Pure Electric Mode Research Articles

Development of Engine Clutch Control for Parallel Hybrid Vehicles

The parallel hybrid configuration in which a clutch is installed between an engine and a motor can shift its operation mode between pure electric and hybrid vehicle mode by engaging or disengaging the clutch. To enhance drivability of the system in shifting its operation mode, it is required to prepare appropriate measures to control the clutch in response to driving conditions. This paper introduces the hydraulic clutch control strategy which is composed of a synchronized engaging and a launch slip engaging maneuver. The strategy also covers the criteria to decide the proper engaging method between above two candidates for current circumstance. This study also deals with the learning algorithm to compensate the variations of the clutch hardware and to realize consistent drivability across all units. The learning algorithm utilizes the traction motor and a pressure sensor to identify the all the variation terms of the clutch with the required level of accuracy

Attenuated total reflection study of bulk and surface polaritons in antiferromagnets and hexagonal ferrites: Propagation at arbitrary angles

We perform a theoretical study of the reflection of infra-red radiation from antiferromagnets and M-type barium hexagonal ferrite using an attenuated total reflection (ATR) geometry. At an arbitrary angle of propagation, the electromagnetic waves in the magnetic materials cannot be separated into the usual pure transverse electric (TE) and pure transverse magnetic (TM) modes. We develop a method to solve for the ATR reflection for arbitrary angles of propagation. Using reflection maps, one can determine the dispersion relations for both bulk and surface polaritons. We find that surface polariton features in the reflection map are present at all angles for both incident TE and TM polarizations, with the exception of TM polarization when the plane of incidence is perpendicular to the applied magnetic field. We also see that the interaction of the incident electromagnetic wave with surface polaritons can cause significant transfer from TE to TM modes (and vice versa) upon reflection. When the surface modes vanish, we see that the remaining bulk mode displays reciprocal behavior.

Design of a hybrid electric fuel cell power train for an urban bus

With the requirements for reducing emissions and improving fuel economy, new markets have become attractive for automotive companies that are developing electric, hybrid, and plug-in vehicles using new technologies candidates to be implemented in the next generations of vehicles. Most of all, hybrid vehicles are attracting interest due to great potential to achieve higher fuel economy and a longer range with respect to pure electric mode but often this solution is not petroleum free. Within a national project CNR TAE Institute is involved in the development of a zero emission hybrid electric city bus based on PEM fuel cell technology able to increase the range at least 30% with respect to the same vehicle in pure electric configuration. Design, control and preliminary results are reported in this paper.

A Dry Clutch Control Algorithm for AMT Systems in a Parallel Hybrid Electric Bus

A clutch is a mechanical device which provides engine torque to the drive shaft of a vehicle. A dry clutch control for AMT (Automated Manual Transmission) systems has been an important issue to improve fuel economy and drivability in hybrid electric systems. In this paper, we propose a dry clutch control system to apply to the parallel hybrid electric bus. In order to analysis dynamic performance of the target vehicle, a vehicle dynamic model including engine, clutch, motor, transmission and vehicle is designed. For gear shifting simulation, the shifting maps for the hybrid electric bus are applied from the analysis results of DP (Dynamic Programming) theory that is one of the optimal control methods. The shifting maps consist of a pure electric mode and a hybrid electric mode calculated by using driving cycles for commercial vehicles. From vehicle dynamic equations, the control algorithm for a dry clutch is organized by using feedback loops based on the value of an engine, a clutch speed, a clutch release travel and an estimated clutch torque. Simulations are performed to analyze the dynamic performance of the proposed clutch control system during gear shifting. As a result, the vehicle model with the designed clutch controller compares to one with only the lockup controller in energy dissipation during gear shifting.

Development of a Powertrain System for Hybrid Electric Vehicle

A new type hybrid power train system was developed for HEV, which can works as power coupling and transmission mechanism with three input shafts, one output shaft and fixed transmission ratios. The HEV adopting this new device can realize three operation modes: hybrid power driving mode, pure electric propulsion mode and electricity generation mode at vehicle stop condition. It can make engine work at optimum fuel consumption area, utilize motor to provide high start torque and realize modes conversion transform at probable rotation speed. The whole structure of this system is simple and easy manufactured, which can meet vehicle driving requirements at complicated conditions.

Predictive energy management of a 4QT series-parallel hybrid electric bus

This paper presents a novel predictive control scheme for a series-parallel hybrid bus. The proposed scheme uses information from GPS together with a data record of the driving along the bus route to schedule the charging and discharging of the energy storage system. Switching between hybrid and pure electric mode is optimized in a receding horizon scheme based on a prediction model that reflects the uncertainty of the future driving. The benefits of the proposed predictive control scheme are shown by a simulation study on measured driving data along a bus route. The simulations show that the predictive control scheme achieves both lower fuel consumption and better control of the energy storage system than can be achieved with a non-predictive controller.

