A review on the key issues for lithium-ion battery management in electric vehicles

The fuel economy and all-electric range (AER) of hybrid electric vehicles (HEVs) are highly dependent on the onboard energy-storage system (ESS) of the vehicle. Energy-storage devices charge during low power demands and discharge during high power demands, acting as catalysts to provide energy boost. Batteries are the primary energy-storage devices in ground vehicles. Increasing the AER of vehicles by 15% almost doubles the incremental cost of the ESS. This is due to the fact that the ESS of HEVs requires higher peak power while preserving high energy density. Ultracapacitors (UCs) are the options with higher power densities in comparison with batteries. A hybrid ESS composed of batteries, UCs, and/or fuel cells (FCs) could be a more appropriate option for advanced hybrid vehicular ESSs. This paper presents state-of-the-art energy-storage topologies for HEVs and plug-in HEVs (PHEVs). Battery, UC, and FC technologies are discussed and compared in this paper. In addition, various hybrid ESSs that combine two or more storage devices are addressed.

Battery, Ultracapacitor, Fuel Cell, and Hybrid Energy Storage Systems for Electric, Hybrid Electric, Fuel Cell, and Plug-In Hybrid Electric Vehicles: State of the Art

Due to limitations of low power density, high cost, heavy weight, etc., the development and application of battery-powered devices are facing with unprecedented technical challenges. As a novel pattern of energization, the wireless power transfer (WPT) offers a band new way to the energy acquisition for electric-driven devices, thus alleviating the over-dependence on the battery. This paper presents an overview of WPT techniques with emphasis on working mechanisms, technical challenges, metamaterials, and classical applications. Focusing on WPT systems, this paper elaborates on current major research topics and discusses about future development trends. This novel energy transmission mechanism shows significant meanings on the pervasive application of renewable energies in our daily life.

Wireless Power Transfer—An Overview

More than a century-old gasoline internal combustion engine is a major contributor to greenhouse gases. Electric vehicles (EVs) have the potential to achieve eco-friendly transportation. However, the major limitation in achieving this vision is the battery technology. It suffers from drawbacks such as high cost, rare material, low energy density, and large weight. The problems related to battery technology can be addressed by dynamically charging the EV while on the move. In-motion charging can reduce the battery storage requirement, which could significantly extend the driving range of an EV. This paper reviews recent advances in stationary and dynamic wireless charging of EVs. A comprehensive review of charging pad, power electronics configurations, compensation networks, controls, and standards is presented.

Wireless Power Transfer for Vehicular Applications: Overview and Challenges

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

Based on the wireless power transfer (WPT) technology, dynamic wireless charging of electric vehicle (EV) is gaining increasing attentions because it promotes the popularization of EV and also serves a new form of clean transportation. In this paper, we introduce the LCC compensation network to WPT system oriented for dynamic wireless EV charging application. First, characteristics of symmetrical T-type network, which is the origin of the favorable LCC compensation network, are summarized. Then, parametric design for both the LCC network used in the secondary side and the LCC network used in the primary side is elaborated theoretically. Furthermore, neighboring effects resulting from the combination of the LCC compensation network and the inevitable inter-coupling between adjacent segments are investigated. Finally, a two-segment LCC compensated dynamic EV charging system is built up and tested with both intra-segment and inter-segment experiments. Spatially averaged output power and dc–dc efficiency of the prototype are measured to be 2.34 kW and 91.3%, respectively. High consistency of the experimental results validates the correctness of the proposed analyses and parametric design method, as well as the suitability of applying LCC network in dynamic wireless EV charging applications.

