International Journal of Electric and Hybrid Vehicles (10 papers in press)

• Hierarchical Hybrid Control of Combined Hybrid ‎Electric Vehicle
  by Mohsen Mohammadian, S.Mohammad Bathaee, Amin HajiZadeh Gastaj‎ 
  Abstract: ‎ This paper deals a novel strategy developed for optimizing the energy flow in a ‎Combined Hybrid Electric Vehicle (CHEV) structure. This method implemented an ‎on-line energy management by a hierarchical hybrid controller between dual sources ‎in this kind of hybrid systems. This structure included two energy sources, battery ‎and the stack of fuel cell and its power train system included an Electric Motor (EM) ‎and Internal Combustion Engine (ICE) in a parallel combination. The proposed ‎method involves an advance supervisory controller in the first layer which captured ‎all of possible operation modes. This layer has been developed by Stateflow toolbox ‎and prepares a proper supervisory environment for this complex structure. In the ‎second layer, an advanced fuzzy hybrid controller has been developed with respect to ‎each of defined modes. With regards the operation modes, the upper layer makes ‎decision to choose the switching chain roles and corresponding controller in the ‎second layer. Finally in the third layer, there are local controllers to regulate the set ‎points of each subsystems to reach the best performance and acceptable operation ‎indexes. ‎ ‎ To verify the effectiveness of the hierarchical intelligent supervisory control ‎method, a simulation study of the multiple energy source assembly control system of ‎the hybrid electric vehicle is carried out on a CHEV structure which is based on ‎developed OOP tool Borland C++ Builder V6. Simulation results show that the ‎energy management concept is working.‎
  Keywords: Combined hybrid electric vehicle; Hierarchical hybrid control; Fuzzy ‎control; Vehicular technology, Artificial neural networks‎
   
• Look-Forward Longitudinal Dynamic Modeling for a Series-Parallel Hybrid Electric Vehicle
  by Mojtaba Shams Zahraei, Seyed. Ali Jazayeri, Mahdi Shahbakhti, Mohammad Sharifirad 
  Abstract: In this research all components which affect the longitudinal dynamics of a typical series-parallel hybrid electric vehicle have been modeled in MATLAB/SIMULINK®. A look-forward model is developed by coupling an experimentally identified and verified mean value engine model together with longitudinal vehicle dynamic. This model consists of sub-models for power split planetary gear set, permanent magnet synchronous motor/generator with the local controllers, and energy storage system. An energy management strategy has been defined to control the complete model in all vehicle operation modes: pure electric, hybrid, power boost, regenerative braking, and engine on/off transient mode. The energy management strategy has been implemented to optimize engine operating conditions. A fuzzy-logic auto-driver model is used to compare the performance of a simulated hybrid vehicle with that of a conventional powertrain in ECE driving cycle. The simulation results indicate a 40% improvement in fuel economy by converting the conventional vehicle into a series-parallel hybrid vehicle.
  Keywords: hybrid electric vehicle (HEV), series-parallel, dynamic modeling, look-forward, control strategy
   
• Performance Modeling and Simulation of a Hybrid Electric Scooter
  by Kean Yap, Vishy Karri 
  Abstract: This paper presents a model developed on the Matlab/Simulink platform for the operation and optimization of a scooter’s hybrid powertrain. The model, which is a parallel hybrid structure, is powered by a two-stroke internal combustion engine (ICE) coupled with an electric hub motor to make up the scooter’s propulsion unit. This model was built and simulation results were shown. The developed Matlab/Simulink model demonstrates the petrol cost and the energy cost are significantly reduced compared to traditional petrol and electric scooters. The costs were reduced significantly per 100 km comparing to traditional petrol scooters and pure electrical scooters. To achieve a longer distance, a hybrid scooter is more reliable. The qualitative trends showed that this approach minimizes the petrol consumption by minimizing the ICE usage for the ECE-15 driving cycle. The emissions analysis will be the next step of this research. In this paper, it is argued that this multi-mode hybrid approach reduces the cost compared to petrol scooters and increases the distance traveled compared to pure electric scooters.
  Keywords: Hybrid scooter, modeling and simulation, powertrain systems.
   
