Discipline: Technology and Engineering
Subcategory: Electrical Engineering
Katrina H. Eccles - Tennessee Technological University
Co-Author(s): Horacio Silva-Saravia, University of Tennessee, Knoxville, TN; Héctor Pulgar-Painemal, University of Tennessee, Knoxville, TN
Renewable energy, especially solar energy, is expected to drastically increase its penetration in the bulk power system during the next decades, following the global trend driven by environmental and economic policies. This higher penetration of solar energy challenges the operation and reliability of the power grid that now has to be prepared to face more variability and uncertainty in the generation side, which may lead to stability problems. One of the main stability concerns is low damped electromechanical oscillations. These oscillations, also called low frequency oscillations, are unwanted for the operation because of the potential damage in the mechanical parts of machines in power plants, congestion in transmission lines, possible power outages and even total blackout of the system. Thus, further studies become necessary to understand the effects of solar power on power system dynamics and to guarantee a safe and reliable integration of solar power into the power grid. This study approaches the problem by analyzing the system eigenvalues of the linearized power system equations. These equations describe the dynamic motion of rotor speeds in the grid under different scenarios of solar generation. Simulations are performed in the classical 9-bus, 3-machine system using the power system simulation tool DIgSILENT PowerFactory. By using Monte Carlo simulation, the probability distribution of the electromechanical modes is obtained. The focus is on characteristics such as damping ratio of electromechanical eigenvalues, which is found to be safe for operation when damping ratios are greater than 5% for all scenarios. Additionally, the effect of different solar plant locations on the electromechanical oscillations is considered. The study finds that some locations within the power grid are more sensitive to changes in solar power, for which some control actions or control schemes are required in order to allowing better damped oscillations. Finally, analytical expressions to describe the probability distribution of the data is expected as future research. This analytical representation may lead to a better understanding of the relationships between solar power variation and power system dynamics. References: H. Silva-Saravia, H. Pulgar-Painemal, and J.M. Mauricio, “Flywheel energy storage model, control and location for improving stability: The Chilean case,” IEEE Transactions on Power Systems, vol. 32, pp. 3111- 3119, July 2017. A. Mills, Dark Shadows, IEEE Power & Energy Magazine, IEEE, 2011, p. 33- 41 K. Zhang, Y. Ye, L. Chen, Y. Zhang, R. M. Gardner and Y. Liu, “FNET observations of low frequency oscillations in the eastern interconnection and their correlation with system events,” 2011 IEEE Power and Energy Society General Meeting, San Diego, CA, 2011, pp. 1-8. S. Pizarro-Ga ́lvez, H. Pulgar-Painemal, and V. Hinojosa-Mateus, “Parametrized modal analysis using DIgSILENT Programming Language,” Ch. 10, Springer, International Publishing, Switzerland, 2014, pp.221- 229.Not Submitted
Funder Acknowledgement(s): This work was supported in part by the National Science Foundation under Grant 1509114. This work also made use of Engineering Research Center shared facilities supported by the Engineering Research Center Program of the National Science Foundation and the Department of Energy under NSF Award No. EEC-1041877 and the CURENT Industry Partnership Program.
Faculty Advisor: H. Pulgar-Painemal, email@example.com
Role: I completed all research in this study with assistance from Horacio Silva-Saravia and Héctor Pulgar-Painemal.