This paper reviews the procedures, layouts and metrics described in the new test manual issued by the Electric Power Research Institute (EPRI), in order to determine the performance and functionality of a utility scale battery energy storage system (BESS). In this approach, the large battery unit is connected to the dc-link of a bidirectional power conversion system (PCS), which may be interfaced with either the utility grid or a load bank for the purpose of estimating the BESS operation and performance characteristics, some of which includes; available charge/discharge energy at rated power, continuous charge/discharge duration, battery ramp rate, and ac round trip efficiency (RTE). The bidirectional converter is operated with different charge and discharge cycles relevant to each specification and the battery state of charge along with electrical measurements at the ac and dc side are monitored and recorded. Also, an electrical equivalent circuit for a utility scale battery unit was developed based on the 1MW/2MWh operational BESS at the LG &E and KU E.W. Brown facility. This model was formulated using an improved method for estimating the battery cell parameters.

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Conference Proceeding

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Notes/Citation Information

Published in 2018 7th International Conference on Renewable Energy Research and Applications (ICRERA).

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The document available for download is the authors’ manuscript version that is accepted for publication. The final published version is copyrighted by IEEE and available as: O. Akeyo, H. Gong, V. Rallabandi, N. Jewell and D. M. Ionel, “Power Utility Tests for Multi-MW High Energy Batteries,” 2018 IEEE International Conference on Renewable Energy Research and Applications (ICRERA), Paris, 2018, pp. 1396-1399. doi:10.1109/ICRERA.2018.8566920

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Funding Information

The support of University of Kentucky, the L. Stanley Pigman endowment, of the SPARK Laboratory, Power and Energy Institute of Kentucky (PEIK), and of LG&E and KUis gratefully acknowledged.