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

A new bidirectional multilevel converter topology called the sparse modular multilevel converter suitable for high power ac/ac applications is presented. The proposed topology has fewer insulated-gate bipolar transistor switches and capacitors compared with conventional approaches. Moreover, a salient feature of the proposed topology is that more than half of the switches are operating in soft switching conditions, which considerably decreases the switching losses of the converter. The theoretical calculations and simulation results are provided to verify the feasibility of the proposed topology.

Sparse AC/AC Modular Multilevel Converter

Concentric neutral cables are commonly used in medium-voltage power distribution systems. Presently, the cable ampacity calculation methods can take into account only the fundamental frequency current and the harmonic currents in the phase conductors. In reality, the cable neutral can carry fundamental frequency and harmonic currents (induced and unbalanced), leading to a further increase of cable temperature. In view of the increased harmonics and load imbalance in power distribution systems and the need to determine their impact on concentric neutral cables, this paper presents a method to estimate the ampacity of concentric neutral cables, especially for multigrounded neutral systems. The proposed cable derating factor can be used to determine the increase in cable loading caused by unbalanced load and harmonics. A chart is also presented as a simplified method for cable ampacity and cable loading estimation, for which only the total harmonic distortion and zero-sequence current ratio of the phase current are needed.

A Method to Estimate the Impact of Harmonic and Unbalanced Currents on the Ampacity of Concentric Neutral Cables

Stochastic programming methods applied to network optimization

A load flow based superposition method is presented to derive the nodal harmonic impedance of an AC network using PSS/E (Power System Simulator for Engineering) through an IPLAN (PSS/E Internal Programming Language) program Using the CIGRE and IEEE guidelines for assessing the network harmonic impedance, harmonic models of the AC network element impedances, eg shunt capacitors and reactors, system load, generator, transmission lines, power cables and grid transformers, are implemented in the IPLAN program The IPLAN program is validated with an IEEE 14Bus Test System Benchmark (supplied by The University of Alberta (UofA), Canada) Therefore, it can be efficiently used to compute the nodal harmonic impedance of the AC network to enable AC harmonic filter design studies to be performed, without the need for any network reduction studies to be performed A practical application of the method is presented for the Gulf Cooperation Council Interconnection Authority (GCCIA) HVDC project This scheme links the 60Hz Saudi Arabian system to the 50Hz Gulf States and required extensive investigation of the network harmonic impedance on both sides of the HVDC link (5 pages)

Nodal harmonic impedance derivation of AC network in PSS/E

The effects of multigrounded neutral (MGN) in three-phase distribution systems are not easy to analyze due to the presence of a fourth conductor-the neutral and its multigrounded arrangement. As a result, the mechanism of voltage swell in MGN feeders becomes difficult to understand. The amount of voltage swell in a MGN feeder is affected by unique factors such as the current in the neutral wire and the neutral-to-phase voltage induction. The purpose of this letter is to reveal and quantify all factors that contribute to voltage swell and substation ground potential rise in an MGN system. The results are expected to help utility engineers to understand the impact of MGN on distribution system operations and to assist their deployment of the MGN schemes

Wilsun Xu

Papers

Sparse AC/AC Modular Multilevel Converter

A Method to Estimate the Impact of Harmonic and Unbalanced Currents on the Ampacity of Concentric Neutral Cables

Stochastic programming methods applied to network optimization

Nodal harmonic impedance derivation of AC network in PSS/E

Characteristics of Voltage Swell in Multigrounded Systems