• Journal of Power Electronics
• /
• v.13 no.3
• /
• pp.429-436
• /
• 2013

Online simulations are utilized to reduce time and cost in the development and performance optimization of plug-in hybrid electric vehicle (PHEV) and electric vehicles (EV) systems. One of the most important factors in an online simulation is the accuracy of the model. In particular, a model of a battery should accurately reflect the properties of an actual battery. However, precise dynamic modeling of high-capacity battery systems, which significantly affects the performance of a PHEV, is difficult because of its nonlinear electrochemical characteristics. In this study, a dynamic model of a high-capacity battery cell for a PHEV is developed through the extraction of the equivalent impedance parameters using electrochemical impedance spectroscopy (EIS). Based on the extracted parameters, a battery cell model is implemented using MATLAB/Simulink, and charging/discharging profiles are executed for comparative verification. Based on the obtained results, the model is optimized for a high-capacity battery cell for a PHEV. The simulation results show good agreement with the experimental results, thereby validating the developed model and verifying its accuracy.

• Journal of Digital Contents Society
• /
• v.15 no.3
• /
• pp.433-438
• /
• 2014

In this paper, we proposed the low power algorithm consider the battery and the task. The proposed algorithm setting the power consumption of unit time consider the capacity of the battery and the target time. Calculate the power consumption of all tasks. Calculate the average power consumption by the task have maximum power consumption and the task have minimum power consumption. Recalculate average power consumption consider the unit time of task. Compare calculated average power consumption and average power consumption of task. Compared results, low power algorithm processing the average power consumption less than or equal calculated power consumption of task. Low-power algorithm is greater than the average power consumption of the task to perform targeted tasks. Low-power processors and the task by dividing the power consumption of the device in large part for the low-power consumption is performed. Experiments [6] were compared with the results of the power consumption. The experimental results [6] is reduced power consumption than the efficiency of the algorithm has been demonstrated.

• Journal of Power Electronics
• /
• v.7 no.4
• /
• pp.318-327
• /
• 2007

The design and performance analysis of a power factor corrected (PFC), single-phase, single switch flyback buck-boost ac-dc converter is carried out for low power battery charging applications. The proposed configuration of the flyback buck-boost ac-dc converter consists of only one switch and operates in discontinuous current mode (DCM), resulting in simplicity in design and manufacturing and reduction in input current total harmonic distortion (THD). The design procedure of the flyback buck-boost ac-dc converter is presented for the battery charging application. To verify and investigate the design and performance, a simulation study of the flyback buck-boost converter in DCM is performed using the PSIM6.0 platform. A laboratory prototype of the proposed single switch flyback buck-boost ac-dc converter is developed and test results are presented to validate the design and developed model of the system.

• Journal of Power Electronics
• /
• v.15 no.6
• /
• pp.1438-1445
• /
• 2015

A new DC-DC power converter is researched for renewable energy and battery hybrid power supplies systems in this paper. At the charging mode, a renewable energy source provides energy to charge a battery via the proposed converter. The operating principle of the proposed converter is the same as the conventional DC-DC buck converter. At the discharging mode, the battery releases its energy to the DC bus via the proposed converter. The proposed converter is a non-isolated high step-up DC-DC converter. The coupled-inductor technique is used to achieve a high step-up voltage gain by adjusting the turns ratio. Moreover, the leakage-inductor energies of the primary and secondary windings can be recycled. Thus, the conversion efficiency can be improved. Therefore, only one power converter is utilized at the charging or discharging modes. Finally, a prototype circuit is implemented to verify the performance of the proposed converter.

• Proceedings of the KIEE Conference
• /
• 2000.11d
• /
• pp.669-671
• /
• 2000

Vehicle electric power system, which consists of two major components; an alternator and a battery, supplies electric power to vehicle electric and electronic systems. In recent years, bigger power supply is required for the rapid demand of the number of vehicle electric and electronic systems. It is important that vehicle power system should be analyzed exactly. For the simulation of vehicle electric power system, appropriate component model of vehicle electric power system should be chosen. In this paper, a simplified and accurate battery model is developed to obtain the battery parameters, and a Variable Alternator Terminal Voltage Model is introduced to described an alternator. The case study shows that simulation results using the suggested models are well agreed with the experiments.

