Dynamic Performance Of Electric Vehicle Research Articles

Automation program for optimum design of electric vehicle powertrain systems based on artificial neural network

Many studies have been conducted on various powertrain systems, such as multi-motor, multi-speed, or both, to enhance the energy efficiency and dynamic performance of electric vehicles (EVs). This study developed an automated design program to obtain the optimal design of EVs for various powertrain systems. The program consists of an EV simulation and artificial neural network (ANN) modeling and optimization tools. The EV simulation tool employs an integrated EV model that can analyze the efficiency and performance of various powertrain systems in a single environment. The ANN modeling and optimization tool first constructs an ANN model, and then performs optimization using the ANN model to address excessive computational efforts arising from the multi-objective genetic algorithm. This study verified the developed program by conducting analysis and optimization of five powertrain systems with the same EV specifications. A multi-objective optimization problem was formulated by considering the design variables as the torque distribution between the motors and gear shifting patterns and ratios of the transmission, and the objectives as the energy consumption and acceleration time. A comparison of the optimization results among the five powertrain systems quantitatively showed the positive effects of the multi-motor and multi-speed powertrain systems. Furthermore, the ANN-based multi-objective optimization process allowed for the efficient determination of the optimum design solutions for the proposed EV powertrain systems. Consequently, these results demonstrated the effectiveness of the automation program in rapid decision-making on EV powertrain system configurations, satisfying each designer’s requirements.

Robust synergetic control of electric vehicle equipped with an improved load torque observer

Abstract For environmental reasons, a great effort was focused on the improvement of the steady-state performance and dynamic performance of electric vehicles (EV). The EV is one of the cleanest and most ecological transport solutions. Accurate knowledge of EV load torque signals is important information for controlling and improving EV active safety. The estimation of load torque in EV drive contributes to cost reduction and solves many of the implementation problems encountered: lack of space, and severe environment. On this basis, in this research, our contribution contains two parts. The first part is the conception of a new scheme of control based on synergetic control (SC) for the speed of an EV propelled by a Six-Phase Permanent Magnet Synchronous Motor (PMSMs) is developed. This control technique offers a fast response, decreases the size of modeled system, and asymptotic stability of the closed-loop system in a vast domain. The second part deals with the synthesis of the sliding mode observer (SMO) to estimate load torque, compensate for strong disturbances and achieve high servo precisions. Moreover, reducing the chattering is inherent in the conventional SMO, we have proposed to replace the switching observer term Ksign with a smooth function and super twisting algorithm. The obtained simulation results proved the high performance assured by the synergetic control such as robustness and dynamic performance, and good estimation accuracy with free chattering even in strong noises.

Mechanism analysis and optimum control of negative airgap eccentricity effect for in-wheel switched reluctance motor driving system

In this paper, the generation mechanism of the negative airgap eccentricity effect for the in-wheel switched reluctance motor (SRM) driving system is analyzed. An independent current chopping control strategy is proposed to achieve optimum control between the response characteristic of the in-wheel motor driving system and the dynamic performance of electric vehicle (EV). Firstly, the electromagnetic characteristic of the studied SRM under airgap eccentricity is studied based on electromagnetic coupling model and circuit driving equation, and the radial electromagnetic force under different airgap eccentricity is verified by adopting the built experiment device. Then, combined with the excitation characteristics of the radial electromagnetic force, the negative dynamic effect of the in-wheel motor driving system is analyzed in the time–frequency domain. Finally, an independent current chopping control strategy for the in-wheel SRM driving system based on vehicle vibration feedback is proposed. The controller parameters including the turn-off angle and chopping current threshold are optimized by data interpolation. Results show that the proposed control strategy can achieve the optimum control between the response characteristics of the in-wheel motor driving system and the vehicle dynamic performance, especially to suppress the vehicle sprung mass acceleration and tire bounce while starting EV.

Enhancement of cooling performance in traction motor of electric vehicle using direct slot cooling method

• DSC(Direct Slot Cooling) has been proposed for high-power and high-torque traction motors. • To evaluate the performance of DSC, we compared it with existing motor-cooling technologies, such as water-jacket, end-tip and channel coolings. • DSC enables a 66% and 94% increase in the applied current density compared to that of water-jacket cooling and end-tip cooling, respectively. • By adopting the DSC model, the winding maximum temperature did not exceed 90 °C in the highway driving mode, even when a high current density of 70 A/mm2 was momentarily applied. The torque of a traction motor for electric vehicles is directly proportional to the electric current applied to the motor winding. Since a power increment is directly linked with an increase in torque, traction motors with high electric current are needed to enhance the dynamic performance of electric vehicles. However, heat loss in the winding, which is proportional to the square of the applied electric current, may cause insulation breakdown in the winding or demagnetisation of permanent magnets in the rotor. In this study, we employed direct slot cooling (DSC) to directly cool motor windings, which are the main heat source in a motor, with cooling fluids. To evaluate the performance of DSC, we compared it with existing motor-cooling technologies, such as water-jacket, end-tip and channel cooling. The performances of the cooling methods were compared based on the change in the pumping power of the cooling fluid and the winding current density. Under two real road driving modes (urban dynamometer and highway driving modes), we compared the change in temperature with time in the traction motor of a compact car with the various cooling methods. The proposed DSC model showed good cooling performance; the winding maximum temperature did not exceed 90 °C in the highway driving mode, even when a high current density of 70 A/mm2 was momentarily applied.

