In this paper, a new four-quadrant (4Q) soft-switching converter for dc motor drives, namely the 4Q zero-voltage-transition (4Q-ZVT) converter, is proposed. It has some definite advantages over their hard-switching counterparts and other soft-switching converters. It offers zero-voltage-switching (ZVS) for all main switches and diodes, as well as unity device voltage and current stresses. It also has simple circuit topology, hence minimum hardware count and low cost.
Here we report the analysis of vehicle usage of a fleet of 15 Hyundai Santa Fe electric-sport-utility-vehicles (e-SUVs), which was tested in Honolulu, Hawaii, from July 2001 to June 2003. The 15 vehicles were dispatched to the Hickam Air Force Base (HAFB), City and County (C&C) of Honolulu, Hawaiian Electric Co. (HECO), and the Hawaii Electric Vehicle Demonstration Project (HEVDP) office for field evaluation. More than 25,000 trips were recorded using on-board data acquisition systems in all vehicles during the two-year period, representing a total driving distance of more than 255,000 km. We used a systematic approach to conduct driving cycle analysis (DCA) from the second-by-second trip data. Detailed breakdown of the driving cycles in terms of driving patterns was generated and summarized as functions of vehicle operating time and mileage for each vehicle over the evaluation period. In this paper, we illustrate how to analyze the vehicle usage from such a DCA and the real-life data in the database. The vehicle usage analysis (VUA) includes frequency and extent of vehicle operation in addition to the DCA. We intend to correlate vehicle performance via DCA and VUA for comparison among different operating organizations to allow us develop a more effective fleet operation in the future.
Most of the additives or activators used today for the negative electrode of lead-acid batteries are fine power of solid materials such as barium sulphate, lignin and carbon black. They are generally called as expander. We found that organic compounds soluble in the acid electrolyte are very effective in order to extend the cycle life and improve the discharge capacity. This paper describes the recent improvements and the working mechanism for the soluble organic activators.
According to the principle of coordinates transform in vector control system and the reduced equation law about motor model, a mathematic model of AC motor is introduced in the MT system, and a simulation model is designed using MATLAB/SIMULINK. The simulation example shows that MATLAB/SIMULINK is an effective simulation tool and the validity of the model is verified as well. As a conclusion, a vector control AC motor has an excellent speed-regulation performance, and is very well competent for working as EV driver.
Eddy dynamometer is widely used in drive motor and ICE's character testing, in which it can't be loaded large torque under lower speed, and can't drag testing motor, and its dynamic response is weak .Also it changes mechanical energy to heat energy, which wastes energy resource. In this paper, a new kind of electric dynamometer based on separate-excited DC generator is introduced to overcome these shortcomings, which realizes large load torque under lower speed, and can measure motor's characters in four quadrants, and has quick dynamic response ability. The electric dynamometer can work in steady speed mode, steady torque mode and steady power mode. It can not only measure motor steady character, but also dynamic character. In this paper, the whole system hardware framework and software will be introduced. DC motor's control method is introduced in detail. At last, experiment results will be shown on.
The drive system of electric vehicle (EV) will suffer various disturbances inevitably during its driving process. In order to overcome the variety of the load, an adaptive control scheme for drive system is developed, and it is applied to the design of HS2000EV's controller. The satisfied result is obtained from the simulations.
A new method for prolonging the life of lead-acid batteries was invented devised by charging the batteries with a high current pulse of a particular pulse width special wavelength. The effectiveness of the new method was verified by prototyping a prototype circuit and conducting charging-discharging cycle tests in a laboratory. The device was named the "High current pulse activator". Moreover, it was experimentally proven that this device was even more effective when used with batteries filled with a polymer additive supplied by ITE.
In this paper, various motors for electric vehicles (EVs) are briefly reviewed. Then the development of doubly salient permanent magnet (DSPM) motors is presented, with emphasis on design and operation, torque production, comparison of pole numbers and discussion of operating modes. An 8/6-pole DSPM motor is designed and built for exemplification. Experimental results of the prototype are given to verify the theoretical analysis, hence confirming that DSPM motors are attractive for modern EVs.
As agricultural machines, many tractors using mainly diesel or turbo engines have been used. Such tractors are compact and highly efficient. However, they cause noise and air pollution. From the viewpoint of ecological environment and avoiding global warming, tractors not using such engines are required to be developed. So far we have conducted to produce electric vehicles including electric motor-cycle. In this report, we explain the technology of electric tillers for agricultural industries. The electric tiller we aim is compact, considering use for garden work. The weight is less than 25 kg, and the size is within 1,100 mm x 600 mm x 1,000 mm. The weight of 25 kg was selected because of being able to carry by hands. The motor used is the one for small-sized electric vehicle. In the project, design, manufacturing, stress analysis, producing electric circuit and control unit, and experiment have been conducted. The design using 3D-CAD and manufacturing was successfully conducted. In regard to control, feedback control remains to study in the future, although the control using potentiometer and H8 microprocessor worked. The other remained research item is to make the tiller to be lighter so that elderly people can use.
