International Journal of Electric and Hybrid Vehicles (16 papers in press)
Analysis of performance improvement in energy storage system for electric vehicles: a review
by V.M. Dileepan, J. Jayakumar
Abstract: The selection of the energy storage system is crucial for electric vehicles. It should have good energy density and considerable power density, and also it must be light weight. So a battery with considerably high energy density must be used in electric vehicles. Lithium ion batteries are very much preferred as electric vehicle batteries. They have high energy density, high life cycle and smooth operation. But the problem related to lithium batteries are they have high temperature sensitivity, and their operation will be affected by over-current charging and over-current discharging beyond their maximum rated values and also be influenced by driving conditions and performance of motors used. So a battery management, control and optimisation system is essential in electric vehicle battery packs. This paper is a review of the design of a novel battery management and control system for lithium ion batteries for performance improvement in electric vehicles.
Keywords: battery; battery management system; control of energy storage system; driving pattern; energy storage system optimisation; electric vehicles; lithium ion battery; motor selection for electric vehicles; performance improvement; vehicle range.
Electric vehicles in India: current trends and future forecasts
by Vishal Shukla
Abstract: As globalisation is increasing, so is the demand for oil-based energy which is ultimately resulting in the rapid fluctuation of the market prices of the crude oil due to the basic principle of economics Law of Demand. This volatility and uncertainty in crude oil's demand and prices create pressure on governments and policymakers to look at new alternatives, one of them being the adaptation of green technologies. Green alternatives seem to be the trend of the future business and markets. Many business giants are compelled to spend heavily on their R & D and come up with innovative technologies focusing mainly on green technologies. In line with the developed countries, India, as a developing economy, is all set to plunge into this new innovative market of Electric Vehicles (EVs) and aims to become a major producer of the EVs for the Indian market as well as the globally. So, this research article aims to explore the expected demand for EVs, the market share, and the contribution of the EVs and associated technologies to foreign trade.
Keywords: disruption; Electric Vehicle; Green Technology; Indian Economy; Innovation; Market Demand.
Research on equivalent fuel consumption minimisation strategy design and optimisation for a plug-in hybrid electric vehicle
by Huan Guo, Weishun Deng, Fan Yu
Abstract: In this paper, an Equivalent fuel Consumption Minimization Strategy (ECMS) based on the optimal fuel economy is proposed and optimised for the Charge Sustaining (CS) period of a Plug-in Hybrid Electric Vehicle (PHEV). To overcome the disadvantages of low convergence rate and insufficient of population evolution, the crossover probability and mutation probability of the Standard Genetic Algorithm (SGA) are improved to be varied along with the iteration and fitness value. Meanwhile, an elite retention strategy is adopted to avoid the population degradation. The fuel equivalent factor is then optimised by Improved Genetic Algorithm (IGA) to obtain the optimal fuel economy. Corresponding hardware-in-the-loop simulations are carried out to verify the effectiveness and rationality of the strategy optimised by IGA. The results indicate that within allowable deviation of the state of charge, the PHEV can obtain better fuel economy by combining the proposed method.
Keywords: plug-in hybrid electric vehicle; charge sustaining; energy management strategy; improved genetic algorithm; fuel economy.
Automatic discovery and selection of most qualified electric vehicle charging station
by Raziq Yaqub, Kaveh Heidary
Abstract: Media reports that Electric Vehicles (EVs) still outnumber public charging stations by more than six to one is consistent with the early stage of electric car deployment. Thus finding charging stations may be a daunting task for EV drivers. Though the issue can be dealt with by providing online directories, web-based charging station locators and GPS-assisted gears, these methods are not adequate, because they do not help EV drivers automatically discover and select the most qualified EV charging station. Thus it will be frustrating for a driver to reach a certain location, or multiple locations, and not find a service because of grid inadequacy, long waiting queue, neighborhood safety, or the value he was looking for. This paper introduces a method and apparatus based on which the smart client installed in an EV would automatically discover, shortlist, and select, or recommend to the EV driver, the most qualified EV charging station.
Keywords: electric vehicle charging stations; most qualified EV charging station
Charging station Discovery; Selection; and Status Server (CDSSS); CDSS Client (CDSSC).
