• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.4
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• pp.440-445
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• 2011

This paper presents a new regenerative brake system of electric vehicles that employs a continuous variable transmission(CVT) and a flywheel. The developed device has advantages over existing regenerative brakes from a standpoint of reliability and versatility in actual driving conditions. The system consists of a CVT, two wheels, a flywheel, a coupling and auxiliary powertrain components. The CVT is designed as a combination of two cones and a roller, which causes the velocity difference between the wheel and the flywheel. The power flow of the flywheel system is controlled by the CVT roller and the coupling through step motors. A prototype has been developed and then its performance has been investigated for various operating conditions. Results show that the storage efficiency of the flywheel is much affected by the vehicle's velocity and it is reduced below 20% for high speed, as compared to the 25% efficiency for an ideal condition. The CVT is a primary factor for lowering the flywheel efficiencies due to large friction and slipping between the cone and the roller.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5357-5365
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• 2013

In this paper, we propose that a model based design for a electric tractor system by using ASM(Automotive Simulation Models). Before developing a realistic electric tractor, it is essential that defining the capacities of power sources and optimizing the parameters of electric tractor. In additionally, because the electric tractor must have not only driving function but also working function, two PMSM are used at electric tractor. ASM which is based on simulink and Carsim were used to design a electric system and powertrain of electric tractor. For verifying the electric tractor system, we compared the design parameters such as max power, state of charge, drive distance, velocity which were carried out by the simulation and experimental method. The predicted results by the development model were in good agreement with the simulation results. According to simulation of tractor, it is possible to arrange the advanced research of dynamical characteristic of tractor and present the guidelines for the electrical driving system.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.893-898
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• 2014

Recently, the interior permanent synchronous motor (IPMSM) has been applied to an integrated starter and generator (ISG) for hybrid electric vehicles. In the design of such a motor, thermal analysis is necessary to maximize the power density because the loss is proportional to the power of a motor. Therefore, a cooling device as a heat sink is required internally. Generally, a cooling system designed with a water jacket structure is widely used for electric motors because it has advantages of simple structure and cooling effectiveness. An effective approach to analyze an electric machine with a water jacket is a thermal equivalent network. This network is composed of thermal resistance, a heat source, and thermal capacitance that consider the conduction, convection, and radiation. In particular, modeling of the cooling channel in a network is challenging owing to the flow of the coolant. In this paper, temperature prediction using a thermal equivalent network is performed in an ISG that has a water cooled system. Then, an experiment is conducted to verify the thermal equivalent network.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.61-67
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• 2012

The in-wheel motor used in green car was designed and constructed for an electric direct-drive traction system. It is difficult to connect cooling water piping because the in-wheel motor is located within the wheel structure. In the air cooling structure for the in-wheel motor, a outer surface on the housing is provided with cooling grooves to increase the heat transfer area. In this study, we carried out the analysis on the fluid flow and thermal characteristics of the in-wheel motor under the effects of motor speed and heat generation. In order to check the problem of heat release, the analysis has been performed using conjugate heat transfer (conduction and convection). As a result, flow fields and temperature distribution inside the in-wheel motor were obtained for base speed condition (1250 rpm) and maximum speed condition (5000 rpm). Also, the thermo-flow characteristics analysis of in-wheel motor for vehicles was performed in consideration of ram air effect. Therefore, we checked the feasibility of the air cooling for the housing geometry having cooling grooves and investigated the cooling performance enhancement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.833-838
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• 2011

Future powertrain technologies will be developed focused on applications of eco-friendly technology for internal combustion engine, electric vehicle and Fuel Cell Electric Vehicle. But it is expected that these cutting edge technologies will not be applied immediately due to lack of infrastructure, technical and economical reasons. Therefore, numerous developments of internal combustion engine will be carried out for the time being. There have been many turbo engine developments undergoing to maximize the engine performance using turbo charger system in accordance with global trend-green technology and downsizing of engine which coincides with HMC's future development strategy. This study reviews the development process and result of plastic intake manifold module which is firstly developed for turbo engine. CAE simulation and experiments were implanted to evaluate design validity.

