Power System Dynamic Performance Committee

The structure of the Subcommittee is a mix of Working Groups and Task Forces, addressing the various technical areas within the scope of the Subcommittee.

Working Group on Voltage Stability
(Chair: Anurag Srivastava)

This group focuses on all aspects of voltage stability, its analysis and methodologies for performing such analyses. The group promotes and helps organize panel sessions, tutorials and other activities related to the study of voltage stability.

Working Group on Power System Dynamic Modeling
(Chair: Claudia Rahman)

This group focuses on all aspects of power system modeling for stability studies. The group promotes and helps organize panel sessions, tutorials and other activities related to this subject.

Working Group on Dynamic Security Assessment
(Chair: Zhenyu (Henry) Huang)

This group focuses on all aspects of dynamic security assessment for both on-line and off-line applications. The group promotes and helps organize panel sessions, tutorials and other activities related to this subject.

Task Force on Microgrid Dynamic Modeling
(Chair: Claudio Canizares)

Based on the report of the “Microgrid Stability Definitions, Analysis, and Modeling” TF, it can be concluded that the models of the different components of the microgrid have a significant impact on the simulation and associated results of dynamic events in these systems. For example, ignoring load unbalancing and/or fast converter switching may yield different dynamic simulation responses for certain system events and conditions; however, the modeling and computational requirements to represent in detail a variety of system elements and conditions could be very onerous, requiring particular software and computer tools that restrict the types of studies that can be performed, limiting dynamic simulations to a few seconds for a reduced number of microgrid components. Therefore, the proposed TF will focus on studying and determining the validity and types of applications of detailed and approximate component models for microgrid dynamic studies and simulations, in the context of the IEEE 1547 standard, such as full and average converter models, unbalanced and balanced converters and loading, dynamic and static loads, feeder and single bus representations, and detailed and simplified controls considering communications delays.

Task Force on Adjustable Speed Pump Storage Modeling
(Chair: Eduard Muljadi)

Provide a forum for researchers, modelers, manufacturers and designers of advanced pumped storage technologies. Modeling to be focused on advanced pumped storage technologies including: adjustable speed doubly fed induction machines with high speed rotor excitation, ternary pumped storage with mechanical clutches and other associated technologies. Coordinate with other groups concerned with the modeling of specific components. Work with ISO’s, RTOs, Transmission Owners, and consultants who prepare system dynamic studies for transmission interconnections and planning. Encourage, organize and recommend, to the Working Group, suggestions for panel session and paper sessions that report on recent advanced pump storage model development activities.

Task Force on Methods for Analysis and Quantification of Power System Resilience
(Co-Chairs: Alex Stankovic and Kevin Tomsovic)

Power systems that rely on communication networks to maintain satisfactory performance face a host of new challenges. In addition to conventional robustness, such systems need to withstand malicious attacks (in the physical and cyber layer) and to learn from past performance. The TF will focus on definitions of resilience that can be quantified with existing emerging data sources in power grids, and propose quantification methods that match each theoretical concept. It will cover passive and active approaches, and include methods to address credible large events due to acts of nature and due to human actors. The TF will initially be concentrating on the study of resilience modeling, analysis, and tools, starting with a comprehensive review of the state-of-the-art in these subjects, which is limited in terms of the ability to quantify various resilience notions. The TF will aim to determine shortcomings of the existing techniques and models, and to propose possible approaches to address the identified issues and limitations.

Task Force on Integrating Relay Models with Electromechanical Simulations
(Chair: Glauco Taranto)

After recent major blackouts, it has been identified that protection systems are a critical reliability infrastructure in modern power systems, and that overly conservative relay settings have contributed to unnecessary tripping. Therefore, the need of enhancing the models of protective relays in simulation tools is a worth continuing effort. A PSRCC WG paper reviewed software relay models and divided them into two categories - phasor models and transient models. The phasor models correspond to the relay models largely used in fundamental frequency steady-state software packages. Whereas, the transient models correspond to the relay models that consider voltage/current waveforms, such as those performed on electromagnetic transient programs. Recent efforts to comply with NERC Standard have emphasized the importance of combining dynamic simulation and protection system modeling for evolving faults, such as in analysis of cascading failure risks, and delayed fault clearing. NERC Standard TPL 001-4 states that “studies shall be performed to assess the impact of the extreme events”. This Task Force will organize those recent efforts and tackle the gap between the two previously mentioned categories, focusing on appropriate modeling issues for large-scale electromechanical dynamics simulation tools. Starting with these two categories reported, the TF will introduce a third one and will propose an adequate nomenclature for all three categories. The TF will describe generic protection models and tools easily accessible and more detailed models and tools not so easily accessible.

