Analysis of a Disturbance Event With Inverter-Based Resources Using EMT Simulations

This paper analyses the impact of a massive integration of distributed inverter based resources (IBR), and of the reduced transmission system short-circuit power on the spread of voltage perturbation on the distribution grids and on their stability. A typical transmission network and generic distribution grids are modelled considering IBR connected at the medium voltage (MV) level. It was assumed a scenario in which a portion of the power system contains 100% of the generation interfaced by power electronic inverters and connected to the distribution grid. EMT simulations were carried out in order to assess the effect of the dynamic voltage support (DVS) capability of IBR. It was shown that in reduced short-circuit level conditions, the DVS helps to reduce the voltage dip during the fault and to ensure a fast voltage recovery after the fault while respecting the Over-Voltage Ride-Through (OVRT) profiles of IBR at MV level.

WPs consist of a large variety of interconnected components including mechanical parts, power electronic devices, control and protection systems, etc. Accurate and generic models for different types of WTs are crucial for reliable design and planning of modern power systems that incorporate WPs. This chapter introduces an effective approach towards detailed modeling and simulation of WPs that employ variable speed WTs. Specifically, converters and their control schemes for DFIG and FSC WTs are thoroughly discussed, and their main parameters are explained. Moreover, software implementation, average value and detailed models, and controller design are addressed. EMTP® is used to verify the accuracy of the generic models under different test cases. Time-domain simulation results are analyzed and compared with the real-life measurements of post-fault transients in the test scenarios. The results confirm that the developed models in conjunction with the EMT simulations can accurately predict the response of DFIG and FSC WTs under both steady-state and transient conditions.

Although power quality (PQ) disturbances events such as rms variations and transients occur in transmission and distribution systems, these datasets are mostly managed through proprietary solutions in different data formats. This paper presents a simple, yet effective, metadata database schema to manage voluminous PQ disturbance events in power systems. A database constructed using the schema can be used to store the metadata providing descriptive and analytical analysis of the disturbance events. Proposed schema defines five classes to store the metadata associated with PQ disturbance events: event, time-series, description, software analysis, and IEEE disturbance classification. The classes that form the schema are presented, then are demonstrated using actual disturbance events captured from a distribution system.

A system for power quality (PQ) disturbance (event) analysis under noisy environment is proposed using wavelet feature (WF) based fuzzy classification method. In practice, the captured signals are often corrupted by noise. Also the nonlinear and non-stationary behavior of PQ events due to various switching devices make the detection and classification tasks more cumbersome. Wavelet transform (WT) has been proven to be an effective tool for extracting inherent features through time-frequency analysis of these events. In this work we exploited WT for noise removal to make the task of detection and/or localisation of events simpler and to decompose the PQ event signals for extracting unique features. These WF are fed into fuzzy classifier for making decision regarding the type of events. We have used fuzzy product aggregation reasoning rule [8] based classifier in the present application. Varieties of PQ events which include voltage sag, swell, momentary interruption, notch, oscillatory transient and spikes are considered to test the performance of proposed approach. Comparative simulation studies revealed the superiority of the proposed method compared to WF based fuzzy explicit, fuzzy k-nearest neighbor and fuzzy maximum likelihood under noisy environment.

Grid event analysis at the Load Dispatch Centers in India is done with the help of synchrophasor data, SCADA Sequence of Events records, analogue data from SCADA/EMS and information from Operator log book records. Protection relay flags, Station Disturbance record and Event logger data record forwarded by the respective transmission substations are used for detailed analysis of an event. This paper discusses a few case studies wherein multiple tripping, complete outage of grid sub-station/ power station which had occurred in southern grid were analysed and remedial actions were proposed to overcome the shortcoming found during analysis

Automated double-ended traveling wave record correlation for transmission line disturbance analysis

TRADER: A package for Tree Ring Analysis of Disturbance Events in R

The article presents an approach to train traffic modelling that allows for the analysis of how railway networks respond to various disturbances, including increased traffic and disturbance events. It discusses different methods of reconfiguration actions in key points of the railway network, which helps reduce delay propagation in the transport system. The 1st part covers building simulation models, which include defining infrastructure, setting train routes, configuring rolling stock, and disturbance scenarios, enabling the analysis of various disruptive events. The simulations allow for testing disturbance scenarios with minimal downtime risk without interfering with the real-world environment. The study results identified key system parameters generating the largest delays, such as platform availability, signaling, and the number of block sections. Probability density distributions for event intervals and durations were analyzed. The Kolmogorov–Smirnov test was used to confirm the fit of empirical distributions with theoretical ones, which were then implemented in the model of railway line No 271, running from Wrocław to Żmigród (Poland). As part of the reconfiguration of this railway line, new platforms were added, the time required for route setting was reduced, and the number of block sections was increased. These actions significantly reduced average delays, improved line capacity, and enhanced the robustness of the railway transport system against disturbances. The reconfiguration effectively reduced delays in areas causing significant time exceedances above 359 s, which was recognized in the Polish railway network as critical.