• A novel control scheme for electric vehicle EV-drive
  by Adel Sharaf, Wen Chen 
  Abstract: Abstract: The paper presents a novel nonlinear error-driven error-scaled multi-loop dynamic speed control scheme for electric vehicle EV-PMDC drives. The proposed nonlinear multi-loop controller is a dynamic self-adjusting regulator to ensure satisfactory reference speed tracking, minimum inrush PMDC-motor current and minimum impact on the limited battery source capacity. It handles the inherent nonlinearity in the EV-Drive moment of inertia, frictional coefficient and load torques. The full four motor EV-Drive is fed from a DC source battery with type-B DC-DC converter (chopper) - pulse width modulated strategy that is fully modulated using the nonlinear multi-loop dynamic error-driven control scheme. As comparison, a classical PID scheme is also presented. Digital simulation results show the effectiveness of the nonlinear multi-loop control strategy and its robustness to tolerate load nonlinearities, especially in combined inertia, frictional coefficient and load torques.
  Keywords: Electric DC Motor drives; Tan-sigmoid error-drive control; PID controller.
   
• Yaw Stability Control of a Four-Independent-Wheel Drive Electric Vehicle
  by Yan-e Zhao 
  Abstract: A yaw stability control system is proposed to improve the handling and stability of a four-independent-wheel drive electric vehicle. The control system comprises an active front steering controller together with a direct yaw-moment controller based on sliding mode control and a dynamic force distribution controller based on optimal sequential quadratic programming method. The function of the control system is to trace the desired yaw rate while maintain the body sideslip angle minimized. The optimum torque-distribution method is applied to adjust each torque of the four wheels. The controller system distributes torque and power to each motor to meet the requirements of each wheel. The effectiveness and validation of the proposed control method are evaluated by experiments and simulations. The results manifest that the designed system can assist drivers in controlling the stability of the vehicle during adverse driving maneuvers and enhance the performances of the EV.
  Keywords: Electric vehicle (EV); Four-wheel drive; Direct yaw-moment control (DYC); Active front steering; Force distribution; Sliding mode control
   
• Principles of modelling and controlling energy sources in hybrid propulsion systems
  by Yonghua CHENG 
  Abstract: In this paper, principles of modelling and controlling energy sources in hybrid propulsion systems are presented. Further, the strategies of energy sources control and management have been evaluated by using the standard test cycle (Artemis) in the test platform, in which the power supply, the super capacitor energy storage and the traction system are composed. The test results show that the power supply can be directly or indirectly controlled to provide the continuous current, while the super capacitor energy storage is controlled to provide the peak current or recuperate the regenerative braking energy. This feature can ensure good operating condition of the power supply (e.g. fuel cell, battery). Hence, long lifetime of power supply, high efficiency of propulsion system and good dynamics of vehicles can be achieved by using the presented strategies in this paper.
  Keywords: Hybrid propulsion system; modelling; super capacitor; converter control and vehicle test cycle
   
• Tool for energy storage system synthesis
  by Jonas Hellgren, Haimin Zhang 
  Abstract: An essential part of Hybrid Electric Vehicles (HEVs) and Electric Vehicles (EVs) is the Energy Storage System (ESS). This paper describes a tool, named Tool for Energy Storage System Synthesis (TESSS), that automatically transforms ESS demands to cost effective ESS design candidates. The following statements characterize the tool: • Mathematical modelling and optimization are essential ingredients. • The handled ESS technologies are batteries of various types, super capacitors and combined ESSs. Combined ESSs include both battery and super capacitor cells. • The optimal design is pointed out by a cost function and requirements. The cost function includes investment cost, wear cost and costs due to energy losses. Examples of requirements are minimal power, maximum package volume and voltage. • TESSS is user friendly and extremely computational efficient due to compiled C code. To exemplify the practical use of the tool, two case studies are also presented in the paper.
  Keywords: battery optimization; battery systems; energy storage system; plug in hybrids; electric propulsion; hybrid electric vehicle; electric vehicle
   
