Coordination of Frequency Reserves in an Isolated Industrial Grid
Equipped with Energy Storage and Dominated by Constant Power Loads
Abstract
Manuscript submitted to the IEEE Transations in Power Systems in October
2022.
Title: Coordination of Frequency Reserves in an Isolated Industrial Grid
Equipped with Energy Storage and Dominated by Constant Power Loads
Abstract:
This paper examines the use of interconnected synchronous system
requirements for frequency containment reserves (FCR) on isolated
industrial grids that use turbogenerators as main source of energy, have
high penetration of wind energy, are equipped with energy storage, and
have a high level of constant power loads coupled by power electronic
converters. Leveraging on the recent Nordic requirements for reserves in
islanded operation (FCRI), we propose an expansion that allows
prioritizing among various reserve providers under different isolated
grid conditions. The study case of a complex, isolated industrial grid
is selected to test this approach. The stability of this grid is
evaluated via eigenvalues and participation factors considering the
detrimental effects of constant power loads. It is demonstrated that, by
prioritizing the reserve allocation to the faster converter-interfaced
storage devices and loads, the overall stability is increased in
addition to allowing the turbogenerators to operate at a more constant
load. The results are supported by computer simulations of a rotating
mass model, of the complex isolated grid in PowerFactory, and by
laboratory power-hardware-in-the-loop tests. The computer simulation
models developed for this paper are made publicly available for
reproducibility purposes.