A communication infrastructure is an essential part to the success of the emerging smart grid. A scalable and pervasive communication infrastructure is crucial in both construction and operation of a smart grid. In this paper, we present the background and motivation of communication infrastructures in smart grid systems. We also summarize major requirements that smart grid communications must meet. From the experience of several industrial trials on smart grid with communication infrastructures, we expect that the traditional carbon fuel based power plants can cooperate with emerging distributed renewable energy such as wind, solar, etc, to reduce the carbon fuel consumption and consequent green house gas such as carbon dioxide emission. The consumers can minimize their expense on energy by adjusting their intelligent home appliance operations to avoid the peak hours and utilize the renewable energy instead. We further explore the challenges for a communication infrastructure as the part of a complex smart grid system. Since a smart grid system might have over millions of consumers and devices, the demand of its reliability and security is extremely critical. Through a communication infrastructure, a smart grid can improve power reliability and quality to eliminate electricity blackout. Security is a challenging issue since the on-going smart grid systems facing increasing vulnerabilities as more and more automation, remote monitoring/controlling and supervision entities are interconnected.

https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1315&context=electricalengineeringfacpub

A Survey on Smart Grid CommunicationInfrastructures: Motivations, Requirements andChallenges

A recurrent neural network based health indicator for remaining useful life prediction of bearings

Electrifying transportation is a promising approach to alleviate the climate change issue. The adoption of electric vehicle into market has introduced significant impacts on various fields, especially the power grid. Various policies have been implemented to foster the electric vehicle deployment and the increasing trend of electric vehicle adoption in the recent years has been satisfying. The continual development of electric vehicle power train, battery and charger technologies have further improved the electric vehicle technologies for wider uptake. Despite the environmental and economical benefits, electric vehicles charging introduce negative impacts on the existing network operation. Appropriate charging management strategies can be implemented to cater for this issue. Furthermore, electric vehicle integration in the smart grid can bring many potential opportunities, especially from the perspective of vehicle-to-grid technology and as the solution for the renewable energy intermittency issue. This paper reviews the latest development in electric vehicle technologies, impacts of electric vehicle roll out and opportunities brought by electric vehicle deployment.

A review on the state-of-the-art technologies of electric vehicle, its impacts and prospects

This paper reviews state of the art maximum power point tracking (MPPT) algorithms for wind energy systems. Due to the instantaneous changing nature of the wind, it is desirable to determine the one optimal generator speed that ensures maximum energy yield. Therefore, it is essential to include a controller that can track the maximum peak regardless of wind speed. The available MPPT algorithms can be classified as either with or without sensors, as well as according to the techniques used to locate the maximum peak. A comparison has been made between the performance of different MPPT algorithms on the basis of various speed responses and ability to achieve the maximum energy yield. Based on simulation results available in the literature, the optimal torque control (OTC) has been found to be the best MPPT method for wind energy systems due to its simplicity. On the other hand, the perturbation and observation (P&O) method is flexible and simple in implementation, but is less efficient and has difficulties determining the optimum step-size.

A review of maximum power point tracking algorithms for wind energy systems

Impedance networks cover the entire of electric power conversion from dc (converter, rectifier), ac (inverter), to phase and frequency conversion (ac-ac) in a wide range of applications. Various converter topologies have been reported in the literature to overcome the limitations and problems of the traditional voltage source, current source as well as various classical buck-boost, unidirectional, and bidirectional converter topologies. Proper implementation of the impedance-source network with appropriate switching configurations and topologies reduces the number of power conversion stages in the system power chain, which may improve the reliability and performance of the power system. The first part of this paper provides a comprehensive review of the various impedance-source-networks-based power converters and discusses the main topologies from an application point of view. This review paper is the first of its kind with the aim of providing a “one-stop” information source and a selection guide on impedance-source networks for power conversion for researchers, designers, and application engineers. A comprehensive review of various modeling, control, and modulation techniques for the impedance-source converters/inverters will be presented in Part II.