In the department of Intelligent Mechanical Systems Engineering, Kochi University of Technology, the synthesis lecture has been being carried out in 3rd and 4th year grades of the undergraduate program. Projects of the synthesis lecture in our laboratory so far have been design and manufacturing of hand-made electric vehicle, motorcycle, and tiller. In this report, the student activity of design and manufacturing for a hand-made motor-assisted tricycle is described. In the past, the four-wheels electric vehicle was produced for the elder drivers. However, the four-wheels vehicle cannot be used in pavements and roads for bicycle or tricycle. In the country-side in local areas in Japan, which is apart from main roadways, a tremendous roads are narrow. Therefore, there is not distinct boarder for roadways and pavements in such areas. From such a viewpoint, the tricycle vehicle was planned for the people who need to use in the country-side. The vehicle was designed for especially elderly drivers by using a motor-assisted tricycle. In our project, the design and manufacturing of a motor-assisted tricycle was conducted. Receiving a development proposal from the Kochi University of Technology for a motor-assisted tricycle, Daioh Machinery Co.,Ltd. designed and manufactured a hand-made motor-assisted tricycle. The Kochi University of Technology assisted Daioh Machinery Co.,Ltd., and three students in the fourth year grade joined the team under the guidance of Daioh Machinery Co.,Ltd. and the university.
The voltage of power circuits used in electric vehicles has increased to 500 V or more. This shift to higher voltages is done to reduce current, harness weight and improve motor-controller's efficiency. The fuses that protect these circuits must shut out DC arcs, yet their performance needs improving. This paper reports the development of a formidable fuse that coats a thin film of hydrogen strage Titanium on copper foil, and its features. This new fuse has shown great potential in protecting high voltage circuits of future electric vehicles, and other high voltage DC electric devices.
Today's emergency transportation by internal combustion engine ambulances has many problems: it has a high vibration for the patient and the medics, it has a limited size of workstation for the medical treatment, it slowly accelerates with jolts and it has a high floor base which makes driving unstable while cornering. An Electric Vehicle ambulance, EV ambulance, is proposed to solve all this problems. The structural design of today's ambulance is compared with the design concept of an EV ambulance. The EV component technologies of an in-wheel drive, component built-in frame and tandem suspension system are applied to the EV ambulance. Four types of ambulances are presented: one based upon the average outer dimensions of a conventional ambulance, second based upon the average inner dimensions of workspace of the medics, third with a driver seat in the middle of the cabin and finally with a diver seat on an elevated position. A dual direction drive is applied in the ambulance and one type of EV ambulance its length is reduced to 2m so that it can enter into buildings. The EV ambulances illustrate that a smooth vibration and high acceleration of 0,4G is reached, the noise inside the cabin is reduced from 90dbA to 60dbA; the floor height is reduced from 50cm to 30cm, 85% of the total inner space can be used as a workspace, and stable drive and cornering is most efficient during an emergency transportation.
To promote environmentally friendly Electric Vehicles (EV's), we have entered an EV converted from a gasoline automobile in the Shikoku EV Rally (since 1999) and collected data for the purpose of improving technical performance. Also, since 2002 we have participated in the Shikoku Ishu Ekiden , a long distance rally around the island of Shikoku and thus have acquired more data for analysis. Using the analysis of the past data, in the 2003 Ekiden a method simulating rally performance was established to modify clearer, and the actual rally results with that of the rally simulation were similar. Our EV received first position in the class competition as well as in the energy efficiency category.
A new method of charging and discharging has developed to improve the performance of charging and discharging of lead-acid batteries. The battery itself has an internal resistance that makes it difficult to control the charging and discharging process because the capacity of the battery is estimated by the potential difference between the two electrodes of the battery, named external voltage. When the effective internal resistance of the battery is increased due to the deterioration, the external voltage is too high to stop charging even though the battery has not stored a sufficient amount of energy. This paper introduces a new method of charging and discharging and the resulted effectiveness of this method to the lead acid battery life prolongation is shown.
The analysis of drive cycle is the basis of vehicular real-control during design and the application of electric vehicles. Beijing will hold the Olympic Games in 2008 and there will be about 1000 electric buses made full use of at that time. The requirements of the electric buses' design according to tested data of two kinds of drive cycles will be analyzed in the paper. And it dictates that the entire considerations of different drive cycles are very important for current electric buses' design and their different requirements of energy and power, which is necessary for E-bus design and the realization of efficient real-time control.
The reaction principium of Li-ion is introduced. The achievements of Li-ion battery are summarized on service performance and security performance. Take the Li-ion battery produced by some corporation for example, the basic performances of domestic Li-ion battery are introduced. The current situation is also explained that the Li-ion battery applied on the electronic vehicle.
ITE activators a mixture of organic polymers and inorganic salt were used for 60Ah dry charge lead-acid batteries and the battery performance was compared to the best Japanese lead-acid batteries. With the ITE organic polymer activator, the Chinese battery performance was found to be much better than Japanese batteries for our 150 ampere test and 12 ampere test.