Distributions of cascade sizes in power system emergency response

A rare-event study of frequency regulation and contingency services from grid-scale batteries

“…This paper continues recent work based on MCMC random sampling which was begun in [25,26]. While the latter papers also made strong simplifications, our goal in the present work is to demonstrate the incorporation of a power system model which is both detailed and adaptable.…”

“…These random disturbances are modelled agnostically and may, for example, represent exogenous shocks and/or endogenous contingencies. They are applied as impulses at time 0 and, as in [26], are modelled as constant power disturbances over the time scale of our simulations. Thus, for example, if the model is used to explore the effect of renewable generation forecast errors then the joint distribution of these disturbances should reflect the historical joint distribution of such errors, and the time scale of the simulation should be comparable to the characteristic time scale of these errors.…”

“…We take the unconditional distribution μ to be the Gaussian distribution in (3.2) above, and let the set normalΥ be a particular system instability. While the underlying sampler is the same as that employed in [26], in the case study of §4. below the system model and simulator aim to be more realistic and we are interested in instabilities relating to two different services provided by BESS (that is, regulation and emergency responses) and their interaction.…”

“…One limitation in that work was the use of dynamics which neglect system voltage transients and are valid only for small disturbances. In order to study cascades of emergency responses caused by larger disturbances, [26] employed third-order dynamics. The latter work established the effect of network connectivity on the conditional distribution of cascade sizes (that is, the number of emergency responses arising from the initial disturbances), namely that these distributions can be highly bimodal in more highly connected networks.…”

Analysis of Load-Altering Attacks Against Power Grids: A Rare-Event Sampling Approach

“…ERs refer to systems designed to protect sensitive power system components from excessive frequency deviations following a change in the active power balance. In this section we provide a brief discussion of ER employed, and refer the reader to [15] and [16] for a detailed mathematical description.…”