Stability Improvement and Overshoot Damping of SS-Compensated EV Wireless Charging Systems With User-End Buck Converters

The multiple fluctuations, such as grid DC input voltage, mutual inductance and the plug-in and plug-out of battery, may lead to instability and deterioration of dynamic performance of electric vehicle (EV) wireless power transfer (WPT) system. The overshoot issue can bring great current stress to EV WPT system, and may induce potential disastrous malfunction of the lithium-ion (Li-ion) battery. This study theoretically reveals the slow dynamic response and large overshoot of a traditional WPT system. For solving these issues, a reliable adaptive feedforward control scheme is proposed and applied in the user-side DC-DC converter, where the communication unit is eliminated. The feedforward loop is proved theoretically to suppress overshoot and system dynamic response. Besides, the feedforward control increases the selective range of control parameters, which can improve the system dynamics. Experiment results verifies that the proposed adaptive feedforward gain allows faster dynamics, and the aforementioned disturbances in EV WPT system can be solved while the system performance is not affected.

Computer Simulation Design of Electric Vehicle Dynamic Performance

New energy vehicles are mainly pure electric new energy vehicles. Pure electric vehicles are powered entirely by batteries, as well as power generators. With the improvement of economic level, scientific and technological progress, as well as the emphasis on energy conservation and emission reduction, the development of pure electric vehicles is more rapid, computer simulation design technology helps to adjust and optimize the dynamic performance of electric vehicles, in 2019, the output of pure electric vehicles reached 56,700, it is expected to reach about 100,000 by 2022. However, due to the limitation of battery technology, the average range of pure electric vehicles is about 200km. So it can only withstand short distances between cities.

Energy Management Strategy Using Equivalent Consumption Minimization Strategy for Hybrid Electric Vehicles

In this paper, an energy management strategy for electric vehicles equipped with fuel cell (FC), battery (BAT), and supercapacitor (SC) is considered, aiming at improving the whole performance under a framework of vehicle to network application. In detail, based on wavelet transform and equivalent consumption minimization strategy (ECMS), the demand power of vehicles is optimized to enhance the lifespan of fuel cell, fuel economy, and dynamic performance of electric vehicles. The wavelet transform is used to separate the high-frequency power in order to provide a peak power and recycle the braking energy. The equivalent consumption minimization strategy is used to distribute the low-frequency power to fuel cell and battery for minimizing the hydrogen consumption. Obtained results are studied using an advanced vehicle simulator, and its effectiveness of the strategy is confirmed, which provides a fundamental control method for the IOV application.

Influence of Rotor-Bearing Coupling Vibration on Dynamic Behavior of Electric Vehicle Driven by In-Wheel Motor

In order to analyze the influence of the rotor-bearing coupling vibration on the dynamic performance of electric vehicles driven by an in-wheel motor, taking a typical four-phase 8/6-pole switched reluctance motor driven electric vehicle without deceleration mechanism as an investigated object, a nonlinear dynamic model of an electric vehicle with the in-wheel motor driving system is established on the basis of considering the motor exciting force and the bearing nonlinear force. Through the numerical simulation, the influence of the rotor-bearing coupling vibration on the dynamic behavior of electric vehicle driven by the in-wheel motor is studied. Here, in this paper, the dynamic characteristics of an electric vehicle with and without motor exciting force and bearing nonlinear force are compared and analyzed. In addition, the influence of the suspension parameters on the dynamic performance of electric vehicle driven by the in-wheel motor is analyzed. According to the results, the influence of the rotor-bearing coupling vibration on the dynamic behavior of the electric vehicle is mainly embodied in the tire vibration acceleration and tire dynamic load. Moreover, the existence of the in-wheel motor driving system will deteriorate the evaluation index of the electric vehicle vibration performance. By choosing appropriate parameters of the vehicle suspension system, the ride comfort of the electric vehicle can be effectively improved.

