Collaboration Demonstrates New Model for Managing Power, Reducing Blackout Risk
Cascading power outages are a series of outages in an electric power system leading to widespread blackouts, which are much more severe than local outages. To avoid outages leading to blackout, secure and stable power system operation must be maintained and oscillations in alternating current (AC) transmitted from a power station to the end-user must be controlled. Researchers have developed a new model to serve as an intelligent oscillation controller that is adaptive to a wide variety of operating conditions. The model was demonstrated in case studies on realistic power grid scenarios for three utilities: New York Power Authority (NYPA), Terna (the sole transmission system operator in Italy), and Saudi Electricity Company (SEC). The team included researchers from the University of Tennessee-Knoxville (UTK) and the Electric Power Research Institute, and made use of a hardware testbed (HTB) operated by the Center for Ultra-Wide-Area Resilient Electric Energy Transmission Networks (CURENT), an NSF Engineering Research Center (ERC) supported by NSF and the U.S. Department of Energy and headquartered at UTK, with partner organizations including Northeastern University, Rensselaer Polytechnic Institute, and Tuskegee University.
Frequency in power transmission refers to the oscillation of alternating current (AC) transmitted from a power station to the end-user in an electric power grid. Oscillations must be damped effectively to maintain secure and stable system operation. One of the main drawbacks of existing oscillation damping controllers is that they are designed based on offline simulations for assumed system conditions and are not adaptive to the varying power system operating conditions. This measurement derived model-based adaptive wide-area damping controller was implemented on CURENT’S HTB. Researchers built and tested a simple, measurement-driven model to depict oscillatory behavior for damping controller design that can adaptively adjust wide-area damping controller parameters for current operating condition. They then demonstrated and verified the model through multiple case studies in power systems in the U.S., Italy, and Saudi Arabia. The benefits of effective damping include enhanced grid stability, mitigation of blackout risk due to oscillation, improved power transfer capability of existing transmission lines for more economic operation, and many others.
CURENT’s HTB is a unique test platform that emulates large-scale power systems by interconnecting modular and reprogrammable power electronic converters in a reconfigurable structure. The converters, also called emulators, can be programmed and controlled in real time to mimic the behaviors of various generation sources (e.g., synchronous machine, solar, and wind), transmission lines, loads, energy storages, HVDC, and other components in power systems with scalable ratings.
After identifying and validating the intelligent oscillation controller, the researchers worked with the three geographically dispersed utilities for further analysis and demonstration in varying conditions such as cascading events and seasonal operating condition variations. Their effort successfully demonstrated the effectiveness of adaptive WADC to accommodate variations in operating conditions, providing better control.
