Search

In this tutorial we present the state-of-the-art as well as new methods for simulating various planning, operation, stability, reliability, and economic models of electric power systems. The discussion is driven by both first-principle models and empirical models. First-principle models result from the fundamental physics and engineering principles that govern the behavior of various components of a grid. Empirical models, on the other hand, are models that result from statistics and data analysis. We overview a wide spectrum of applications starting from planning models with a time-scale of simulation in years to real-time models where the time-scale can be in the order of milliseconds. We present a list of simulation software popularly used by the power engineering research community across the world. The increasingly important roles of power electronics, communication and computing, model aggregation, hybrid simulation, faster-than-real-time simulation, and co-simulation in emulating the daily operation of a grid are enumerated. The importance of research testbeds for testing, verification and validation of complex grid models at various temporal and spatial scales is also highlighted. The overall goal is to provide a vision on how simulations and their supporting implementation methods can help us in understanding the evolving behavior of tomorrow’s power networks as a truly intelligent cyber-physical system. [ABSTRACT FROM PUBLISHER]

Abstract: This paper addresses the solvability of power flow for AC–DC system with sequential methods. As one of most wieldy used power flow analysis methods for AC–DC systems, this method solves the AC and HVDC systems iteratively. This paper shows that the solvability of the problem depends on a linearized coefficient matrix G , which integrated the information of the network and HVDC control modes. To analyze the singularity of G , all of the physically feasible combinations of the control modes are classified into seven categories. The conditions for the singularity of G are analyzed in detail. Systematical conditions for solvability of power flow with sequential methods for AC–DC systems are derived mathematically. Some numerical studies validate the proposed theoretical results. [Copyright &y& Elsevier]

Accurate bus-oriented, three-phase modeling of power systems is desirable for advanced applications and has become practical due to increased computational capability. To assist research activities in this area, this paper presents a benchmark three-phase test system. The proposed system is based on the 24-bus IEEE Reliability Test System that has been converted into a 24-substation, breaker-oriented, three-phase model. The model is available in electronic form at the site: http:llpscal.ece.gatech.edu/testsys/. The proposed model is intended for use in research for three-phase power flow analysis, reliability analysis, fault analysis, transient stability, evaluation of fault currents through specific breakers, risk assessment of breaker failures, and other applications. [ABSTRACT FROM AUTHOR]

The power grid is not only a network interconnecting generators and loads through a transmission and distribution system, but is overlaid with a communication and control system that enables economic and secure operation. This multilayered infrastructure has evolved over many decades utilizing new technologies as they have appeared. This evolution has been slow and incremental, as the operation of the power system consisting of vertically integrated utilities has, until recently, changed very little. The monitoring of the grid is still done by a hierarchical design with polling for data at scanning rates in seconds that reflects the conceptual design of the 1960s. This design was adequate for vertically integrated utilities with limited feedback and wide-area controls; however, the thesis of this paper is that the changing environment, in both policy and technology, requires a new look at the operation of the power grid and a complete redesign of the control, communication and computation infrastructure. We provide several example novel control and communication regimes for such a new infrastructure. [ABSTRACT FROM AUTHOR]

The problem of defining and classifying power system stability has been addressed by several previous CIGRE and IEEE Task Force reports. These earlier efforts, however, do not completely. reflect current industry needs, experiences and understanding. In particular, the definitions are not precise and the classifications do not encompass all practical instability scenarios. This report developed by a Task Force, set up jointly by the CIGRE Study Committee 38 and the IEEE Power System Dynamic Performance Committee, addresses the issue of stability definition and classification in power systems from a fundamental viewpoint and closely examines the practical ramifications. The report aims to define power system stability more precisely, provide a systematic basis for its classification, aid discuss linkages to related issues such as power system reliability and security. [ABSTRACT FROM AUTHOR]

In this paper, the numerical analysis of a multistage formulation of the distribution expansion problem developed is presented. The approximate objective function is employed without sacrificing optimality. A complete nonlinear mathematical programming optimization is employed to identify the global optimum. The algorithm is applied here to two practical test cases. Details of the input data and configuration of test systems as well as the solutions are listed and discussed. Computational considerations are addressed. [ABSTRACT FROM AUTHOR]

In this paper, the objectives and detailed analysis of the multistage distribution expansion are presented. The problem is modeled as a directed graph minimum edge cost network flow problem. This new formulation details a multistage framework within a single mathematical program while addressing several deficiencies of previous approaches. The accuracy of a single step approximation of the objective function, without using the conventional linearization techniques, is discussed. Each of the constraints is introduced in terms of industry standard practices. Detailed numerical results for practical study cases are provided in a separate paper. [ABSTRACT FROM AUTHOR]

This paper resulted from the research aimed at introducing modeling and simulation as a major methodological approach for enhancing power engineering education. The reasons for such an approach an explained first. Different options and uses of the modeling and simulation tools are discussed next. Several implementations of the teaching examples ate outlined. The paper ends with the conclusions reached based on the study. [ABSTRACT FROM AUTHOR]

Presents a study which proposed a fast method for use in on-line voltage security assessment. Localized concept and electrical distance in static security analysis; Methodology used; Application of the method to the test systems.

Presents a parallel across space implementation of a Waveform Relaxation (WR) based algorithm. Power system dynamic simulation; Waveform relaxation algorithm; Improving WR convergence and efficiency; Sequent symmetry S81 shared memory machine; Task partitioning in parallel implementations; Test results; Conclusion

Seeks to identify likely deregulations scenarios in electric power system operations. Technical issues associated with Load Frequency Control; Standards and algorithms needed for the operation of key components; Vertically integrated utility; Load increases.