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.

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

Smart Grid - The New and Improved Power Grid:

http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

1 Introduction 2 Electromagnetic Transients 3 Synchronous Machine Modeling 4 Synchronous Machine Control Models 5 Single-Machine Dynamic Models 6 Multimachine Dynamic Models 7 Multimachine Simulation 8 Small-Signal Stability 9 Energy Function Methods Appendix A: Integral Manifolds for Model Bibliography Index

Power System Dynamics and Stability

Energy is an essential ingredient of socio-economic development and economic growth. Renewable energy sources like wind energy is indigenous and can help in reducing the dependency on fossil fuels. Wind is the indirect form of solar energy and is always being replenished by the sun. Wind is caused by differential heating of the earth's surface by the sun. It has been estimated that roughly 10 million MW of energy are continuously available in the earth's wind. Wind energy provides a variable and environmental friendly option and national energy security at a time when decreasing global reserves of fossil fuels threatens the long-term sustainability of global economy. This paper reviews the wind resources assessment models, site selection models and aerodynamic models including wake effect. The different existing performance and reliability evaluation models, various problems related to wind turbine components (blade, gearbox, generator and transformer) and grid for wind energy system have been discussed. This paper also reviews different techniques and loads for design, control systems and economics of wind energy conversion system.

A review of wind energy technologies

One of the primary causes of major transmission line outages are extreme weather conditions particularly lightning, wind and conductor icing (e.g., Quebec, US ice storms of 1998). The statistical results of a detailed analysis of Alberta Power Limited's transmission line outage database and Alberta Environmental Service weather databases over a 20 year period are investigated in this paper. The analysis reveals the significance of the geographical location of the transmission lines and their frequency of outages. The paper also reveals that the number of transmission line outages is not necessarily proportional to the physical length of the line for many transmission lines which contradicts may published methodologies. The paper provides the basic framework for constructing advanced probabilistic reliability models of transmission line networks (e.g., Markov models and Monte Carlo simulation models) based on the historical Canadian Electricity Association's utility equipment reliability database and the Environmental Service weather data bases.

An analysis of extreme-weather-related transmission line outages

A major feature of the smart grid is its diverse load management opportunities for customers, which calls for innovative techniques for load monitoring. This paper presents a method to monitor loads in commercial and small industrial facilities using a set of distributed voltage sensors and current estimation algorithms. The technique is especially suited for facilities where it is difficult to measure loads directly but the load voltages can be sensed. A state-estimation-like current estimation algorithm is proposed to estimate the load currents using the voltages sensed at the terminals of the loads. Currents and powers collected from a limited number of panels are also utilized to provide redundancy for the estimation. Case studies have shown that the proposed method represents a promising alternative measurement strategy for load monitoring.

Load Monitoring Using Distributed Voltage Sensors and Current Estimation Algorithms

Configuring a shunt capacitor as a detuned C-type filter is an effective way to mitigate the capacitor caused harmonic resonance. A design method has been developed recently that can guarantee the damping performance of the filter even if the system impedance data is not available. This article further improves the design method by considering the case where the system impedance data is available. It also answers the question if cost can be reduced by utilizing known system impedance data. For this purpose, the cost and power loss characteristics of the filter are investigated and included in the design. The performance of various design methods is compared from the perspectives of resonance-mitigation, power loss, cost, and robustness. The results have shown that the system independent design leads to superior performance except for the power loss. A guide on how to design the detuned C-type filter is recommended.

Comparative Studies on Design Methods for Detuned C-Type Filter

Stray voltages have always been a concern to utility companies and customers. But methods to troubleshoot and monitor nonroutine stray voltage problems are very limited. This paper presents a passive, measurement-based method to identify the contributors to the common cause of stray voltages, the neutral-to-earth voltage (NEV) rise at the service entrance point. The paper shows that the NEV can be decoupled into two components: those related to the customer under investigation and those outside the customer facility. A method to quantify the relative contributions of the two components is proposed. A new concept called current return ratio is introduced to facilitate the decoupling and to quantify the grounding conditions of the system. This paper presents the background, circuit model, concept, and theory of the proposed method.

A Method to Determine Stray Voltage Sources—Part I: Concept and Theory

The widespread adoption of energy efficient but harmonic-producing loads in residential homes has led to increased injection of harmonic currents into transmission systems. In response to this situation, a novel filtering scheme that can reduce the harmonic penetration into transmission systems is proposed. The scheme utilizes the tertiary winding of a substation transformer to construct a tuned low-impedance path for the harmonic currents. The proposed scheme is capable of trapping two zero-sequence harmonics and three nonzero-sequence harmonics simultaneously. A design procedure has been developed. Performance of the scheme is evaluated and demonstrated through simulation studies. In addition, economic analysis reveals that the scheme is a cost-effective solution in comparison with other applicable methods.

Wilsun Xu

Papers

An analysis of extreme-weather-related transmission line outages

Load Monitoring Using Distributed Voltage Sensors and Current Estimation Algorithms

Comparative Studies on Design Methods for Detuned C-Type Filter

A Method to Determine Stray Voltage Sources—Part I: Concept and Theory

A Filtering Scheme to Reduce the Penetration of Harmonics into Transmission Systems