Electric vehicles (EV), including Battery Electric Vehicle (BEV), Hybrid Electric Vehicle (HEV), Plug-in Hybrid Electric Vehicle (PHEV), Fuel Cell Electric Vehicle (FCEV), are becoming more commonplace in the transportation sector in recent times. As the present trend suggests, this mode of transport is likely to replace internal combustion engine (ICE) vehicles in the near future. Each of the main EV components has a number of technologies that are currently in use or can become prominent in the future. EVs can cause significant impacts on the environment, power system, and other related sectors. The present power system could face huge instabilities with enough EV penetration, but with proper management and coordination, EVs can be turned into a major contributor to the successful implementation of the smart grid concept. There are possibilities of immense environmental benefits as well, as the EVs can extensively reduce the greenhouse gas emissions produced by the transportation sector. However, there are some major obstacles for EVs to overcome before totally replacing ICE vehicles. This paper is focused on reviewing all the useful data available on EV configurations, battery energy sources, electrical machines, charging techniques, optimization techniques, impacts, trends, and possible directions of future developments. Its objective is to provide an overall picture of the current EV technology and ways of future development to assist in future researches in this sector.

https://www.preprints.org/manuscript/201705.0090/v1/download

A Comprehensive Study of Key Electric Vehicle (EV) Components, Technologies, Challenges, Impacts, and Future Direction of Development

Review of wearable thermoelectric energy harvesting: From body temperature to electronic systems

The world population depends highly on fossil fuels, particularly for transportation and power generation. This dependency leads to oil price increases because of the depletion of fossil fuels. Burning of fossil fuels also increases greenhouse gas emissions that are greatly responsible for global warming. Thus, electric vehicles (EVs) are considered one of the premium solutions in the land transportation system because they can significantly reduce the dependency on crude oil and minimize transportation-related carbon dioxide emissions along with other pollutants. This study presents an extensive review of the three key areas of EV research, namely, EV charging technologies, the various impacts of EVs, and optimal EV charging station (CS) placement and sizing. Several technical publications related to EV charging technologies are highlighted, and the performance comparison of different EV technologies is discussed. A review of literature on these key areas reveals an increasing interest in these topics in the last decade, with the impacts of EV on the electric power system and the optimal placement and sizing of CS issues widely investigated. By providing an overview of these areas, this study demonstrates the current issues and challenges of widespread deployment of EVs in the market as well as the future research direction in this field. A total of 185 publications are arranged and appended for quick referencing.

A review of the stage-of-the-art charging technologies, placement methodologies, and impacts of electric vehicles

The impending environmental issues and growing concerns for global energy crises are driving the need for new opportunities and technologies that can meet significantly higher demand for cleaner and sustainable energy systems. This necessitates the development of transportation and power generation systems. The electrification of the transportation system is a promising approach to green the transportation systems and to reduce the issues of climate change. This paper inspects the present status, latest deployment, and challenging issues in the implementation of Electric vehicles (EVs) infrastructural and charging systems in conjunction with several international standards and charging codes. It further analyzes EVs impacts and prospects in society. A complete assessment of charging systems for EVs with battery charging techniques is explained. Moreover, the beneficial and harmful impacts of EVs are categorized and thoroughly reviewed. Remedial measures for harmful impacts are presented and benefits obtained therefrom are highlighted. Bidirectional charging offers the fundamental feature of vehicle to grid technology. In this paper, the current challenging issues due to the massive deployment of EVs, and upcoming research trends are also presented. It is envisioned that the researchers interested in such areas can find this paper valuable and an informative one-stop source.

A Comprehensive Study of Implemented International Standards, Technical Challenges, Impacts and Prospects for Electric Vehicles

The Rogowski coil is an old device for current measurement. It has been modified and improved over a century and is still being studied for new applications. The Rogowski coil has various advantages over conventional magnetic current transformers (CTs). Not only can it be used instead of CT, but also it has various utilizations in other fields. This paper provides a brief review on different aspects of the Rogowski coil and its advancement procedure, during last decades. In this paper, the history of the coil is brifely reviewed and its bases and applications are discussed. The Rogowski coil is analyzed from different points of view, including different integration techniques in the output stage, models for the Rogowski coil, experimental methods for parameter measurement in models, and method for determining the damping resistor. Finally, a brief review over different applications of the coil ends this paper.

