Plug-in Electric Vehicle System Research Articles

A High-Efficiency Charging Service System for Plug-in Electric Vehicles Considering the Capacity Constraint of the Distribution Network

It takes electric vehicles (EVs) a long time to charge, which is bound to influence the charging experience of vehicle owners. At the same time, large-scale charging behavior also brings about large load pressure on, and elevates the overload risk of, the power distribution network. To solve these problems, we proposed a high-efficiency charging service system based on charging reservation and charging pile binding services. The system can shorten the average charging time of EVs and improve the average immediate utilization rate of new energy sources at charging stations (CSs). In addition, the system also guarantees that the EVs are charged within the allowable range of the capacity of the distribution network and avoids overloading of the distribution network caused by the charging of EVs. The key support for the utility of the system is rooted in the three-level CS selection model and the CS energy control algorithm (CSECA) proposed in the research. Finally, the proposed model and algorithm were verified to be valid through numerous simulation experiments.

A Single-Phase Integrated Onboard Battery Charger Using Propulsion System for Plug-in Electric Vehicles

Plug-in electric vehicles (PEVs) are equipped with onboard level-1 or level-2 chargers for home overnight or office daytime charging. In addition, off-board chargers can provide fast charging for traveling long distances. However, off-board high-power chargers are bulky, expensive, and require comprehensive evolution of charging infrastructures. An integrated onboard charger capable of fast charging of PEVs will combine the benefits of both the conventional onboard and off-board chargers, without additional weight, volume, and cost. In this paper, an innovative single-phase integrated charger, using the PEV propulsion machine and its traction converter, is introduced. The charger topology is capable of power factor correction and battery voltage/current regulation without any bulky add-on components. Ac machine windings are utilized as mutually coupled inductors, to construct a two-channel interleaved boost converter. The circuit analyses of the proposed technology, based on a permanent magnet synchronous machine (PMSM), are discussed in details. Experimental results of a 3-kW proof-of-concept prototype are carried out using a ${\textrm{220-V}}_{{\rm{rms}}}$ , 3-phase, 8-pole PMSM. A nearly unity power factor and 3.96% total harmonic distortion of input ac current are acquired with a maximum efficiency of 93.1%.

Hierarchical Supervisory Control System for PEVs Participating in Frequency Regulation of Smart Grids

This paper proposes a two-level hierarchical supervisory control system for plug-in electric vehicles (PEVs) participating in frequency regulation in microgrids with interconnected areas. At the lower level, decentralized fuzzy logic control systems are designed for individual PEVs which locally adjust the V2G power flow rates from each vehicle to the grid according to the frequency deviation in each area and the vehicle’s current state of charge (SOC), while maintaining the SOC level above the driver’s requested SOC lower limit. At the grid level, a centralized supervisory control system is used to coordinate the injected power from generating units and PEVs based on the grid demand. Simulation results are presented and analyzed to investigate the performance of the proposed two-level system in a network consisting of three interconnected areas populated with PEVs under load disturbances and wind power fluctuations.

The Plug-in Electric Vehicle System from Technologies to Consumers

This paper discusses the recent National Academies’ study Overcoming Barriers to Deployment of Plug-in Electric Vehicles. The study committee concluded that, if policy makers continue to pursue PEV deployment, continuing federal funding for battery research and purchase tax credits is important to reduce vehicle cost. The committee also considered federal investments in deploying charging infrastructure. It recommended further study to understand the relationship between infrastructure and vehicle deployment and use before additional direct federal investment in charging infrastructure installation.

A comprehensive optimized model for on-board solar photovoltaic system for plug-in electric vehicles: energy and economic impacts

Summary Environmental concerns along with high energy demand in transportation are leading to major development in sustainable transportation technologies, not the least of which is the utilization of clean energy sources. Solar energy as an auxiliary power source of on-board fuel has not been extensively investigated. This study focuses on the energy and economic aspects of optimizing and hybridizing, the conventional energy path of plug-in electric vehicles (EVs) using solar energy by means of on-board photovoltaic (PV) system as an auxiliary fuel source. This study is novel in that the authors (i) modeled the comprehensive on-board PV system for plug-in EV; (ii) optimized various design parameters for optimum well-to-tank efficiency (solar energy to battery bank); (iii) estimated hybrid solar plug-in EVs energy generation and consumption, as well as pure solar PV daily range extender; and (iv) estimated the economic return of investment (ROI) value of adding on-board PVs for plug-in EVs under different cost scenarios, driving locations, and vehicle specifications. For this study, two months in two US cities were selected, which represent the extremities in terms of available solar energy; June in Phoenix, Arizona and December in Boston, Massachusetts to represent the driving conditions in all the US states at any time followed by assessment of the results worldwide. The results show that, by adding on-board PVs to cover less than 50% (around 3.2 m2) of the projected horizontal surface area of a typical passenger EV, the daily driving range could be extended from 3.0 miles to 62.5 miles by solar energy based on vehicle specifications, locations, season, and total time the EV remains at Sun. In addition, the ROI of adding PVs on-board with EV over its lifetime shows only small negative values (larger than −45%) when the price of electricity remains below $0.18/kWh and the vehicle is driven in low-solar energy area (e.g. Massachusetts in the US and majority of Europe countries). The ROI is more than 148% if the vehicle is driven in high-solar energy area (e.g. Arizona in the US, most Africa countries, Middle East, and Mumbai in India), even if the electricity price remains low. For high electricity price regions ($0.35/kWh), the ROI is positive and high under all driving scenarios (above 560%). Also, the reported system has the potential to reduce electricity consumption from grid by around 4.5 to 21.0 MWh per EV lifetime. A sensitivity analysis has been carried out, in order to study the impacts of the car parked in the shade on the results. Copyright © 2016 John Wiley & Sons, Ltd.

Developing a Test Procedure to Evaluate Electric Vehicle Supply Equipment and Chargers

This paper describes the processes used and the choices made while developing a procedure to evaluate Electric Vehicle Supply Equipment (EVSE) and Plug-in Electric Vehicle (PEV) chargers and provides some results of the testing process. The procedure defines the battery charging system (i.e., the battery charger, EVSE, battery storage system, auxiliary loads, and vehicle). Each test element is evaluated in terms of function, reliability, safety, quality, cost, efficiency and power quality. The development of a charging system evaluation procedure comes from Southern California Edison’s (SCE) responsibility to ensure safe and reliable function and to minimize system impact. Up to one million PEVs have been projected to be operating in SCE’s service area by 2020. SCE must not only serve these PEVs, but must ensure that they do not have a negative impact on the utility grid. Therefore it is critical that SCE understand the impact of those battery charging systems. SCE also supports the creation of standards to limit wasted energy and negative power quality impacts that these battery charging systems may create. SCE is also using the test procedure to evaluate EVSEs and PEV charging systems for implementation in SCE’s fleet. The results of this procedure are used to give fleet managers the information needed to acquire the most effective and efficient PEV charging equipment. The results will also tell a fleet manager or PEV owner what EVSE would work best with their selected vehicle or vice versa. The procedure provides for the discovery of PEV and EVSE individual and compatibility issues before the PEV is deployed. The final result ensures optimum performance of the PEV system. Through this process, SCE has been able to work with manufacturers of PEVs and EVSEs in order to improve the functionality, robustness, and interoperability of the products.