• Neighborhood Electric Vehicle Development With Individual Traction on Rear Wheels
  by Guillermo A. Magallan, Cristian H. De Angelo, Guillermo O. Garcia 
  Abstract: A simple traction control implementation of a Neighborhood Electric Vehicle is presented. An electronic differential traction control is performed by using two independent field-oriented controlled induction motors mounted in the rear wheels. In order to reproduce the mechanical differential behavior an equal-torque traction control is carried out using only induction motors currents and speeds measurements. A basic self-blocking control is introduced to avoid uncontrolled wheel acceleration during equal-torque control action. The traction system allows energy recovery for batteries during the vehicle braking through the induction motors regenerative braking. Standard industrial induction motors are rewound to operate with safe low voltage (28 Vrms) and to use standard DC-Link 42V, while maintaining the original motor power. Two three-phase MosFet inverters are built for these motor power requirements. The whole system is controlled using a single digital signal processor, TMS320F2812. Experimental results for different vehicle maneuvers are presented validating the right traction control operation.
  Keywords: Electric vehicle; differential traction control; induction motor control; DSP based control prototype.
   
• Comparative Performance Analysis of Input-output Feedback Linearization and Field Oriented Control of Traction Induction Machines in Electric and Hybrid Electric Propulsion systems
  by Tooraj Abbasian Nadjafabadi, Farzad R. Salmasi 
  Abstract: Induction machines are the main core of many multidisciplinary systems such as propulsion systems in electric and hybrid electric vehicles. In a traction drive, a very good dynamic response with smooth torque without jittering should be achieved. Besides, commanded flux may be altered occasionally due to efficiency optimization. So, a very good dynamic response in the presence of variable torque and flux profiles is the main responsibility of the traction motor controller. Field oriented control has been widely utilized in induction motor drives as a favorable approach. An alternative to field oriented control approach is the nonlinear input output feedback linearization (IOFL) method, which is a member of the direct torque controllers (DTC) set. Furthermore, it is well known that neglecting iron loss in the controller equations detunes its tracking capability. This paper aims to compare the well known indirect field oriented control with IOFL for traction induction machines while stator core loss is compensated. For this purpose, a modified IOFL is proposed, which is compared with modified field oriented controller with stator core loss compensation. The problem of parameter mismatch is also investigated for both approaches. A complex programmable logic device (CPLD) based digital controller is implemented for the experimental setup. Simulation and experimental results show that the proposed compensated IOFL controller has better performance in transient state of flux comparing with compensated field oriented control approach, so it is a better candidate for traction induction motors.
  Keywords: induction motor; input-output feedback linearization; field oriented control; stator core loss
   
• DESIGN AND IMPLEMENTATION OF AUTOMATED FLEXIBLE MULTI SOURCE CHARGING SYSTEM FOR HYBRID ELECTRIC VEHICLE
  by Srinivasarao Gorantla 
  Abstract: Scarcity and cost of fossil fuels, combined with their green house gas emissions, make the development of non-fossil fuel based methods of transportation a high priority task. This paper proposes the designing and sizing of a Multiple Input Hybrid Charging System (MIHCS) to be used in an Hybrid electrical vehicle propulsion, it includes a Fuel cell generator, Solar cell charger, I.C Engine, Flywheel storage system, ON board sources and a combined Energy storage system(ESS) comprising of a battery pack. Based on the speed range of the vehicle, multiple sources like (i) Solar energy (ii) Fuel cells (iii) Wind power are automatically selected for the propulsion or charging purpose by using computer and interfacing circuits. To realize this logic, a program has been developed in ‘C’language. This logic also helps in controlling charging and discharging times of the batteries placed in Energy storage unit
  Keywords: Hybrid Electric vehicle, Vehicle control circuit, Solar cells, Fuel cells, ON-Board System, System Control