We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Random graphs

MATPOWER is an open-source Matlab-based power system simulation package that provides a high-level set of power flow, optimal power flow (OPF), and other tools targeted toward researchers, educators, and students. The OPF architecture is designed to be extensible, making it easy to add user-defined variables, costs, and constraints to the standard OPF problem. This paper presents the details of the network modeling and problem formulations used by MATPOWER, including its extensible OPF architecture. This structure is used internally to implement several extensions to the standard OPF problem, including piece-wise linear cost functions, dispatchable loads, generator capability curves, and branch angle difference limits. Simulation results are presented for a number of test cases comparing the performance of several available OPF solvers and demonstrating MATPOWER's ability to solve large-scale AC and DC OPF problems.

/pdf/matpower-steady-state-operations-planning-and-analysis-tools-1v40ihity5.pdf

MATPOWER: Steady-State Operations, Planning, and Analysis Tools for Power Systems Research and Education

The Smart Grid, regarded as the next generation power grid, uses two-way flows of electricity and information to create a widely distributed automated energy delivery network. In this article, we survey the literature till 2011 on the enabling technologies for the Smart Grid. We explore three major systems, namely the smart infrastructure system, the smart management system, and the smart protection system. We also propose possible future directions in each system. colorred{Specifically, for the smart infrastructure system, we explore the smart energy subsystem, the smart information subsystem, and the smart communication subsystem.} For the smart management system, we explore various management objectives, such as improving energy efficiency, profiling demand, maximizing utility, reducing cost, and controlling emission. We also explore various management methods to achieve these objectives. For the smart protection system, we explore various failure protection mechanisms which improve the reliability of the Smart Grid, and explore the security and privacy issues in the Smart Grid.

/pdf/smart-grid-the-new-and-improved-power-grid-a-survey-4jypbbgv3j.pdf

Smart Grid — The New and Improved Power Grid: A Survey

The increasing interest in integrating intermittent renewable energy sources into microgrids presents major challenges from the viewpoints of reliable operation and control. In this paper, the major issues and challenges in microgrid control are discussed, and a review of state-of-the-art control strategies and trends is presented; a general overview of the main control principles (e.g., droop control, model predictive control, multi-agent systems) is also included. The paper classifies microgrid control strategies into three levels: primary, secondary, and tertiary, where primary and secondary levels are associated with the operation of the microgrid itself, and tertiary level pertains to the coordinated operation of the microgrid and the host grid. Each control level is discussed in detail in view of the relevant existing technical literature.

Trends in Microgrid Control

Smart Grid - The New and Improved Power Grid:

This paper proposes a method for choosing the best composite power system expansion plan considering a probabilistic reliability criterion. The proposed method minimizes the investment budget (economics) for constructing new transmission lines subject to deterministic (demand constraint) and probabilistic reliability criteria (LOLER), while considering the uncertainties of system elements. It models the power system expansion problem as an integer programming one. The method solves for the optimal strategy using a probabilistic theory-based branch and bound method that utilizes a network flow approach and the maximum flow-minimum cut set theorem. Although the proposed method is applied to a simple sample study, the test results demonstrate that the proposed method is suitable for solving the power system expansion planning problem subject to practical future uncertainties

A basic method for composite power system expansion planning considering probabilistic reliability criteria

Relationship between wind power, electric vehicles and charger infrastructure in a two-settlement energy market

This paper proposes three methods for choosing the transmission system expansion plan considering three reliability constraints, which are deterministic reliability criterion, probabilistic reliability criterion and security criterion based on N-alpha contingency in order to give more successful market operation. The proposed method minimizes total investment cost. It models the transmission system expansion problem as an integer programming one. The method solves for the optimal strategy using a branch and bound method that utilizes a network flow approach and the maximum flow-minimum cut set theorem. The 21 bus system case study results demonstrate that the proposed method is practical for solving the power system expansion planning problem subject to practical future uncertainties.

Transmission System Expansion Plans in View Point of Deterministic, Probabilistic and Security Reliability Criteria

In this paper we review and expand our previous work on developing random topology networks as a way to generate synthetic power grid data. We first present an algorithm that is able to generate the small-world “eletric” topology appropriate for a transmission network. Next we re-examine the definitions of the proposed numerical measure called “Bus Type Entropy”, to characterize the correlated assignment of generation, load, and connection buses in a real power grid, using the IEEE test cases and newly obtained realistic grid data. In order to study the scaling property of bus type assignment versus network work, we revise the entropy definition for better statistical property and improved numerical stability. We then develop an more efficient search algorithm for the best bus type assignments with the help of the derived scaling function. Finally we introduce some most recent work to generate other electrical parameters such as generation capacities and load settings.

Generating synthetic electric power system data with accurate electric topology and parameters

In electricity markets where supply and demand drives the price for the purchase and sale of electricity, generating firms change capacity for various reasons including load level, policy, and varying market conditions. These types of fluctuating production patterns can result in the reduction of market efficiency. In an inefficient market, where the price for electricity exceeds marginal cost, the locational marginal price (LMP) is often used to measure market efficiency. Stochastically driven changes in the market are captured by this approach, however, these random changes (frequently observed in efficient markets as well) do not affect market efficiency in the long run. Conversely, a slow, consistent change is not captured by the snap-shot approach and affects the efficiency significantly. Therefore, it is necessary to construct an algorithm that captures only consistent changes that truly affect market efficiency. Fractal analysis can characterize a price behavior in the electricity markets because the price exhibits a self-similarity. Once a system undergoes a change, the fractal dimension of the system reflects the change. In this paper, an approach using nonlinear time series analysis is proposed and tested on actual offer behavior observed in the electricity markets in the United States.

Robert J. Thomas

Papers

A basic method for composite power system expansion planning considering probabilistic reliability criteria

Relationship between wind power, electric vehicles and charger infrastructure in a two-settlement energy market

Transmission System Expansion Plans in View Point of Deterministic, Probabilistic and Security Reliability Criteria

Generating synthetic electric power system data with accurate electric topology and parameters

Nonlinear time series analysis on the offer behaviors observed in an electricity market