Impedance-Source Networks for Electric Power Conversion Part I: A Topological Review

Single-stage topology and the maximum power point tracking (MPPT) algorithm have advantages such as simple configuration and high efficiency in grid-connected photovoltaic (PV) systems However, in conventional systems, current and voltage sensors of PV system are normally used for MPPT This paper presents a low-cost single-stage grid- connected PV system without PV current sensor with a modified MPPT method This method is not derived from complex state equations and is not dependent on any circuit parameters It simply calculates the output power of the inverter to replace the input power of the PV systems in the MPPT algorithm The new algorithm is simulated by using Matlab/Simulink software and implemented in the experimental prototype With the one-stage configuration and PV current sensorless method, the prototype is suitable for lowcost implementation in the practice

The low-cost single-stage grid connected photovoltaic system with a modified MPPT method

Typical dual-motor or multiple-motor applications include industrial machine, heating ventilation air conditioning equipment, automobiles, and many others The traditional method to control a dual-motor is using two separate processors developed for power circuits In this paper, a proposed control scheme using only one controller to drive a dual-inverter supplying voltage directly to two separate motors is described The field oriented control (FOC) technique is investigated to control motors in the proposed control configuration The proposed scheme is absolutely useful and necessary for vehicle applications because its outstanding contribution of reduced number of controllers helps to save space in a car and decreases overall costs in automobile mass production All control algorithms to drive dual-motor system are implemented by software program only implemented by a digital signal processor (DSP) controller without any additional processor or hardware prototype Simplicity, flexibility, and possibility of dual three-phase inverter for the two-motor system control in vehicle applications are the major considerations in this study

Dual Three-Phase Inverter Using a Single Processor to Drive Two Motors in Electric Vehicle Applications

This paper presents an effective control scheme for an electric vehicle battery charger where a symmetrical bridgeless power factor-corrected converter and a buck converter are cascaded. Both converters have been popular in industries because of their high efficiency, low cost, and compact size, hence combining these two converters makes the overall battery charging system strongly efficient. Moreover, this charger topology can operate under universal input voltage condition and attain a desired battery voltage and charging current without any ripple. In order to reduce the system cost, an estimating ac input voltage technique is introduced, which especially does not require the converter component information and therefore it is robust to the circuit parameters variation. Additionally, by adopting a duty ratio feed-forward path in current control loop, a unity input power factor and zero input current harmonic are achieved. The feasibility and practical value of the proposed approach are verified by simulation and experimental results.

AC voltage sensorless control of battery charger system in electric vehicle applications

This paper presents a new space vector modulation (SVM) method for a three-phase five-leg indirect matrix converter (IMC) to drive a three-phase open-end winding load. The inverter stage of the new IMC topology is composed of five legs instead of the conventional six legs for the three-phase open-end winding load applications. The SVM method to drive the five-leg IMC is developed to operate the inverter stage as two independent three-phase inverters with five legs. The proposed configuration has the advantages such as sinusoidal input/output current waveforms, ability to boost voltage transfer ratio up to 1.5, and zero common-mode voltage across the open-end phase windings; its performance is not deteriorated compared to that of the six-leg inverter in spite of the reduced leg. Simulated results are presented to verify the effectiveness of the proposed topology and its SVM method.

A SVM method for five-leg indirect matrix converters with open-end winding load

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Hong-Hee Lee

Papers

The low-cost single-stage grid connected photovoltaic system with a modified MPPT method

Dual Three-Phase Inverter Using a Single Processor to Drive Two Motors in Electric Vehicle Applications

AC voltage sensorless control of battery charger system in electric vehicle applications

A SVM method for five-leg indirect matrix converters with open-end winding load

Improved Reactive Power Sharing and Harmonic Voltage Compensation in Islanded Microgrids Using Resistive-Capacitive Virtual Impedance