Hybrid Electric Vehicle Traction Research Articles

A Sliding Mode DITC Cruise Control for SRM With Steepest Descent Minimum Torque Ripple Point Tracking

Switched reluctance motors are frequently quoted for electric and hybrid electric vehicle traction. However, high torque ripple is a common restraining disadvantage. This article proposes a design method for model following sliding mode as cruise controller, considering a direct instantaneous torque controller as part of the controlled plant. In addition, a back-electromotive force cancelation is incorporated by modifying the torque reference using the developed model. A minimum torque ripple point tracking (MTRPT) that actuates over the turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> angle is proposed through an adaptation from the steepest descent maximum power point tracking algorithm. The turn- <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> angle is also controlled, aiming for enhanced torque regulation. The cruise controller is Lyapunov stable, robust to parameter variations, and is capable of rejecting load disturbances. Experimental results show that the MTRPT convergence time is around <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\text{2.5 s}$</tex-math></inline-formula> for a load step and around <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\text{1.625 s}$</tex-math></inline-formula> for a speed step. Besides, the speed tracking capability of the proposed system returns an MAE of 0.9223% and 1.0884% for the ECE-R15 and for the EUDC driving schedules, respectively. The MTRPT is capable of reducing the torque ripple by 14.6% in low speeds (ECE-R15) and by 10.1% at high speeds (EUDC). The results show that the proposed system is well founded for electric and hybrid electric vehicles applications.

Analysis of the Impact of Magnetic Materials on Cogging Torque in Brushless DC Motor

The cogging torque is the most significant issue in permanent magnet applications, since it has a negative impact on machine performance. In this article, the impact of magnetic materials on cogging torque is analyzed on brushless DC motors (BLDC). The effect of neodymium magnets (NdFeB), compression molded magnet, and samarium cobalt (SmCo) magnet on the cogging torque is analyzed to the BLDC motor designed for hybrid electric vehicle traction that has the peak power rating of 50 kW motor with 48 stator slots and 8 rotor poles. With the presence of these three magnetic materials, the cogging torque is estimated independently using multiposition simulation. The multiposition is simulated using a transient application that runs at constant speed. The results of cogging torque, rotational speed, angular position of BLDC motor, and magnetic flux density distribution have been presented. Also, the maximal, mean, minimal, rectified mean, and rms values of cogging torque were provided.

Modelling and Control by Neural Network of Electric Vehicle Traction System

Modelling and control by neural network of hybrid electric vehicle traction system is presented in this paper. The electric drive is composed by a battery bank and an ultracapacitor connected in parallel through bidirectional DC converters and a Brushless DC Motor driven by a three-phase inverter. In the electric drive control loop is implemented a NARMA neural network. The mechanical model comprises a gearbox and a model of the road-wheel friction force and vehicle aerodynamics. All the masses and inertia are expressed relative to the rotor of the motor. The model is studied by simulations with two driving cycles and an assessment of the available energy from regenerative braking is performed. The percentage of recycled energy from regenerative braking is assessed.DOI: http://dx.doi.org/10.5755/j01.eie.24.3.20974

HEV Motor Comparison of IPMSM With Nd Sintered Magnet and Heavy Rare-Earth Free Injection Magnet in the Same Size

In the near future, usage of heavy rare-earth element needs to be reduced, due to resource risk and rising price with vehicle electrification. This paper compared two hybrid electric vehicle traction motors of the same size using Nd sintered magnet and heavy rare-earth free magnet. We designed two interior permanent magnet synchronous motors varying only the rotor design and material. A new motor was developed using heavy rare-earth free magnet with performance and size equal to Nd sintered motor. The rotor shape was designed as the one of a synchronous reluctance motor to overcome the lack of heavy rare-earth free motor torque. The motor performance was verified with a series of experiments.

