On-Line Estimation Assessment of Power Systems Inertia With High Penetration of Renewable Generation

Abstract

Large-scale deployment of renewable energy sources in power systems is basically motivated by two universally recognized challenges: the need to reduce as far as possible the environmental impact of the massive increase of energy request and the dependency on fossil-fuel. Renewable energy sources are interfaced to the network by means of interfacing power converters which inherently exhibit zero inertia differently from the conventional synchronous generators. This matter jointly to the high level of time variability of the renewable resources involve dramatically frequency changes, recurrent frequency oscillations and high variability of frequency profile in general. The need of a fast estimation of time variability of the power system inertia arises at the aim of predicting critical conditions. Based on the analysis of some actual data of the Italian Transmission Network, in this paper the authors propose an autoregressive model which is able to describe the dynamic evolution of the power system inertia. More specifically, the inertia is modeled as the sum of a periodic component and a noise stochastic process distributed according a non-Gaussian model. The numerical results reported in the last part of the paper, demonstrating the efficiency and precision of estimation of inertia, allow justifying the assumptions of the above modeling.

Comprehensive Review on Detection and Classification of Power Quality Disturbances in Utility Grid With Renewable Energy Penetration

“…Maiden application of a variant of KF algorithm known as local ensemble transform-based KF for power system harmonic estimation is presented in [53]. Detection of grid fundamental voltage and harmonic components using a modified Kalman filter [54] for renewable energy penetration has been presented in [55].…”

Power System Inertia Estimation Using HVDC Power Perturbations

“…Probing methods of inertia estimation, whether controlled [12] or, as in this investigation, ambient can directly inform power system operators, but frequency and time series measurements can also be used to improve statistical estimations, such as [13]. It is worth noting that such statistical investigations and estimations may require probes of differing magnitudes, at different frequencies and with various generation mixes if they are to remain accurate [14] especially as wind plant implement frequency response [15].…”

“…The swing equation is the basis of most estimates of power system inertia, with [16] providing a good example; however this analysis uses simulated data with a very low noise component. When dealing with real data it is common to employ filters, such as those discussed in [13] - [15]. In this investigation the integration of power with respect to time to give energy delivered is employed as a method to smooth the signal; logic is then applied to make an estimate of power system frequency.…”

Analysis and Improvement of an Algorithm for the Online Inertia Estimation in Power Grids with RES

“…Numerous strategies have been proposed, but many of them rely on post-fault data [9]- [13] or injection of probing signals [14], making them not suitable for continuous inertia estimation. Some methods to estimate inertia under normal operating conditions use statistical models trained on historical data [15], [16], that is often not easily accessible.…”