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Limited battery power and poor engine efficiency at cold temperature results in low plug in hybrid vehicle (PHEV) fuel economy and high emissions. Quick rise of battery temperature is not only important to mitigate lithium plating and thus preserve battery life, but also to increase the battery power limits so as to fully achieve fuel economy savings expected from a PHEV. Likewise, it is also important to raise the engine temperature so as to improve engine efficiency (therefore vehicle fuel economy) and to reduce emissions. One method of increasing the temperature of either component is to maximize their usage at cold temperatures thus increasing cumulative heat generating losses. Since both components supply energy to meet road load demand, maximizing the usage of one component would necessarily mean low usage and slow temperature rise of the other component. Thus, a natural trade-off exists between battery and engine warm-up.

In this study, a molten salt-based high temperature nanofluid is explored for solar thermal energy conversion applications. The efficacy of the nanofluid as a heat transfer fluid (HTF) in concentrating solar power systems is explored in this study. The molten salt can enable higher operating temperature resulting in enhancement of the overall system efficiency for power generation (using, for example, a Rankine cycle or Stirling cycle). However, the usage of the molten salt as the HTF is limited due to their low specific heat capacity values (compared with, for example, water or silicone oils). The low specific heat of molten salt can be enhanced by doping small amount of nanoparticles. Solvents doped with minute concentration of nanoparticles are termed as "Nanofluids." Nanofluids are considered as attractive coolants for thermal management applications due to their anomalously enhanced thermal properties (compared with the neat solvent).

The desirable braking system of a land vehicle is that it can stop the vehicle or reduce the vehicle speed as quickly as possible, maintain the vehicle direction stable and recover kinetic energy of the vehicle as much as possible. In this paper, an electronically controlled braking system for EV and HEV has been proposed, which integrates regenerative braking, automatic control of the braking forces of front and rear wheels and wheels antilock function together. When failure occurs in the electric system, the braking system can function as a conventional man-actuated braking system. Control strategies for controlling the braking forces on front and rear wheels, regenerative braking and mechanical braking forces have been developed. The braking energy that can be potentially recovered in typical driving cycle has been calculated. The antilock performance of the braking system has been simulated.

Significant amount of energy is lost in frequent braking, automatic transmission and engine idling for a conventional engine powered passenger car while driving in cities. In this paper, a mild hybrid vehicle drive train has been introduced. It uses a small electric motor with floating stator, called TRANSMOTOR and small and a battery pack. The transmotor functions as a generator, engine starter, frictionless clutch (electric torque coupler), regenerative braking and propelling. The mild hybrid drive train can effectively reduce the urban-driving fuel consumption by regenerative braking, eliminate of energy losses in conventional automatic transmission and engine idling. The drive train can use low voltage system (42V for example), due to the low electric power rating, and is more similar to conventional drive train than full hybrid vehicle. Therefore, less effort is needed to evolve it from conventional vehicles.

In this paper, a mild hybrid drive train has been proposed. A small electric motor with low rated voltage (42 V) is used to (1) propel the vehicle at low speed, (2) replace the fluid-coupled torque converter and (3) realize regenerative braking. With proper design and control, the fuel economy in urban driving can be significantly improved without much change from conventional drive train to the mild hybrid drive train.

New dc to dc converter topologies are presented which are suitable for high density high power supplies. Topological variations of the basic inverse dual converter (IDC) circuit such as the transformer coupled, the multiphase and the multipulse derivation of the single phase IDC have been analysed and some simulation results have been presented. It has been shown in a recent publication [1] that the single phase IDC offers a buck-boost operation over wide range without transformer, bidirectional power flow, and complementary commutation of the switches. The topologies examined in this paper have additional features such as lower device and component stresses, and smaller filter requirements, resulting in smaller size and weight. Some performance and possible applications are also examined. Finally the IDCs for serial and parallel power distribution, and ac tapping of the IDC are discussed.

