• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.5
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• pp.145-150
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• 2013

Recently, many vehicles have applied electric parts for saving fuel consumption and reducing levels of environmental pollution. ISG (integrated starter & generator) is one of main electric parts and can improve fuel efficiency by using idle stop & go function and regenerative braking system. However, if ISG driving inverter works under the continuously high load condition, it will make the performance and durability of the inverter decreased with rising temperature. In this study, we carried out the analysis on the fluid flow and thermal characteristics of the inverter. As a result, we found the MOSFET of the air cooled inverter was increased up to $116^{\circ}C$ over the limit temperature. On the other hand, the liquid cooled type inverter's MOSFET was decreased by about $17^{\circ}C$ compared to that of the air cooled inverter. Therefore, we verified the feasibility of the liquid cooled type using the present cooling structure.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.74-79
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• 2019

The military vehicle produces electric power through an engine-integrated serial hybrid generator that is connected to the engine and does not have a separate generator installation space. However, depending on the mechanical characteristics of the connection between the generator and the engine, iron oxide for internal rusting and lubrication grew scattered. The iron oxide is adhered to the starter to deteriorate the starting performance, and there is a problem that the noise of the leg due to wear of the gear is increased. To solve this problem, the connection spline material and the surface treatment of the engine were improved and the shape was changed to a grease sealing type to prevent the generation of iron oxide inside. As the shape of the generator connector composing the shafting system was changed, the integrity of the structure was confirmed through the torsional endurance test. In addition, through the actual vehicle load test, it was verified that no corrosion occurred during the target life span without internal corrosion. It was confirmed that the anti-scattering structure of the grease effectively suppresses the generation of iron oxide, thereby reducing the noise generated from the generator. In this paper, we propose a fundamental solution to the degradation of the starter and the noise generation by preventing the back corrosion caused by the serial hybrid generator installed between the engine and the transmission.

• Aerospace Engineering and Technology
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• v.9 no.2
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• pp.204-209
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• 2010

The current status of the development of pyrostarters, which play a role as a turbo pump starter in liquid propellant propulsion systems by supplying pressurized gas to power turbines for engine start, has been introduced. Firstly, the development history is briefly summarized, and secondly the current technical status in core parts for the development of pryrostarters such as solid propellants, internal ballistics, rupture discs, and igniters are presented. The current technical achievements could make it feasible to fulfill the development requirements for pyrostarters.

• Proceedings of the KIPE Conference
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• 2004.11a
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• pp.5-9
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• 2004

본 논문에서는, 벨트 연결형 기동발전기(Integrated Starter Generators)를 이용하여 승용 자동차에서 엔진 기동 시 발생하는 토크 맥동을 억제하는 방법을 제안하였다. 기동발전기의 빠른 토크 응답성을 통하여 내연기관의 기동 시 발생하는 저 주파수의 진동을 억제하여 승용차의 승차감을 개선하고자 한다. 특히 벨트를 통하여 구동되는(또는 구동하는) 벨트 연결형 기동발전기에 있어 벨트의 특성 분석과 모델링을 통하여 효과적인 맥동토크 억제 법을 제시하였다.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.112-117
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• 2002

This paper will present the basic concept and technical trends of the 42V system for the future vehicles structure that is in the process of research and development by the world-wide vehicle manufacturers and the suppliers. The power conversion equipment on the vehicles and an ISG(Integrated Starter Generator) for 42V are introduced. The fundamental research related to the advanced automaker's technical trends and investigations are performed.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.231-233
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• 1995

The new hybrid scheme for electric bus is presented in this paper. This system is composed of a three-phase AC induction motor, one inveter and one system controller. The motor can be acted as starter, motor itself, alternator, generator and retarder. Various functions are simulated. The design stage has been finished. And the various experimental tests are undertaken now.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.882-883
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• 2011

This paper deals with comparison on Electromagnetic losses of slotted and slotless high-speed PM Machine for Micro Turbine. Losses are consist of core losses, copper losses and eddy current losses. We are using both analytical method and 2D Finite Element Method for more detailed losses analysis. And then We compare Electromagnetic losses of slotted and slotless PM synchronous machine. This machine has designed of a generator of 800W, 400000rpm and a starter of 400W, 200000rpm.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2524-2527
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• 2007

Solid propellant gas generators (SPGG) play a role as a turbopump starter in liquid propellant propulsion systems by supplying pressurized gas to power turbines for engine start. For such a purpose, the propellants should burn with a relative low flame temperature and the combustion gas should not contain corrosive constituents such as chlorine compounds. In accordance with these requirements, stabilized AN-based propellants have been usually used as the most appropriate oxidizer for propellant compositions. However, the burning area of the propellant intends to increase to satisfy the required mass flux because of its low burning rate. Consequently the burning area incensement brings on the SPGG size augmentation. A flow restriction such as filters is applied to decrease the SPGG size by rising up the combustion pressure resulting in increasing the burning rate. The feasibility of the size reduction of SPGG by the employment of filters have been studied. The preliminary results of this study show that the considerable reduction of SPGG size would be achievable just by installing a filter with relatively high pressure loss coefficient.

• Journal of Magnetics
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• v.18 no.4
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• pp.487-493
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• 2013

The automotive industry is showing widespread interest in belt-driven electric motor-assisted (e-Assist) systems. A belt-driven assist system (BAS) starts and assists the combustion engine in place of the conventional generator. In this study, a water-cooled wound rotor synchronous motor (WRSM) for the e-Assist system was designed and analyzed. The performance of the WRSM was compared with that of an interior permanent magnet synchronous motor (IPMSM). The WRSM efficiency can be improved for the BAS by adjusting the field flux at high speeds. The field current map to obtain the maximum efficiency based on the speed and torque was developed. To control the field flux via field current control in the WRSM, a general H-bridge circuit was added to the WRSM inverter to get the rapid current response in the high-speed region; the characteristics were compared with the chopper circuit. A WRSM developed for the belt-driven e-Assist system and a prototype 115 V power electronic converter to drive the WRSM were tested with a 900 cc combustion engine. The test results showed that the WRSM-type e-Assist system had good characteristics and could successfully start and assist the 900 cc combustion engine.