Energetic macroscopic representation and inversion-based control of fuel cells in a series hybrid race vehicle system
by Zainab Asus, El-Hassane Aglzim, Daniela Chrenko, Luis Le Moyne
Abstract: This paper studies the replacement of the engine and generator as a range extender in a hybrid racing car with a fuel cell system. A model of the original system of the car using a range extender consisting of an internal combustion engine and electric generator has been developed respecting the action-reaction principle used by Energetic Macroscopic Representation (EMR) and its Inversion-Based Control (IBC) to organise its subsystems' interconnections according to the physical causality. Results from drive tests of the real car on racing circuit are used to validate the model. The objective of this paper is to study the parameterisation and the integration of the fuel cell stack components based on this model. A diagnosis on the applicability of a control strategy as well as the improvements that can be effected by implementing a fuel cell system can be obtained using this model.
Keywords: hybrid vehicle; fuel cell; control strategy; energetic macroscopic representation; modelling.
Research on high speed avoidance path tracking of pure electric vehicles
by Jian Wang, Jun Yang, Peng Yu
Abstract: High-speed avoidance assisted driving technology can improve the driving safety of automobiles and is one of the key technologies of autonomous automobiles. The sigmoid function with continuously changing curvature is introduced to design a high-speed avoidance path. Based on the two-degrees-of-freedom vehicle dynamics model, a linear sliding mode auto-disturbance rejection path tracking controller is designed to control the actual yaw rate of the vehicle to track the ideal yaw rate of the planned path. Based on CARSIM software, a front-drive pure electric vehicle is established, and the control effect is verified by CARSIM and SIMULINK joint simulation method. The simulation results show that the path tracking controller can ensure that the pure electric vehicle tracks the ideal planned path and that the vehicle avoids the vehicles in front safely at high speed.
Keywords: high-speed avoidance; pure electric vehicles; path tracking; joint simulation.
Drivetrain modelling and parameter calculation for an electric bus with fixed or two-speed gearbox
by Martin Novak, Jaroslav Novak, Josef Morkus, Lubomir Musalek, Oleg Sivkov
Abstract: This paper presents drivetrain calculations for an electric bus. Parameters such as motor parameters, gear parameters and motor efficiency map calculation are used. The goal of the calculation is to select the suitable motor and gearbox. Synthetic driving cycle SORT2 and real-life driving cycles measured on bus lines are used. Based on the bus manufacturer assignment, only Permanent Magnet Synchronous Machines (PMSM) are considered. The motor output power is considered in the range of 120-160 kW. Also the selection of axle gear ratios was limited to 6.19, 6.5 and 7.35, as those are readily available. The considered gearbox was either a fixed one, with gear ratio of 1.8, or a two-speed gearbox with a gear ratio of 1 and 1.8. The calculations have shown that a two-speed gearbox can decrease the energy consumption. However, the improvement over a fixed gearbox is only in the range of 1-3%, dependent on the motor option and driving cycle. For the given parameters, the two-speed gearbox does not improve the overall bus parameters since it increases the complexity, cost, size, and maintenance, and worsens the reliability.
Keywords: electric vehicles; motor drives; permanent magnet motors; torque control; variable speed drives.
Technical analysis for implementing BS-VI automotive emissions norms with respect to electric vehicle production by 2020 in India
by Devendra Vashist, Farhan Mukhtar
Abstract: Automotive pollutants include carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (HC), particulate matter (PM, mostly soot) and oxides of sulphur (SOx). Government of India has decided to implement BS-VI norms by April 2020. Another direction in which the auto sector is likely to move is electric mobility. In this research, a comparative study in terms of financial and social-economic costs is made between challenges to be faced by the auto sector shifting toward electric mobility and making BS VI compliance vehicles. For the analysis, M&M e20 and Maruti Suzuki Alto 800 brand which are similar size and volume, but powered by two different sources, were chosen for the study. From the analysis, it is observed that shorter mileage, frequent battery recharging, frequent maintenance and less charging infrastructure are areas that have to be addressed by the auto industry for commercial viability. Lithium ion batteries are least suitable but research on sodium ion batteries is in initial stages in India. For BS VI compliance, the Lean Electronic Fuel Injection System (LEFIS) and Exhaust Gas Recirculation (EGR) have to be implemented. Based on the analysis, it is recommended that the industry should adopt a hybrid model before completely switching to electric mobility.
Keywords: electric vehicles; BS VI norms; emissions; lean electronic fuel injection system; exhaust gas recirculation.
