• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.40 no.6
• /
• pp.403-408
• /
• 2016

Lithium-ion batteries are commonly employed in hybrid electric vehicles (HEVs), and achieving high energy density in the battery has been one of the most critical issues in the automotive industry. Because liquid cooling containing antifreeze is important in automotive batteries to enable cold starts, an effective geometric configuration for high-cooling performance should be carefully investigated. Battery cooling with antifreeze has also been considered to realize successful cold starts. In this article, we theoretically investigate a specific property of an antifreeze cooling battery system, and we perform numerical modeling to satisfy the required thermal specifications. Because a typical battery system in HEVs consists of multiple stacked battery cells, the cooling performance is determined mainly by the special properties of antifreeze in the coolant passage, which dissipates heat generated from the battery cells. We propose that the required cooling performance can be realized by performing numerical simulations of different geometric configurations for battery cooling. Furthermore, we perform a theoretical analysis as a design guideline to optimize the cooling performance with minimum power consumption by the cooling pump.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.21 no.1
• /
• pp.92-98
• /
• 2013

There are lots of studies about hybrid electric vehicles (HEVs) because of the global warming and energy problems. Series and parallel HEVs are the common types of many developing hybrid vehicle types. Series HEV uses engine only as the generator for the battery but parallel HEV utilizes engine for driving and generating of the vehicle. In this paper, backward simulations based on dynamic programming were conducted for the fuel economy analysis of two different types of hybrid transit buses depending on driving cycles. It is shown that there is a relation between the type of HEV and the characteristics of driving cycles. Regarding the aggressiveness, the series hybrid bus is more efficient than the parallel system on highly aggressive driving cycle. On the other hand, the parallel hybrid bus is more efficient than the series system on low aggressive driving cycle. Based on this results of the paper, it is expected to choose more efficient type of the hybrid buses according to the driving cycle.

• Journal of Auto-vehicle Safety Association
• /
• v.10 no.2
• /
• pp.36-42
• /
• 2018

UNECE/WP29/GRPE/EVE has recently defined that the power of a hybrid electric vehicle is the system power. Although a method for measuring the maximum power of a hybrid electric vehicle is presented by KATRI, it does not consider charging and discharging characteristics of traction batteries. This study provides a maximum power measurement method which reflects the charging and discharging characteristics of traction batteries in NOVC-HEVs (Not Off Vehicle Charging-Hybrid Electric Vehicles). Both methods are compared with regard to the output measurement results.

• Journal of Electrical Engineering and Technology
• /
• v.6 no.4
• /
• pp.527-534
• /
• 2011

In the present paper, the characteristics of Mega-Flux$^{(R)}$, JNEX-Core$^{(R)}$, amorphous and ferrite cores are compared to the inductor of buck-boost converters for Hybrid Electric Vehicles. Core losses are analyzed at the condition of 10 kHz sine wave excitations, and permeability fluctuations vs. temperature and magnetizing force will be analyzed and discussed. Under the specifications of the buck-boost converter for 20 kW THS-II, the power inductor will be designed with Mega-Flux$^{(R)}$ and JNEX-Core$^{(R)}$, and informative simulation results will be provided with respect to dc bias characteristics, core and copper losses.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.5
• /
• pp.1096-1106
• /
• 2013

This paper presents the control of a Permanent Magnet Electric Variable Transmission (PM-EVT) for Hybrid Electric Vehicles (HEVs). Consisting of two electric machines, the EVT realizes the power split function in an electromagnetic way rather than in a mechanical way. A specific PM-EVT has been designed for Toyota Prius II. The control scheme of the entire vehicle is deduced using the Energetic Macroscopic Representation methodology. The energy management strategy yields local control references. A specific attention is paid for the field weakening for wide speed range. Simulation results are provided to illustrate the EVT modeling and control.

• Proceedings of the KIEE Conference
• /
• 2001.07b
• /
• pp.1275-1277
• /
• 2001

Growing environmental and economic concerns have lead to recent efforts to produce more fuel efficient and lower emissions vehicles. Hybrid Electric Vehicles(ab. HEVs) are the most promising designs to reach these goals. In this paper, We present an of a Power Tra the Hybrid Electric Vehicle(at. PTHEV). We int a different concept of PTHEV than in the pr research of PTHEV. This PTHEV includes benefits of serial(Minimum emission and Max efficiency) and parallel(Maximum Power efficiency by direct drive engine) PTHEV. Also mechanism can avoid driving the engine in the speed regions.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.2
• /
• pp.192-198
• /
• 2013

The rapidly growing demand for electric power systems in electric vehicles (EVs) and hybrid electric vehicles (HEVs) require simpler, cost-effective, and higher performance components. In this paper, a novel power conversion system for hybrid electric vehicles is proposed for these needs. The proposed power conversion system reduces the conversion system cost while preserving same functionality. The proposed power conversion system can boost multi-sources to drive a traction motor and to store energy at the same time reducing number of switching components. In this paper, all operational modes of the proposed converter are explained in detail and verified by a computer simulation first. Then, the topology and operational modes are experimentally verified. Based on the results, the feasibility of the proposed multi-mode single leg power conversion system for EV and HEV applications is discussed.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.18 no.2
• /
• pp.199-204
• /
• 2013

Recently, the demand for fuel efficient electric vehicles (EVs) and hybrid electric vehicles (HEVs) has been growing globally. Due to the increased number of switching devices in the electrified vehicles, the probability of the semiconductor device failure is much higher than in other application areas. A sudden failure in one of the power switches and insufficient power management ability in the systems not only decreases system performance, but also leads to critical safety problems. In this paper, novel switch open circuit fault detection method is proposed, and the proposed approach is verified by experiments.

• New & Renewable Energy
• /
• v.4 no.4
• /
• pp.65-71
• /
• 2008

Considering the world's environmental problem, HEVs are projected as one of the solution. The keys of the HEV cruise control are expanding the use of electric motor and operating the internal combustion engine in the efficient region. This paper presents a new structure of SOC sustaining model where state-machine control is used. The proposed model defines battery charging and discharging as states and SOC of the battery as control variables. In this paper, we introduce various methods in deterministic rule-based control for HEV and describe a new SOC sustaining controller used by state-machine.

• International Journal of Automotive Technology
• /
• v.6 no.5
• /
• pp.529-536
• /
• 2005

This paper presents a novel design of a fuzzy control strategy (FCS) based on torque distribution for parallel hybrid electric vehicles (HEVs). An empirical load-regulating vehicle operation strategy is developed on the basis of analysis of the components efficiency map data and the overall energy conversion efficiency. The aim of the strategy is to optimize the fuel economy and balance the battery state-of-charge (SOC), while satisfying the vehicle performance and drivability requirements. In order to accomplish this strategy, a fuzzy inference engine with a rule-base extracted from the empirical strategy is designed, which works as the kernel of a fuzzy torque distribution controller to determine the optimal distribution of the driver torque request between the engine and the motor. Simulation results reveal that compared with the conventional strategy which uses precise threshold parameters the proposed FCS improves fuel economy as well as maintains better battery SOC within its operation range.