• Transactions of The Korea Fluid Power Systems Society
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• v.5 no.4
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• pp.1-9
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• 2008

In this paper, an energy regeneration algorithm is proposed to make the maximum use of the regenerative braking energy for a parallel hybrid electric vehicle(HEV) equipped with a continuous variable transmission(CVT). The regenerative algorithm is developed by considering the battery state of charge(SOC), vehicle velocity and motor capacity. The hydraulic module consists of a reducing valve and a power unit to supply the front wheel brake pressure according to the control algorithm. In order to evaluate the performance of the regenerative braking algorithm and the hydraulic module, a hardware-in-the-loop simulation (HILS) is performed. In the HILS system, the brake system consists of four wheel brakes and the hydraulic module. Dynamic characteristics of the HEV are simulated using an HEV simulator. In the HEV simulator, each element of the HEV powertrain such as internal combustion engine, motor, battery and CVT is modelled using MATLAB/$Simulink^{(R)}$. In the HILS, a driver operates the brake pedal with his or her foot while the vehicle speed is displayed on the monitor in real time. It is found from the HILS that the regenerative braking algorithm and the hydraulic module suggested in this paper provide a satisfactory braking performance in tracking the driving schedule and maintaining the battery state of charge.

• Journal of Auto-vehicle Safety Association
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• v.6 no.2
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• pp.61-66
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• 2014

This paper described on the motion of hybrid tractor trajectory for powertrain system. The dynamics behavior used to the tractor according to the characteristics of the road surface using $Daful^@$ analysis. The tractor industry is facing to a big problem about rising gas price and exhaust gas environment. Because it was possible overcoming the past drawback, hybrid vehicle had been decided as the best technical way since it has started operating the internal combustion engine with the electric power as the motive power. The vehicle structures have designed the model of a major power transmission factor. The simulation realized in this paper that motion of tractor being turned by torque and force of each joints. Driving characteristics, especially in recent years, IVHS (Intelligent Vehicle Tractor / System) technology, while receiving a lot of attention because of the tractor and the need to pursue high function is emerging as a more and more.

• Journal of Drive and Control
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• v.16 no.2
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• pp.80-90
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• 2019

Fuel cell hybrid electric vehicle is an attractive solution to reduce pollutants, such as noise and carbon dioxide emission. This study presents an approach for energy management and control algorithm based on energetic macroscopic representation for a fuel cell hybrid electric vehicle that is powered by proton exchange membrane fuel cell, battery and supercapacitor. First, the detailed model of the fuel cell hybrid electric vehicle, including fuel cell, battery, supercapacitor, DC-DC converters and powertrain system, are built on the energetic macroscopic representation. Next, the power management strategy was applied to manage the energy among the three power sources. Moreover, the control scheme that was based on back-stepping sliding mode control and inversed-model control techniques were deduced. Simulation tests that used a worldwide harmonized light vehicle test procedure standard driving cycle showed the effectiveness of the proposed control method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5156-5163
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• 2011

Electric Motorcycle is one of the most promising candidates for future transportation because of its outstanding fuel economy and environmental pollution. Before prototyping a realistic electric motorcycle, a reliable simulation program is required to test the capacities of the power sources and optimize the parameters of an electric motorcycle. This process can reduce the expenses during the designing of an electric motorcycle system. In this paper, we present an electric motorcycle system simulation program implemented on Matlab, which can model drivetrain and powertrain systems in an easy, natural way within Simulink and PSAT. And the analysis of design parameters such as max power, capacity, state of charge, slope angle is carried out by the simulation and experimental method. The predicted results by the development model were a good agreement with experimentally obtained results.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.182-186
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• 2007

This paper studied performance characteristics of hybrid automotive to replace existing fossil fuel vehicles. Specially, about power split type HEV that is T-HEV's drive system when a vehicle drives at steady speed, monitored both output of each engine, motor and generator and battery SOC (state of charge) and analyzed performance characteristic of power transmission system and electricity power parts. This study shows those that acquired and analyzed information from signals between HCU and each controller of actual T- vehicle. From this study, it is confirmed that each conditions of EV and HEV drive can be a improvement with respect to the fuel efficiency of vehicles.