Potential of range extender electric vehicles (REEVS)

With the increasing global concern on negative environmental effect from the transportation sector, conventional automobile technologies will not be viable for much longer. Countries like the EU and China have introduced emission related regulations which are stricter than ever. This has compelled automotive manufacturer to turn to Electric Vehicles (EV) as the most effective solution to this issue. There are mainly two types of EV, namely Battery Electric Vehicle (BEV) and Hybrid Electric Vehicle (HEV). Both has its own strength and shortcomings, BEV with zero emission but limited range while HEV has better range at the expense of higher emission. Extended Range Electric Vehicle (EREV) provides a midpoint between these options. This option provides the best of both worlds by allowing users to switch between both systems depending on the vehicle's operating condition. This paper aims to presents a variety of Range Extender (RE) configurations based on its working principle and type of fuel used. Internal combustion engine, fuel cell, and microturbine are what RE is commonly powered by. The advantages and disadvantages are evaluated and compared to determine the optimal option. It was concluded that depending on fuel availability, space, and efficiency requirement, each configuration has its own merit.

World Electric Vehicle Journal

Emissions from the transportation sector are significant contributors to climate change and health problems because of the common use of gasoline vehicles. Countries in the world are attempting to transition away from gasoline vehicles and to electric vehicles (EVs), in order to reduce emissions. However, there are several practical limitations with EVs, one of which is the “range anxiety” issue, due to the lack of charging infrastructure, the high cost of long-ranged EVs, and the limited range of affordable EVs. One potential solution to the range anxiety problem is the use of range extenders, to extend the driving range of EVs while optimizing the costs and performance of the vehicles. This paper provides a comprehensive review of different types of EV range extending technologies, including internal combustion engines, free-piston linear generators, fuel cells, micro gas turbines, and zinc-air batteries, outlining their definitions, working mechanisms, and some recent development...

IEEE Transactions on Vehicular Technology, 2000

The use of electric vehicles (EVs) is advantageous because of zero emission, but their market penetration is limited by one disadvantage, i.e., energy storage. Battery EVs (BEVs) have a limited range, and their batteries take a long time to charge, compared with the time it takes to refuel the tank of a vehicle with an internal combustion engine (ICE). Fuel cells (FCs) can be added to an EV as an additional energy source. These are faster to refill and will therefore facilitate the transition from vehicles running on fossil fuel to electricity. Different EV setups with FC strategies are presented and compared. The results of the setups are presented by range, efficiency, and price. These show the negative effect on the range when purpose-designed setups are driven above the design requirement as the range drops considerably. The simulations also showed the necessity of good FC control when driving in start/stop city cycles. Simulations with the New European Driving Cycle (NEDC) showed that efficiency fell by at least 15% for the FC hybrid EV (FCHEV) when compared with BEVs.

2014

Electric cars have the disadvantage of a limited range, and drivers may experience a range anxiety. This range anxiety can be solved by adding a range extender. But, the range extender should be light so as not to significantly increase the weight of the original vehicle. In urban areas with dense traffic (usually developing countries), the average speed around cities is typically lower than 50km/h. This means, the rolling resistance losses are more important than aerodynamic losses, and a weight reduction results in a bigger electrical range. Therefore, smaller and lighter range extenders are of much interest. The contribution of this paper is to indicate the possibility of range extenders with less than 25 kg with a capacity of 150 to 200 cc to suit a condition where weight counts. In this paper, the cost, environmental and grid impacts of going electric are also discussed. The effect of high altitude and driving style on the performance of an electric vehicle is assessed. The challenges and opportunities of vehicle electrification between countries with decarbonated power generation and fossil fuel dominated power generation are highlighted. Throughout the article, the case of Ethiopia is taken as an example.

World Electric Vehicle Journal, 2013

Hydrogen-powered vehicles have long shown great potential to displace fuel. However, due to the lack of infrastructure and the high cost of the components, the technology has not yet been introduced in the market. On the other hand, current battery electric vehicles (BEVs) also hold great promise, but their market penetration is limited due to their range. This study seeks to address the limitations of both technologies with regard to the medium-duty vehicle market by assessing the fuel displacement and costbenefit potential of adding fuel cell systems to double the current range of BEVs. The addition of a fuel cell system will address drivers' anxiety over the range of BEVs while minimizing the powertrain cost through optimized component sizing.