Characterization and Scalable Modeling of Power Semiconductors for Optimized Design of Traction Inverters with Si- and SiC-Devices

Silicon carbide (SiC) based power semiconductors are expected to contribute to an increase in inverter efficiency, switching frequencies, maximum permissible junction temperature, and system power density. This paper presents a comparison of silicon (Si) and SiC device technologies for the use in hybrid electric vehicle traction inverters. SiC-JFETs and SiC-MOSFETs are characterized and a scalable loss and scalable thermal modeling approach is used to find the optimum chip area for each Si or SiC traction inverter. This procedure also provides a proper technical comparison of the semiconductor technologies. The progressed simulations using standardized drive cycles and thermal-electrical coupled semiconductor models permit an inverter performance evaluation close to real load situations, leading to an improved estimation of the benefit which can be expected from systems utilizing SiC technology. This paper concludes that the SiC devices can lead to a reduction in chip area and semiconductor losses by more than 50% at the same time in hard switching applications with partial load dominated mission profiles.

Study on interior permanent magnet synchronous motors for hybrid electric vehicle traction drive application considering permanent magnet type and temperature

Recently, interior permanent magnet synchronous motors (Interior-PMSMs) have become known as a good candidate for hybrid electric vehicle (HEV) traction drive application due to their unique merits. However, the dynamic and steady-state behaviors of these motors are quite dependent on the permanent magnet (PM) type, conguration, and volume in rotor structures. This paper uses a novel structure of Interior-PMSMs for traction applications with fragmental buried rotor magnets in order to achieve low torque ripple, iron losses, and cogging torque. In this paper, rst, the eect of the PM type on a d-q equivalent circuit model is examined. Next, the design and simulation of an Interior-PMSM for HEV traction drive application, in order to extract the output values of the motor and sensitivity analysis of the PM type, are done using a 3-dimensional nite element method model. We then present the back electromotive force, power factor, cogging torque, ux density, torque per ampere diagram, PM volume, and constant power speed ratio value behavior of the designed Interior-PMSM with dierent PMs in the rotor structure, and we discuss the eect of temperature variation on these output parameters. This study can help designers in the design approach of such motors.

DC–AC Cascaded H-Bridge Multilevel Boost Inverter With No Inductors for Electric/Hybrid Electric Vehicle Applications

This paper presents a cascaded H-bridge multilevel boost inverter for electric vehicle (EV) and hybrid EV (HEV) applications implemented without the use of inductors. Currently available power inverter systems for HEVs use a dc-dc boost converter to boost the battery voltage for a traditional three-phase inverter. The present HEV traction drive inverters have low power density, are expensive, and have low efficiency because they need a bulky inductor. A cascaded H-bridge multilevel boost inverter design for EV and HEV applications implemented without the use of inductors is proposed in this paper. Traditionally, each H-bridge needs a dc power supply. The proposed design uses a standard three-leg inverter (one leg for each phase) and an H-bridge in series with each inverter leg which uses a capacitor as the dc power source. A fundamental switching scheme is used to do modulation control and to produce a five-level phase voltage. Experiments show that the proposed dc-ac cascaded H-bridge multilevel boost inverter can output a boosted ac voltage without the use of inductors.

Influence of temperature and electrolyte on the performance of activated-carbon supercapacitors

For hybrid electric vehicle traction applications, energy storage devices with high power density and energy efficiency are required. A primary attribute of supercapacitors is that they retain their high power density and energy efficiency even at −30 °C, the lowest temperature at which unassisted starting must be provided to customers. More abuse-tolerant electrolytes are preferred to the high-conductivity acetonitrile-based systems commonly employed. Propylene carbonate based electrolytes are a promising alternative. In this work, we compare the electrochemical performance of two high-power density electrical double layer supercapacitors employing acetonitrile and propylene carbonate as solvents. From this study, we are able to elucidate phenomena that control the resistance of supercapacitor at lower temperatures, and quantify the difference in performance associated with the two electrolytes.