Validation of power system transient stability results

Simulation of the transient stability problem of a power system, which is the assessment of the short term angular and voltage stability of the system following a disturbance, is of vital importance. It is widely known in the industry that different transient stability packages can give substantially different results for the same (or at least similar) system models. The goal of this work is to develop validation methodologies for different transient stability software packages with a focus on Western Electricity Coordinating Council (WECC) system models. We discuss two specific approaches developed and implemented to validate the transient stability results. The sources of discrepancies seen in the results from different packages are investigated. This enables us to identify the differences in the implementation of dynamic models in different transient stability softwares. In this process, we present certain key analyses of the WECC system models for different contingencies

Iterative Matrix Pencil Method for Power System Modal Analysis

This paper introduces a modal analysis approach termed as the Iterative Matrix Pencil method. It uses the Matrix Pencil Method as the primary tool for mode identification, and adds to it by utilizing the concept of a cost function in order to reduce the number of signals needed to identify the modes for a large system. The method is tested for a variety of large synthetic power grids in this paper, with the cost function being reported to measure accuracy. A sensitivity analysis is also considered, showing how this new method behaves when adjusting the two primary user-based inputs; the number of iterations, and the SVD threshold

Stability Considerations for a Synchronous Interconnection of the North American Eastern and Western Electric Grids

This paper presents some of the stability considerations for an ac interconnection of the North American Eastern and Western electric grids. Except for a brief time around 1970, the North American Eastern and Western grids have operated asynchronously, with only small power transfers possible through a few back-to-back HVDC ties. This paper provides results from a study showing that an ac interconnection may be possible with only modest changes to the existing transmission grid. The paper’s main focus is on the dynamic aspects of such an interconnection. The paper also shows how newer visualization techniques can be leveraged to show the results of larger-scale, long duration dynamic simulations. Results are given for a 110,000-bus model of the actual North American electric grid and an 82,000-bus synthetic grid

Application of Large-Scale Synthetic Power System Models for Energy Economic Studies

Due to information confidentiality issues, there is limited access to actual power system models that represent features of actual power grids for teaching, training, and research purposes. The authors\u27 previous work describes the process of creating synthetic transmission networks, with statistics similar to those of actual power grids. Thus, this paper outlines a systematic methodology to augment the synthetic network base case for energy economic studies. The key step is to determine generator cost models by fuel type and capacity. Based on statistics summarized from the actual grids, two approaches are proposed to assign coefficients to generator cost models. To illustrate the proposed creation procedure, we describe the construction of a synthetic model for Electric Reliability Council of Texas footprint. Simulation results are presented to verify that the created test system is able to represent the behavior of actual power systems

Building Synthetic Power Transmission Networks of Many Voltage Levels, Spanning Multiple Areas

Synthetic power grids, that is, test cases designed to match realistic structural and statistical characteristics of actual grids, are useful for research, development, and demonstration of innovations, since the cases are fictitious and thus free from data confidentiality issues. Building on previous work, this paper addresses a couple of related problems in the transmission network synthesis process. These issues appear as created cases become larger and involve multiple areas and overlapping nominal voltage levels. A fast, scalable hierarchical clustering is designed to assign voltage levels to substations considering the needs of the system, the specific constraints of the area, and smooth interconnections between neighboring areas with different voltage levels. A line topology generation framework is considered that is appropriate for many networks of different voltage levels, constructed together for a useful, realistic grid. These methods are demonstrated in a new 2000 bus test case, validated and publicly released

Towards the Automation of Remedial Action Schemes Design

The constantly evolving nature of the grid is compelling the design process of Remedial Action Schemes (RAS) to keep up with the changes. This paper proposes a flexible and computationally efficient approach to automatically determine RAS corrective actions that alleviate line overloading violations. Statistical and functional characteristics summarized from RAS implemented in real power systems are used to guide the design parameters. This paper also leverages sensitivity-based techniques to determine corrective actions for specific contingencies quickly without repeated numerical simulations