• Korea Petroleum Association Journal
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• s.276
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• pp.46-49
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• 2010

• Korea Petroleum Association Journal
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• s.281
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• pp.43-48
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• 2011

• Journal of Energy Engineering
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• v.18 no.1
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• pp.31-36
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• 2009

There are several types of environment friendly vehicle being developed by auto manufactures. HEV (Hybrid Electric Vehicle) is most applicable one among them in actuality. HEV has two power sources, one is an internal combustion engine, the other one is an electric device. The HEV is developed for reducing fuel consumption and emissions. We selected the diesel engine as a main power source of HEV. The tests were carried out under different driving cycles which was CBDBUS (Central Business Driving Bus Schedule) and HWFET (Highway Fuel Economy Test). This research presents a simulation for the fuel economy and the emission of heavy diesel hybrid vehicle according to the SHEV (Serial Hybrid Electric Vehicle), PHEV (Parallel Hybrid Electric Vehicle), Plug-in SHEV and plug-in PHEV.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.582-594
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• 2016

Most studies on hybrid buses are on large-sized buses and not mid-sized low-floor buses. This study uses MATLAB simulation to evaluate the fuel efficiency of such buses powered by diesel. Based on the results, a hybrid electric vehicle system is recommended for the best combination of power and gear ratio. A parallel hybrid system was selected for the hybridization, which transmits front and rear wheel power independently. The necessary power to satisfy the target performance was calculated, and the applicable capacity area was designed. Dynamic programing was used to create and optimize a component sizing algorithm, which was used to scale the capacity of each component of the power source to satisfy the design criteria. The fuel efficiency rate, optimum power source capacity, and gear ratio can be improved by converting a conventional bus into a parallel hybrid bus.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2979-2984
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• 2013

This paper proposes a modeling and controller design method of Flywheel Energy Storage System(FESS) for solving the unstable operation problem in hybrid generation system with wind turbine and diesel generator applied in island area. FESS is considered as a permanent magnetic synchronous machine connected to flywheel because of its efficiency. The controller of FESS is composed of AC/DC/AC back-to-back converter. The AC/DC converter is designed to charge/discharge according to the frequency variation and the DC/AC converter to operate to keep the DC bus voltage constant. The proposed modeling and controller design method of FESS was applied to hybrid generation system with wind turbine and diesel generator. The unstable operation problem owing to wind variations was solved through simulation results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.2
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• pp.27-33
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• 2013

In this study we analyzed the on-road driving performance of two parallel-type diesel-hybrid buses which have been driven in Daegu metropolitan area. A real-time on-board data logger was facilitated to measure the vehicle information such as vehicle speed, idle stop, state of charge of battery, and engine operating conditions. These diesel-hybrid buses ran as a commuter at Daegu Exco area and Dalsung industrial complex. The driving pattern in Exco area comprised more frequent idle stop and relatively lower speed than at Dalsung area, where comprised no idle stop. Due to those different driving patterns, the fuel economy at Dalsung showed $3.7\;km/{\ell}$, which is about 8% higher than that of Exco. The main causes of this come from the higher portion of regenerative braking and higher speed which moves to the operating points of diesel engine with a lower fuel consumption.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.5
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• pp.170-175
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• 2003

A control algorithm is developed for highly efficient operation of auxiliary power unit (APU) that consists of a diesel engine and a directly coupled induction generator in series hybrid electric Bus (SHEB). In a series hybrid configuration the APU supplies the electric power needed for maintaining the state of charge (SOC) of the battery unit in various conditions of vehicle operation. As the rotational speed of generator does not depend on the vehicle speed, an optimized operation of engine-generator unit based on the efficiency map of each component can be achieved. The output torque of diesel engine can be controlled by the amount of fuel injection, and the power converted from mechanical to electrical energy can be adjusted by generate control unit (GCU) using the decoupling vector control of torque and flux. As for the given reference of the generating power, the multiply of speed and torque, many combinations of operating speed and torque are possible. The algorithm decides the new operating point based on the engine efficiency map and generator characteristic curve. During the transition of operating points, the speed controller saturation is avoided using variable limit and filtering of generator torque reference. A test rig and SHEB consist of a 1.5L diesel engine and a 30kw induction generator are constructed by Hyundai Motor Company.