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

This paper investigates the harmonics produced from electric arc furnace (EAF) operation. It gives an example of arc furnace modeling as a harmonic voltage source. The total harmonic distortion of the voltage and the current at the point of common coupling (PCC) are addressed and the need to alleviate this distortion to cope with IEEE 519 recommended limits is discussed. The effect of arc length variation on the main electrical parameters of concern such as arc power, power factor and total harmonic distortion is investigated. Also, a sensitivity study to determine the effect of applying a capacitor bank alone on the voltage and current total harmonic distortion is presented.

Investigation and mitigation of harmonics from electric arc furnaces

Undetected open conductor condition is a threat to the safe operation of power plants and industrial facilities. Open conductor condition is especially difficult to detect in a system with certain ${{{\bf Y}}_{{\boldsymbol g}}}$ connected primary windings, unloaded transformers. This paper presents a novel open conductor condition monitoring scheme for such systems. The scheme utilizes natural voltage disturbances as test signals and detects the open conductor condition by analyzing the responses of the transformer neutral current to these signals. A detection criterion is established based on sequence domain circuit analysis and on considering background voltage unbalances. Implementation issues, including the hardware requirements and the overall monitoring algorithm, are discussed. Simulation and experimental results prove that the proposed scheme can monitor the open conductor condition effectively.

An Open Conductor Condition Monitoring Scheme Using Natural Voltage and Current Disturbances

Open access permits all players to inject real power into a system with few restrictions. As generators also provide reactive power to the system, there is a general conception that their Q-outputs are supportive to system security and should be financially compensated. Our research results show, however, that a generator's Q-output has double-applications. One is to support the shipment of its own active power, and the other is to support system security. Therefore, compensation should be made to the second component only. The main purpose of this paper is to introduce the problem and demonstrate the phenomena of the dual functions of generators Q-output. Simple systems are used to illustrate the phenomena. Analytical separation of the components is presented for these simple systems. Case-specific separation methods are also developed to demonstrate the problem. The paper contributes to introducing the phenomenon, as well as demonstrating its importance for defining fair compensation schemes for reactive power support services. It also shows that methods need to be developed to solve the problem for large-scale real-life power systems, Preliminary, but potential, ideas are discussed.

http://ieeexplore.ieee.org/iel5/7659/20924/00970318.pdf

Investigation on the dual functions of generator reactive power support

Inter-harmonics are defined as the spectrum components that have frequencies between two harmonics. This letter points out that these fractional-harmonic components are not always the result of actual inter-harmonic sources. The signal sampling window size and position for Fourier analysis, as well as the time-varying characteristic of the signals, can all be factors leading to the so-called inter-harmonic components. Case studies illustrate that the inter-harmonic definition can be misleading and needs to be improved.

On the Ambiguity of Defining and Measuring Inter-Harmonics

Harmonic resonance has become an important concern for the application of shunt capacitors in recent years A potential solution to address this challenge is to convert a shunt capacitor into a passive filter This paper presents design methods to configure a shunt capacitor as a C-type filter or a third-order high-pass filter with guaranteed resonance-free performance The concept of resonance-free condition is first introduced in this paper It is then used to develop filter design methods that always meet the resonance-free condition The two filter configurations are also compared It was found that the third-order high-pass filter has more advantages than the C-type filter Another useful finding of this work is that the filter parameters, as determined using the proposed design methods, are independent of the system conditions As a result, a lookup table for the filter parameters has been created to facilitate immediate use by the industry

Wilsun Xu

Papers

Investigation and mitigation of harmonics from electric arc furnaces

An Open Conductor Condition Monitoring Scheme Using Natural Voltage and Current Disturbances

Investigation on the dual functions of generator reactive power support

On the Ambiguity of Defining and Measuring Inter-Harmonics

Resonance-free shunt capacitors-configurations, design methods and comparative analysis