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:

Testing auction mechanisms using humans in a controlled environment provides an excellent and inexpensive means for evaluating their relative merits. This paper describes a framework for testing the efficacy of various supply-side auctions including one with price-responsive load and a soft-cap market. These are compared to a nonuniform price discriminative auction also inappropriately termed a "pay-as-bid" auction. Experimental evidence to date based on uniform price market testing has shown an ability of price responsive load to mitigate high volatility and average price.

/pdf/powerweb-testing-of-various-auction-clearing-mechanisms-for-5ancsbgtkp.pdf

PowerWeb testing of various auction clearing mechanisms for electricity

How to Make Employee Networks Really Work

The Cornell SuperOPF is used to illustrate how the system costs can be determined for a reliable network (the amount of conventional generating capacity needed to maintain System Adequacy is determined endogenously). Eight cases are studied to illustrate the effects of geographical distribution, ramping costs and load response to customers payment in the wholesale market, and the amount of potential wind generation that is dispatched. The proposed regulatory changes for electricity markets are 1) to establish a new market for ramping services, 2) to aggregate the loads of customers on a distribution network so that they can be represented as a single wholesale customer on the bulk-power transmission network and 3) to make use of controllable load to mitigate the variability of wind generation as an alternative to upgrading the capacity of the transmission network. The cost of ramping reduces the amount of potential wind generation that is dispatched because of the inherent variability of wind speeds. The analysis evaluates whether the ability to dispatch some load that is not time-sensitive, such as charging the batteries in electric vehicles over night above the minimum usage requirement, can be an effective way to use more of the potential wind generation without upgrading the transfer capacity of a transmission network. The expectation is that more wind generation can be dispatched at times when load is relatively low and congestion on the network is not a major limitation.

Integrating Wind Power: Can Controllable Load Substitute for Transmission Upgrades?

We describe a formulation of the thermal unit commitment problem that includes AC network constraints, which allows taking into account VAr production as a criterion for generator commitment for the first time. The formulation makes it possible to use the Lagrangian Relaxation technique as a solution algorithm even though the network constraints are not linear. Although the solution method is computationally intensive, the problem exhibits a separation structure and a price coordination schedule that suggest several ways of improving the performance. Preliminary test results are reported.

Scheduling of thermal units with a nonlinear load flow network model

The electric power industry in many countries has been restructured in the hope of a more economically efficient system In the restructured system, traditional operating and planning tools based on true marginal cost do not perform well since information required is strictly confidential For developing a new tool, it is necessary to understand offer behavior The main objective of this study is to create a new tool for power system planning For the purpose, this dissertation develops models for a market and market participants 
A new model is developed in this work for explaining a supply-side offer curve, and several variables are introduced to characterize the curve Demand is estimated using a neural network, and a numerical optimization process is used to determine the values of the variables that maximize the profit of the agent The amount of data required for the optimization is chosen with the aid of nonlinear dynamics To suggest an optimal demand-side bidding function, two optimization problems are constructed and solved for maximizing consumer satisfaction based on the properties of two different types of demands: price-based demand and must-be-served demand Several different simulations are performed to test how an agent reacts in various situations The offer behavior depends on locational benefit as well as the offer strategies of competitors

/pdf/electric-power-market-agent-design-2ybqakccts.pdf

Robert J. Thomas

Papers

PowerWeb testing of various auction clearing mechanisms for electricity

How to Make Employee Networks Really Work

Integrating Wind Power: Can Controllable Load Substitute for Transmission Upgrades?

Scheduling of thermal units with a nonlinear load flow network model

Electric power market agent design