Neighborhood Electric Vehicles Research Articles

Design of Traction Motor for Mitigating Energy Consumption of Light Electric Vehicle Considering Material Properties and Drive Cycles

Light electric vehicles (LEVs) are usually used as neighborhood electric vehicles (NEVs) for the second vehicle or car-sharing service. For LEVs, it is important to reduce energy consumption to have greater mileage at the same battery capacity. One of the direct ways to decrease energy consumption is the efficiency improvement of the traction motor, which is the main propulsion system. Also, the weight reduction of the traction motor can be a solution to energy usage mitigation. This paper suggested the design process of a traction motor for LEV considering material properties to minimizing the energy consumption of the vehicle. During the design process, vehicle simulation was adopted to calculate energy consumption. In addition, traction motor and battery which are the key components of LEV were mathematically modeled and used in the simulation. Using them, energy consumption was estimated within the change of stack length of the traction motor for some drive cycles. Finally, from these simulations, optimum power density is determined which minimizes energy consumption.

Wound field synchronous motor with hybrid circuit for neighborhood electric vehicle traction improving fuel economy

Increasing the low mileage associated with electric vehicles is a major requirement. Improving the efficiency of the traction motor is one solution to solve the mileage problem. In this study, we propose a method to improve the efficiency of a wound field synchronous motor (as the traction motor) in case of neighborhood electric vehicles. The wound field synchronous motor is a salient pole machine that generates a negative reluctance torque when operating in the second quadrant, reducing its efficiency. However, second quadrant operation is inevitable due to voltage limitation in the high-speed range. Here, we propose a hybrid circuit comprising U, V, W windings and X, Y, Z windings. The high-speed efficiency of the wound field synchronous motor is improved by changing the connection between the windings. Further, a neighborhood electric vehicle with a wound field synchronous motor was simulated using an advanced vehicle simulator (ADVISOR) to verify the proposal. The hybrid circuit increased the fuel economy of the electric vehicle by up to 3.8%. Finally, a validation experiment was conducted using a fabricated motor prototype.

Optimal Control of a Hybrid Battery/Supercapacitor Storage for Neighborhood Electric Vehicles

Abstract Neighborhood Electric Vehicles (NEVs) are an important class of electric vehicles for short range and low speed applications. They are often smaller than highway electric vehicles and cheaper to buy due to their limited features. Most NEVs are powered using lead acid battery packs which are more affordable than other battery technologies. The lead acid batteries used in NEVs offer limited range and limited service life and have to be replaced approximately every three years. Although the performance and range expectations for NEVs are lower than for highway electric vehicles, improving efficient use of the stored charge can save energy and extend the life of the battery pack. An optimally controlled supercapacitor battery hybrid is proposed in this paper to minimize the effects of peak current demands on the battery during an NEV driving cycle. The hybrid storage system shows the ability to reduce the peak current drawn from the battery, which is an important factor in determining battery useable capacity per single charge and the length of battery life. This improvement will lead to lower operating costs for NEVs that will result from significantly lower energy losses and longer battery life.

Model study of a fuel cell range extender for a neighborhood electric vehicle (NEV)

Abstract Fuel cell systems have the potential to provide high-efficiency, low-cost power for Neighborhood Electric Vehicles (NEVs). Model results are presented examining the utility of placing a hydrogen PEM fuel cell on-board a Miles Electric ZX40ST work truck NEV as an “after-market add-on” range extender to the existing battery electric drive train, thereby creating a NEVx. Through the development and use of the Sandia-Miles-Altergy Range Test (SMART) model, we have examined the potential for a number of PEM fuel cell stack systems (with varying output power), combined with various hydrogen storage and electrical storage system configurations to achieve the desired range extension for a single 8-h work shift. Furthermore, we have evaluated the “well-to-wheels” (WTW) and greenhouse gas (GHG) reductions, and assessed the costs (both capital and O&M) for the different NEVx configurations and operating profiles. This analysis demonstrates that a NEVx incorporating a PEM fuel cell range extender provides a viable means of providing the desired range (or equivalently the runtime) while increasing the vehicle's versatility and maintaining its zero-emissions rating. A 5 kW fuel cell system with 2.6 kg of hydrogen stored at 2265 psi in conventional steel cylinders can meet the demands of the low-power duty cycles envisioned for the NEVx. A slightly higher powered NEVx with a 7.5 kW fuel cell offers the same advantages in operating profiles that require more power, for example with frequent starts, sustained higher speeds, or hilly routes. While currently expensive, the total cost per mile of the fuel cell range extender is comparable to conventional gasoline vehicles. The WTW GHG emissions of the NEVx are 40%–85% lower than those for a comparable gasoline powered vehicle, depending on the particular drive profile and sources of both hydrogen and electricity. The analysis shows that a fuel cell range extender can maintain the vehicle battery pack at a high state of charge (SOC) throughout the operating profile, thereby extending overall battery life and reducing charging time. The fuel cell range extender is currently envisioned as a drop-in retrofit for the existing Miles Electric ZX40ST work truck. However, with sufficient demand, a fully integrated new vehicle system could be both more efficient and less expensive. If designed into the NEVx from the start, the cost, weight, and emissions could all be reduced while increasing the payload space and versatility.

