• Journal of Electrical Engineering and Technology
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• 제4권4호
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• pp.499-509
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• 2009

Electric vehicles (EV) are developing fast during this decade due to drastic issues on the protection of environment and the shortage of energy sources, so new technologies allow the development of electric vehicles (EV) by means of electric motors associated with static converters. The proposed propulsion system consists of two induction motors (IM) that ensure the drive of the two back driving wheels. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling, independently, every driving wheel to turn at different speeds in any curve. This paper presents the study of an hybrid Fuzzy-sliding mode control (SMC) strategy for the electric vehicle driving wheels, stability improvement, in which the fuzzy logic system replace the discontinuous control action of the classical SMC law. Our electric vehicle fuzzy-sliding mode control's simulated in Matlab SIMULINK environment, the results obtained present the efficiency of the proposed control with no overshoot, the rising time is perfected with good disturbances rejections comparing with the classical control law.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.730-734
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• 2007

National projects on renewable energy and new energy are driven more actively than ever in many countries for the exhaustion of fossil fuel energy from the turn of the century. Such activities began to spread out in railway industry with centering around west European countries. Electric energy is generated on the hybrid vehicle itself, which contributes to reduction of the cost for construction of the infrastructure required for the supply of electric power. Hybrid tram is mainly composed of propulsion system to control electric energy, automatic guidance system to control steering and operation, and central vehicle unit to control and monitor major electronic devices. Generation and supply of electric power are made by the combination of engine generator and battery, or fuel cell and super capacitor.

• Journal of Power Electronics
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• 제11권4호
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• pp.449-455
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• 2011

Electric drive vehicles (EDV) have received much attention recently because of their environmental and energy benefits. In an EDV, the motor drive system directly influences the performance of the propulsion system. However, the available DC voltage is limited, which limits the maximum speed of the motors. At high speeds, the inverter voltage increases if the square wave (SW) voltage (six-step operation) is used. Although conventional direct torque control (DTC) has several advantages, it cannot work in the six-step mode required in high-speed applications. In this paper, a single-mode seamless DTC for AC motors is proposed. In this scheme, the trajectory of the reference flux changes continuously between circular and hexagonal paths. Therefore, the armature voltage changes smoothly from a high-frequency switching pattern to a square wave pattern without torque discontinuity. In addition, because multi-mode controllers are not used, implementation is more straightforward. Simulation results show the voltage pattern changes smoothly when the motor speed changes, and consequently, torque control without torque discontinuity is possible in the field weakening area even with a six-step voltage pattern.

• 전력전자학회논문지
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• 제26권5호
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• pp.357-363
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• 2021

Eco-friendly hybrid railroad propulsion system with fuel-cell and battery was suggested to reduce carbon dioxide gas and replace retired diesel railroads. Lithium-ion battery with high energy/power density and long lifetime is selected as the energy source at the battery side due to its excellent performance. However, the performance of lithium-ion batteries was affected by temperature, current rate, and operating condition. Temperature is known to be the most influential factor in changing battery parameters. In addition, appropriate thermal management is required to ensure the safe and effective operation of lithium-ion battery. Electro-thermal coupled model with varying parameter depends on temperature, and state-of-charge (SOC) is suggested to estimate battery temperature. The electric-thermal coupled model contains diffusion current using parameter identification by adaptive control algorithm when considering thermal diffusion effect. An experiment under forced convection was conducted using cylindrical cell and 18 parallel-connected battery module to demonstrate the method.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1407-1413
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• 2011

This paper studied on the VVVF Inverter for 1C4M propulsion system of railway traction. The paper includes the comparison along a VVVF Inverter electric power conversion element for an electric railcar(GTO, IGBT). These inverters are composed of high power IGBTs and controlled by compact control units. The stack is simplified and optimized by using plate bus and IGBT driver units of hybrid-type.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1978-1983
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• 2008

With the increase in population, the area of human activities has expanded, resulting in the dramatic increase in the need for transportation system. Various infrastructures necessary for efficient logistics, however, have not been supplied enough and the logistics efficiency in Korea is in a bad situation now. As a result of the situation, the demand for the railroad transportation system that can provide large volume transportation has increased dramatically. An electric railway system is composed of high-tech subsystems, among which main electric equipment such as motors and converter are critical components determining the performance of electric vehicle. Among the on-board equipments, traction equipment is important part that has influence on safety and performances of vehicles. We is studied for high-speed train of foreign countries. From this research, we knows that axle weight of HEMU-400x is reasonable within 13ton.

• 한국군사과학기술학회지
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• 제15권5호
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• pp.543-549
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• 2012

Hybrid electric propulsion systems are expected as future primary combat platforms because the systems can supply enough electric power, easily locate components inside vehicles, and maneuver without undesired noise. However, increasing electric/electronic/software usage causes abnormal failure patterns which have not been noticeable in conventional automotive. Recently, the functional safety standard for road vehicles were enacted and vehicle manufacturers request their components which satisfy standardized quality. This research analyzes functional safety standards(IEC 61508 and ISO 26262) and compares the standards for road vehicles with military standards of system safety. Strategies to apply functional safety in the combat hybrid electric vehicle are scrutinized.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.370-371
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• 2012

• 한국항공운항학회지
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• 제29권3호
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• pp.52-65
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• 2021

A large amount of time and cost is consumed due to congestions caused by an increasing number of cars which results in a lot of emissions. To overcome these problems, a new electric vertical takeoff and landing (eVTOL) aircraft is being considered. Since vertical take off and landing without a separate runway is realized and electricity is used as a power source, it could solve the saturated ground traffic congestions without emissions. In this paper, the initial sizing was performed based on the Nexus 6HX of Belltextron which is a tilt-ducted fan type. In this study, the electric propulsion system that only uses battery was implemented instead of current Nexus 6HX hybrid electric propulsion. Aerodynamic analyses were performed using OpenVSP and XFLR5. Power-to-weight ratio, wing loading, estimated weight were calculated with these analyses.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.95-97
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• 2007

This paper proposes a mathematical modelling about Leviation Force and Propulsion Force in a system, where Primary and Secondary LSRM air-gap is irregular. This can be a suitable model for Magnetically levitation Train, where Primary and Secondary air-gap mechanically has to control simultaneously Levitation Force and Propulsion Force.