• Proceedings of the KIPE Conference
• /
• 1999.07a
• /
• pp.497-500
• /
• 1999

고속전철의 보조 전원 장치는 차량에 탑재되므로 소형화, 경량화 및 고신뢰성이 요구된다. 보조전원 장치중 Battery Charge는 고압의 직류전원(670Vdc)을 저압의 직류전원(83Vdc)으로 변환하여 객차(Trailer Car : 50kW) 및 동력차(Power Car : 10Kw)에 필요한 직류전원을 안정되게 공급하고 Battery Charger의 고장 발생 시를 대비해 Battery의 최적 충전상태를 유지해야 한다. 기술개발의 최종 목표는 고효율, 고신뢰성 밧데리 충전기 시스템 개발, EMI 저감, 부피와 무게의 소형경량화, 최적 스위칭 기술 및 회로 개발이다. IGBT에 대해 소프트 스위칭 기법을 사용하여 스위칭 손실 저감 및 소자의 스트레스의 저감으로 전력 변환 장치의 효율 향상과 소자의 신뢰성을 확보하였고, 스위칭 주파수를 높여 변압기나 인덕터등의 자기 소자의 크기를 줄였다. Battery Charger를 단일 모듈로 구성하기 보다 5kW 모듈을 여러개 조합한 다중모듈방법으로 병렬 운전하므로써 입출력 전류리플룰 감소시켰으며 시스템의 안정성과 신뢰성을 높일 수 있었다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.20 no.4
• /
• pp.344-350
• /
• 2015

A battery management system requires accurate information on the battery state of charge (SOC) to achieve efficient energy management of electric vehicle and renewable energy systems. Although correct SOC estimation is difficult because of the changes in the electrical characteristics of the battery attributed to ambient temperature, service life, and operating point, various methods for accurate SOC estimation have been reported. On the basis of piecewise linear (PWL) modeling technique, this paper proposes a simple SOC observer for lithium-polymer batteries. For performance evaluation, the SOC estimated by the PWL SOC observer, the SOC measured by the battery-discharging experiment and the SOC estimated by the extended Kalman filter (EKF) estimator were compared through a PSIM simulation study.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.26 no.4
• /
• pp.241-248
• /
• 2021

A battery state-of-health (SOH) estimation algorithm using a machine learning-based linear regression method is proposed for estimating battery aging. The proposed algorithm analyzes the change trend of the open-circuit voltage (OCV) curve, which is a parameter related to SOH. At this time, a section with high linearity of the SOH and OCV curves is selected and used for SOH estimation. The SOH of the aged battery is estimated according to the selected interval using a machine learning-based linear regression method. The performance of the proposed battery SOH estimation algorithm is verified through experiments and simulations using battery packs for electric vehicles.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.4
• /
• pp.48-56
• /
• 2012

The object of this paper is the controller for supplying stably power in a separate house in which a hybrid electrical storage system with a stand-alone photovoltaic/wind power generation system and a small generator is applied. In the photovoltaic/wind hybrid power system used in the separate house, when only the battery is used in sunless days, the capacity of the battery is become larger. In particular, as in recent days, if cloudy days are frequent due to anomaly climate, it is difficult to estimate the number of sunless days. Accordingly, it is preferable to build the electrical storage system that numbers of sunshineless days are to be controlled and a shortage amount of the power generation capacity is to be handled by a small generator system. In order to supply stably power of new renewable energy such as solar to any separate houses, it is preferable to reduce the capacity of battery by decreasing the number of sunless days when estimating the capacity of battery and to drive the small generator for compensation of the power shortage. Such system needs components including inverters for photovoltaic and wind power generation system, batteries and controllers for automatically driving the small generator, based upon the nature of the stand-alone house, and it is preferable to use the controller having a simpler and higher stability by adopting the all-in-one scheme to facilitate its maintenance.

• Journal of Electrical Engineering and Technology
• /
• v.11 no.2
• /
• pp.300-308
• /
• 2016

Application of demand-side resources to automatic generation control (AGC) has a great significance for improving the dynamic control performance of power system frequency regulation. This paper investigates the possibility of providing regulation services by demand-side energy storage in electric vehicle battery swapping stations (BSS). An interaction framework, namely station-to-grid (S2G), is presented to integrate BSS energy storage into power grid for giving benefits to frequency regulation. The BSS can be regarded as a lumped battery energy storage station through S2G framework. A supplementary AGC method using demand-side BSS energy storage is developed considering the vehicle user demand of battery swapping. The effects to the AGC performance are evaluated through simulations by using a two-area interconnected power grid model with step and random load disturbance. The results show that the demand-side BSS can significantly suppress the frequency deviation and tie-line power fluctuations.