The opportunity for the application of Wireless Power Transmission (WPT) technologies is growing. Applications covering terrestrial, airborne and space missions are evolving. Concepts for terrestrial systems for powering remotely located regions by the use of renewable energy sources; airborne systems used for remote observation, communication relay, and environmental monitoring; and space based systems for potentially powering the elements of a space infrastructure are being developed. This paper will present the history of wireless power transmission systems and summarize current and future applications and technology. Design constraints for terrestrial systems, airborne platforms and space systems will be presented.

A fuel cell/battery hybrid system for an electric vehicle was characterized under simulated driving conditions. The fuel cell is a 72 cell stack with 270 cm2 per cell of active electrode area. It has a continuous output of 1500 Watts and a peak power of 3000 Watts operating on hydrogen and atmospheric pressure air. The batteries are a tubular flooded lead-acid type. Seven 6 volt modules were connected in series with each module having a normal capacity of 205 Ahr. The fuel cell battery hybrid system was laboratory tested using a variable load battery cycler to simulate electric vehicle operation over a Modified Simplified Federal Urban Driving Schedule (MSFUDS). The fuel cell/battery hybrid operated successfully under steady state and dynamic conditions with the performance of the fuel cell only slightly degraded under the dynamic conditions of MSFUDS compared to steady state operation.

Artificial Neural Network(ANN) techniques are used to develop a system to detect High Impedance Faults(HIFs) in electric power distribution lines. Encouraging results were observed with a simple Multi-layer Perceptron(MLP) trained with the backpropagation learning algorithm. Although the results are not significantly better than those reported with other algorithmic approaches, ANN techniques have potential advantages over the other approaches; namely, ability to train the system easily to accommodate different feeder characteristics, ability to adapt and so become a better detector with experience and better fault tolerance. When these features are incorporated, the system is expected to perform better than existing systems. The system we developed for the current phase, the training strategies used, the tests conducted and the results obtained are discussed in this paper. Also background discussions on existing HIF detection techniques, and ANN techniques can be found in this paper.

A empirically based mathematical model of a lead-acid battery for use in the Texas A&M University's Electrically Peaking Hybrid (ELPH) computer simulation is presented. The battery model is intended to overcome intuitive difficulties with currently available models by employing direct relationships between state-of-charge, voltage, and power demand. The model input is the power demand or load. Model outputs include voltage, an instantaneous battery efficiency coefficient and a state-of-charge indicator. A time and current dependent voltage hysteresis is employed to ensure correct voltage tracking inherent with the highly transient nature of a hybrid electric drivetrain.

The operation of an electrically peaking hybrid vehicle (ELPH) can be divided into two basic modes. • Constant or cruising speed mode in which a small internal combustion engine (ICE) is used to power the vehicle. • Peak power mode in which the combination of an electric motor and ICE is used to supply peak power for acceleration and limited-duration steep hill climbing of the vehicle. A method, by which the engine size and the speed reduction ratio from the engine to drivewheels can be developed based on the cruising mode, is presented in this paper. The electric motor power rating and the motor gear ratio to the drive wheels can then be determined, based on the acceleration and gradeability. The results show that a simple single-gear transmission would be a good selection for overall performance.

This paper discusses a new computer simulation tool, V-Elph, which extends the capabilities of previous modeling and simulation efforts by facilitating in-depth studies of any type of hybrid or all electric configuration or energy management strategy through visual programming and by creating components as hierarchical subsystems which can be used interchangeably as embedded systems. V-Elph is composed of detailed models of four major types of components: electric motors, internal combustion engines, batteries, and vehicle dynamics which can be integrated to simulate drive trains having all electric, series hybrid, and parallel hybrid configurations. V-Elph was written in the Matlab/Simulink graphical simulation language and is portable to most computer platforms. A simulation study of a sustainable, electrically-peaking hybrid-electric vehicle was performed to illustrate the applicability of V-Elph to hybrid and electric vehicle design.