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

Inaccurate reactive power sharing and voltage distortion at the point of common coupling (PCC) always exist in a parallel inverter system due to feeder impedance mismatches and nonlinear load disturbances. An enhanced inverter control scheme through an output impedance adjustment is proposed to address these issues. Inverter output impedance is regulated considering fundamental and harmonic frequencies, and accurate power sharing and improved PCC voltage quality are realized at the steady state. In addition, the compensation scheme is easily applied in multiple parallel inverters without any prior knowledge of the feeder impedance. Experimental results with three parallel inverters validate the feasibility of the proposed control scheme.

Accurate power sharing and harmonic mitigation scheme for parallel operation of single-phase voltage source inverters

In this paper, a control strategy for a four-leg indirect matrix converter under unbalanced load condition is described. The four-leg indirect matrix converter can synthesise any desired three-phase line-to-neutral voltage. In order to obtain the reference output voltage under unbalanced load condition, the control strategy for four-leg indirect matrix converter is based on the decomposition of the output voltages and currents into positive, negative and zero sequence components. The classical proportional-integral (PI) controllers are applied to control the d, q components in synchronously rotating frame in all three sequences. In this paper, a carrier-based PWM is also introduced to generate PWM signals because this method is easily to implement compared with SVPWM method. Finally, simulation results are shown to verify the feasibility of proposed control scheme. (6 pages)

The control strategy for a four-leg indirect matrix converter with unbalanced load

Common-Mode Voltage and Current Harmonic Reduction for Five-Phase VSIs with Model Predictive Current Control

The precise and fast position control of motor for the embroidery machine drive is very important to improve an operating efficiency. In this paper, the method to control rapidly and precisely the position of PMSM by adjusting the proportional gain in the position controller to a position error is suggested. Through simulation studies, the position of PMSM reaches rapidly reference position without any overshoots.

Development of servo motor drive systems for embroidery machines

This paper is to present the technique for fault detection for four-switch three-phase inverter fed induction motor drive. The proposed method requires only motor currents and DC-link current to be measured for detecting and identifying the power switch in which the open circuit fault or short circuit fault has occurred. Furthermore, a diagnosis controller using ANN for real-time fault detection of power switches is suggested. A computer simulation program is developed using Matlab/Simulink together with the neural network toolbox for training the ANN-controller. This method has been validated experimentally using kit ACE 1104 (DSPACE).

Hong-Hee Lee

Papers

Accurate power sharing and harmonic mitigation scheme for parallel operation of single-phase voltage source inverters

The control strategy for a four-leg indirect matrix converter with unbalanced load

Common-Mode Voltage and Current Harmonic Reduction for Five-Phase VSIs with Model Predictive Current Control

Development of servo motor drive systems for embroidery machines

Fault detection using ANN for four switch Three Phase Inverter fed induction motor drive