Task Force on Stability definitions and characterization of dynamic behavior in systems with high penetration of power electronic interfaced technologies
(Co-Chairs: Nikos Hatziargyriou and Jovica Milanovic; Secretary: Claudia Rahmann)

A report published in 2004, namely the "Definition and classification of power system stability IEEE/CIGRE joint task force on stability terms and definitions" by P. Kundur, J. Paserba, V. Ajjarapu, G. Andersson, A. Bose, C. Canizares, N. Hatziargyriou, D. Hill, A. Stankovic, C. Taylor, T. Van Cutsem and V. Vittal, is presently the de facto document on the definition of stability terms in power systems. This document is the key reference on power system stability definitions and will likely remain so for many years to come. However, since 2004 to the present day there have been significant and continuing changes in resource mix, the structure and operation of power systems. The future power systems will be characterised by i) blurred boundaries between transmission and distribution systems, ii) mix of wide range of electricity generating technologies including conventional hydro, thermal, nuclear and most importantly power electronics (PE) interfaced intermittent renewable generation; iii) responsive and highly flexible, typically power electronics interfaced, demand and storage with significant temporal and spatial uncertainty; iv) proliferation of power electronics (HVDC, FACTS devices); v) new types, largely PE connected, load devices); v) significantly higher reliance on the use of measurement data including global (Wide Area Monitoring) signals for system identification, characterization and control and vi) Information and Communication Technology embedded within the power system network and its components. In order to successfully model, analyze and ultimately control such systems and their dynamic behavior following a disturbance and to ensure high level of consistency and transparency of approaches taken and terminology used by both academic researchers and industry practitioners it is essential to revisit some of the existing and introduce new terms and definitions, where appropriate, that will adequately reflect and describe the existing and future dynamic behaviour of evolving power systems. It is likely that new definitions are needed to address some of the new emerging phenomena and technologies. The key issue governing the change in dynamic behaviour of the system is the reduction of system inertia due to power electronics connected generation, storage and load technologies. Some of the issues that need to be addressed in this context include definition of penetration levels (e.g., nominal, instantaneous, etc.) of non-synchronous power/energy sources leading to reduction of inertia in the system, calculation of equivalent inertia in the system, relevance of "system frequency" in the context of asynchronously connected areas and generation etc. This Task Force, aims to address the issue of stability definition and classification in power systems with increasing and high penetration of power electronic interfaced generation and loads, from a fundamental viewpoint and to closely examine the practical ramifications of envisaged changes in system structure on system dynamic behaviour and stability. The report aims to define power system stability and contributing phenomena more precisely and provide a systematic basis for its classification.

NOTE: This Task Force reports directly to the PSDP Committee Officers. Its members must be formally invited by one of the TF Co-Chairs. The work of this Task Force is now finished with the publication of the respective TF report.

Link to the Final Report

Task Force on Microgrid Stability, Analysis, and Modeling (Co-Chairs: Claudio Canizares and James Rilley; Secretary: Rodrigo Palma)

Microgrids present some unique characteristics, compared to transmission systems, associated with their distribution voltage levels and generation equipment, such as unbalanced operation, low X/R ratio that couples P and Q, inverter-based generation and storage, low inertia, limited voltage control, and the significant effect of generation and load variations on its operation. These particular issues have a significant impact on the stability of islanded microgrids, especially at the moment of connection to and disconnection from a main grid, presenting new and especial modeling and analysis challenges that need to be better qualified and quantified. Hence, the TF will concentrate on the study of islanded microgrid stability modeling, analysis, and tools, starting with a comprehensive review of the state-of-the-art in these subjects, which is limited at the moment, to determine shortcomings of the existing techniques and models, and propose possible approaches to address the identified issues and limitations.

Link to the Final Report

Task Force on Test Systems for Voltage Stability and Security Assessment (Chair: Thierry Van Cutsem; Secretary: Mevludin Glavic)

This report documents the work of the IEEE PES Task Force on Test Systems for Voltage Stability Analysis and Security Assessment. The report starts with a short introduction about the motivation and the scope of the work. Next, the models of respectively the Nordic and the RVS test systems are presented in detail, together with a sample of long-term dynamic simulations of their responses to large disturbances. Appendices are devoted to complementary analyses and simulation results obtained with other time-domain simulation software.

Link to the Final Report

Task Force on Turbine-Governor Modeling (Chair: Pouyan Pourbeik)

The purpose of this Task Force was to review and make recommendations related to the use of models for turbine-governors for power system simulations. Although recent documents published by CIGRE, WECC and others have provided newly developed models for use in modeling thermal turbine-governors, modern combined-cycle power plants and hydro-turbines, there is benefit to reviewing these recommendations and consolidating them with the usage of older models that still exist in commonly used simulation programs. The Task Force made general recommendations on which models are applicable for which tasks and which models are presently considered obsolete. Also, the Task Force identified deficiencies in existing models and made recommendations on improving them.

Link to the Final Report

Task Force on Modal Identification of Electromechanical Modes (Chair: Juan Sanchez-Gasca)

The Task Force focused on identification based either on simulation or ambient data and compiled one single document on techniques developed after Prony, including ERA, Pencil, N4SID, YW, and HHT. Methods, as well as applications were reviewed.

Link to the Final Report

Task Force on Impact of Industry Restructuring on System Dynamic Performance (Chair: Claudio Canizares, Secretary: Federico Milano)

The purpose of this Task Force was to investigate the impact of industry restructuring on system dynamic performance. The Task Force sponsored conference sessions and tutorials and published research articles in the IEEE. The specific tasks were: (1) to survey system dynamic performance situations under various power market and trading arrangements around the world with emphasis on the comparison before and after restructuring; (2) to investigate the major new factors resulting from market restructuring that affect system dynamic performance; (3) to study the interaction between power markets and system dynamic performance; (4) to review the current development of new tools for dynamic performance management, such as stability constrained optimal power flow.