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:

Smart grid has modernized the way electricity is generated, transported, distributed, and consumed by integrating advanced sensing, communications, and control in the day-to-day operation of the grid. Electricity is a core utility for the functioning of society and for the services provided by information and communication technologies (ICTs). Several concepts of the smart grid, such as dynamic pricing, distributed generation, and demand management, have significantly impacted the operation of ICT services, in particular, communication networks and data centers. Ongoing energy-efficiency and operational expenditures reduction efforts in communication networks and data centers have gained another dimension with those smart grid concepts. In this paper, we provide a comprehensive survey on the smart grid-driven approaches in energy-efficient communications and data centers, and the interaction between smart grid and information and communication infrastructures. Although the studies on smart grid, energy-efficient communications, and green data centers have been separately surveyed in previous studies, to this end, research that falls in the intersection of those fields has not been properly classified and surveyed yet. We start our survey by providing background information on the smart grid and continue with surveying smart grid-driven approaches in energy-efficient communication systems, followed by energy, cost and emission minimizing approaches in data centers, and the corresponding cloud network infrastructure. We discuss the open issues in smart grid-driven approaches in ICTs and point some important research directions such as the distributed renewable energy generation capability-coupled communication infrastructures, optimum energy-efficient network design for the smart grid environment, the impact of green communication techniques on the reliability and latency requirements of smart grid data, workload consolidation with smart grid-awareness, and many more.

Energy-Efficient Information and Communication Infrastructures in the Smart Grid: A Survey on Interactions and Open Issues

The necessity to promote smart grid (SG) has been recognized with a strong consensus. The SG integrates electrical grids and communication infrastructures and forms an intelligent electricity network working with all connected components to deliver sustainable electricity supplies. Many advanced communication technologies have been identified for SG applications with a potential to significantly enhance the overall efficiency of power grids. In this paper, the challenges and applications of communication technologies in SG are discussed. In particular, we identify three major challenges to implement SG communication systems, including standards interoperability, cognitive access to unlicensed radio spectra, and cyber security. The issues to implement SG communications on an evolutional path and its future trends are also addressed. The aim of this paper is to offer a comprehensive review of state-of-the-art researches on SG communications.

Smart Grid Communication: Its Challenges and Opportunities

Many operations in power grids, such as fault detection and event location estimation, depend on precise timing information. In this paper, a novel Time Synchronization Attack (TSA) is proposed to attack the timing information in smart grid. Since many applications in smart grid utilize synchronous measurements and most of the measurement devices are equipped with global positioning system (GPS) for precise timing, it is highly probable to attack the measurement system by spoofing the GPS. The effectiveness of TSA is demonstrated for three applications of phasor measurement unit (PMU) in smart grid, namely transmission line fault detection, voltage stability monitoring and event locationing. The validity of TSA is demonstrated by numerical simulations.

Time Synchronization Attack in Smart Grid: Impact and Analysis

Recent developments in smart grid technology have spawned interest in the use of phasor measurement units to help create a reliable power system transmission and distribution infrastructure. Wide-area monitoring systems (WAMSs) utilizing synchrophasor measurements can help with understanding, forecasting, or even controlling the status of power grid stability in real-time. A power system frequency monitoring network (FNET) was first proposed in 2001 and was established in 2004. As a pioneering WAMS, it serves the entire North American power grid through advanced situational awareness techniques, such as real-time event alerts, accurate event location estimation, animated event visualization, and post event analysis. Several papers published in the past several years discussed the FNET structure and its functionality. This paper presents some of the latest implementations of FNET's applications, which add significant capacities to this system for observing power system problems.

Wide-Area Frequency Monitoring Network (FNET) Architecture and Applications

A fast islanding detection tool can help power dispatchers monitor and control power system operations. Frequency monitoring network (FNET) is a low cost and quickly deployable wide-area phasor measurement system at the distribution system level. The frequency disturbance recorder (FDR) in FNET is actually a single-phase phasor measurement unit (PMU) installed at ordinary 120 V outlets in the sense that it measures the voltage phase angle, amplitude, and frequency from a single-phase voltage source. Based on the data collected by the FDRs deployed in the North American power grid, two islanding detection methods, the frequency difference method and the change of angle difference method, are proposed. The nine real cases recorded, including islanding cases, generation trip cases, load shedding cases and oscillation cases, are presented to verify the proposed methods of islanding detection. Sensitivity analysis on the thresholds of the frequency deviation and angle deviation is done based on the real measurement data for obtaining the insensitive interval of two thresholds. The results show that the proposed methods can correctly detect power system islanding, and will not be falsely triggered by generation trips, load shedding and system oscillations.

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Application of wide area measurement systems to islanding detection of bulk power systems

The inter-area oscillations occurring in the Eastern Interconnection (EI) are investigated by six typical cases using the FNET data. The matrix pencil method of multiple signals is used for the modal analysis. The parameters related to mode shape are calculated. The mode shapes for the dominant mode are revealed for each case. Analysis results depict a view of inter-area mode distribution in the Eastern Interconnection.

Inter-area oscillation analysis using wide area voltage angle measurements from FNET

Electromechanical oscillations associated with power system stability problems have been a primary concern of system planning, operation and control for decades. With growing loads, the need for long distance power exchange between power companies leads to the frequent occurrence of instability phenomena including oscillations. The growth of synchrophasor measurement-based Wide-Area Monitoring System (WAMS) technology in recent years provides the platform for real-time system dynamic monitoring and analysis which has never before been realised. The North American Frequency Monitoring Network (FNET), as the only WAMS that covers the entire North American power grid, has the capability to realise accurate, high density, continuous monitoring of large interconnected power system dynamics. This paper presents an automatic power system oscillation detection method based on FNET phase angle measurements. In addition, dynamic characteristics obtained from modal analysis of 28 FNET event cases are also introduced. The technique used for modal decomposition and reconstruction is called the Matrix Pencil method, which comes from the pencil-of-function approach. This is a very computationally efficient and noise robust signal processing method for dynamic information extraction. Inter-area oscillations, which are associated with groups of generators, are the only concern in this paper. Copyright © 2010 John Wiley & Sons, Ltd.

Phase angle-based power system inter-area oscillation detection and modal analysis

Analysis of power system dynamics helps to understand the operation of a power system. Therefore, it is significant to design and develop advanced visualization tools to interpret frequency, voltage magnitude, and phase angle information so that it can be presented to the operators in an intuitive manner. On the basis of the measurement data collected by widely-distributed frequency disturbance recorders (FDRs), visualization tools have been implemented for the FNET system. A number of FNET visualization tools are discussed in this paper, including real-time visualization, animated event replay, visualization of oscillation mode analysis and visualization of propagation effects in two dimensional systems. These tools correlate the FDR measurements with their corresponding geographical information, and transform the combined matrices into different graphic formats using various computer techniques and programming languages. The graphics generated by these tools facilitate power system operation by allowing an operator to monitor power system dynamics, perform post-event analysis and identify modal oscillations more efficiently.

Lang Chen

Papers

Wide-Area Frequency Monitoring Network (FNET) Architecture and Applications

Application of wide area measurement systems to islanding detection of bulk power systems

Inter-area oscillation analysis using wide area voltage angle measurements from FNET

Phase angle-based power system inter-area oscillation detection and modal analysis

Visualization of wide area measurement information from the FNET system