In the following remarks, we present new developments in social theory and cultural analysis that converge in a particular focus on a third perspective beyond the distinction between inside and outside. This focus on “thirdness” transcends the classical structuralist paradigm of binary classification. It is especially sensitive for the analysis of sudden surprises, paradoxical twists, and disturbing events in history and social life and, thus, contrasts to the assumption of progress and orderly linear development. We outline this new paradigm with respect to three different domains: garbage, monsters, and victims.

Phasor Measurement Units (PMUs) are devices that can not only measure but also time stamp voltage, current, frequency, among electric power system parameters. PMUs take these synchronized measurements as fast as 60 times per second and compared with the traditional 2–4 second SCADA measurements, PMUs bring a much clear and real-time picture of what is happening in the power system. PMUs have been increasingly deployed across transmission power grids worldwide. In the USA this has been primarily done by utilities through projects sponsored mainly by US Department of Energy Smart Grid grants. There are different applications that synchrophasors can provide, including off-line and real-time applications. However, due to budget constraints, technology development and characteristics specific to each electric power system, not all applications are equally suitable for each system. This paper provides a methodology for PMU applications prioritization based on the analysis and results of wide area disturbance events as well as other factors that are described in detailed.

Global scale electrodynamic coupling of the auroral and equatorial dynamo regions

This paper presents analysis results of synchronized phasor data from 10 disturbance events recorded in the US Eastern Interconnection (EI). The phasor data covers a wide region in the EI, allowing for the study of disturbance propagation, interarea modes, and oscillations in voltages and currents. The analysis is not straightforward because the EI is a meshed system with adequate interarea mode damping. Disturbances involving tripping a single large generator unit produce very short interarea swing responses. Islanding events involving regions at the perimeter, however, provide more prominent responses for analysis.

Parallelization of EMT simulations for integration of inverter-based resources

The “Lines and Geoglyphs of Nasca and Palpa” in Peru are among the most well-known UNESCO World Heritage Sites globally, and an exemplar of site where heritage assets cannot be separated from their natural and anthropogenic environment. The site is exposed to interactions with natural processes, as well as human presence. In this work, 3-m resolution synthetic aperture radar (SAR) StripMap HIMAGE HH-polarised scenes acquired by the X-band COSMO-SkyMed constellation are exploited to track two events of human-induced landscape disturbance that occurred in December 2014 and January 2018. Pre-, cross-, and post-event interferometric SAR (InSAR) pairs characterised by small temporal and normal baselines allow the detection of temporal decorrelation associated with the two events, the extent and time reference of which match with online photographic and video evidence, published literature, web news, and press releases by the Ministry of Culture in Peru. Further elements enhancing the understanding of the 2018 event come from 10-m resolution Sentinel-2B satellite data that reveal the occurrence of apparent changes of surface reflectance due to uncovering of the light grey-yellow clay underneath the darker pebble constituting the fragile surface of the Pampa de Jumana. This scientific study confirms that SAR imagery archives, such as those being built by COSMO-SkyMed for Nasca, prove valuable for the retrospective analysis and digital recording of human-induced landscape disturbance events from space. These archives therefore act as essential sources of geospatial information on the conservation history of heritage sites and assets.

A novel system for power quality (PQ) disturbance (event) classification under noisy environment is proposed using slantlet transform (SLT) and fuzzy logic based classifier. SLT is used for extraction of inherent features called as slantlet feature (SF) through time-frequency analysis of PQ events. It is found to be an effective tool for better time localization compared to wavelet transform and extraction of appropriate and informative features from signal under noisy environment, which enhances the classification accuracy. These features are thus utilized for improved classification using fuzzy logic in this paper. We have used fuzzy product aggregation reasoning rule based classifier in the proposed method. Varieties of PQ events which include voltage sag, swell, momentary interruption, notch, oscillatory transient and spikes are considered to test the performance. Comparative simulation studies revealed the superiority of the proposed method compared to SF and wavelet feature based three other fuzzy classifiers under noisy environment.