Analysing vibration environment of a power battery in a running electric vehicle
by Ruixue Liu, Zhichao Hou, Shuyu Wang, Deke Sheng
Abstract: Power batteries in electric vehicles are subjected to vibration during the vehicles driving. The vibration environment may affect battery performance by connection failure and capacity degradation. Thus, clarifying battery vibration characteristics when a vehicle is driven on real roads is the basis for understanding battery performance in their service conditions and for structure improvement. The acceleration responses at multiple points on the bottom of a power battery are measured when a commercial electric vehicle is driven on various road types (including typical city road and some reinforced road conditions) in this study to better understand the vibration levels at different positions of the battery during vehicle driving. Indicators, namely the standard deviation of the acceleration root-mean-square (SD-ARMS) and fatigue damage spectrum (FDS), are introduced to analyse vibration differences among various measured positions and with vibration test standards. The FDS is calculated by combining various road types in a certain proportion according to Chinese road conditions, representing 600,000 km of driving, the compulsory scrappage driving distance in China. Time-forced vibration test profiles are derived based on the calculated maximum and minimum FDS curves. The measured results indicate inconsistency in vibration levels among the sampling points, especially in the Z direction. The standard deviation of the multipoint ARMS is approximately 40% of its mean value. Additionally, the vibration levels in the three directions are obviously discrepant. The fatigue damage values computed from the measured vibration signals and from standard vibration profiles significantly deviate. The research in this paper is the first to reveal practical vibration inconsistency of battery cells at different positions in a battery pack, and provides a method to evaluate vibration level, and to generate vibration profiles for durability assessment of batteries in a laboratorial vibration environment.
Keywords: power battery; vibration analysis; fatigue damage spectrum; road test.
Control and optimisation of a dual-motor coupling drive system of pure electric vehicle based on multi-island genetic algorithm
by Qingyong Zhang, Yongjun Luo, Weiping Lin, Yaru Wang, Xingjian Wu
Abstract: In order to improve the endurance of pure electric vehicle, improving the energy use is an effective way to increase the mileage. Energy use can be effectively improved by using the new structure of dual motor coupling drive system as the power source. The new structure improves energy use through eight mode switching. In this paper, CRUISE is used to build the vehicle model of a pure electric vehicle, and its control strategy is established by Simulink. The reliability of the model and control strategy is verified by using CRUISE and Simulink joint simulation method, and the parameters in the control strategy are optimised by the multi-island genetic algorithm. So as to provide a scheme for the research of improving the energy use rate of the pure electric vehicle.
Keywords: dual motor coupling; mode switch; multi-island genetic algorithm; joint simulation.
Performance enhancement analysis of brushless permanent magnet synchronous machine for electric vehicles
by Bharathi Thangaraj, Ramesh Subramanian
Abstract: This article considers the brushless machine that is used in electric vehicle applications. The main objective is to reduce the cogging torque and enhance the electromagnetic and thermal performance of the Brushless Permanent Magnet Synchronous Machine (BLPMSM). This can be achieved through optimised stator and rotor design by introducing notches in stator teeth as well as optimising the magnet dimensions in the rotor. The electromagnetic analysis of the machine is performed using transient 2-D with motion solver in MagNet simulation software, and the thermal analysis of the machine is simulated using ThermNet software. Based on the optimisation results, the proposed machine is modelled and simulated for electromagnetic and thermal analysis. Finally, the proposed machine is tested with electric vehicle powertrain simulation block sets. The simulation results show that the proposed concept of notching technique along with optimised parameters can be suitable for enhancing the performance of electric vehicles.
Keywords: brushless permanent magnet synchronous machine; cogging torque; drive cycle; electric vehicle simulation; electromagnetic analysis; finite element analysis; thermal analysis; powertrain simulation.
Electric vehicle transmission types and setups: a general review
by Dimitrios Rimpas, Pavlos Halkiadakis
Abstract: Over the last decade, electric vehicles (EV) have changed the global automobile industry driven by the progress of electronics and powertrain systems. New controllers are manufactured and research has been made not only on motors but on transmissions as well. This paper focuses on describing the types of gearboxes available - continuous variable, automatic, manual - with their pros and cons and the experiments done with different gearsets (plan and gear numbers) single or multigear transmissions on urban or highway cycles to maximise energy efficiency. Gearshift strategies are also a big area of interest alongside simulations testing various gear ratios handled by complex controllers and control algorithms to ensure smooth driving and performance with minimal to low jerk and torque interruption. The aim of this paper is to completely report the work done on transmission software and hardware improvements and also on the top of the shelf technology that the current EVs implement.