Impacts of low-speed vehicles on transportation infrastructure and safety

There are increasing numbers of low-speed electric vehicles (LSV) on public roadways. These vehicles are designed to be used within protected environments and on roadways with a maximum posted speed of 25 mph. Currently these vehicles are not subject to the same federal requirements for occupant protection as passenger cars. The research reported in the paper investigated safety standards, operating regulations, and LSV manufacturer materials from sources around the world. The purpose of the research was to determine positive and negative impacts that LSV, including Neighborhood Electric Vehicles (NEVs) and Medium Speed Electric Vehicles (MSEVs), are likely to have for the states such as Oregon, and whether adjustments in state regulations are needed to ensure that LSV do not negatively impact road safety and traffic operations, or expose the LSV operators to undue risk. The U.S. and Canadian federal motor vehicle safety agencies have harmonized their regulations and stipulated the maximum operating speed of these vehicles, however state and local roadway authorities have regulated the maximum speed of roadways and intersection characteristics on which these vehicles can operate. The significant recommendations of this research are: (i) appropriate state statues for LSV should be amended such that LSV are limited to public roadways with a maximum operating speed of 25 mph, and they are restricted to crossing higher speed roadways at four-way Stop or signal controlled intersections, (ii) local transportation authorities should develop parallel or secondary low-speed roadway networks that connect residential neighborhoods with major activity centers.

Neighbourhood Electric Vehicles in Mature Suburbs

This is a Report on the first phase of a demonstration of Neighborhood Electric Vehicles (NEVs) in the South Bay Subregion of Los Angeles County. The project is sponsored by the South Bay Cities Council of Governments (SBCCOG) and funded by the South Coast Air Quality Management District (AQMD). Active use of the first demonstration phase began May 1, 2010 and ran for 18 months ending October 31, 2011. This Report, based on the 18 months of data collection and analysis, aims to identify the positive role NEVs can play in addressing the following issues: • Reducing green house gas emissions, criteria air pollutants, and consumption of fossil fuels by passenger vehicles and light trucks. • Informing government plans and policies currently being formulated, including the 2012 Regional Transportation Plan, California Energy Commission’s initiative for electric vehicle readiness, and the California Air Resources Board AB 118 vehicle voucher program. • Implementing the Sustainable South Bay Strategy with its mobility initiative based on transitioning the gasoline fueled passenger vehicle fleet to some form of electric vehicle. Because this study is extremely data rich, a very detailed and scientific analysis has been completed for a somewhat small sample size of 29 participating households. From these findings it is clear that significant GHG and criteria air pollutant reductions could be achieved from wide spread use of NEVs for suburban residential driving. This research has also identified numerous market barriers that prevent wide spread adoption of NEVs as well as strategies to overcome market barriers such as production quality, speed limitations, and NEV prices.

The Electric Vehicle Fleet Experience at Southern California-Edison

Southern California-Edison (SCE) currently operates the largest fleet of electric vehicles (EVs) in North America. SCE’s EV experiences began in 1987 with prototype and electric conversions, such as the Conceptor G-Van, the Pentastar TEVan, and U.S.E. Sedan. Between 1994 and 1997, after the passage of the Energy Policy Act of 1992, SCE began using early OEM EVs, such as the Ford Ecostar and Chrysler TEVan, as well as early Toyota RAV4 EVs. The current fleet consists of 295 battery electric vehicles, primarily Toyota RAV4 EVs used by meter readers, with an additional 33 Ford Th!nk and GEM neighborhood electric vehicles used at company field offices for security patrols. The EV fleet has accumulated approximately 15 million zero-tailpipe-emission miles. In addition, the EV Technical Center (EVTC) in Pomona is constantly testing a variety of hybrid, plug-in hybrid, and fuel cell vehicles for potential use in Southern California-Edison’s fleet.This paper chronicles EV fleet operational experiences by Southern California-Edison and insights into lessons learned from dealing with deployment obstacles. Much of the information focuses on the Toyota RAV4 EV due to the relatively large number of these vehicles in the fleet.

Hybrid and plug-in hybrid electric vehicle performance testing by the US Department of Energy Advanced Vehicle Testing Activity

The Advanced Vehicle Testing Activity (AVTA), part of the U.S. Department of Energy's FreedomCAR and Vehicle Technologies Program, has conducted testing of advanced technology vehicles since August 1995 in support of the AVTA goal to provide benchmark data for technology modeling, and vehicle development programs. The AVTA has tested full size electric vehicles, urban electric vehicles, neighborhood electric vehicles, and hydrogen internal combustion engine powered vehicles. Currently, the AVTA is conducting baseline performance, battery benchmark and fleet tests of hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV). Testing has included all HEVs produced by major automotive manufacturers and spans over 2.5 million test miles. Testing is currently incorporating PHEVs from four different vehicle converters. The results of all testing are posted on the AVTA web page maintained by the Idaho National Laboratory.

US Department of Energy Hybrid Electric Vehicle Battery and Fuel Economy Testing

The advanced vehicle testing activity (AVTA), part of the US Department of Energy's FreedomCAR and Vehicle Technologies Program, has conducted testing of advanced technology vehicles since August 1995 in support of the AVTA goal to provide benchmark data for technology modelling, and research and development programs. The AVTA has tested over 200 advanced technology vehicles including full-size electric vehicles, urban electric vehicles, neighborhood electric vehicles, and internal combustion engine vehicles powered by hydrogen. Currently, the AVTA is conducting a significant evaluation of hybrid electric vehicles (HEVs) produced by major automotive manufacturers. The results are posted on the AVTA web page maintained by the Idaho National Laboratory. Through the course of this testing, the fuel economy of HEV fleets has been monitored and analyzed to determine the ‘real world’ performance of their hybrid energy systems, particularly the battery. The initial fuel economy of these vehicles has typically been less than that determined by the manufacturer and also varies significantly with environmental conditions. Nevertheless, the fuel economy and, therefore, battery performance, has remained stable over the life of a given vehicle (160 000 miles).