Determining Inertia of 60 Hz Japan Power System using PMUs from Power Loss Event

Assessment of the Center of Inertia and Regional Inertia with Load Contribution via a Fully Data-Driven Method

“…Other approaches address the COI's estimation [7]- [12], without discussing the regional inertia estimation. Likewise, some works tackle the regional inertia estimation to some extent classifying them by their distinct characteristics into the following categories: (i) disturbance methods [13]- [21]; (ii) probing signal methods [22], [23]; and (iii) ambient-signal methods [24]- [31]. As we are interested in regional inertia estimation, which entails larger systems, the occurrence of severe events is fairly greater than for a single machine, for instance, providing a reasonable amount of opportunities for estimation.…”

“…In [20], the equivalent inertia of a power system is estimated using the recursive least-squares (RLS) by fitting oscillation data, where an initial model is estimated with a non-recursive system identification method. The authors in [21] estimate the inertia of areas from the 60Hz Japan system using frequency and rate of change of frequency measurements applying a frequency spectrum and performing mode shape analysis. Here, they find that PMUs further away from the COI of the system provide imprecise estimations due to the effect of inter-area oscillation.…”

“…It is evident in the literature that regional inertia estimation methods do not consider the proper estimation of the COI frequency [21], [32] and the load contribution to the effective inertia, making simple assumptions. The assumption that loads contribute to the inertia response is well established in [33], but overall ignored until recent years with the high penetration of CCG in modern systems.…”

“…To assess the performance of the fully data-driven methodology in finding the COI and estimating the regional inertia, nonlinear time-domain simulations are performed using the ANATEM simulation software [44] with a total time of 20 s. Since our methodology adopts the disturbance approach according to [13]- [21], all simulations include disturbances provoked by load steps occurring at 0.6s at the higher load buses. Active power and frequency measurements are collected using 60 phasors per second in fulfillment with the synchrophasor standard [45].…”