Thomas J. King

Frequency Regulation and Oscillation Damping Contributions of Variable-Speed Wind Generators in the U.S. Eastern Interconnection (EI)

The U.S. Eastern Interconnection (EI) is one of the largest electric power grids in the world and is expected to have difficulties in dealing with frequency regulation and oscillation damping issues caused by the increasing wind power. On the other side, variable-speed wind generators can actively engage in frequency regulation or oscillation damping with supplementary control loops. This paper creates a 5% wind power penetration simulation scenario based on the 16 000-bus EI system dynamic model and developed the user-defined wind electrical control model in PSSE that incorporates additional frequency regulation and oscillation damping control loops. The potential contributions of variable-speed wind generations to the EI system frequency regulation and oscillation damping are evaluated and simulation results demonstrate that current and future penetrations of wind power are promising in the EI system frequency regulation and oscillation damping.

Impact of Governor Deadband on Frequency Response of the U.S. Eastern Interconnection

This paper documents the effort to perform dynamic model validation for the U.S. Eastern Interconnection (EI) by modeling the governor deadband. The Western Electricity Coordinating Council-modified 1981 IEEE type 1 turbine governor model (WSIEG1) was added to the EI model. A frequency response sensitivity study is conducted to look at the impacts of a few major factors. The significance of modeling governor dead band is evident. Simulated frequency responses are adjusted and validated against the measurements collected by the frequency monitoring network. Two actual events are replicated in a 16 000-bus EI dynamic model. This paper demonstrates the need for a comprehensive effort on governor dead band modeling by the industry.

Visualizing Energy Resources Dynamically on Earth

For the North American hurricane season, in partnership with the Tennessee Valley Authority (TVA) and working with the U.S. Department of Energy, Office of Electricity Delivery and Reliability, we have developed a capability that helps visualize the status of the electric transmission system infrastructure. The capability toolkit, called VERDE - Visualizing Energy Resources Dynamically on Earth, takes advantage of the Google Earthreg platform to display spatio-temporally informed power grid and related data. Custom libraries describe the electrical transmission network in the Eastern United States and the dynamic status of each transmission line. Standard Google Earth layers provide rich spatial context. In addition to live status, VERDE provides a framework and mechanism to ingest predictive models, data from different sources, and response.

Improvement of timing reliability and data transfer security of synchrophasor measurements

Synchronized phasor measurements are becoming one of the key measurement elements of wide area measurement systems in advanced power system monitoring, protection, and control applications. Availability of global positioning system (GPS) provides the possibility of wide-area deployment of Phasor Measurement Unit (PMU) and Frequency Disturbance Recorder (FDR) in power system. GPS is the only timing source for PMU and FDR so far, and they will cease to work when GPS signal is lost or unstable. In addition, phasor data is transferred over the Internet without any encryption, which exposes data to cyber-attacks. The purpose of this paper is to develop an alternative GPS independent timing synchronization method for PMU and FDR, and to implement an encryption system without disrupting real-time data delivery. Primary test results confirm improvement of timing reliability and data transfer security of synchrophasor measurements.

A survey on next-generation power grid data architecture

The operation and control of power grids will increasingly rely on data. A high-speed, reliable, flexible and secure data architecture is the prerequisite of the next-generation power grid. This paper summarizes the challenges in collecting and utilizing power grid data, and then provides reference data architecture for future power grids. Based on the data architecture deployment, related research on data architecture is reviewed and summarized in several categories including data measurement/actuation, data transmission, data service layer, data utilization, as well as two cross-cutting issues, interoperability and cyber security. Research gaps and future work are also presented.

Frequency response of the Eastern Interconnection due to increased wind generation

Wind powered electricity generation is gaining ground in the Eastern Interconnection (EI). Wind turbines create electricity from what is widely hailed as zero-cost, emission-free fuel. However, the technology does present engineering challenges. Compared to traditional synchronous machines, wind turbines contribute almost no inertia to the power system. Since most turbines do not have governor or exciter units either, their ability to regulate frequency disturbances, or potential lack thereof, is a concern for utilities. This study takes the Multiregional Modeling Working Group (MMWG) EI model as a base case and removes governor units, modifies generator inertia values, and disables exciter controls to simulate the frequency response of the EI with different levels of wind penetration.

Developing dynamic models for the 2030 Eastern Interconnection grid

The Eastern Interconnection Planning Collaborative (EIPC) has established three major power flow cases for the 2030 Eastern Interconnection (EI) grid based on various levels of energy and environmental policies, technology advances, and load growth. This paper documents the procedures of developing 2030 EI dynamic models using parameters from the Multiregional Modeling Working Group (MMWG) model and using the generic models. The constructed model is validated indirectly using the synchronized phasor measurement by displacing wind machines with conventional generators.

Variable-speed wind generation control for frequency regulation in the Eastern Interconnection (EI)

The United States Eastern Interconnection (EI) might go through some profound changes due to the increasing penetration of wind power in this bulk grid, including the worsening of the frequency response. However, the fast response speed of electronic converter devices makes it possible that the kinetic energy stored and/or wind power reserve (if it exists) in variable-speed wind generation could be injected into the power grid in a fast manner. This portion of fast, injected active power could contribute to frequency regulation of the EI significantly if implemented with appropriate control schemes. This paper introduces the basic theories of fast active power control techniques of variable-speed wind generation. This paper then describes a user-defined wind electrical control model with fast active power controllers built in PSS/E. Based on the 16,000-bus EI system dynamic model, a dynamic case with realistic penetration of wind power is created. Taking advantage of the user-defined wind electrical control model, the potential contribution of variable-speed wind generation to the EI system frequency regulation is evaluated. Simulation results demonstrate that current and future wind generation sources are promising in providing frequency regulation in EI system.

Data Architecture for the Next-Generation Power Grid: Concept, Framework, and Use Case

To support next-generation power grid monitoring, protection, and control, we re-view and synthesize the new requirements and challenges of the enabling data architecture. We outline the necessary elements and a framework for the data architecture including the data path, synchronization and alignment layer, high-speed stream processing, databases, data service layer, and the interaction with analytics & control applications. We select and discuss wide-area damping control, a representative real-time closed-loop control application, as a use case to demonstrate the proposed data architecture.

Oscillation damping contributions of variable-speed wind generators in the Eastern Interconnection (EI)

The United States Eastern Interconnection (EI) might go through some profound changes due to the increasing penetration of wind power in this bulk grid, such as the worsening of inter-area oscillations across the interconnection. However, the fast response speed of power electronics devices makes it possible for properly-timed electrical power from variable-speed wind generators to be injected into the power grid. These electronics devices can be controlled in a fast manner and, thus, can significantly contribute to oscillation damping if implemented with appropriate control schemes. In this paper, a user-defined wind electrical control model with a wind oscillation damping controller is built in PSS®E. Then a dynamic case, with realistic penetration of wind power, is created based on the 16,000-bus EI dynamic model. Taking advantage of the user-defined wind electrical control model and EI system dynamic model, the potential contribution of variablespeed wind generators to the EI system oscillation damping is evaluated. Simulation results demonstrate that, at current and future penetration levels, wind generators represent a promising tool for damping oscillations in the EI.