Energies

A range extender (RE) is a device used in electric vehicles (EVs) to generate electricity on-board, enabling them to significantly reduce the number of required batteries and/or extend the vehicle driving range to allow occasional long trips. In the present work, an efficiency-oriented RE based on a small motorcycle engine modified to the efficient over-expanded cycle, was analyzed, tested and simulated in a driving cycle. The RE was developed to have two points of operation, ECO: 3000 rpm, very high efficiency with only 15 kW; and BOOST: 7000 rpm with 35 kW. While the ECO strategy was a straightforward development for the over-expansion concept (less trapped air and a much higher compression ratio) the BOOST strategy was more complicated to implement and involved the need for throttle operation. Initially the concepts were evaluated in an in-house model and AVL Boost® (AVL List Gmbh, Graz, Austria), and proved feasible. Then, a BMW K75 engine was altered and tested on a brake dynam...

Archives of Current Research International, 2019

Electric vehicle is a sustainable development which is capable of transforming the transport sector. It is a sustainable alternative to internal combustion engine-based vehicle. Its technology is based on utilization of sustainable energy resources which are eco-friendly and replenishes in nature. Wide deployment of electric vehicle is expected to minimize the challenge of fossil fuel depletion and greenhouse emissions are expected to be reduced. However, despite all aforementioned advantages of the electric vehicle, its wide deployment faces some challenges including cost, size and range anxiety. Electric vehicles have limited range which is one of the major factors affecting its market penetration. Researchers highlighted several strategies/methods of extending its driving range. Thus, this work presents a review of different strategies proposed on range extension of the electric vehicle. The strengths and weaknesses of some of the proposed methods are also presented in this work.

Journal of Mechanical Engineering and Sciences, 2016

Electric vehicles have several disadvantages compared to conventional vehicles, such as their road ability and vehicle weight. To overcome these problems, range-extended engine technology has been developed. A range extender is a generator set that consists of an internal combustion engine coupled with a generator that operates when it is required. A vehicle simulator was deployed to compare the performance of three types of range-extended engines i.e. 1-cylinder 389 cc, 1-cylinder 494 cc and 2-cylinder 988 cc gasoline engines. The best type chosen was afterwards to be coupled with an electric vehicle. The performance data of each internal combustion engine was collected using experiment and simulation data. Two types of driving cycle, the Federal Test Procedure cycle and Artemis Rural Road cycle, were chosen to compare the optimum road ability of the vehicle. The result shows that the 2-cylinder 988 cc range-extended engine has the best performance, with an electrical motor energy consumption decrease of up to 83.26%, fuel consumption increase for the range-extended engine of up to 3.91 L/km, and a road ability increase of up to 232.79% compared to a pure electric vehicle.

Applied Sciences, 2021

For smart cities using clean energy, optimal energy management has made the development of electric vehicles more popular. However, the fear of range anxiety—that a vehicle has insufficient range to reach its destination—is slowing down the adoption of EVs. The integration of an auxiliary power unit (APU) can extend the range of a vehicle, making them more attractive to consumers. The increased interest in optimizing electric vehicles is generating research around range extenders. These days, many systems and configurations of extended-range electric vehicles (EREVs) have been proposed to recover energy. However, it is necessary to summarize all those efforts made by researchers and industry to find the optimal solution regarding range extenders. This paper analyzes the most relevant technologies that recover energy, the current topologies and configurations of EREVs, and the state-of-the-art in control methods used to manage energy. The analysis presented mainly focuses on finding ...

International Journal of Automotive Technology, 2015

It is convenient to use the generator of a range extender also for starting the engine. The torque needed by the engine at the early stage of engine cranking has been modeled. The sum of the torques developed by the starter/generator and the rotational inertia including the flywheel, have to be sufficiently large in order to overcome the compression torque so as to ensure a successful start of the engine. In order to minimize the torque required from the electric motor, the concept of flywheel effect can be used. This brings the possibility to downsize the converter. By reducing the torque demand from the motor, one can limit the current drawn from the source, thereby giving reliability to the switching devices.