Applying LCC Compensation Network to Dynamic Wireless EV Charging System

Due to the strong nonlinearity, coupling characteristics, external disturbance, and complex driving conditions, it is difficult to establish an accurate mathematical model for the autonomous ground vehicle (AGV). This requires the AGV path following controller to have strong robustness. In this paper, a robust AGV path following control strategy that is based on nonsingular terminal sliding mode (NTSM) and active disturbance rejection control (ADRC) is presented. First, the complex path following problem is simplified to a simple yaw angle tracking problem by constructing a desired yaw angle function that satisfies that the displacement deviation of AGV converges to zero when the actual yaw angle approaches the desired yaw angle. Second, an NTSM-ADRC controller is designed for the system, which uses the extended state observer to estimate and compensate the unmodeled dynamics and unknown external perturbations of the system in real time. In order to improve response characteristics of the controller, the nonlinear error feedback control law is designed by combining the NTSM and exponential approximation law. In contrast to the existing work, the improved controller can use the simple two-degree-of-freedom linear vehicle dynamic model to provide good performance in a range of driving conditions. Finally, the CarSim–Simulink simulation results of typical conditions show that the proposed control strategy can make the AGV follow the reference path quickly and accurately while ensuring the stability of the vehicle and has strong robustness.

Path Following Control of Autonomous Ground Vehicle Based on Nonsingular Terminal Sliding Mode and Active Disturbance Rejection Control

The invention relates to an intelligent home system which comprises a server and intelligent home terminals having a browser function, wherein the server at least comprises an intelligent home WEB server, on which various home Web services are integrated; the intelligent home WEB server is externally connected to an internet, for realizing various remote control of a user; the intelligent home WEB server is internally connected to each of the intelligent home terminals through a local area network; the intelligent home terminals are connected to at least one control terminal in wired or wireless manner, for finishing information transformation between the server and the control terminal and sending transformed information to the intelligent home WEB server or the control terminal; the control terminal, as an actuator of the intelligent home system, is directly connected to various domestic appliances, for directly controlling the domestic appliances; the intelligent home terminals are provided with fixed IP (Internet Protocol) addresses; and the control terminal connected to the intelligent home terminals is used for uniformly addressing

Intelligent home system

In this paper, we present a simple method to extend the feasible rated charging zone of a four-coil coupled wireless charging system (WCS) by optimizing the compensate capacitors of the coils. With the proposed optimizing method, the tolerant lateral misalignment of our WCS prototype has been extended to 44.3 $\%$ of the coil size, achieving a 38.3 $\%$ relative improvement.

Improving the Misalignment Tolerance of Wireless Charging System by Optimizing the Compensate Capacitor

Magnetically resonant wireless power transfer (WPT) technique excels in delivering power over a relatively long distance, and WPT systems for bio-implants have been successfully developed. However, the preconception of resonant-operating results in a fact that most previous works pay little attention to the optimization of the compensate capacitors; these design methods cannot meet the newly arisen challenges when designing a high-power wireless charging system (WCS) for electric vehicles (EVs). This paper presents a design method featuring compensate capacitor optimizing for better design of practical kilowatt-level WCS. Comparison with conventional frequency tuning method is made based on equivalent circuit model analysis. Compensating characteristics of a typical WCS are studied to find out how the compensate capacitors affect the systemic performance. Furthermore, considering peculiar constraints and requirements of EV-oriented WCS, we present detailed optimizing procedure and adjustment criterion. Finally, correctness and effectiveness of the proposed optimizing method are verified by a 3.3-kW wireless charging prototype. A transfer efficiency value of 92% over 21 cm and 88.5% over 36 cm is achieved; voltages of the transmit and receive coils are simultaneously minimized and balanced for security.

Lifang Wang

Papers

Applying LCC Compensation Network to Dynamic Wireless EV Charging System

Path Following Control of Autonomous Ground Vehicle Based on Nonsingular Terminal Sliding Mode and Active Disturbance Rejection Control

Intelligent home system

Improving the Misalignment Tolerance of Wireless Charging System by Optimizing the Compensate Capacitor

Compensate Capacitor Optimization for Kilowatt-Level Magnetically Resonant Wireless Charging System