Research on a Sliding Mode Vector Control System Based on Collaborative Optimization of an Axial Flux Permanent Magnet Synchronous Motor for an Electric Vehicle

In this paper, a sliding mode vector control system based on collaborative optimization of an axial flux permanent magnet synchronous motor (AFPMSM) for an electric vehicle is proposed. In order to increase the high efficiency range of electric vehicles and improve the cruising range, a collaborative optimization control strategy is firstly proposed. Due to the use of a dual stator-single rotor AFPMSM, the multi-motor efficiency optimization map and torque cooperative control are used to realize the working mode conversion of single stator and double stator, and the torque ripple caused by the working mode conversion is improved by fuzzy control. In order to improve the torque tracking capability, speed limiting characteristics, and operating characteristics, a speed limit and current vector control strategy based on a sliding mode controller is proposed and studied. The dynamic performance of electric vehicles is improved by a sliding mode vector control. Finally, a drive control system was developed for the proposed control strategy, and the complete vehicle test was carried out. The collaborative optimization control experiment and torque tracking and speed limiting experiments verify the correctness and effectiveness of the proposed control strategy. The acceleration performance and endurance experiments show that the proposed control strategy can effectively improve the cruising range and the acceleration performance of electric vehicles.

Modeling and control of an air supply system for a heavy duty PEMFC engine

Air supply system is one important subsystems in a PEMFC engine system. Research on modeling of centrifugal air compressor for easy and accurate control and control strategy of air supply system based on the centrifugal air compressor model are of great importance and significance in engineering. Based on the working characteristics of the centrifugal air compressor in our 150 kW PEMFC engine system for a hybrid tram, a semi-mechanical semi-imperial air supply system model was established. Then the model was embedded in the fuel cell control system for dynamic control of the centrifugal air compressor following the duty cycle of the engine, and a compound feed-forward PID control method for the air system was proposed. Experimental and simulation results show that the air system model performs quite good celerity and accuracy. The compound feed-forward PID control method is able to make full use of the fast response characteristic of centrifugal air compressor, with dynamic response time greatly shortened, and the steady control accuracy requirements achieved. The model and the control method proposed in this paper could be used to optimize the control of the air supply system and to better the dynamic performance of electric vehicle powered by PEMFC engine.

Design, Commissioning and Testing of an Electrodynamometer Based on PM Synchronous Machines

This paper addresses the design, simulation, commissioning and testing of an electrodynamometer (ED) to assessthe dynamic performance of Electric Vehicles (EV). The EV-ED system is comprised of two electric machines coupledmechanically. The traction machine is a 7.75 kW Permanent Magnet Synchronous Motor which is controlled by meansof a vector control and it is coupled mechanically to a similar machine which is used as a mechanical load. The loadmachine was fed by two DC/AC converters connected by the DC bus allowing bidirectional power flow. Theelectrodynamometer was controlled by means of a National Instruments electronic board and Labview software.Several load profiles and inertias were programmed to emulate an Electric Vehicle (EV). The traction machine drivewas implemented with a PP75T120 Powerex Inverter. PWM generation and control strategy were implemented on aMC56F8357 Freescale Digital Signal Controller (DSC). The speed control of the traction machine was validated fordifferent driving cycles. Matlab/Simulink simulations of the machine control and electrodynamometer along withexperimental results illustrating the response of the machine control under the characteristic load profile of an EV arepresented and analyzed. Traction and regenerative breaking stages are analyzed and discussed broadly.

Simulation Research on Dynamic Performance of Electric Vehicle Based on ADVISOR

The research of the dynamic performance is particularly important so as to improve the performance of electric vehicles. The method of computer modeling and simulation can be used to reduce the expense and shorten design cycle. The theory of dynamic performance standards of electric vehicle performance is introduced, and then, the main component of electric vehicle and the whole vehicle model are built up based on the advanced vehicle simulation software ADVISOR platform, which is developed by U.S. National Renewable Energy Laboratory. The curve results of the dynamic performance are obtained after the simulation of virtual electric vehicle, and it is consistent with the actual vehicle movement. At the same time, the simulation results can be served as essential reference for development and improvement of new vehicles.

Novel Control Scheme with Z-Source Inverter in Improving the Dynamic Performance of Electric Vehicles

Novel Control Scheme with Z-Source Inverter in Improving the Dynamic Performance of Electric Vehicles

Novel Control Scheme with Z-Source Inverter in Improving the Dynamic Performance of Electric Vehicles

Novel Control Scheme with Z-Source Inverter in Improving the Dynamic Performance of Electric Vehicles

Selection of Power Train Components and Simulation of Dynamic Performance of Electric Vehicles

Electric vehicles have the ability to drastically reduce petroleum use. As the battery used in EVs appears to be the main technical barriers both from a performance and cost perspective, the main efforts have been focused on how to select appropriate power train system for the better dynamic performance. This paper introduces some methods of parameters design of EV’s main power train components, such as the lithium-ion battery and AC induction motor. Then we build a battery model, a motor model and vehicle simulation models using ADVISOR software. Meanwhile, this paper proposes simulation results of the entire vehicle’s dynamic performance, which shows that the power train components’ parameters designed here basically meet the vehicle’s requirements.