Permanent Magnet (PM) Motors are popular choices for hybrid electric vehicle (HEV) powertrain applications. The effects of the excessive heat in the magnets can degrade the performance of these machines if not dealt properly. It is therefore critical to develop a complete and representative model of the heat processes in the electric motors. In this paper, a simplified analytical model is developed as a thermal circuit with a network of interconnected nodes and thermal resistances representing the heat processes within the SPMSM. Both losses induced by sinusoidal and PWM waveform voltage supplies are calculated respectively as heat sources in the thermal circuit. Because temperature-rise inside the magnets caused by eddy current loss can lead to the unpredictable deterioration of the magnets, the circuit takes into consideration the eddy current loss developed in the permanent magnets. The thermal circuit is then solved in MATLAB through a system of linear equations. The results of the analytical model are confirmed through 3-D finite element analysis (FEA) simulation in Ansoft ePhysics software.
This paper proposes a novel linear magnetic-geared machine for the free-piston generator in range-extended electric vehicles. The key is to integrate a linear magnetic gear into a linear permanent magnet synchronous machine to form a single machine, which can offer high efficiency and high power density for electricity generation. The low-speed mover of the proposed machine is directly coupled with the pistons of the internal combustion engine and reciprocates with the pistons. Due to the magnetic gear effect, the high-speed mover which is also the translator of the synchronous machine can travel at high speeds, hence offering high power density design and generating electricity with a high voltage. By using finite element analysis, the machine performance is analyzed and verified.
It has been shown that none of any energy sources which own high specific energy or high specific power, but not both, can solely fulfil all the demands of hybrid electric vehicle (HEV) in some circumstances. In this paper a simulation model for battery/ultra-capacitor hybrid energy storage system (B/UC HESS) was presented by Matlab/Simulink. Based on the model a low-pass filtering control strategy which adopts ultra-capacitor as load leveling device was developed with a goal of improving battery life. The simulation results under different urban driving cycles show the validity of the model. The peak charge/discharge currents are smoothed effectively, which benefits the battery lifetime improvement. The experiment results also show that the buffering effect of ultra-capacitor has optimized the charging and discharging processes of Ni-MH battery considerably.
In this study, the first order model and the second order equivalent circuit models of NiMH battery for electric vehicle were used to determinate the battery state of charge. Different parameters for equivalent circuit models were explained. There are four phases in the battery change and discharge, which are charge phase, change idle phase, discharge phase, discharge idle phase. All of these phases are discussed and analyzed. For different phases of charge and discharge, mathematical relationships between parameters and state of charge were built. The calculation results fit well with the experimental results. A precision comparison between the first order model and the second order model was undertaken.
Currently, the permanent magnet motors PMM represent an attractive solution in the electric traction field, thanks to their higher performances than other electric motors. In this context, this work represents an analytical study and validation by the finite element method of two configurations, the radial flux permanent magnet synchronous motors with exterior rotor PMSMER and with interior rotor PMSMIR. This paper is divided into two sections: In the first section, we represent the analytical study based on electromagnetic law of the two structures PMSMER and PMSMIR. In the second section, we represent a comparative study of the two structure performances.
In hybrid electric vehicles (HEVs), the power network takes an ever-important role, which functions to adjust the engine operating region for less emissions, to incorporate the electric machine for higher overall efficiency, and to feed the increasing demand of electric loads with different voltage levels. Furthermore, more and more mechanically, pneumatically or hydraulically driven systems are gradually superseded by electrically driven systems. In this paper, the key issues, the main components, the powertrain arrangements and the voltage levels of the power network in HEVs are discussed.
In this paper the Power-Oriented Graphs (POG) technique is used for modelling planetary gears and hybrid automotive systems. The POG technique allows to graphically describe the dynamic model of any type of physical system (in different energetic domains) putting in evidence the power flows within the modelled systems. The POG schemes are easy to use, easy to understand even by a neophyte and can be directly implemented in Simulink. Because of the POG modular structure, complex physical systems can be modelled by composing subsystems models. Following this approach a whole power-split hybrid vehicle is modelled, starting from modelling its main subsystems: planetary gear, multi-phase synchronous motor and vehicle dynamics. Simulation results of the modelled hybrid system are reported at the end of the paper.
A new type of boat, the Plug-in Hybrid Electric Boat (PHEB), was developed by electrifying a boat, and it is hoped that this will contribute to the environmental issues and reduce the use of oil. The system of the PHEB, the fuel consumption, the magnitude of vibrations and the generated noise are described in this paper. Boats which run by battery have already existed for some while. However, the smallness of energy-density in a battery, as well as the unreliability due to the evaluation of the residual battery energy, has been made it difficult to be applied for a larger ship. Accordingly, a system, which can be applied to both engine-powered and battery-powered sailing, depending on the situation, has been developed and the system was named a Plug-in Hybrid Electric Boat (PHEB). A 22 ft-length prototype boat was manufactured, and the system has proved to have both high reliability-which is the essential advantage of an internal-combustion engine-and the quietness and cleanness which are typical features of electric boats. The results of the tests are also described in this paper.
Electric bus powered by Mn-type lithium ion battery module with 53 kWh was developed. The running test was examined in the local city in Japan. The relation between running time and voltage, current and electric power consumption were investigated. The electric bus was run when the lithium ion battery module was discharged between 380 and 270 V. On one charge, it was also found from the running test that the railcar could run for 74 km. The running performance of electric bus was equivalent to the diesel bus. It was found that the electric bus powered by lithium ion battery was effective for the replace of diesel type bus.