A Novel Approach to Mitigating Power System Communication Failures

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

Electric utilities face the challenge of providing dependable power to end-users, which requires a reliable communication network. This project investigates approaches to deal with time-varying delays in the communication network. The intellectual merit of the project is based on introducing a novel mathematical approach for controllers operating in a power system network, which are designed to limit energy expenditures while reducing the actuation effort and relaxing communication requirements. The approach is applied to wide-area power system damping controls that are robust to failure in measurements and communications without degrading the stability and performance of the system. The broader impacts of the project include contributions to the science of networked systems and reliability of large network control systems. Moreover, the project has characteristics that undergraduate and pre-college students should find attractive: stability and control of critical infrastructures, state-of-the-art computer applications, and high relevance to societal problems. The project will develop a novel approach to ensure the reliability and resiliency of power systems in the presence of communication failures that introduce time-varying delays in control signal delivery. Time-scale theory is introduced for the first time by the PIs to solve the problem of intermittent information transmission, which shows promise for providing less conservative requirements on the communication system. The information in the power system network is transmitted between network resources (substations, control centers, generators, actuators, sensors, and so on) at deterministic and random time intervals due to communication unreliability or capability limits of actuators. The aim is to estimate the maximum allowable value of the duration of interruption of information transmission that does not violate the stability of the system. We formulate the problem as continuous/discrete switched system on a non-uniform time domain such that the system switches between a continuous-time subsystem (when the communication occurs without any interruption) and a discrete-time subsystem (when the communication fails and the control is held on and not evolving), by introducing deterministic and stochastic time scales theory. This theory will investigate event-triggered controls through communication channels in the context of sensor/actuator networks where the triggering times are not equidistant and may be deterministic or stochastic. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.