Elimination of the water‐layer response from multi‐component source and receiver marine electromagnetic data

ABSTRACTThis paper presents the theory to eliminate from the recorded multi‐component source, multi‐component receiver marine electromagnetic measurements the effect of the physical source radiation pattern and the scattering response of the water‐layer. The multi‐component sources are assumed to be orthogonally aligned above the receivers at the seabottom. Other than the position of the sources, no source characteristics are required. The integral equation method, which for short is denoted by Lorentz water‐layer elimination, follows from Lorentz' reciprocity theorem. It requires information only of the electromagnetic parameters at the receiver level to decompose the electromagnetic measurements into upgoing and downgoing constituents. Lorentz water‐layer elimination replaces the water layer with a homogeneous half‐space with properties equal to those of the sea‐bed. The source is redatumed to the receiver depth.When the subsurface is arbitrary anisotropic but horizontally layered, the Lorentz water‐layer elimination scheme greatly simplifies and can be implemented as deterministic multi‐component source, multi‐component receiver multidimensional deconvolution of common source gathers. The Lorentz deconvolved data can be further decomposed into scattering responses that would be recorded from idealized transverse electric and transverse magnetic mode sources and receivers. This combined electromagnetic field decomposition on the source and receiver side gives data equivalent to data from a hypothetical survey with the water‐layer absent, with idealized single component transverse electric and transverse magnetic mode sources and idealized single component transverse electric and transverse magnetic mode receivers.When the subsurface is isotropic or transverse isotropic and horizontally layered, the Lorentz deconvolution decouples into pure transverse electric and transverse magnetic mode data processing problems, where a scalar field formulation of the multidimensional Lorentz deconvolution is sufficient. In this case single‐component source data are sufficient to eliminate the water‐layer effect.We demonstrate the Lorentz deconvolution by using numerically modeled data over a simple isotropic layered model illustrating controlled‐source electromagnetic hydrocarbon exploration. In shallow water there is a decrease in controlled‐source electromagnetic sensitivity to thin resistors at depth. The Lorentz deconvolution scheme is designed to overcome this effect by eliminating the water‐layer scattering, including the field's interaction with air.

Optimal operation of the power-split hybrid electric vehicle powertrain

A discussion on how to manage the hybrid electric vehicle powertrain is dealt with in this paper. An approach to analyse the optimal operation of a power-split hybrid electric vehicle is suggested on the basis of multi-objective optimization. A quasi-static powertrain model is developed and an entire space of operational choices is explored in order to find an attainable set of the optimal operation candidate group. Using this concept, two types of simulation are developed: the first simulation is based on the minimization of the equivalent fuel consumption and the latter simulation uses dynamic optimization. By analysing and comparing the results, choosing a single optimal operation point by minimizing the equivalent fuel consumption was found to give almost as high an energy efficiency as the theoretical maximum performance obtained by optimal control simulation. The results did not show a noticeable difference except in the case of high-power load conditions. From this analysis, a threshold is also proposed for vehicle operation in the pure electric vehicle mode.

Approximate Dynamic Programming Applied to Parallel Hybrid Powertrains

The extra degree of freedom offered in hybrid electric vehicles have inspired many researchers to formulate and solve optimal control problems of various kinds. This paper presents an Approximate Dynamic Programming scheme that efficiently solves the optimal power split between the internal combustion engine and the electric machine in parallel hybrid powertrains. Gear switches and switches between hybrid and pure electric mode are formally treated. The scheme combines two ideas to reduce the computational time of the iterations performed in the dynamic programming. First, the value function is approximated using piecewise linear functions on a sparse grid. Secondly, by using model approximation the iterations performed in the dynamic programming are reduced to solving scalar quadratic problems. In the simulations the approximation scheme is able to find a good approximation of the optimal control trajectory.

Discovery of Bragg confined hybrid modes with high Q factor in a hollow dielectric resonator

The authors report on observation of Bragg confined mode in a hollow cylindrical dielectric cavity. A resonance was observed at 13.4GHz with an unloaded Q factor of order 2×105, which is more than a factor of 6 above the dielectric loss limit. Previously, such modes have only been realized from pure transverse electric modes with no azimuthal variations and only the Eϕ component. From rigorous numeric simulations, it is shown that the mode is a hybrid mode with nonzero azimuthal variations and with dominant Er and Eϕ electric field components and Hz magnetic field component.

Cherenkov Instability due to Unmagnetized Electron Beam in Periodically Corrugated Waveguide

Cherenkov instability driven by an unmagnetized electron beam in a periodically corrugated waveguide is studied by developing a new version of self-consistent linear theory. The conventional space charge and cyclotron modes of magnetized beam degenerate in this case. The normal electromagnetic modes are pure transverse magnetic (TM) and transverse electric (TE) modes in axisymmetric cases and are hybrid modes having both TM and TE components in nonaxisymmetric cases. Using the developed linear theory, the axisymmetric and nonaxisymmetric Cherenkov instabilities due to the unmagnetized beam in the periodic system are examined numerically. The unmagnetized beam can excite the axisymmetric TM and nonaxisymmetric hybrid modes. A comparison of the numerically obtained results is made with those of the recent C-band Pasotron experiment.