The Rogowski Coil Principles and Applications: A Review

High-Frequency Current Sensor for Power Network On-line Measurements

In this paper a determining of LCL-filter for grid-connected buck-boost inverter based on unfolding circuit is presented. The main idea is reducing the amplitude of high-switching harmonic, which introduces a significant part to the grid current spectrum. This leads to reduce the THD value of the output current. A suitable ratio of inductances of LCL-filter can provide a necessary accuracy of the energy. The simulation results are presented as a verification of the design of LCL-filter. The closed-loop control system based on the proportional-resonant controller is used to check theoretical statements.

Design of LCL-Filter for Grid-Connected Buck-Boost Inverter Based on Unfolding Circuit

In modern power systems, since most loads are inductive by nature, there is an ongoing power quality issue and researchers’ interest in improving the power factor is widespread, as inductive loads have a low power factor that depletes the system’s capacity and has an adverse effect on the voltage level. The measurement and acute analysis of voltage- and current-level waveforms is essential to tackle power quality issues. This article presents a detailed case study and analysis of real-time data measured from a frequency converter, which is used to operate the motor of a ventilation system. The output of the frequency converter is a highly distorted current wave. A hybrid Fourier transform (FT)- and wavelet transform-based solution has been proposed here to diagnose and identify the causes of motor failure in the ventilation system. The traditional FT did not give a detailed analysis of this type of signal, which is highly contaminated by noise. Therefore, first, the signal is preprocessed for data denoising using the wavelet transform. Second, the Fourier analysis is performed on the filtered signal for frequency analysis and segregation of fundamental frequency components, higher-order harmonics, and suppressed noise. The spectrum analysis reveals that the noise is generated due to the rapidly switching circuits in the frequency converter and this unfiltered signal at the output of the frequency converter causes motor failure.

Spectrum Analysis for Condition Monitoring and Fault Diagnosis of Ventilation Motor: A Case Study

Electrical outages cause economical loss but in many cases lead also to broken devices. Similarly, repeated voltage fluctuation may result in overstress of the components of the grid which leads to electrical failure. Before any electrical fault, usually, some smaller-scale anomalies occur in load current or voltage. These anomalies can usually be detected from measured quantities by using the Fourier transform and by analyzing voltage changes indicated as additional frequency components. However, the noise present in the real signal makes this analysis less accurate. Therefore, a wavelet transform based denoising method is proposed here along with Fourier transform to overcome this problem. In this paper, a discussion on the options for real-time diagnostics of an electrical grid is presented. The methods are compared and analyzed to assess the reliability of the proposed method. The anomalies observed are linked to unexpected voltage RMS values which correspond to variations in frequency domain components.

Requirements to Data Acquisition and Signal Analysis for Electrical Grid Condition Monitoring

Some of the most severe faults in electrical power networks are caused by faulty insulation or short-circuits. These events are accompanied by traces of partial discharges and traveling waves and recording such pulsed signals accurately is the key for providing effective on-line status monitoring of power lines. Capturing the high-frequency transients is very essential to protection means of local power systems employing power converters and smart-grids [1]. In this paper, operation of an inductive current sensor for on-line measurements is analyzed at high frequencies. Analysis focuses on the aspects of external components used with the sensor but also the connecting components linking the sensor to the measurement circuitry. Some practical aspects are discussed that can help to improve measurement accuracy and effectiveness.

Lauri Kutt

Papers

High-Frequency Current Sensor for Power Network On-line Measurements

Design of LCL-Filter for Grid-Connected Buck-Boost Inverter Based on Unfolding Circuit

Spectrum Analysis for Condition Monitoring and Fault Diagnosis of Ventilation Motor: A Case Study

Requirements to Data Acquisition and Signal Analysis for Electrical Grid Condition Monitoring

Magnetic current sensor stray components in high frequency operation and their effects