Keywords: transmission; controllers; electric vehicle; gearshift; gear ratio; gearbox.
Design and testing of a supercapacitor storage system for the flash recharge of electric buses
by Luca Pugi, Adriano Alessandrini, Riccardo Barbieri, Lorenzo Berzi, Marco Pierini, Fabio Cignini, Antonino Genovese, Fernando Ortenzi
Abstract: This work proposes a hybrid storage for urban transport systems in order to reduce recharge time and increase its life and reliability. The proposed system is applied to a pre-existing electrical vehicle introducing through proposed revamping procedure also a methodology for a fast integration of the proposed system on different vehicles. Finally, the system is calibrated and tested showing how the proposed control layout really simplifies vehicle commissioning.
Keywords: mechatronics; flash charge; supercapacitors; hybrid storage.
Advancements in power conditioning units for electric vehicle applications: a review
by Ravindranath Tagore Yadlapalli, Anuradha Kotapati, Rajani Kandipati
Abstract: Fuel cells are renowned for their direct energy conversion, quiet operation, fuel flexibility and zero CO2 emissions. However, each fuel cell produces a very low output voltage of around 0.5 V to 0.7 V. Therefore, it is essential to design high voltage gain DC-DC converters for boosting such low voltages either from a single fuel cell or fuel cell stack, besides minimising the current ripples. Furthermore, DC-AC converters are required to produce an AC output voltage for either the single-phase or the three-phase utility loads. This paper presents a review on various prominent DC-DC and DC-AC converter topologies. The performance of various DC-DC converter topologies is analysed in terms of number of components, converter switching frequency, galvanic isolation, power rating and efficiency. This paper emphasises the use of ultra- and super-capacitors for meeting the load dynamics as well as elimination of second harmonic currents. The salient features of potential DC-AC converters with low total harmonic distortion and high efficiency are presented. This paper is very useful for researchers and design engineers for choosing the right topology.
Keywords: fuel cell; distributed generation; regenerative fuel cells; energy storage.
Low impact vehicle battery supply chains: assessing the impacts of alternative procurement strategies
by Carlo Rafele, Claudio Gallo, Giulio Mangano, Anna Corinna Cagliano, Antonio Carlin
Abstract: This work aims at supporting decision-making related to make or buy strategies for procuring batteries assembled on electric and hybrid vehicles for a car manufacturer that is introducing new models in its portfolio. In particular, several supply chain scenarios have been defined according to the battery architecture. The results show that the purchase of complete batteries implies the highest costs and CO2 emissions. On the contrary, buying single components helps to improve these aspects, but it requires a certain level of vertical integration by the car manufacturer together with specific knowhow. Finally, purchasing modules result in the lowest costs owing to a reduced number of trips due to the product structure. Thus, this paper proposes a framework to guide automotive companies in effectively designing make or buy strategies in their battery supply chain by comparing alternative vertical integration levels.
Keywords: supply chain; low impact vehicle; automotive companies; vehicle battery; procurement; make or buy; electric vehicle; hybrid vehicle; scenario analysis; logistics.
Hybrid cars: past, present and future
by Saurav Kumar Singh, Bhavesh Kumar, Namrata Nanda
Abstract: With constant load, the internal burning engine (and any added heat engine) works finest. If the engine can continuously work close to its optimum operating point, there will be a dramatic increase in efficiency and longevity, a reduction in complexity and costs, and a much relaxed and cheaper control of emissions. But, electrical drive is great for variable loads. Competence remains high, extreme rotation is available even at low power output, and under braking electrical energy can be recovered resourcefully from mechanical energy. In order to fully capitalise on these fundamental characteristics, hybrid driven trains aim to combine the internal combustion engine and the electric motor in a synergistic manner. Although there has been hybrid drive for more than twenty years, there is much scope for further enhancement. Continuous price decrease in electrical components bringing power to the axle and technology used for battery with further enhancement of internal combustion engines planned specifically for hybrid driving can lower costs and increase efficiency, by offering enhanced driving experience. Although we have a lot of cheap oil, it is the need of the hour to move to more sustainable sources eventually. Over the coming decades, CO2 emissions from oil combustion have become an important economic as well as moral consideration.
Keywords: batteries; lithium-ion; lead acid; nickel cadmium; gasoline; electric vehicles.