynamic parameters to the generators in the IEEE 14-bus test system and show an example in which increasing synthetic inertia exercised through loads may lead to problematic instabilities.

An optimization problem called “the feeder addition problem” is defined to determine potential locations for adding interties between feeders in a legacy radial distribution system to improve the reliability in the islanded mode of operation - a desired feature under the Smart Grid Initiative. Numerical bounds are established on the growth of the feeder addition problem. The feeder addition problem in a popular test system is handled using two different optimization methods to balance cost and reliability for utility applications. To approximate the power output of the distributed generation sources considered, an empirical equation incorporating the capacity factors of renewable energy-based distributed generation sources and results of an industry survey is used. Both optimization methods are shown to improve the system reliability for cases where the distributed generation output exceeded feeder demand.

Modernization of the electric power system in the United States is driven by the Smart Grid Initiative. Many changes are planned in the coming years to the distribution side of the U.S. electricity delivery infrastructure to embody the idea of “smart distribution systems.” However, no functional or technical definition of a smart distribution system has yet been accepted by all.